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735 <body class="article">
\r
737 <h1>RRQFORTH Reference Documentation</h1>
\r
738 <span id="author">Ralph Ronnquist <ralph.ronnquist@gmail.com></span><br />
\r
741 <div class="sect1">
\r
742 <h2 id="_word_index">Word Index</h2>
\r
743 <div class="sectionbody">
\r
744 <div class="paragraph"><p><a href="#p_lparen">( (left parenthesis)</a>  
\r
745 <a href="#p_colon">: (colon)</a>  
\r
746 <a href="#p_semicolon">: (semi-colon)</a>  
\r
747 <a href="#p_comma">, (comma)</a>  
\r
748 <a href="#p_dot">. (dot)</a>  
\r
749 <a href="#p_double_quote">" (double-quote)</a>  
\r
750 <a href="#p_quote">' (single-quote)</a>  
\r
751 <a href="#p_left_bracket">[ (left bracket)</a>  
\r
752 <a href="#p_right_bracket">] (right bracket)</a>  </p></div>
\r
753 <div class="paragraph"><p><a href="#p_lessthan"><</a>  
\r
754 <a href="#p_lessequal"><=</a>  
\r
755 <a href="#p_equal">=</a>  
\r
756 <a href="#p_unequal">!=</a>  
\r
757 <a href="#p_greaterthan">></a>  
\r
758 <a href="#p_greaterequal">>= </a>  
\r
759 <a href="#p_0equal">0=</a>  
\r
760 <a href="#p_0less">0<</a>  
\r
761 <a href="#p_minus">-</a>  
\r
762 <a href="#p_mult">*</a>  
\r
763 <a href="#p_plus">+</a>  
\r
764 <a href="#p_div">/</a>  
\r
765 <a href="#p_shift_left"><<</a>  
\r
766 <a href="#p_shift_right">>></a>  
\r
767 <a href="#p_shift_signed_right">s>></a>  
\r
768 <a href="#p_bracketed_quote">[']</a>  </p></div>
\r
769 <div class="paragraph"><p><a href="#p_get">@</a>  
\r
770 <a href="#p_put">!</a>  
\r
771 <a href="#p_Cget">C@</a>  
\r
772 <a href="#p_Cput">C!</a>  
\r
773 <a href="#p_2get">2@</a>  
\r
774 <a href="#p_2put">2!</a>  
\r
775 <a href="#p_put_plus">!+</a>  
\r
776 <a href="#p_get_n_increment">@n++</a>  
\r
777 <a href="#p_get_n_decrement">@n--</a>  
\r
778 <a href="#p_Ccomma">C,</a>  
\r
779 <a href="#p_literal_string">S"</a>  
\r
780 <a href="#p_gtR">>R</a>  
\r
781 <a href="#p_Rget">R@</a>  
\r
782 <a href="#p_Rgt">R></a>  
\r
783 <a href="#p_rbpn">R[n]</a>  </p></div>
\r
784 <div class="paragraph"><p><a href="#data_stack">DATA-STACK</a>  
\r
785 <a href="#return_stack">RETURN-STACK</a>  
\r
787 <a href="#p_branch">BRANCH</a>  
\r
788 <a href="#p_0branch">0BRANCH</a>  
\r
789 <a href="#p_1branch">1BRANCH</a>  
\r
791 <a href="#p_2drop">2DROP</a>  
\r
792 <a href="#p_2dup">2DUP</a>  
\r
793 <a href="#p_2over">2OVER</a>  
\r
794 <a href="#p_2swap">2SWAP</a>  </p></div>
\r
795 <div class="paragraph"><p><a href="#p_abs">ABS</a>  
\r
796 <a href="#p_again">AGAIN</a>  
\r
797 <a href="#p_allot">ALLOT</a>  
\r
798 <a href="#p_and">AND</a>  
\r
799 <a href="#inline_code">[ASM]</a>  </p></div>
\r
800 <div class="paragraph"><p><a href="#p_base">BASE</a>  
\r
801 <a href="#p_begin">BEGIN</a>  
\r
802 <a href="#p_break">BREAK</a>  </p></div>
\r
803 <div class="paragraph"><p><a href="#p_cfa2flags_get">CFA>FLAGS@</a>  
\r
804 <a href="#p_cfa2tfa">CFA>TFA</a>  
\r
805 <a href="#p_clear_stream">CLEAR-STREAM</a>  
\r
806 <a href="#p_create">CREATE</a>  
\r
807 <a href="#p_current_wordlist">CURRENT-WORDLIST</a>  </p></div>
\r
808 <div class="paragraph"><p><a href="#p_decimal">DECIMAL</a>  
\r
809 <a href="#p_depth">DEPTH</a>  
\r
810 <a href="#p_digits">DIGITS</a>  
\r
811 <a href="#p_divmod">/MOD</a>  
\r
812 <a href="#p_dfa2tfa">DFA>TFA</a>  
\r
813 <a href="#p_dodoes">doDOES</a>  
\r
814 <a href="#p_does">DOES></a>  
\r
815 <a href="#p_dofasm">doFASM</a>  
\r
816 <a href="#p_doforth">doFORTH</a>  
\r
817 <a href="#p_dostring">doSTRING</a>  
\r
818 <a href="#p_dovalue">doVALUE</a>  
\r
819 <a href="#p_dovariable">doVARIABLE</a>  
\r
820 <a href="#p_drop">DROP</a>  
\r
821 <a href="#p_dup">DUP</a>  </p></div>
\r
822 <div class="paragraph"><p><a href="#p_else">ELSE</a>  
\r
823 <a href="#p_emit">EMIT</a>  
\r
824 <a href="#p_end">END</a>  
\r
825 <a href="#p_erase">ERASE</a>  
\r
826 <a href="#p_evaluate_stream">EVALUATE-STREAM</a>  
\r
827 <a href="#p_execute">EXECUTE</a>  
\r
828 <a href="#p_exit">EXIT</a>  </p></div>
\r
829 <div class="paragraph"><p><a href="#p_false">FALSE</a>  
\r
830 <a href="#p_fdemit">FDEMIT</a>  
\r
831 <a href="#p_fdtell">FDTELL</a>  
\r
832 <a href="#p_find">FIND</a>  
\r
833 <a href="#p_forth">FORTH</a>  </p></div>
\r
834 <div class="paragraph"><p><a href="#p_here">HERE</a>  
\r
835 <a href="#p_hex">HEX</a>  </p></div>
\r
836 <div class="paragraph"><p><a href="#p_if">IF</a>  
\r
837 <a href="#p_ifagain">IFAGAIN</a>  
\r
838 <a href="#p_ifbreak">IFBREAK</a>  
\r
839 <a href="#p_immediate">IMMEDIATE</a>  
\r
840 <a href="#p_input">INPUT</a>  </p></div>
\r
841 <div class="paragraph"><p><a href="#p_literal">LIT</a>  
\r
842 <a href="#p_load_buffer_size">LOAD-BUFFER-SIZE</a>  
\r
843 <a href="#p_load_file">LOAD-FILE</a>  </p></div>
\r
844 <div class="paragraph"><p><a href="#p_args">MAIN-ARGS</a>  
\r
845 <a href="#p_malloc">MALLOC</a>  </p></div>
\r
846 <div class="paragraph"><p><a href="#p_negate">NEGATE</a>  
\r
847 <a href="#p_nip">NIP</a>  
\r
848 <a href="#p_nl">NL</a>  
\r
849 <a href="#p_not">NOT</a>  
\r
850 <a href="#p_number">NUMBER</a>  </p></div>
\r
851 <div class="paragraph"><p><a href="#p_open_file">OPEN-FILE</a>  
\r
852 <a href="#p_or">OR</a>  
\r
853 <a href="#p_over">OVER</a>  </p></div>
\r
854 <div class="paragraph"><p><a href="#p_pad">PAD</a>  
\r
855 <a href="#p_pick">PICK</a>  
\r
856 <a href="#p_program_version">PROGRAM_VERSION</a>  </p></div>
\r
857 <div class="paragraph"><p><a href="#p_quit">QUIT</a>  </p></div>
\r
858 <div class="paragraph"><p><a href="#p_read_stream_char">READ-STREAM-CHAR</a>  
\r
859 <a href="#p_read_word">READ-WORD</a>  
\r
860 <a href="#p_realloc">REALLOC</a>  
\r
861 <a href="#p_roll">ROLL</a>  
\r
862 <a href="#p_rot">ROT</a>  
\r
863 <a href="#p_rbp">RSP</a>  </p></div>
\r
864 <div class="paragraph"><p><a href="#p_sp">SP</a>  
\r
865 <a href="#p_state">STATE</a>  
\r
866 <a href="#p_stdin">STDIN</a>  
\r
867 <a href="#p_stream">STREAM</a>  
\r
868 <a href="#p_stream_nchars">STREAM-NCHARS</a>  
\r
869 <a href="#p_strlen">STRLEN</a>  
\r
870 <a href="#p_strncmp">STRNCMP</a>  
\r
871 <a href="#p_strncpy">STRNCPY</a>  
\r
872 <a href="#p_swap">SWAP</a>  
\r
873 <a href="#p_system">SYSTEM</a>  </p></div>
\r
874 <div class="paragraph"><p><a href="#p_tell">TELL</a>  
\r
875 <a href="#p_dot_temp">.TEMP</a>  
\r
876 <a href="#p_terminate0">TERMINATE0</a>  
\r
877 <a href="#p_tfa2cfa">TFA>CFA</a>  
\r
878 <a href="#p_tfa2dfa">TFA>DFA</a>  
\r
879 <a href="#p_tfa2flags_get">TFA>FLAGS@</a>  
\r
880 <a href="#p_tfa2namez">TFA>NAMEZ</a>  
\r
881 <a href="#p_then">THEN</a>  
\r
882 <a href="#p_this_word">THIS-WORD</a>  
\r
883 <a href="#p_true">TRUE</a>  
\r
884 <a href="#p_tuck">TUCK</a>  </p></div>
\r
885 <div class="paragraph"><p><a href="#p_unstream">UNSTREAM</a>  </p></div>
\r
886 <div class="paragraph"><p><a href="#p_verboseQ">VERBOSE?</a>  </p></div>
\r
887 <div class="paragraph"><p><a href="#p_within">WITHIN</a>  
\r
888 <a href="#p_words">WORDS</a>  </p></div>
\r
889 <div class="paragraph"><p><a href="#p_xor">XOR</a>  </p></div>
\r
890 <div class="paragraph"><p><a href="#p_calltrace">[calltrace]</a>  
\r
891 <a href="#p_setup_signals">[setup_signals]</a>  </p></div>
\r
894 <div class="sect1">
\r
895 <h2 id="_word_descriptions">Word Descriptions</h2>
\r
896 <div class="sectionbody">
\r
897 <div class="paragraph"><p><a id="inline_code"></a></p></div>
\r
898 <div class="sect2">
\r
899 <h3 id="_word_asm">Word: [ASM]</h3>
\r
900 <div class="literalblock">
\r
901 <div class="content">
\r
902 <pre><code>data stack: ( -- )</code></pre>
\r
904 <div class="paragraph"><p>"[ASM]" is a function word that introduces inline assembly in an
\r
905 RRQFORTH definition. Such assembly code may return to subsequence
\r
906 RRQFORTH executon by means of the following instruction sequence:</p></div>
\r
907 <div class="exampleblock">
\r
908 <div class="content">
\r
909 <div class="listingblock">
\r
910 <div class="content">
\r
911 <pre><code> mov rsi,forthcode
\r
914 forthcode:</code></pre>
\r
917 <div class="paragraph"><p>Note that the FORTH compiler does not invoke an assembler so any
\r
918 inline assembly code must be provided in its binary form.</p></div>
\r
919 <div style="text-align:center">
\r
920 _______________________________________________________
\r
922 <div class="paragraph"><p><a id="p_0branch"></a></p></div>
\r
924 <div class="sect2">
\r
925 <h3 id="_word_0branch">Word: 0BRANCH</h3>
\r
926 <div class="literalblock">
\r
927 <div class="content">
\r
928 <pre><code>Data stack: ( v -- )</code></pre>
\r
930 <div class="paragraph"><p>"0BRANCH" is a function word that implements execution conditional by
\r
931 means of optionally adding the subsequent branch offset, or not, to
\r
932 the point of execution. If the value, v, is 0 then the branch offset
\r
933 is added, and otherwise execution continues with the cell following
\r
934 the branch offset in the definition.</p></div>
\r
935 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
936 definition take up a cell of 8 bytes. The offset is relative to the
\r
937 cell address immediately subsequent to the offset cell. In other
\r
938 words, offset 0 is not branching anywhere and an offset of -16 would
\r
939 make a tight loop back to the branch instruction itself. The latter
\r
940 would pull data stack values until and including the first non-zero
\r
942 <div class="paragraph"><p>See also <a href="#p_1branch">1BRANCH</a>, <a href="#p_branch">BRANCH</a>, <a href="#p_if">IF</a>,
\r
943 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
944 <div style="text-align:center">
\r
945 _______________________________________________________
\r
947 <div class="paragraph"><p><a id="p_0equal"></a></p></div>
\r
949 <div class="sect2">
\r
950 <h3 id="_word_0">Word: 0=</h3>
\r
951 <div class="literalblock">
\r
952 <div class="content">
\r
953 <pre><code>Data stack: ( v -- 0/-1 )</code></pre>
\r
955 <div class="paragraph"><p>"0=" is a function word that replaces a value with its logical
\r
956 complement; the result is zero if the value non-zero, and the result
\r
957 is non-zero if the value is zero.</p></div>
\r
958 <div class="paragraph"><p>This is the same function as <a href="#p_not">NOT</a>.</p></div>
\r
959 <div style="text-align:center">
\r
960 _______________________________________________________
\r
962 <div class="paragraph"><p><a id="p_0less"></a></p></div>
\r
964 <div class="sect2">
\r
965 <h3 id="_word_0_lt">Word: 0<</h3>
\r
966 <div class="literalblock">
\r
967 <div class="content">
\r
968 <pre><code>Data stack: ( v -- 0/-1 )</code></pre>
\r
970 <div class="paragraph"><p>"0<" is a function word that replaces a value with -1 if the value is
\r
971 less than 0, and 0 otherwise.</p></div>
\r
972 <div class="exampleblock">
\r
973 <div class="content">
\r
974 <div class="sidebarblock">
\r
975 <div class="content">
\r
976 <div class="title">Definition concept for 0<</div>
\r
977 <div class="paragraph"><p>( v — 0/1 ) : 0= 0 SWAP < ;</p></div>
\r
980 <div class="paragraph"><p>See also <a href="#p_swap">SWAP</a> and <a href="#p_lessthan"><</a>.</p></div>
\r
981 <div style="text-align:center">
\r
982 _______________________________________________________
\r
984 <div class="paragraph"><p><a id="p_1branch"></a></p></div>
\r
986 <div class="sect2">
\r
987 <h3 id="_word_1branch">Word: 1BRANCH</h3>
\r
988 <div class="literalblock">
\r
989 <div class="content">
\r
990 <pre><code>Data stack: ( v -- )</code></pre>
\r
992 <div class="paragraph"><p>"1BRANCH" is a function word that implements execution conditional by
\r
993 means of optionally adding the subsequent branch offset, or not, to
\r
994 the point of execution. If the value, v, is non-zero then the branch
\r
995 offset is added, and otherwise execution continues with the cell
\r
996 following the branch offset in the definition.</p></div>
\r
997 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
998 definition take up a cell of 8 bytes. The offset is relative to the
\r
999 cell address immediately subsequent to the offset cell. In other
\r
1000 words, offset 0 is not branching anywhere and an offset of -16 would
\r
1001 make a tight loop back to the branch instruction itself. The latter
\r
1002 would pull data stack values until and including the first zero value.</p></div>
\r
1003 <div class="paragraph"><p>See also <a href="#p_0branch">0BRANCH</a>, <a href="#p_branch">BRANCH</a>, <a href="#p_if">IF</a>,
\r
1004 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1005 <div style="text-align:center">
\r
1006 _______________________________________________________
\r
1008 <div class="paragraph"><p><a id="p_2drop"></a></p></div>
\r
1010 <div class="sect2">
\r
1011 <h3 id="_word_2drop">Word: 2DROP</h3>
\r
1012 <div class="literalblock">
\r
1013 <div class="content">
\r
1014 <pre><code>Data stack: ( v1 v2 -- )</code></pre>
\r
1016 <div class="paragraph"><p>"2DROP" is a function word that plainly discards the top 2 cells from
\r
1017 the data stack.</p></div>
\r
1018 <div style="text-align:center">
\r
1019 _______________________________________________________
\r
1021 <div class="paragraph"><p><a id="p_2dup"></a></p></div>
\r
1023 <div class="sect2">
\r
1024 <h3 id="_word_2dup">Word: 2DUP</h3>
\r
1025 <div class="literalblock">
\r
1026 <div class="content">
\r
1027 <pre><code>Data stack: ( v1 v2 -- v1 v2 v1 v2 )</code></pre>
\r
1029 <div class="paragraph"><p>"2DUP" is a function word that duplicates the top 2 cells on the data
\r
1031 <div class="exampleblock">
\r
1032 <div class="content">
\r
1033 <div class="sidebarblock">
\r
1034 <div class="content">
\r
1035 <div class="title">Definition concept for 2DUP</div>
\r
1036 <div class="paragraph"><p>( v1 v2 — v1 v2 v1 v2 ) : 2DUP OVER OVER ;</p></div>
\r
1039 <div style="text-align:center">
\r
1040 _______________________________________________________
\r
1042 <div class="paragraph"><p><a id="p_2get"></a></p></div>
\r
1044 <div class="sect2">
\r
1045 <h3 id="_word_2">Word: 2@</h3>
\r
1046 <div class="literalblock">
\r
1047 <div class="content">
\r
1048 <pre><code>Data stack: ( a -- v2 v1 )</code></pre>
\r
1050 <div class="paragraph"><p>"2@" is a function word that pushes the two concecutive values v1 and
\r
1051 v2 from the address a onto the data stack. Value v1 is from address a
\r
1052 and value v2 is from address a + 8.</p></div>
\r
1053 <div style="text-align:center">
\r
1054 _______________________________________________________
\r
1056 <div class="paragraph"><p><a id="p_2over"></a></p></div>
\r
1058 <div class="sect2">
\r
1059 <h3 id="_word_2over">Word: 2OVER</h3>
\r
1060 <div class="literalblock">
\r
1061 <div class="content">
\r
1062 <pre><code>Data stack: ( v1 v2 v3 v4 -- v1 v2 v3 v4 v1 v2 )</code></pre>
\r
1064 <div class="paragraph"><p>"2OVER" is a function word that replicates the second duble-cell pair
\r
1065 onto the top of the data stack. This is similar to <a href="#p_over">OVER</a> but
\r
1066 working with cell pairs rather than single cells.</p></div>
\r
1067 <div class="exampleblock">
\r
1068 <div class="content">
\r
1069 <div class="sidebarblock">
\r
1070 <div class="content">
\r
1071 <div class="title">Definition concept for 2OVER</div>
\r
1072 <div class="paragraph"><p>( v1 v2 v3 v4 — v1 v2 v3 v4 v1 v2 ) : 2OVER 3 PICK 3 PICK ;</p></div>
\r
1075 <div style="text-align:center">
\r
1076 _______________________________________________________
\r
1078 <div class="paragraph"><p><a id="p_2put"></a></p></div>
\r
1080 <div class="sect2">
\r
1081 <h3 id="_word_2_2">Word: 2!</h3>
\r
1082 <div class="literalblock">
\r
1083 <div class="content">
\r
1084 <pre><code>Data stack: ( v2 v1 a -- )</code></pre>
\r
1086 <div class="paragraph"><p>"2!" is a function word that stors two concecutive values v1 and v2 to
\r
1087 the address a from the data stack. Value v1 is stored at address a and
\r
1088 value v2 is stored at address a + 8.</p></div>
\r
1089 <div style="text-align:center">
\r
1090 _______________________________________________________
\r
1092 <div class="paragraph"><p><a id="p_2swap"></a></p></div>
\r
1094 <div class="sect2">
\r
1095 <h3 id="_word_2swap">Word: 2SWAP</h3>
\r
1096 <div class="literalblock">
\r
1097 <div class="content">
\r
1098 <pre><code>Data stack: ( v1 v2 v3 v4 -- v3 v4 v1 v2 )</code></pre>
\r
1100 <div class="paragraph"><p>"2SWAP" is a function word the reorgnizes the top 4 cells swappping
\r
1101 the upper and lower pair. This is similar to <a href="#p_swap">SWAP</a> but
\r
1102 working with cell pairs rather than single cells.</p></div>
\r
1103 <div class="exampleblock">
\r
1104 <div class="content">
\r
1105 <div class="sidebarblock">
\r
1106 <div class="content">
\r
1107 <div class="title">Definition concept for 2SWAP</div>
\r
1108 <div class="paragraph"><p>( v1 v2 v3 v4 — v3 v4 v1 v2 ) : 2SWAP 3 ROLL 3 ROLL ;</p></div>
\r
1111 <div style="text-align:center">
\r
1112 _______________________________________________________
\r
1114 <div class="paragraph"><p><a id="p_Ccomma"></a></p></div>
\r
1116 <div class="sect2">
\r
1117 <h3 id="_word_c">Word: C,</h3>
\r
1118 <div class="literalblock">
\r
1119 <div class="content">
\r
1120 <pre><code>Data stack: ( v -- )</code></pre>
\r
1122 <div class="paragraph"><p>"C," (C-comma) is a function word that puts a byte on the
\r
1123 <a href="#p_here">HERE</a> heap. The least significant byte of the value is put
\r
1124 at the current free head address, which also is incremented.</p></div>
\r
1125 <div class="exampleblock">
\r
1126 <div class="content">
\r
1127 <div class="sidebarblock">
\r
1128 <div class="content">
\r
1129 <div class="title">Definition concept for C,</div>
\r
1130 <div class="paragraph"><p>: C, HERE @ 1 ALLOT C! ; ( v — ; Claim 1 byte and put lsb value there )</p></div>
\r
1133 <div class="paragraph"><p>See also <a href="#p_colon">:</a>, <a href="#p_comma">[p_comma]</a>. <a href="#p_here">HERE</a>, <a href="#p_get">@</a>,
\r
1134 <a href="#p_allot">ALLOT</a>, <a href="#p_Cput">C!</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1135 <div style="text-align:center">
\r
1136 _______________________________________________________
\r
1138 <div class="paragraph"><p><a id="p_cfa2tfa"></a></p></div>
\r
1140 <div class="sect2">
\r
1141 <h3 id="_word_cfa_gt_tfa">Word: CFA>TFA</h3>
\r
1142 <div class="literalblock">
\r
1143 <div class="content">
\r
1144 <pre><code>Data stack: ( cfa -- tfa )</code></pre>
\r
1146 <div class="paragraph"><p>"CFA>TFA" is a function word that pushes word tfa of the given cfa.</p></div>
\r
1147 <div class="exampleblock">
\r
1148 <div class="content">
\r
1149 <div class="sidebarblock">
\r
1150 <div class="content">
\r
1151 <div class="title">Definition concept for CFA>TFA</div>
\r
1152 <div class="paragraph"><p>: CFA>TFA 14 - @ ;</p></div>
\r
1155 <div style="text-align:center">
\r
1156 _______________________________________________________
\r
1158 <div class="paragraph"><p><a id="p_Cget"></a></p></div>
\r
1160 <div class="sect2">
\r
1161 <h3 id="_word_c_2">Word: C@</h3>
\r
1162 <div class="literalblock">
\r
1163 <div class="content">
\r
1164 <pre><code>Data stack: ( a -- v )</code></pre>
\r
1166 <div class="paragraph"><p>"C@" is a function word that pushes the byte value v from the address a.</p></div>
\r
1167 <div style="text-align:center">
\r
1168 _______________________________________________________
\r
1170 <div class="paragraph"><p><a id="p_Cput"></a></p></div>
\r
1172 <div class="sect2">
\r
1173 <h3 id="_word_c_3">Word: C!</h3>
\r
1174 <div class="literalblock">
\r
1175 <div class="content">
\r
1176 <pre><code>Data stack: ( v a -- )</code></pre>
\r
1178 <div class="paragraph"><p>"C!" is a function word that stores the byte value v (the least
\r
1179 significant byte of the cell) at the address a.</p></div>
\r
1180 <div style="text-align:center">
\r
1181 _______________________________________________________
\r
1183 <div class="paragraph"><p><a id="p_Rget"></a></p></div>
\r
1185 <div class="sect2">
\r
1186 <h3 id="_word_r">Word: R@</h3>
\r
1187 <div class="literalblock">
\r
1188 <div class="content">
\r
1189 <pre><code>Data stack: ( -- v ) Return stack: ( v -- v )</code></pre>
\r
1191 <div class="paragraph"><p>"R@" is a function word that "copies" the top return stack value onto
\r
1192 the data stack.</p></div>
\r
1193 <div style="text-align:center">
\r
1194 _______________________________________________________
\r
1196 <div class="paragraph"><p><a id="p_Rgt"></a></p></div>
\r
1198 <div class="sect2">
\r
1199 <h3 id="_word_r_gt">Word: R></h3>
\r
1200 <div class="literalblock">
\r
1201 <div class="content">
\r
1202 <pre><code>Data stack: ( -- v ) Return stack: ( v -- )</code></pre>
\r
1204 <div class="paragraph"><p>"R>" is a function word that "moves" the top return stack value onto
\r
1205 the data stack.</p></div>
\r
1206 <div style="text-align:center">
\r
1207 _______________________________________________________
\r
1209 <div class="paragraph"><p><a id="p_abs"></a></p></div>
\r
1211 <div class="sect2">
\r
1212 <h3 id="_word_abs">Word: ABS</h3>
\r
1213 <div class="literalblock">
\r
1214 <div class="content">
\r
1215 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
1217 <div class="paragraph"><p>"ABS" is a function word that replaces a value with its absolute
\r
1218 value. To that end, the values are 64-bit signed integers.</p></div>
\r
1219 <div style="text-align:center">
\r
1220 _______________________________________________________
\r
1222 <div class="paragraph"><p><a id="p_again"></a></p></div>
\r
1224 <div class="sect2">
\r
1225 <h3 id="_word_again">Word: AGAIN</h3>
\r
1226 <div class="literalblock">
\r
1227 <div class="content">
\r
1228 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
1230 <div class="paragraph"><p>"AGAIN" is an immediate function word that is used together with
\r
1231 <a href="#p_begin">BEGIN</a> and instead of <a href="#p_end">END</a> to implement structured
\r
1232 execution control. AGAIN scans the datastack for the nearest preceding
\r
1233 BEGIN marker and lays out an unconditional branch from this point the
\r
1234 beginning of the block during execution. It thereafter performs the
\r
1235 <a href="#p_end">END</a> compile action to end the block.</p></div>
\r
1236 <div style="text-align:center">
\r
1237 _______________________________________________________
\r
1239 <div class="paragraph"><p><a id="p_allot"></a></p></div>
\r
1241 <div class="sect2">
\r
1242 <h3 id="_word_allot">Word: ALLOT</h3>
\r
1243 <div class="literalblock">
\r
1244 <div class="content">
\r
1245 <pre><code>Data stack: ( n -- )</code></pre>
\r
1247 <div class="paragraph"><p>"ALLOT" is a function word that merely increments the <a href="#p_here">HERE</a>
\r
1248 variable with <code>n</code> so as to claim that amount of the heap.</p></div>
\r
1249 <div class="exampleblock">
\r
1250 <div class="content">
\r
1251 <div class="sidebarblock">
\r
1252 <div class="content">
\r
1253 <div class="title">Defintion concept for ALLOT</div>
\r
1254 <div class="paragraph"><p>( n — ) : ALLOT HERE @ + HERE ! ;</p></div>
\r
1257 <div class="exampleblock">
\r
1258 <div class="content">
\r
1259 <div class="paragraph"><div class="title">Usage example 1: claim 16 bytes for variable FOO</div><p>CREATE FOO DROP HERE @ 16 ALLOT</p></div>
\r
1261 <div style="text-align:center">
\r
1262 _______________________________________________________
\r
1264 <div class="paragraph"><p><a id="p_and"></a></p></div>
\r
1266 <div class="sect2">
\r
1267 <h3 id="_word_and">Word: AND</h3>
\r
1268 <div class="literalblock">
\r
1269 <div class="content">
\r
1270 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
1272 <div class="paragraph"><p>"AND" is a function word that replaces a value pair with their bitwise
\r
1273 conjunction; each bit is 1 if the corresponding bits of both operands
\r
1274 are 1 and 0 if not.</p></div>
\r
1275 <div style="text-align:center">
\r
1276 _______________________________________________________
\r
1278 <div class="paragraph"><p><a id="p_args"></a></p></div>
\r
1280 <div class="sect2">
\r
1281 <h3 id="_word_main_args">Word: MAIN-ARGS</h3>
\r
1282 <div class="literalblock">
\r
1283 <div class="content">
\r
1284 <pre><code>Data stack: ( -- p[argv** argc] )</code></pre>
\r
1286 <div class="paragraph"><p>"ARGS" is a value word that holds a pointer to the command line data
\r
1287 block which consists of a count cell followed by that many asciiz
\r
1288 pointers and then a 0 cell.</p></div>
\r
1289 <div class="exampleblock">
\r
1290 <div class="content">
\r
1291 <div class="listingblock">
\r
1292 <div class="title">Usage example 2: the command line argument block</div>
\r
1293 <div class="content">
\r
1294 <pre><code>ARGS -> 8 bytes: count of non-zero asciiz pointers following
\r
1295 8 bytes: command name string
\r
1296 8 bytes: first argument string
\r
1298 8 zero</code></pre>
\r
1301 <div style="text-align:center">
\r
1302 _______________________________________________________
\r
1304 <div class="paragraph"><p><a id="p_base"></a></p></div>
\r
1306 <div class="sect2">
\r
1307 <h3 id="_word_base">Word: BASE</h3>
\r
1308 <div class="literalblock">
\r
1309 <div class="content">
\r
1310 <pre><code>Data stack: ( -- a )</code></pre>
\r
1312 <div class="paragraph"><p>"BASE" is a variable word for the numerical base used by input and
\r
1313 output functions, <a href="#p_number">NUMBER</a> and <a href="#p_dot">[p_dot]</a>, when
\r
1314 translating numbers between cell value form and text form. The
\r
1315 numerical base is set to 10 or 16 by <a href="#p_decimal">DECIMAL</a> and
\r
1316 <a href="#p_hex">HEX</a> respectively, and those are the only two bases currently
\r
1317 supported.</p></div>
\r
1318 <div class="paragraph"><p>See also <a href="#p_digits">DIGITS</a>, which holds the mapping table from
\r
1319 digits to text.</p></div>
\r
1320 <div style="text-align:center">
\r
1321 _______________________________________________________
\r
1323 <div class="paragraph"><p><a id="p_begin"></a></p></div>
\r
1325 <div class="sect2">
\r
1326 <h3 id="_word_begin">Word: BEGIN</h3>
\r
1327 <div class="literalblock">
\r
1328 <div class="content">
\r
1329 <pre><code>Data stack: Compiling: ( -- a 0 )</code></pre>
\r
1331 <div class="paragraph"><p>"BEGIN" is an immediate function word that is used together with
\r
1332 <a href="#p_ifbreak">IFBREAK</a>, <a href="#p_ifagain">IFAGAIN</a> and <a href="#p_end">END</a> to
\r
1333 implement structured execution control. BEGIN simply places the
\r
1334 address for resolving branches back to this point during execution,
\r
1335 and then a 0 as a marker so as to allow for an unknown number of block
\r
1336 exit points.</p></div>
\r
1337 <div class="exampleblock">
\r
1338 <div class="content">
\r
1339 <div class="listingblock">
\r
1340 <div class="title">Usage example 3:</div>
\r
1341 <div class="content">
\r
1342 <pre><code>: WTELL ( tfa -- ; Print word pname )
\r
1343 24 + DUP 8 + SWAP @ TELL SP EMIT
\r
1346 : WORDS ( wordlist -- ; Print all words of word list )
\r
1356 <div style="text-align:center">
\r
1357 _______________________________________________________
\r
1359 <div class="paragraph"><p><a id="p_bracketed_quote"></a></p></div>
\r
1361 <div class="sect2">
\r
1362 <h3 id="_word">Word: [']</h3>
\r
1363 <div class="literalblock">
\r
1364 <div class="content">
\r
1365 <pre><code>Data stack: ( -- cfa ) Input stream: word</code></pre>
\r
1367 <div class="paragraph"><p>"[']" is an immediate function word that reads the next word on the
\r
1368 input stream and pushes its cfa.</p></div>
\r
1369 <div class="exampleblock">
\r
1370 <div class="content">
\r
1371 <div class="sidebarblock">
\r
1372 <div class="content">
\r
1373 <div class="title">Definition concept for [']</div>
\r
1374 <div class="paragraph"><p>: ['] IMMEDIATE ' ;</p></div>
\r
1377 <div style="text-align:center">
\r
1378 _______________________________________________________
\r
1380 <div class="paragraph"><p><a id="p_branch"></a></p></div>
\r
1382 <div class="sect2">
\r
1383 <h3 id="_word_branch">Word: BRANCH</h3>
\r
1384 <div class="literalblock">
\r
1385 <div class="content">
\r
1386 <pre><code>Data stack: ( -- )</code></pre>
\r
1388 <div class="paragraph"><p>"BRANCH" is a function word that implements execution transfer by
\r
1389 means of adding the subsequent branch offset to the point of
\r
1390 execution.</p></div>
\r
1391 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
1392 definition take up a cell of 8 bytes. The offset is relative to the
\r
1393 cell address immediately subsequent to the offset cell. In other
\r
1394 words, offset 0 is not branching anywhere and an offset of -16 would
\r
1395 make a tight loop back to the branch instruction itself. The latter
\r
1396 would pull data stack values until and including the first zero value.</p></div>
\r
1397 <div class="paragraph"><p>See also <a href="#p_0branch">0BRANCH</a>, <a href="#p_1branch">1BRANCH</a>, <a href="#p_if">IF</a>,
\r
1398 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1399 <div style="text-align:center">
\r
1400 _______________________________________________________
\r
1402 <div class="paragraph"><p><a id="p_break"></a></p></div>
\r
1404 <div class="sect2">
\r
1405 <h3 id="_word_break">Word: BREAK</h3>
\r
1406 <div class="paragraph"><p>"BREAK" is an immediate function word that lays out an unconditional
\r
1407 branch out of an enclosing xef:p_begin[BEGIN]-<a href="#p_end">END</a> block.
\r
1408 Similar to <a href="#p_ifbreak">IFBREAK</a> it lays out the branch cell
\r
1409 followed by a reserved cell for the branch offset, and inserts the
\r
1410 resolution address just above the required 0 on the data stack.</p></div>
\r
1411 <div class="exampleblock">
\r
1412 <div class="content">
\r
1413 <div class="listingblock">
\r
1414 <div class="title">Usage example 4: unconditional break with a condition.</div>
\r
1415 <div class="content">
\r
1416 <pre><code>: WTELL ( tfa -- ; Print word pname )
\r
1417 24 + DUP 8 + SWAP @ TELL SP EMIT
\r
1420 : WORDS ( wordlist -- ; Print all words of word list )
\r
1422 @ DUP IF DUP WTELL ELSE BREAK THEN
\r
1430 <div class="paragraph"><p>See also <a href="#p_branch">BRANCH</a>, <a href="#p_0branch">0BRANCH</a>,
\r
1431 <a href="#p_1branch">1BRANCH</a>, <a href="#p_if">IF</a>, <a href="#p_else">ELSE</a>,
\r
1432 <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1433 <div style="text-align:center">
\r
1434 _______________________________________________________
\r
1436 <div class="paragraph"><p><a id="p_calltrace"></a></p></div>
\r
1438 <div class="sect2">
\r
1439 <h3 id="_word_calltrace">Word: [calltrace]</h3>
\r
1440 <div class="paragraph"><p>"[calltrace]" is a variable word that ccontains a small assembly
\r
1441 snippet that may be used for debugging when running under <code>gdb</code>.</p></div>
\r
1442 <div style="text-align:center">
\r
1443 _______________________________________________________
\r
1445 <div class="paragraph"><p><a id="p_cfa2flags_get"></a></p></div>
\r
1447 <div class="sect2">
\r
1448 <h3 id="_word_cfa_gt_flags">Word: CFA>FLAGS@</h3>
\r
1449 <div class="literalblock">
\r
1450 <div class="content">
\r
1451 <pre><code>Data stack: ( cfa -- flags )</code></pre>
\r
1453 <div class="paragraph"><p>"CFA>FLAGS@" is a function word that pushes word flags of the given cfa.</p></div>
\r
1454 <div class="exampleblock">
\r
1455 <div class="content">
\r
1456 <div class="sidebarblock">
\r
1457 <div class="content">
\r
1458 <div class="title">Defintion concept for CFA>FLAGS@</div>
\r
1459 <div class="paragraph"><p>: CFA>FLAGS@ 16 - @ 16 + ;</p></div>
\r
1462 <div style="text-align:center">
\r
1463 _______________________________________________________
\r
1465 <div class="paragraph"><p><a id="p_clear_stream"></a></p></div>
\r
1467 <div class="sect2">
\r
1468 <h3 id="_word_clear_stream">Word: CLEAR-STREAM</h3>
\r
1469 <div class="literalblock">
\r
1470 <div class="content">
\r
1471 <pre><code>Data stack: ( stream -- )</code></pre>
\r
1473 <div class="paragraph"><p>"CLEAR-STREAM" is a function word that discards whatever is currently
\r
1474 remaining in the buffer for the stream, so that a subsequent read will
\r
1475 pull in more data from its source.</p></div>
\r
1476 <div class="paragraph"><p>See also <a href="#p_read_stream_char">READ-STREAM-CHAR</a>.</p></div>
\r
1477 <div style="text-align:center">
\r
1478 _______________________________________________________
\r
1480 <div class="paragraph"><p><a id="p_colon"></a></p></div>
\r
1482 <div class="sect2">
\r
1483 <h3 id="_word_3">Word: :</h3>
\r
1484 <div class="literalblock">
\r
1485 <div class="content">
\r
1486 <pre><code>Data stack: ( -- ) Input stream: word</code></pre>
\r
1488 <div class="paragraph"><p>":" (colon) is a function word that starts a new forth definition.
\r
1489 This includes reading the next word for making a new dictionary entry
\r
1490 and setting evaluation state to compiling mode.</p></div>
\r
1491 <div class="exampleblock">
\r
1492 <div class="content">
\r
1493 <div class="sidebarblock">
\r
1494 <div class="content">
\r
1495 <div class="title">Definition concept for :</div>
\r
1496 <div class="paragraph"><p>: : doFORTH READ-WORD CREATE TFA>CFA ! ] ;</p></div>
\r
1499 <div class="paragraph"><p>See also <a href="#p_doforth">doFORTH</a>, <a href="#p_read_word">READ-WORD</a>,
\r
1500 <a href="#p_create">CREATE</a>, <a href="#p_tfa2cfa">TFA>CFA</a>, <a href="#p_put">!</a>,
\r
1501 <a href="#p_left_bracket">]</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1502 <div style="text-align:center">
\r
1503 _______________________________________________________
\r
1505 <div class="paragraph"><p><a id="p_comma"></a></p></div>
\r
1507 <div class="sect2">
\r
1508 <h3 id="_word_4">Word: ,</h3>
\r
1509 <div class="literalblock">
\r
1510 <div class="content">
\r
1511 <pre><code>Data stack: ( v -- )</code></pre>
\r
1513 <div class="paragraph"><p>"," (comma) is a function word that puts a cell value on the
\r
1514 <a href="#p_here">HERE</a> heap.</p></div>
\r
1515 <div class="exampleblock">
\r
1516 <div class="content">
\r
1517 <div class="sidebarblock">
\r
1518 <div class="content">
\r
1519 <div class="title">Definition concept for ,</div>
\r
1520 <div class="paragraph"><p>: , HERE @ 8 ALLOT ! ; ( v — ; Claim 8 bytes and put value there )</p></div>
\r
1523 <div class="paragraph"><p>See also <a href="#p_colon">:</a>, <a href="#p_Ccomma">[p_Ccomma]</a>. <a href="#p_here">HERE</a>, <a href="#p_get">@</a>,
\r
1524 <a href="#p_allot">ALLOT</a>, <a href="#p_put">!</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1525 <div style="text-align:center">
\r
1526 _______________________________________________________
\r
1528 <div class="paragraph"><p><a id="p_create"></a></p></div>
\r
1530 <div class="sect2">
\r
1531 <h3 id="_word_create">Word: CREATE</h3>
\r
1532 <div class="literalblock">
\r
1533 <div class="content">
\r
1534 <pre><code>Data stack: ( char* n -- tfa )</code></pre>
\r
1536 <div class="paragraph"><p>"CREATE" is a function word that allocates a "word header" with the
\r
1537 indicated [n:char*] print name, and returns the "TFA" (Token Field
\r
1538 Address) of the word. The header memory layout is as follows:</p></div>
\r
1539 <div class="exampleblock">
\r
1540 <div class="content">
\r
1541 <div class="listingblock">
\r
1542 <div class="title">Layout 1: rrqforth word structure</div>
\r
1543 <div class="content">
\r
1544 <pre><code>struct WORD
\r
1545 TFA 8 link ; tfa of previous word
\r
1546 pCFA 8 cfap ; CFA = Code Field Address of this word
\r
1548 PFA 8 length ; length of pname representation
\r
1549 ? pname ; the pname bytes
\r
1550 1 nul ; a forced nul byte following the pname
\r
1551 pTFA 8 tfap ; TFA = Token Field Address of this word
\r
1552 OFF 8 doff ; entry offset for FORTH level execution
\r
1553 CFA 8 doer ; word execution semantics
\r
1554 DFA 0 content ; DFA = Data Field Address
\r
1555 end_struct</code></pre>
\r
1558 <div class="paragraph"><p>A "word" is generally understod as a marker in memory for some content
\r
1559 as held in the memory space following the DFA (Data Field Address).</p></div>
\r
1560 <div class="paragraph"><p>The words CFA (Code Field Address) is the most important field for
\r
1561 RRQFORTH execution, as holding a jump address to the assembly code
\r
1562 that implements the particular execution semantics for the word.
\r
1563 "CREATE" will assign this as "dovariable", which makes the word push
\r
1564 its DFA when executed. This is changed to "doforth" for RRQFORTH
\r
1565 function words initiated by ":" (aka "COLON") or changed to "dovalue"
\r
1566 for RRQFORTH constants created by "CONSTANT".</p></div>
\r
1567 <div class="exampleblock">
\r
1568 <div class="content">
\r
1569 <div class="sidebarblock">
\r
1570 <div class="content">
\r
1571 <div class="title">Definition concept for CREATE</div>
\r
1572 <div class="paragraph"><p>HERE @ R> ( save tfa on RS )
\r
1573 R@ CURRENT-WORD @ DUP @ , ! ( link in a new word )
\r
1574 DUP 49 + R@ + , ( pCFA )
\r
1577 HERE @ ROT ROT MEMCPY 0 C, ( pname + NUL )
\r
1580 doVARIABLE ( CFA, default semantics )</p></div>
\r
1583 <div class="exampleblock">
\r
1584 <div class="content">
\r
1585 <div class="listingblock">
\r
1586 <div class="title">Usage example 5: a possible definition of CONSTANT</div>
\r
1587 <div class="content">
\r
1588 <pre><code>: CONSTANT READ-WORD CREATE TFA>DFA doVALUE OVER 8 - ! ! ;</code></pre>
\r
1591 <div class="paragraph"><p>See also <a href="#p_put">!</a>, <a href="#p_plus">+</a>, <a href="#p_comma">[p_comma]</a>, <a href="#p_get">@</a>,
\r
1592 <a href="#p_Ccomma">[p_Ccomma]</a>, <a href="#p_current_word">CURRENT-WORD</a>, <a href="#p_dup">DUP</a>,
\r
1593 <a href="#p_here">HERE</a>, <a href="#p_herememcpy">HERE</a>, <a href="#p_Rget">R@</a>, <a href="#p_rot">ROT</a>,
\r
1594 and <a href="#p_dovariable">doVARIABLE</a>,
\r
1595 as well as <a href="#p_execute">EXECUTE</a>
\r
1596 about the range of "doer" assignments and their meanings.</p></div>
\r
1597 <div style="text-align:center">
\r
1598 _______________________________________________________
\r
1600 <div class="paragraph"><p><a id="p_current_wordlist"></a></p></div>
\r
1602 <div class="sect2">
\r
1603 <h3 id="_word_current_wordlist">Word: CURRENT-WORDLIST</h3>
\r
1604 <div class="literalblock">
\r
1605 <div class="content">
\r
1606 <pre><code>Data stack: ( -- a )</code></pre>
\r
1608 <div class="paragraph"><p>"CURRENT-WORDLIST" is a variable word that points out the DFA of the
\r
1609 current word list word for <a href="#p_find">FIND</a> to use finding words. The
\r
1610 word list word content is as follows:</p></div>
\r
1611 <div class="exampleblock">
\r
1612 <div class="content">
\r
1613 <div class="listingblock">
\r
1614 <div class="title">Layout 2: word list word content</div>
\r
1615 <div class="content">
\r
1616 <pre><code> 8 TFA of latest word in the word list
\r
1617 8 DFA of the/a subsequent word list to search through</code></pre>
\r
1620 <div class="paragraph"><p>Note that word lists are chained by "extension" and in general it ends
\r
1621 with the <a href="#p_forth">FORTH</a> word list. Initially the
\r
1622 <a href="#p_system">SYSTEM</a> word list is the only other word list.</p></div>
\r
1623 <div style="text-align:center">
\r
1624 _______________________________________________________
\r
1626 <div class="paragraph"><p><a id="data_stack"></a></p></div>
\r
1628 <div class="sect2">
\r
1629 <h3 id="_word_data_stack">Word: DATA-STACK</h3>
\r
1630 <div class="literalblock">
\r
1631 <div class="content">
\r
1632 <pre><code>Data stack: ( -- a )</code></pre>
\r
1634 <div class="paragraph"><p>"DATA-STACK" is a variable word that harbours the data stack.</p></div>
\r
1635 <div style="text-align:center">
\r
1636 _______________________________________________________
\r
1638 <div class="paragraph"><p><a id="p_decimal"></a></p></div>
\r
1640 <div class="sect2">
\r
1641 <h3 id="_word_decimal">Word: DECIMAL</h3>
\r
1642 <div class="literalblock">
\r
1643 <div class="content">
\r
1644 <pre><code>Data stack: ( -- )</code></pre>
\r
1646 <div class="paragraph"><p>"DECIMAL" is a function word that sets <a href="#p_base">BASE</a> to 10.</p></div>
\r
1647 <div class="exampleblock">
\r
1648 <div class="content">
\r
1649 <div class="sidebarblock">
\r
1650 <div class="content">
\r
1651 <div class="title">Definition concept for DECIMAL</div>
\r
1652 <div class="paragraph"><p>: DECIMAL 10 BASE ! ;</p></div>
\r
1655 <div style="text-align:center">
\r
1656 _______________________________________________________
\r
1658 <div class="paragraph"><p><a id="p_depth"></a></p></div>
\r
1660 <div class="sect2">
\r
1661 <h3 id="_word_depth">Word: DEPTH</h3>
\r
1662 <div class="literalblock">
\r
1663 <div class="content">
\r
1664 <pre><code>Data stack: ( -- v )</code></pre>
\r
1666 <div class="paragraph"><p>"DEPTH" is a function word that pushes the count of data stack cells
\r
1667 onto the data stack.</p></div>
\r
1668 <div style="text-align:center">
\r
1669 _______________________________________________________
\r
1671 <div class="paragraph"><p><a id="p_dfa2tfa"></a></p></div>
\r
1673 <div class="sect2">
\r
1674 <h3 id="_word_dfa_gt_tfa">Word: DFA>TFA</h3>
\r
1675 <div class="literalblock">
\r
1676 <div class="content">
\r
1677 <pre><code>Data stack: ( dfa -- tfa )</code></pre>
\r
1679 <div class="paragraph"><p>"DFA>TFA" is a function word that pushes word tfa of the given dfa.</p></div>
\r
1680 <div class="exampleblock">
\r
1681 <div class="content">
\r
1682 <div class="sidebarblock">
\r
1683 <div class="content">
\r
1684 <div class="title">Definition concept for DFA>TFA</div>
\r
1685 <div class="paragraph"><p>: DFA>TFA 24 - @ ;</p></div>
\r
1688 <div style="text-align:center">
\r
1689 _______________________________________________________
\r
1691 <div class="paragraph"><p><a id="p_digits"></a></p></div>
\r
1693 <div class="sect2">
\r
1694 <h3 id="_word_digits">Word: DIGITS</h3>
\r
1695 <div class="literalblock">
\r
1696 <div class="content">
\r
1697 <pre><code>Data stack: ( -- a )</code></pre>
\r
1699 <div class="paragraph"><p>"DIGITS" is a variable word that holds the character array for mapping
\r
1700 digit values to characters. It contains the 16 characters 0-9 and a-f.</p></div>
\r
1701 <div style="text-align:center">
\r
1702 _______________________________________________________
\r
1704 <div class="paragraph"><p><a id="p_div"></a></p></div>
\r
1706 <div class="sect2">
\r
1707 <h3 id="_word_5">Word: /</h3>
\r
1708 <div class="literalblock">
\r
1709 <div class="content">
\r
1710 <pre><code>Data stack: ( v1 v2 -- q )</code></pre>
\r
1712 <div class="paragraph"><p>"/" (div) is a function word that replaces a pair of values with the
\r
1713 results of signed integer division of the first, v1, divided by the
\r
1714 second, v2. To that end, the values are 64-bit signed integers. The
\r
1715 result is the integer quotient, q, and the discarded remainder, r,
\r
1716 where q and r are the respectively largest and smallest integers to
\r
1717 satisfy the formula:</p></div>
\r
1718 <div class="literalblock">
\r
1719 <div class="content">
\r
1720 <pre><code> v1 = q * v2 + r</code></pre>
\r
1722 <div style="text-align:center">
\r
1723 _______________________________________________________
\r
1725 <div class="paragraph"><p><a id="p_divmod"></a></p></div>
\r
1727 <div class="sect2">
\r
1728 <h3 id="_word_mod">Word: /MOD</h3>
\r
1729 <div class="literalblock">
\r
1730 <div class="content">
\r
1731 <pre><code>Data stack: ( v1 v2 -- q r )</code></pre>
\r
1733 <div class="paragraph"><p>"/MOD" (div-mod) is a function word that replaces a pair of values
\r
1734 with the results of signed integer division of the first, v1, divided
\r
1735 by the second, v2. To that end, the values are 64-bit signed integers.
\r
1736 The result is the integer quotient, q, and the remainder, r, where q
\r
1737 and r are the respectively largest and smallest integers to satisfy
\r
1738 the formula:</p></div>
\r
1739 <div class="literalblock">
\r
1740 <div class="content">
\r
1741 <pre><code> v1 = q * v2 + r</code></pre>
\r
1743 <div style="text-align:center">
\r
1744 _______________________________________________________
\r
1746 <div class="paragraph"><p><a id="p_dodoes"></a></p></div>
\r
1748 <div class="sect2">
\r
1749 <h3 id="_word_dodoes">Word: doDOES</h3>
\r
1750 <div class="literalblock">
\r
1751 <div class="content">
\r
1752 <pre><code>Data stack: ( -- a )</code></pre>
\r
1754 <div class="paragraph"><p>"doDOES" is a variable word whose value is the implementation of the
\r
1755 <a href="#p_does">[p_does]</a> execution semantics. This is the same as
\r
1756 <a href="#p_doforth">doFORTH</a> but it starts at an offset into the word
\r
1757 concerned.</p></div>
\r
1758 <div style="text-align:center">
\r
1759 _______________________________________________________
\r
1761 <div class="paragraph"><p><a id="p_does"></a></p></div>
\r
1763 <div class="sect2">
\r
1764 <h3 id="_word_does_gt">WORD: DOES></h3>
\r
1765 <div class="literalblock">
\r
1766 <div class="content">
\r
1767 <pre><code>Data stack: ( -- )</code></pre>
\r
1769 <div class="paragraph"><p>"DOES>" is a function that in execution mode does nothing but in
\r
1770 compilation mode it changes the execution semantics assignments for
\r
1771 the most recent word to use the <code>dodoes</code> sematics with adjustment
\r
1772 offset to the current heap address. I.e., the word being defined will
\r
1773 have its execution start at whatever comes after "DOES>".</p></div>
\r
1774 <div class="exampleblock">
\r
1775 <div class="content">
\r
1776 <div class="sidebarblock">
\r
1777 <div class="content">
\r
1778 <div class="title">Defintion concept for DOES></div>
\r
1779 <div class="paragraph"><p>: DOES> IMMEDIATE
\r
1780 STATE @ != IF ( only for compilation mode )
\r
1781 CURRENT-WORDLIST @ @ TFA>CFA ( cfa of current word )
\r
1782 doDOES OVER ! ( set up doer )
\r
1783 HERE @ OVER 8 + - SWAP 8 - ! ( set up offset
\r
1788 <div class="paragraph"><p>See also
\r
1789 <a href="#p_put">!</a>,
\r
1790 <a href="#p_unequal">!⇒></a>,
\r
1791 <a href="#p_minus">→></a>,
\r
1792 <a href="#p_get">@</a>,
\r
1793 <a href="#p_current_wordlist">CURRENT-WORDLIST</a>,
\r
1794 <a href="#p_here">HERE</a>,
\r
1795 <a href="#p_if">IF</a>,
\r
1796 <a href="#p_immediate">IMMEDIATE</a>,
\r
1797 <a href="#p_over">OVER</a>,
\r
1798 <a href="#p_state">STATE</a>,
\r
1799 <a href="#p_swap">SWAP</a>,
\r
1800 <a href="#p_tfa2cfa">TFA>CFA</a>,
\r
1801 <a href="#p_then">THEN</a>,
\r
1802 <a href="#p_dodoes">doDOES</a>,
\r
1803 as well as <a href="#p_execute">EXECUTE</a>
\r
1804 about the range of "doer" assignments and their meanings.</p></div>
\r
1805 <div style="text-align:center">
\r
1806 _______________________________________________________
\r
1808 <div class="paragraph"><p><a id="p_dofasm"></a></p></div>
\r
1810 <div class="sect2">
\r
1811 <h3 id="_word_dofasm">Word: doFASM</h3>
\r
1812 <div class="literalblock">
\r
1813 <div class="content">
\r
1814 <pre><code>Data stack: ( -- a )</code></pre>
\r
1816 <div class="paragraph"><p>"doFASM" is a variable word whose value is the implementation of the
\r
1817 execution semantics for assembly code content.</p></div>
\r
1818 <div style="text-align:center">
\r
1819 _______________________________________________________
\r
1821 <div class="paragraph"><p><a id="p_doforth"></a></p></div>
\r
1823 <div class="sect2">
\r
1824 <h3 id="_word_doforth">Word: doFORTH</h3>
\r
1825 <div class="literalblock">
\r
1826 <div class="content">
\r
1827 <pre><code>Data stack: ( -- a )</code></pre>
\r
1829 <div class="paragraph"><p>"doFORTH" is a variable word whose value is the implementation of the
\r
1830 RRQFORTH execution semantics.</p></div>
\r
1831 <div style="text-align:center">
\r
1832 _______________________________________________________
\r
1834 <div class="paragraph"><p><a id="p_dostring"></a></p></div>
\r
1836 <div class="sect2">
\r
1837 <h3 id="_word_dostring">Word: doSTRING</h3>
\r
1838 <div class="literalblock">
\r
1839 <div class="content">
\r
1840 <pre><code>Data stack: ( -- a )</code></pre>
\r
1842 <div class="paragraph"><p>"doFASM" is a variable word whose value is the implementation of the
\r
1843 execution semantics for assembly code implemented words. In those
\r
1844 cases the execution leads to the word content.</p></div>
\r
1845 <div class="paragraph"><p>The register context at entry to an assembly code implemented word is
\r
1846 as follows:</p></div>
\r
1847 <div class="listingblock">
\r
1848 <div class="content">
\r
1849 <pre><code> rax = cfa* of word to execute
\r
1850 rsi = cell* in the calling definition, after calling cell
\r
1851 rsp = data stack pointer
\r
1852 rbp = return stack pointer</code></pre>
\r
1854 <div class="paragraph"><p>The assembly code must ensure that <code>rsi</code> is preserved and that <code>rsp</code>
\r
1855 and <code>rbp</code> are used according to their roles.</p></div>
\r
1856 <div style="text-align:center">
\r
1857 _______________________________________________________
\r
1859 <div class="paragraph"><p><a id="p_dot"></a></p></div>
\r
1861 <div class="sect2">
\r
1862 <h3 id="_word_6">Word: .</h3>
\r
1863 <div class="literalblock">
\r
1864 <div class="content">
\r
1865 <pre><code>Data stack: ( v -- )</code></pre>
\r
1867 <div class="paragraph"><p>"." is a function word that prints the top stack value to stdout using
\r
1868 the current <a href="#p_base">BASE</a> (either <a href="#p_decimal">DECIMAL</a> or
\r
1869 <a href="#p_hex">HEX</a>).</p></div>
\r
1870 <div style="text-align:center">
\r
1871 _______________________________________________________
\r
1873 <div class="paragraph"><p><a id="p_dot_temp"></a></p></div>
\r
1875 <div class="sect2">
\r
1876 <h3 id="_word_temp">Word: .TEMP</h3>
\r
1877 <div class="literalblock">
\r
1878 <div class="content">
\r
1879 <pre><code>Data stack: ( v -- char* n )</code></pre>
\r
1881 <div class="paragraph"><p>".TEMP" is a function word that renders a cell value as an integer
\r
1882 using the current <a href="#p_base">BASE</a>, which is either
\r
1883 <a href="#p_decimal">DECIMAL</a> or <a href="#p_hex">HEX</a>. In <a href="#p_decimal">DECIMAL</a>
\r
1884 <a href="#p_base">BASE</a>, a negative value is rendered as such with a leading
\r
1885 minus sign, whereas <a href="#p_hex">HEX</a> <a href="#p_base">BASE</a> rendering is
\r
1886 unsigned.</p></div>
\r
1887 <div style="text-align:center">
\r
1888 _______________________________________________________
\r
1890 <div class="paragraph"><p><a id="p_double_quote"></a></p></div>
\r
1892 <div class="sect2">
\r
1893 <h3 id="_word_7">Word: "</h3>
\r
1894 <div class="literalblock">
\r
1895 <div class="content">
\r
1896 <pre><code>data stack: ( -- char n ) Input stream: ...."</code></pre>
\r
1898 <div class="paragraph"><p>""" (double quote) is a function word that copies the input stream
\r
1899 text up to next double quote to <a href="#p_pad">PAD</a>, and returns the
\r
1900 [n:char*] cell pair for that string.</p></div>
\r
1901 <div style="text-align:center">
\r
1902 _______________________________________________________
\r
1904 <div class="paragraph"><p><a id="p_dovalue"></a></p></div>
\r
1906 <div class="sect2">
\r
1907 <h3 id="_word_dovalue">Word: doVALUE</h3>
\r
1908 <div class="literalblock">
\r
1909 <div class="content">
\r
1910 <pre><code>Data stack: ( -- a )</code></pre>
\r
1912 <div class="paragraph"><p>"doVALUE" is a variable word whose value is the implementation of the
\r
1913 execution semantics for cell values, which are variables with a single
\r
1914 64-bit cell holding the value.</p></div>
\r
1915 <div class="paragraph"><p>The execution of this result in pushing the value:</p></div>
\r
1916 <div class="literalblock">
\r
1917 <div class="content">
\r
1918 <pre><code>Resulting data stack: ( -- v )</code></pre>
\r
1920 <div style="text-align:center">
\r
1921 _______________________________________________________
\r
1923 <div class="paragraph"><p><a id="p_dovariable"></a></p></div>
\r
1925 <div class="sect2">
\r
1926 <h3 id="_word_dovariable">Word: doVARIABLE</h3>
\r
1927 <div class="literalblock">
\r
1928 <div class="content">
\r
1929 <pre><code>Data stack: ( -- a )</code></pre>
\r
1931 <div class="paragraph"><p>"doVARIABLE" is a variable word whose value is the implementation of
\r
1932 the execution semantics for "variables", which basically are markers
\r
1933 into the heap for some number block of memory.</p></div>
\r
1934 <div class="paragraph"><p>The execution of a variable results in pushing its content address:</p></div>
\r
1935 <div class="literalblock">
\r
1936 <div class="content">
\r
1937 <pre><code>Resulting data stack: ( -- a )</code></pre>
\r
1939 <div style="text-align:center">
\r
1940 _______________________________________________________
\r
1942 <div class="paragraph"><p><a id="p_drop"></a></p></div>
\r
1944 <div class="sect2">
\r
1945 <h3 id="_word_drop">Word: DROP</h3>
\r
1946 <div class="literalblock">
\r
1947 <div class="content">
\r
1948 <pre><code>Data stack: ( v -- )</code></pre>
\r
1950 <div class="paragraph"><p>"DROP" is a function word that discards the top stack cell.</p></div>
\r
1951 <div style="text-align:center">
\r
1952 _______________________________________________________
\r
1954 <div class="paragraph"><p><a id="p_dup"></a></p></div>
\r
1956 <div class="sect2">
\r
1957 <h3 id="_word_dup">Word: DUP</h3>
\r
1958 <div class="literalblock">
\r
1959 <div class="content">
\r
1960 <pre><code>Data stack: ( v -- v v )</code></pre>
\r
1962 <div class="paragraph"><p>"DUP" is a function word that duplicates the top stack cell.</p></div>
\r
1963 <div style="text-align:center">
\r
1964 _______________________________________________________
\r
1966 <div class="paragraph"><p><a id="p_else"></a></p></div>
\r
1968 <div class="sect2">
\r
1969 <h3 id="_word_else">Word: ELSE</h3>
\r
1970 <div class="literalblock">
\r
1971 <div class="content">
\r
1972 <pre><code>Data stack: Compiling: ( a -- a )</code></pre>
\r
1974 <div class="paragraph"><p>"ELSE" is an immediate function word that is used together with
\r
1975 <a href="#p_if">IF</a> and <a href="#p_then">THEN</a> to implement structured execution
\r
1976 control. ELSE lays out an unresolved unconditional branch as an ending
\r
1977 for the "then-part" of the structured statement, and it then performs
\r
1978 the branch resolution for the "else-part". To that end it replaces the
\r
1979 stacked address which pin-points the foot address the branch offset to
\r
1980 resolve, so that at execution time there is an appropriate conditional
\r
1981 branch past the "then-part" and the "else-part" of the "structured
\r
1982 statement".</p></div>
\r
1983 <div style="text-align:center">
\r
1984 _______________________________________________________
\r
1986 <div class="paragraph"><p><a id="p_emit"></a></p></div>
\r
1988 <div class="sect2">
\r
1989 <h3 id="_word_emit">Word: EMIT</h3>
\r
1990 <div class="literalblock">
\r
1991 <div class="content">
\r
1992 <pre><code>Data stack: ( c -- )</code></pre>
\r
1994 <div class="paragraph"><p>"EMIT" is a function word that puts the given character code to
\r
1995 standard output (file descriptor 1). The character is the least
\r
1996 significant byte of the top cell.</p></div>
\r
1997 <div style="text-align:center">
\r
1998 _______________________________________________________
\r
2000 <div class="paragraph"><p><a id="p_end"></a></p></div>
\r
2002 <div class="sect2">
\r
2003 <h3 id="_word_end">Word: END</h3>
\r
2004 <div class="literalblock">
\r
2005 <div class="content">
\r
2006 <pre><code>Data stack: Compiling: ( a 0 * -- )</code></pre>
\r
2008 <div class="paragraph"><p>"END" is an immediate function word that is used together with
\r
2009 <a href="#p_begin">BEGIN</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a> to
\r
2010 implement structured execution control. END processes the data stack
\r
2011 to resolve any dangling <a href="#p_ifbreak">IFBREAK</a> branch offset for the
\r
2012 block of the matching <a href="#p_begin">BEGIN</a>.</p></div>
\r
2013 <div style="text-align:center">
\r
2014 _______________________________________________________
\r
2016 <div class="paragraph"><p><a id="p_equal"></a></p></div>
\r
2018 <div class="sect2">
\r
2019 <h3 id="_word_8">Word: =</h3>
\r
2020 <div class="literalblock">
\r
2021 <div class="content">
\r
2022 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2024 <div class="paragraph"><p>"=" is a function word that replaces a pair of values with -1 of the
\r
2025 values are equal, and 0 otherwise.</p></div>
\r
2026 <div style="text-align:center">
\r
2027 _______________________________________________________
\r
2029 <div class="paragraph"><p><a id="p_erase"></a></p></div>
\r
2031 <div class="sect2">
\r
2032 <h3 id="_word_erase">Word: ERASE</h3>
\r
2033 <div class="literalblock">
\r
2034 <div class="content">
\r
2035 <pre><code>Data stack: ( a n -- )</code></pre>
\r
2037 <div class="paragraph"><p>"ERASE" is a function word that stores n NUL bytes at address a an up.</p></div>
\r
2038 <div style="text-align:center">
\r
2039 _______________________________________________________
\r
2041 <div class="paragraph"><p><a id="p_evaluate_stream"></a></p></div>
\r
2043 <div class="sect2">
\r
2044 <h3 id="_word_evaluate_stream">Word: EVALUATE-STREAM</h3>
\r
2045 <div class="literalblock">
\r
2046 <div class="content">
\r
2047 <pre><code>Data stack: ( stream -- ??? 0/1 ) Input stream: ......</code></pre>
\r
2049 <div class="paragraph"><p>"EVALUATE-STREAM" is a function word that reads words separated by
\r
2050 whitespace from the stream until it discovers an unknown word, or the
\r
2051 stream is exhausted. Depending on <a href="#p_state">STATE</a>, the words are
\r
2052 either executed or compiled, and all ther stack and heap effects are
\r
2053 preserved. "EVALUATE-STREAM" returns with an additional 0 or 1 on the
\r
2054 stack to respectively indicate that the last word was unkown, i.e. not
\r
2055 found (<a href="#p_find">FIND</a>) in the current word list
\r
2056 (<a href="#p_current_wordlist">CURRENT-WORDLIST</a>) and not a
\r
2057 <a href="#p_number">NUMBER</a> of the current <a href="#p_base">BASE</a>.</p></div>
\r
2058 <div class="paragraph"><p>Note that numbers in the current <a href="#p_base">BASE</a> are treated as known
\r
2059 words that are parsed into cell values. If interpreting, then the
\r
2060 value is left on the stack. If compiling, then the value is added to
\r
2061 the heap subsequent to first adding <a href="#p_literal">LIT</a>, which is done
\r
2062 so as to make that value be push to the data stack upon a later
\r
2063 execution.</p></div>
\r
2064 <div class="paragraph"><p>In the <a href="#p_decimal">DECIMAL</a> base, the number word may begin with a
\r
2065 minus sign.</p></div>
\r
2066 <div class="paragraph"><p>The words are read and executed one by one, accounting for whether its
\r
2067 a number word or not, whether it is an <a href="#p_immediate">IMMEDIATE</a> word
\r
2068 or not, and whether the state at the time of execution indicates
\r
2069 "compiling" of "interpreting". Immediate words are executed in both
\r
2070 interpreting and compiling state, while other words have their CFA get
\r
2071 added to the heap so as to gain their execution effect upon a later
\r
2072 execution.</p></div>
\r
2073 <div class="paragraph"><p>Note that "EVALUATE-STREAM" keeps the stream (pointer) on the return
\r
2074 stack while reading, parsing and executing.</p></div>
\r
2075 <div class="paragraph"><p>If "EVALUATE-STREAM" ends with 0, then <a href="#p_this_word">THIS-WORD</a> holds
\r
2076 the [n:chars] reference of the offending word in the stream buffer.</p></div>
\r
2077 <div style="text-align:center">
\r
2078 _______________________________________________________
\r
2080 <div class="paragraph"><p><a id="p_execute"></a></p></div>
\r
2082 <div class="sect2">
\r
2083 <h3 id="_word_execute">Word: EXECUTE</h3>
\r
2084 <div class="literalblock">
\r
2085 <div class="content">
\r
2086 <pre><code>Data stack: ( cfa -- )</code></pre>
\r
2088 <div class="paragraph"><p>"EXECUTE" is a function word that transfers the execution to the
\r
2089 indicated "Code Field Address", which typically is the CFA of an
\r
2090 RRQFORTH word with the CFA cell containing a jump address for the code
\r
2091 that implements the execution semnatics of the word.</p></div>
\r
2092 <div class="paragraph"><p>The following execution semantics are predefined:</p></div>
\r
2093 <div class="ulist"><ul>
\r
2096 assembler implemented words constitute their own execution
\r
2102 <a href="#p_doforth">[p_doforth]</a> implements the FORTH machine. This treats the word
\r
2103 content as a succession of cells that hold the cfa pointers for the
\r
2104 words that make of the definition. As is customary in FORTH
\r
2105 machines, the advance through that succession is provided by each
\r
2106 word code ending making an explicit jump to its successor. The
\r
2107 <a href="#p_return_stack">RETURN-STACK</a> serves as a call stack for tracking
\r
2108 the nesting of FORTH executions by saving the "addresses" of the
\r
2114 <a href="#p_dodoes">[p_dodoes]</a> implements the variation of starting the FORTH
\r
2115 execution somewhere within a definition rather than at the
\r
2121 <a href="#p_dostring">[p_dostring]</a>, <a href="#p_dovalue">[p_dovalue]</a> and <a href="#p_dovariable">[p_dovariable]</a> implement
\r
2122 different common ways of using word content other the as FORTH
\r
2127 <div style="text-align:center">
\r
2128 _______________________________________________________
\r
2130 <div class="paragraph"><p><a id="p_exit"></a></p></div>
\r
2132 <div class="sect2">
\r
2133 <h3 id="_word_exit">Word: EXIT</h3>
\r
2134 <div class="literalblock">
\r
2135 <div class="content">
\r
2136 <pre><code>Data stack: ( -- )</code></pre>
\r
2138 <div class="paragraph"><p>"EXIT" is a function word that implements the ending of a FORTH
\r
2139 definition and its threading to the subsequent step of the calling
\r
2140 definition.</p></div>
\r
2141 <div style="text-align:center">
\r
2142 _______________________________________________________
\r
2144 <div class="paragraph"><p><a id="p_false"></a></p></div>
\r
2146 <div class="sect2">
\r
2147 <h3 id="_word_false">Word: FALSE</h3>
\r
2148 <div class="literalblock">
\r
2149 <div class="content">
\r
2150 <pre><code>Data stack: ( -- 0 )</code></pre>
\r
2152 <div class="paragraph"><p>"FALSE" is a value word representing logical false.</p></div>
\r
2153 <div style="text-align:center">
\r
2154 _______________________________________________________
\r
2156 <div class="paragraph"><p><a id="p_fdemit"></a></p></div>
\r
2158 <div class="sect2">
\r
2159 <h3 id="_word_fdemit">Word: FDEMIT</h3>
\r
2160 <div class="literalblock">
\r
2161 <div class="content">
\r
2162 <pre><code>Data stack: ( c fd -- )</code></pre>
\r
2164 <div class="paragraph"><p>"FDEMIT" is a function word that puts the given character code to the
\r
2165 given file descriptor. The character is the least significant byte of
\r
2166 the data stack cell.</p></div>
\r
2167 <div style="text-align:center">
\r
2168 _______________________________________________________
\r
2170 <div class="paragraph"><p><a id="p_fdtell"></a></p></div>
\r
2172 <div class="sect2">
\r
2173 <h3 id="_word_fdtell">Word: FDTELL</h3>
\r
2174 <div class="literalblock">
\r
2175 <div class="content">
\r
2176 <pre><code>Data stack: ( char* n fd -- )</code></pre>
\r
2178 <div class="paragraph"><p>"FDTELL" is a function word that prints a string to the given file
\r
2179 descriptor.</p></div>
\r
2180 <div style="text-align:center">
\r
2181 _______________________________________________________
\r
2183 <div class="paragraph"><p><a id="p_find"></a></p></div>
\r
2185 <div class="sect2">
\r
2186 <h3 id="_word_find">Word: FIND</h3>
\r
2187 <div class="literalblock">
\r
2188 <div class="content">
\r
2189 <pre><code>Data stack: ( char* n -- [ char* n 0 ]/[ tfa ] )</code></pre>
\r
2191 <div class="paragraph"><p>"FIND" is a function word that searches the current word list search
\r
2192 path for the given [n:char*] word, and returns the TFA of the matching
\r
2193 word if any. Otherwise FIND preserves the initial data stack but adds
\r
2194 0 to it.</p></div>
\r
2195 <div class="paragraph"><p>The word is sought starting with the
\r
2196 <a href="#p_current_wordlist">CURRENT-WORDLIST</a> word list, for the first
\r
2197 occurence of a match. If not found, the search continues with the
\r
2198 subsequent word list, and so on.</p></div>
\r
2199 <div class="paragraph"><p>When a word is found, then the data stack is changed by discarding the
\r
2200 [n:char*] double cell string pointer and pushing (only) the TFA of the
\r
2201 matching word instead.</p></div>
\r
2202 <div style="text-align:center">
\r
2203 _______________________________________________________
\r
2205 <div class="paragraph"><p><a id="p_forth"></a></p></div>
\r
2207 <div class="sect2">
\r
2208 <h3 id="_word_forth">Word: FORTH</h3>
\r
2209 <div class="literalblock">
\r
2210 <div class="content">
\r
2211 <pre><code>data stack: ( -- a )</code></pre>
\r
2213 <div class="paragraph"><p>"FORTH" is a variable word for the FORTH word list, which does not
\r
2214 have any subsequent word list.</p></div>
\r
2215 <div style="text-align:center">
\r
2216 _______________________________________________________
\r
2218 <div class="paragraph"><p><a id="p_get"></a></p></div>
\r
2220 <div class="sect2">
\r
2221 <h3 id="_word_9">Word: @</h3>
\r
2222 <div class="literalblock">
\r
2223 <div class="content">
\r
2224 <pre><code>Data stack: ( a -- v )</code></pre>
\r
2226 <div class="paragraph"><p>"@" is a function word that pushes the value v from the address a.</p></div>
\r
2227 <div style="text-align:center">
\r
2228 _______________________________________________________
\r
2230 <div class="paragraph"><p><a id="p_get_n_decrement"></a></p></div>
\r
2232 <div class="sect2">
\r
2233 <h3 id="_word_n">Word: @n--</h3>
\r
2234 <div class="literalblock">
\r
2235 <div class="content">
\r
2236 <pre><code>Data stack: ( a n -- v )</code></pre>
\r
2238 <div class="paragraph"><p>"@n--" is a function word that pushes the value from the address, a,
\r
2239 then decrements the cell at that address by n.</p></div>
\r
2240 <div class="exampleblock">
\r
2241 <div class="content">
\r
2242 <div class="sidebarblock">
\r
2243 <div class="content">
\r
2244 <div class="title">Defintion concept for @n++</div>
\r
2245 <div class="paragraph"><p>: @n++ OVER @ DUP ROT - ROT ! ;</p></div>
\r
2248 <div style="text-align:center">
\r
2249 _______________________________________________________
\r
2251 <div class="paragraph"><p><a id="p_get_n_increment"></a></p></div>
\r
2253 <div class="sect2">
\r
2254 <h3 id="_word_n_2">Word: @n++</h3>
\r
2255 <div class="literalblock">
\r
2256 <div class="content">
\r
2257 <pre><code>Data stack: ( a n -- v )</code></pre>
\r
2259 <div class="paragraph"><p>"@n++" is a function word that pushes the value from the address, a,
\r
2260 then increments the cell at that address by n.</p></div>
\r
2261 <div class="exampleblock">
\r
2262 <div class="content">
\r
2263 <div class="sidebarblock">
\r
2264 <div class="content">
\r
2265 <div class="title">Defintion concept for @n++</div>
\r
2266 <div class="paragraph"><p>( a n — v ) : @n++ OVER @ DUP ROT + ROT ! ;</p></div>
\r
2269 <div style="text-align:center">
\r
2270 _______________________________________________________
\r
2272 <div class="paragraph"><p><a id="p_greaterequal"></a></p></div>
\r
2274 <div class="sect2">
\r
2275 <h3 id="_word_gt">Word: >=</h3>
\r
2276 <div class="literalblock">
\r
2277 <div class="content">
\r
2278 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2280 <div class="paragraph"><p>">=" is a function word that replaces a pair of values with -1 if the
\r
2281 first, v1, is greater than or equal to the second, v1, otherwise 0. To
\r
2282 that end, the values are 64-bit signed integers.</p></div>
\r
2283 <div style="text-align:center">
\r
2284 _______________________________________________________
\r
2286 <div class="paragraph"><p><a id="p_greaterthan"></a></p></div>
\r
2288 <div class="sect2">
\r
2289 <h3 id="_word_gt_2">Word: ></h3>
\r
2290 <div class="literalblock">
\r
2291 <div class="content">
\r
2292 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2294 <div class="paragraph"><p>">" is a function word that replaces a pair of values with -1 if the
\r
2295 first, v1, is greater than the second, v1, otherwise 0. To that end,
\r
2296 the values are 64-bit signed integers.</p></div>
\r
2297 <div style="text-align:center">
\r
2298 _______________________________________________________
\r
2300 <div class="paragraph"><p><a id="p_gtR"></a></p></div>
\r
2302 <div class="sect2">
\r
2303 <h3 id="_word_gt_r">Word: >R</h3>
\r
2304 <div class="literalblock">
\r
2305 <div class="content">
\r
2306 <pre><code>Data stack: ( v -- ) Return stack: ( -- v )</code></pre>
\r
2308 <div class="paragraph"><p>">R" is a function word that "moves" the top data stack value onto the
\r
2309 return stack.</p></div>
\r
2310 <div style="text-align:center">
\r
2311 _______________________________________________________
\r
2313 <div class="paragraph"><p><a id="p_here"></a></p></div>
\r
2315 <div class="sect2">
\r
2316 <h3 id="_word_here">Word: HERE</h3>
\r
2317 <div class="literalblock">
\r
2318 <div class="content">
\r
2319 <pre><code>Data stack: ( -- a )</code></pre>
\r
2321 <div class="paragraph"><p>"HERE" is a variable word that keeps the lowest address of the free
\r
2322 allocation space. It get updated by all words that allocate memory.</p></div>
\r
2323 <div class="exampleblock">
\r
2324 <div class="content">
\r
2325 <div class="sidebarblock">
\r
2326 <div class="content">
\r
2327 <div class="title">allocate 1024 bytes on the heap</div>
\r
2328 <div class="paragraph"><p>1024 HEAP @ + HEAP !</p></div>
\r
2331 <div class="paragraph"><p>See also <a href="#p_allot">ALLOT</a>.</p></div>
\r
2332 <div style="text-align:center">
\r
2333 _______________________________________________________
\r
2335 <div class="paragraph"><p><a id="p_hex"></a></p></div>
\r
2337 <div class="sect2">
\r
2338 <h3 id="_word_hex">Word: HEX</h3>
\r
2339 <div class="literalblock">
\r
2340 <div class="content">
\r
2341 <pre><code>Data stack: ( -- )</code></pre>
\r
2343 <div class="paragraph"><p>"HEX" is a function word that sets <a href="#p_base">BASE</a> to 16, which uses
\r
2344 letters a-f as additional digits. (Uppercase letter are also accepted
\r
2345 on input).</p></div>
\r
2346 <div class="exampleblock">
\r
2347 <div class="content">
\r
2348 <div class="sidebarblock">
\r
2349 <div class="content">
\r
2350 <div class="title">Definition concept for HEX</div>
\r
2351 <div class="paragraph"><p>: HEX 16 BASE ! ;</p></div>
\r
2354 <div style="text-align:center">
\r
2355 _______________________________________________________
\r
2357 <div class="paragraph"><p><a id="p_if"></a></p></div>
\r
2359 <div class="sect2">
\r
2360 <h3 id="_word_if">Word: IF</h3>
\r
2361 <div class="literalblock">
\r
2362 <div class="content">
\r
2363 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2365 <div class="paragraph"><p>"IF" is an immediate function word that is used together with
\r
2366 <a href="#p_else">ELSE</a> and <a href="#p_then">THEN</a> to implement structured execution
\r
2367 control. IF results in layout of a <a href="#p_0branch">0BRANCH</a> instruction
\r
2368 with an unresolved branch offset, and places the address for resolving
\r
2369 this instruction on the datastack. This address will then be resolved
\r
2370 and asssigned by a subsequent <a href="#p_else">ELSE</a> or <a href="#p_then">THEN</a> so
\r
2371 that at execution time there is an appropriate conditional branch past
\r
2372 the "then-part" of the "structured statement".</p></div>
\r
2373 <div style="text-align:center">
\r
2374 _______________________________________________________
\r
2376 <div class="paragraph"><p><a id="p_ifagain"></a></p></div>
\r
2378 <div class="sect2">
\r
2379 <h3 id="_word_ifagain">Word: IFAGAIN</h3>
\r
2380 <div class="literalblock">
\r
2381 <div class="content">
\r
2382 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2384 <div class="paragraph"><p>"IFAGAIN" is an immediate function word that is used together with
\r
2385 <a href="#p_begin">BEGIN</a>, <a href="#p_ifbreak">BREAK</a> and <a href="#p_end">END</a> to implement
\r
2386 structured execution control. IFAGAIN scans the datastack for the
\r
2387 nearest preceding BEGIN marker and lays out a branch from this point
\r
2388 the beginning of the block during execution.</p></div>
\r
2389 <div style="text-align:center">
\r
2390 _______________________________________________________
\r
2392 <div class="paragraph"><p><a id="p_ifbreak"></a></p></div>
\r
2394 <div class="sect2">
\r
2395 <h3 id="_word_ifbreak">Word: IFBREAK</h3>
\r
2396 <div class="literalblock">
\r
2397 <div class="content">
\r
2398 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2400 <div class="paragraph"><p>"IFBREAK" is an immediate function word that is used together with
\r
2401 <a href="#p_begin">BEGIN</a>, <a href="#p_ifagain">IFAGAIN</a> and <a href="#p_end">END</a> to
\r
2402 implement structured execution control. IFBREAK simply places the
\r
2403 address for resolving branches from this point the end of the block
\r
2404 during execution.</p></div>
\r
2405 <div style="text-align:center">
\r
2406 _______________________________________________________
\r
2408 <div class="paragraph"><p><a id="p_immediate"></a></p></div>
\r
2410 <div class="sect2">
\r
2411 <h3 id="_word_immediate">Word: IMMEDIATE</h3>
\r
2412 <div class="literalblock">
\r
2413 <div class="content">
\r
2414 <pre><code>Data stack: ( -- )</code></pre>
\r
2416 <div class="paragraph"><p>"IMMEDIATE" is an immediate function word that sets the flags field of
\r
2417 the most recent word to 1, thereby making that word an immediate word.</p></div>
\r
2418 <div class="exampleblock">
\r
2419 <div class="content">
\r
2420 <div class="sidebarblock">
\r
2421 <div class="content">
\r
2422 <div class="title">Definition concept for IMMEDIATE</div>
\r
2423 <div class="paragraph"><p>: IMMEDIATE IMMEDIATE 1 CURRENT-WORDLIST @ @ 16 + ! ;</p></div>
\r
2426 <div class="paragraph"><p>See also <a href="#p_colon">:</a>, <a href="#p_current_wordlist">CURRENT-WORDLIST</a>,
\r
2427 <a href="#p_get">@</a>, <a href="#p_plus">+</a>, <a href="#p_put">!</a>, and <a href="#p_semicolon;">[p_semicolon;]</a>.</p></div>
\r
2428 <div style="text-align:center">
\r
2429 _______________________________________________________
\r
2431 <div class="paragraph"><p><a id="p_input"></a></p></div>
\r
2433 <div class="sect2">
\r
2434 <h3 id="_word_input">Word: INPUT</h3>
\r
2435 <div class="literalblock">
\r
2436 <div class="content">
\r
2437 <pre><code>Data stack: ( -- a )</code></pre>
\r
2439 <div class="paragraph"><p>"INPUT" is a variable word for the input stream buffer used by
\r
2440 <a href="#p_evaluate_stream">EVALUATE-STREAM</a>.</p></div>
\r
2441 <div style="text-align:center">
\r
2442 _______________________________________________________
\r
2444 <div class="paragraph"><p><a id="p_left_bracket"></a></p></div>
\r
2446 <div class="sect2">
\r
2447 <h3 id="_word_10">Word: [</h3>
\r
2448 <div class="literalblock">
\r
2449 <div class="content">
\r
2450 <pre><code>Data stack: ( -- )</code></pre>
\r
2452 <div class="paragraph"><p>"[" (left bracket) is a function word that sets the stream evaluation
\r
2453 mode to be intepreting. In this mode, words are executed immediately
\r
2454 after parsing, by invoking their "doer".</p></div>
\r
2455 <div class="exampleblock">
\r
2456 <div class="content">
\r
2457 <div class="sidebarblock">
\r
2458 <div class="content">
\r
2459 <div class="title">Definition concept for [</div>
\r
2460 <div class="paragraph"><p>: [ IMMEDIATE 0 STATE ! ;</p></div>
\r
2463 <div style="text-align:center">
\r
2464 _______________________________________________________
\r
2466 <div class="paragraph"><p><a id="p_lessequal"></a></p></div>
\r
2468 <div class="sect2">
\r
2469 <h3 id="_word_lt">Word: <=</h3>
\r
2470 <div class="literalblock">
\r
2471 <div class="content">
\r
2472 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2474 <div class="paragraph"><p>"<=" is a function word that replaces a pair of values with -1 if the
\r
2475 first, v1, is less than or equal to the second, v1, otherwise 0. To
\r
2476 that end, the values are 64-bit signed integers.</p></div>
\r
2477 <div style="text-align:center">
\r
2478 _______________________________________________________
\r
2480 <div class="paragraph"><p><a id="p_lessthan"></a></p></div>
\r
2482 <div class="sect2">
\r
2483 <h3 id="_word_lt_2">Word: <</h3>
\r
2484 <div class="literalblock">
\r
2485 <div class="content">
\r
2486 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2488 <div class="paragraph"><p>"<" is a function word that replaces a pair of values with -1 if the
\r
2489 first, v1, is less than the second, v1, otherwise 0. To that end, the
\r
2490 values are 64-bit signed integers.</p></div>
\r
2491 <div style="text-align:center">
\r
2492 _______________________________________________________
\r
2494 <div class="paragraph"><p><a id="p_literal"></a></p></div>
\r
2496 <div class="sect2">
\r
2497 <h3 id="_word_lit">Word: LIT</h3>
\r
2498 <div class="literalblock">
\r
2499 <div class="content">
\r
2500 <pre><code>Data stack: ( -- v )</code></pre>
\r
2502 <div class="paragraph"><p>"LIT" is a function word that pushes the cell subsequent and moves
\r
2503 excution past that. The literal value is thus layed out as if a
\r
2504 subsequent CFA pointer in the containing definition, and the LIT
\r
2505 execution will make the execution skip past that and instead contine
\r
2506 with the CFA pointer following the value.</p></div>
\r
2507 <div class="paragraph"><p>It’s not a good idea to use "LIT" interactively.</p></div>
\r
2508 <div class="exampleblock">
\r
2509 <div class="content">
\r
2510 <div class="sidebarblock">
\r
2511 <div class="content">
\r
2512 <div class="title">Definition concept for LIT</div>
\r
2513 <div class="paragraph"><p>: LIT R> DUP 8 + >R @ ;</p></div>
\r
2516 <div style="text-align:center">
\r
2517 _______________________________________________________
\r
2519 <div class="paragraph"><p><a id="p_literal_string"></a></p></div>
\r
2521 <div class="sect2">
\r
2522 <h3 id="_word_s">Word: S"</h3>
\r
2523 <div class="literalblock">
\r
2524 <div class="content">
\r
2525 <pre><code>Data stack: ( -- chars* n )</code></pre>
\r
2527 <div class="paragraph"><p>"S"" is a function word that pushes the [n:char] pointer for a string
\r
2528 inlined subsequently to it in the containing definition. This is
\r
2529 similar to <a href="#p_lit">LIT</a> but for a string literal.</p></div>
\r
2530 <div class="exampleblock">
\r
2531 <div class="content">
\r
2532 <div class="sidebarblock">
\r
2533 <div class="content">
\r
2534 <div class="title">Definition concept for LIT</div>
\r
2535 <div class="paragraph"><p>: LIT R> DUP @ 2DUP + 8 + >R SWAP 8 + SWAP ;</p></div>
\r
2538 <div style="text-align:center">
\r
2539 _______________________________________________________
\r
2541 <div class="paragraph"><p><a id="p_load_buffer_size"></a></p></div>
\r
2543 <div class="sect2">
\r
2544 <h3 id="_word_load_buffer_size">Word: LOAD-BUFFER-SIZE</h3>
\r
2545 <div class="literalblock">
\r
2546 <div class="content">
\r
2547 <pre><code>data stack: ( -- a )</code></pre>
\r
2549 <div class="paragraph"><p>"LOAD-BUFFER-SIZE" is a variable word telling the buffer size in bytes
\r
2550 that <a href="#p_load_file">LOAD-FILE</a> should use.</p></div>
\r
2551 <div style="text-align:center">
\r
2552 _______________________________________________________
\r
2554 <div class="paragraph"><p><a id="p_load_file"></a></p></div>
\r
2556 <div class="sect2">
\r
2557 <h3 id="_word_load_file">Word: LOAD-FILE</h3>
\r
2558 <div class="literalblock">
\r
2559 <div class="content">
\r
2560 <pre><code>data stack: ( chaz* -- * 0/1 )</code></pre>
\r
2562 <div class="paragraph"><p>"LOAD-FILE" is a function word that evaluates a text file. It opens a
\r
2563 file via <a href="#p_open_file">OPEN-FILE</a> and sets up a stream with a
\r
2564 buffer of <a href="#p_load_buffer_size">LOAD-BUFFER-SIZE</a> bytes for
\r
2565 reading it. The stream is passed to
\r
2566 <a href="#p_evaluate_stream">EVALUATE-STREAM</a> for processing its words. Upon
\r
2567 its return the file is closed and the stream memory is reclaimed, and
\r
2568 then the function returns whatever
\r
2569 <a href="#p_evaluate_stream">EVALUATE-STREAM</a> returns.</p></div>
\r
2570 <div style="text-align:center">
\r
2571 _______________________________________________________
\r
2573 <div class="paragraph"><p><a id="p_lparen"></a></p></div>
\r
2575 <div class="sect2">
\r
2576 <h3 id="_word_11">Word: (</h3>
\r
2577 <div class="literalblock">
\r
2578 <div class="content">
\r
2579 <pre><code>Data stack: ( -- )</code></pre>
\r
2581 <div class="paragraph"><p>"(" (left parenthesis) is a function word that scans and ignores words
\r
2582 until the next right parenthesis, or the end of the stream. This is
\r
2583 used for comments in RRQFORTH code.</p></div>
\r
2584 <div class="paragraph"><p>Note that the terminating right parenthesis is a word, i.e. must have
\r
2585 whitespace before and after it.</p></div>
\r
2586 <div style="text-align:center">
\r
2587 _______________________________________________________
\r
2589 <div class="paragraph"><p><a id="p_malloc"></a></p></div>
\r
2591 <div class="sect2">
\r
2592 <h3 id="_word_malloc">Word: MALLOC</h3>
\r
2593 <div class="literalblock">
\r
2594 <div class="content">
\r
2595 <pre><code>Data stack: ( n -- a )</code></pre>
\r
2597 <div class="paragraph"><p>"MALLOC" is a word that allocates memory using mmap of at least n
\r
2598 bytes and returns the lowest address of the allocated block.</p></div>
\r
2599 <div class="paragraph"><p>Note that this makes new page allocations for the process from the
\r
2600 kernel, and the granularity is in pages, i.e. a multiple of 4 kb.</p></div>
\r
2601 <div class="paragraph"><p>The memory is allocated with READ and WRITE access but not EXEC
\r
2602 access, and flagged as PRIVATE, ANONYMOUS and LOCKED. See the "man
\r
2603 page" of mmap for details.</p></div>
\r
2604 <div class="paragraph"><p>See also <a href="#p_stream">STREAM</a></p></div>
\r
2605 <div style="text-align:center">
\r
2606 _______________________________________________________
\r
2608 <div class="paragraph"><p><a id="p_minus"></a></p></div>
\r
2610 <div class="sect2">
\r
2611 <h3 id="_word_12">Word: -</h3>
\r
2612 <div class="literalblock">
\r
2613 <div class="content">
\r
2614 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2616 <div class="paragraph"><p>"-" (minus) is a function word that replaces a pair of values with the
\r
2617 result of reducing the first, v1, with the second, v2. To that end,
\r
2618 the values are 64-bit signed integers.</p></div>
\r
2619 <div style="text-align:center">
\r
2620 _______________________________________________________
\r
2622 <div class="paragraph"><p><a id="p_mult"></a></p></div>
\r
2624 <div class="sect2">
\r
2625 <h3 id="_word_13">Word: *</h3>
\r
2626 <div class="literalblock">
\r
2627 <div class="content">
\r
2628 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2630 <div class="paragraph"><p>"*" is a function word that replaces a pair of values with the result
\r
2631 of multiplying them. To that end, the values are 64-bit signed
\r
2632 integers, and clipping the result to the least signifcant 64 bits.</p></div>
\r
2633 <div style="text-align:center">
\r
2634 _______________________________________________________
\r
2636 <div class="paragraph"><p><a id="p_negate"></a></p></div>
\r
2638 <div class="sect2">
\r
2639 <h3 id="_word_negate">Word: NEGATE</h3>
\r
2640 <div class="literalblock">
\r
2641 <div class="content">
\r
2642 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
2644 <div class="paragraph"><p>"NEGATE" is a function word that replaces a value with its
\r
2645 2’s-complement negation. To that end, the values are 64-bit signed
\r
2646 integers.</p></div>
\r
2647 <div style="text-align:center">
\r
2648 _______________________________________________________
\r
2650 <div class="paragraph"><p><a id="p_nip"></a></p></div>
\r
2652 <div class="sect2">
\r
2653 <h3 id="_word_nip">Word: NIP</h3>
\r
2654 <div class="literalblock">
\r
2655 <div class="content">
\r
2656 <pre><code>Data stack: ( v1 v2 -- v2 )</code></pre>
\r
2658 <div class="paragraph"><p>"NIP" is a function word that discards the second of the top two cells
\r
2659 on the data stack.</p></div>
\r
2660 <div class="exampleblock">
\r
2661 <div class="content">
\r
2662 <div class="sidebarblock">
\r
2663 <div class="content">
\r
2664 <div class="title">Definition concept for NIP</div>
\r
2665 <div class="paragraph"><p>: NIP SWAP DROP ;</p></div>
\r
2668 <div style="text-align:center">
\r
2669 _______________________________________________________
\r
2671 <div class="paragraph"><p><a id="p_nl"></a></p></div>
\r
2673 <div class="sect2">
\r
2674 <h3 id="_word_nl">Word: NL</h3>
\r
2675 <div class="literalblock">
\r
2676 <div class="content">
\r
2677 <pre><code>Data stack: ( -- v )</code></pre>
\r
2679 <div class="paragraph"><p>"NL" is a value word pushing a newline character onto the data stack.</p></div>
\r
2680 <div style="text-align:center">
\r
2681 _______________________________________________________
\r
2683 <div class="paragraph"><p><a id="p_not"></a></p></div>
\r
2685 <div class="sect2">
\r
2686 <h3 id="_word_not">Word: NOT</h3>
\r
2687 <div class="literalblock">
\r
2688 <div class="content">
\r
2689 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
2691 <div class="paragraph"><p>"NOT" is a function word that replaces a value with its bitwise
\r
2692 complement; each bit is zero if non-zero, and non-zero if zero.</p></div>
\r
2693 <div class="paragraph"><p>Compare with <<p_0equal,0⇒>.</p></div>
\r
2694 <div style="text-align:center">
\r
2695 _______________________________________________________
\r
2697 <div class="paragraph"><p><a id="p_number"></a></p></div>
\r
2699 <div class="sect2">
\r
2700 <h3 id="_word_number">Word: NUMBER</h3>
\r
2701 <div class="literalblock">
\r
2702 <div class="content">
\r
2703 <pre><code>Data stack: ( char n -- [ 0 ]/[ v 1 ] )</code></pre>
\r
2705 <div class="paragraph"><p>"NUMBER" is a function word that parses a text number using
\r
2706 <a href="#p_base">BASE</a> as numerical base, then returns the result number and
\r
2707 a 1 on top, or just a 0 if the word didn’t parse.</p></div>
\r
2708 <div class="paragraph"><p>A number consists of, first an optional minus sign, if in
\r
2709 <a href="#p_decimal">DECIMAL</a> base, then digits 0-9 and, if in <a href="#p_hex">HEX</a>
\r
2710 base, letters a-f or A-F for values 10-15. I.e. the normal positive or
\r
2711 negative decimal integers or normal (positive only) hexadecimal
\r
2712 integers.</p></div>
\r
2713 <div style="text-align:center">
\r
2714 _______________________________________________________
\r
2716 <div class="paragraph"><p><a id="p_open_file"></a></p></div>
\r
2718 <div class="sect2">
\r
2719 <h3 id="_word_open_file">Word: OPEN-FILE</h3>
\r
2720 <div class="literalblock">
\r
2721 <div class="content">
\r
2722 <pre><code>Data stack: ( chaz* -- fd )</code></pre>
\r
2724 <div class="paragraph"><p>"OPEN-FILE" is a function word that opens the file named by the zero
\r
2725 terminated character string and returns the file descriptor, or if
\r
2726 less than 0, the system call error code.</p></div>
\r
2727 <div style="text-align:center">
\r
2728 _______________________________________________________
\r
2730 <div class="paragraph"><p><a id="p_or"></a></p></div>
\r
2732 <div class="sect2">
\r
2733 <h3 id="_word_or">Word: OR</h3>
\r
2734 <div class="literalblock">
\r
2735 <div class="content">
\r
2736 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2738 <div class="paragraph"><p>"OR" is a function word that replaces a value pair with their bitwise
\r
2739 disjunction; each bit is 1 if the corresponding bits of any operand
\r
2740 is 1 and 0 if not.</p></div>
\r
2741 <div style="text-align:center">
\r
2742 _______________________________________________________
\r
2744 <div class="paragraph"><p><a id="p_over"></a></p></div>
\r
2746 <div class="sect2">
\r
2747 <h3 id="_word_over">Word: OVER</h3>
\r
2748 <div class="literalblock">
\r
2749 <div class="content">
\r
2750 <pre><code>Data stack: ( v1 v2 -- v1 v2 v1 )</code></pre>
\r
2752 <div class="paragraph"><p>"OVER" is a function word that duplicates the second top stack cell on
\r
2753 the data stack.</p></div>
\r
2754 <div style="text-align:center">
\r
2755 _______________________________________________________
\r
2757 <div class="paragraph"><p><a id="p_pad"></a></p></div>
\r
2759 <div class="sect2">
\r
2760 <h3 id="_word_pad">Word: PAD</h3>
\r
2761 <div class="literalblock">
\r
2762 <div class="content">
\r
2763 <pre><code>Data stack: ( -- a )</code></pre>
\r
2765 <div class="paragraph"><p>"PAD" is a variable word for a 1 kb data space that is used by
\r
2766 <a href="#p_double_quote">[p_double_quote]</a> (only), and otherwise free for temporary use.</p></div>
\r
2767 <div style="text-align:center">
\r
2768 _______________________________________________________
\r
2770 <div class="paragraph"><p><a id="p_pick"></a></p></div>
\r
2772 <div class="sect2">
\r
2773 <h3 id="_word_pick">Word: PICK</h3>
\r
2774 <div class="literalblock">
\r
2775 <div class="content">
\r
2776 <pre><code>Data stack: ( vu...v1 v0 u -- vu...v1 v0 vu )</code></pre>
\r
2778 <div class="paragraph"><p>"PICK" is a function word that pushes the u:th data stack cell down
\r
2779 from top onto the data stack. 0 indicates the top cell making it the
\r
2780 same as <a href="#p_dup">DUP</a>, and 1 indicates the second top cell making it
\r
2781 the same as <a href="#p_over">OVER</a>.</p></div>
\r
2782 <div style="text-align:center">
\r
2783 _______________________________________________________
\r
2785 <div class="paragraph"><p><a id="p_plus"></a></p></div>
\r
2787 <div class="sect2">
\r
2788 <h3 id="_word_43">Word: +</h3>
\r
2789 <div class="literalblock">
\r
2790 <div class="content">
\r
2791 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2793 <div class="paragraph"><p>"+" (plus) is a function word that replaces a pair of values with the
\r
2794 result of adding them. To that end, the values are 64-bit signed
\r
2795 integers.</p></div>
\r
2796 <div style="text-align:center">
\r
2797 _______________________________________________________
\r
2799 <div class="paragraph"><p><a id="p_program_version"></a></p></div>
\r
2801 <div class="sect2">
\r
2802 <h3 id="_word_program_version">Word: PROGRAM_VERSION</h3>
\r
2803 <div class="literalblock">
\r
2804 <div class="content">
\r
2805 <pre><code>Data stack: ( -- char* length )</code></pre>
\r
2807 <div class="paragraph"><p>"PROGRAM_VERSION" is a string variable hilding the version string.</p></div>
\r
2808 <div style="text-align:center">
\r
2809 _______________________________________________________
\r
2811 <div class="paragraph"><p><a id="p_put"></a></p></div>
\r
2813 <div class="sect2">
\r
2814 <h3 id="_word_14">Word: !</h3>
\r
2815 <div class="literalblock">
\r
2816 <div class="content">
\r
2817 <pre><code>Data stack: ( v a -- )</code></pre>
\r
2819 <div class="paragraph"><p>"!" is a function word that stores the cell value v at the address a.</p></div>
\r
2820 <div style="text-align:center">
\r
2821 _______________________________________________________
\r
2823 <div class="paragraph"><p><a id="p_put_plus"></a></p></div>
\r
2825 <div class="sect2">
\r
2826 <h3 id="_word_15">Word: !+</h3>
\r
2827 <div class="literalblock">
\r
2828 <div class="content">
\r
2829 <pre><code>Data stack: ( a n -- )</code></pre>
\r
2831 <div class="paragraph"><p>"!+" is a function word that adds n to the cell value at a.</p></div>
\r
2832 <div class="exampleblock">
\r
2833 <div class="content">
\r
2834 <div class="sidebarblock">
\r
2835 <div class="content">
\r
2836 <div class="title">definition concept for !+</div>
\r
2837 <div class="paragraph"><p>( a n — ) : !+ OVER @ + SWAP ! ;</p></div>
\r
2840 <div style="text-align:center">
\r
2841 _______________________________________________________
\r
2843 <div class="paragraph"><p><a id="p_quit"></a></p></div>
\r
2845 <div class="sect2">
\r
2846 <h3 id="_word_quit">Word: QUIT</h3>
\r
2847 <div class="literalblock">
\r
2848 <div class="content">
\r
2849 <pre><code>Data stack: ??</code></pre>
\r
2851 <div class="paragraph"><p>"QUIT" is a function word that implements the root execution loop of
\r
2852 RRQFORTH. First it resets the stacks to their original settings, and
\r
2853 thereafter it enters loop of reading words from <a href="#p_stdin">STDIN</a> and
\r
2854 executing them.</p></div>
\r
2855 <div style="text-align:center">
\r
2856 _______________________________________________________
\r
2858 <div class="paragraph"><p><a id="p_quote"></a></p></div>
\r
2860 <div class="sect2">
\r
2861 <h3 id="_word_16">Word: '</h3>
\r
2862 <div class="literalblock">
\r
2863 <div class="content">
\r
2864 <pre><code>data stack: ( -- cfa ) Input stream: word</code></pre>
\r
2866 <div class="paragraph"><p>"'" (single quote) is a function word that reads and find the next
\r
2867 word on the input stream and pushes its cfa.</p></div>
\r
2868 <div style="text-align:center">
\r
2869 _______________________________________________________
\r
2871 <div class="paragraph"><p><a id="p_rbp"></a></p></div>
\r
2873 <div class="sect2">
\r
2874 <h3 id="_word_rsp">Word: RSP</h3>
\r
2875 <div class="literalblock">
\r
2876 <div class="content">
\r
2877 <pre><code>Data stack: ( -- a )</code></pre>
\r
2879 <div class="paragraph"><p>"RSP" is a function word that pushes the return stack pointer value
\r
2880 onto the data stack.</p></div>
\r
2881 <div style="text-align:center">
\r
2882 _______________________________________________________
\r
2884 <div class="paragraph"><p><a id="p_rbpn"></a></p></div>
\r
2886 <div class="sect2">
\r
2887 <h3 id="_word_r_n">Word: R[n]</h3>
\r
2888 <div class="literalblock">
\r
2889 <div class="content">
\r
2890 <pre><code>Data stack: ( n -- a )</code></pre>
\r
2892 <div class="paragraph"><p>"R[n]" is a function word that pushes the address for the n:th cell on
\r
2893 the top return stack value onto the data stack.</p></div>
\r
2894 <div class="exampleblock">
\r
2895 <div class="content">
\r
2896 <div class="sidebarblock">
\r
2897 <div class="content">
\r
2898 <div class="title">Defintion concept for R[n]</div>
\r
2899 <div class="paragraph"><p>( n — a ) : R[n] 8 * RSP + ;</p></div>
\r
2902 <div style="text-align:center">
\r
2903 _______________________________________________________
\r
2905 <div class="paragraph"><p><a id="p_read_stream_char"></a></p></div>
\r
2907 <div class="sect2">
\r
2908 <h3 id="_word_read_stream_char">Word: READ-STREAM-CHAR</h3>
\r
2909 <div class="literalblock">
\r
2910 <div class="content">
\r
2911 <pre><code>Data stack: ( stream -- c )</code></pre>
\r
2913 <div class="paragraph"><p>"READ-STREAM-CHAR" is a function word that gets the next character
\r
2914 from the given stream buffer, possibly refilling the buffer if it is
\r
2915 backed by a file descriptor. The refill is done by a SYS_READ call
\r
2916 when more characters are needed. The next character is pushed on the
\r
2917 stack, unless the stream is exhausted in which case the -1 is pushed
\r
2918 instead.</p></div>
\r
2919 <div class="paragraph"><p>See also <a href="#p_stream">STREAM</a>.</p></div>
\r
2920 <div style="text-align:center">
\r
2921 _______________________________________________________
\r
2923 <div class="paragraph"><p><a id="p_read_word"></a></p></div>
\r
2925 <div class="sect2">
\r
2926 <h3 id="_word_read_word">Word: READ-WORD</h3>
\r
2927 <div class="literalblock">
\r
2928 <div class="content">
\r
2929 <pre><code>Data stack: ( stream -- char* n )</code></pre>
\r
2931 <div class="paragraph"><p>"READ-WORD" is a function word that "reads" the next whitespace
\r
2932 separated word from the given stream and returns the [n:char*] duoble
\r
2933 cell pointer for it. The characters of the word are copied to
\r
2934 <a href="#p_pad">PAD</a>, and there is a limit of 1024 characters.</p></div>
\r
2935 <div class="paragraph"><p>At the end of the stream READ-WORD returns 0 length.</p></div>
\r
2936 <div class="exampleblock">
\r
2937 <div class="title">Special syntax 1: Whitespace</div>
\r
2938 <div class="content">
\r
2939 <div class="paragraph"><p>All character codes less or equal to 32 are regarded as "whitespace".</p></div>
\r
2941 <div class="exampleblock">
\r
2942 <div class="title">Special syntax 2: Rest-of-line comment</div>
\r
2943 <div class="content">
\r
2944 <div class="paragraph"><p>The "#" character following whitespace starts a line comment and the
\r
2945 rest of the line is ignored. Note that this is also recognised with
\r
2946 <a href="#p_lparen">parethesis commenting</a>.</p></div>
\r
2948 <div style="text-align:center">
\r
2949 _______________________________________________________
\r
2951 <div class="paragraph"><p><a id="p_realloc"></a></p></div>
\r
2953 <div class="sect2">
\r
2954 <h3 id="_word_realloc">Word: REALLOC</h3>
\r
2955 <div class="literalblock">
\r
2956 <div class="content">
\r
2957 <pre><code>Data stack: ( a m n -- a )</code></pre>
\r
2959 <div class="paragraph"><p>"REALLOC" is a word that reallocates memory using mremap of address a
\r
2960 of size m to be size n bytes and returns the lowest address of the
\r
2961 allocated block.</p></div>
\r
2962 <div class="paragraph"><p>Note that this makes new page allocations for the process from the
\r
2963 kernel, and the granularity is in pages, i.e. a multiple of 4 kb.</p></div>
\r
2964 <div class="paragraph"><p>The memory is reampped using the MREMAP_MAYMOVE flag,</p></div>
\r
2965 <div class="paragraph"><p>See also <a href="#p_malloc">MALLOC</a></p></div>
\r
2966 <div style="text-align:center">
\r
2967 _______________________________________________________
\r
2969 <div class="paragraph"><p>compile.asm: WORD p_right_bracket,<em>]</em>,fasm</p></div>
\r
2970 <div class="paragraph"><p><a id="p_right_bracket"></a></p></div>
\r
2972 <div class="sect2">
\r
2973 <h3 id="_word_17">Word: ]</h3>
\r
2974 <div class="literalblock">
\r
2975 <div class="content">
\r
2976 <pre><code>Data stack: ( -- )</code></pre>
\r
2978 <div class="paragraph"><p>"]" (right bracket) is a function word that sets the stream evaluation
\r
2979 mode to be compiling. In this mode words parsed into CFA pointers
\r
2980 which are placed on the heap in the given order, unless the word is
\r
2981 flagged as <a href="#p_immediate">IMMEDIATE</a> or a <a href="#p_number">NUMBER</a>. An
\r
2982 immediate word is executed immediately, and a number is parsed and
\r
2983 left on the stack.</p></div>
\r
2984 <div class="paragraph"><p>Note that a word is parsed as a number only if it is not found in the
\r
2985 wordlist; i.e., the word list may contain definitions for numbers.</p></div>
\r
2986 <div class="exampleblock">
\r
2987 <div class="content">
\r
2988 <div class="sidebarblock">
\r
2989 <div class="content">
\r
2990 <div class="title">Definition concept for ]</div>
\r
2991 <div class="paragraph"><p>: ] 1 STATE ! ;</p></div>
\r
2994 <div style="text-align:center">
\r
2995 _______________________________________________________
\r
2997 <div class="paragraph"><p><a id="p_roll"></a></p></div>
\r
2999 <div class="sect2">
\r
3000 <h3 id="_word_roll">Word: ROLL</h3>
\r
3001 <div class="literalblock">
\r
3002 <div class="content">
\r
3003 <pre><code>Data stack: ( vu...v1 v0 u -- ...v1 v0 vu )</code></pre>
\r
3005 <div class="paragraph"><p>"ROLL" is a function word that "moves" the u:th data stack cell down
\r
3006 from top onto the data stack while discarding it. 0 indicates the top
\r
3007 cell; 1 indicates the second top cell making it the same as
\r
3008 <a href="#p_swap">SWAP</a>; 2 indicates the third top cell making it the same as
\r
3009 <a href="#p_rot">ROT</a>.</p></div>
\r
3010 <div style="text-align:center">
\r
3011 _______________________________________________________
\r
3013 <div class="paragraph"><p><a id="p_rot"></a></p></div>
\r
3015 <div class="sect2">
\r
3016 <h3 id="_word_rot">Word: ROT</h3>
\r
3017 <div class="literalblock">
\r
3018 <div class="content">
\r
3019 <pre><code>Data stack: ( v1 v2 v3 -- v2 v3 v1 )</code></pre>
\r
3021 <div class="paragraph"><p>"ROT" is a function word that "rotates" the top three data stack cells
\r
3022 such that the third becomes the first while the second becomes third
\r
3023 and the first becomes the second.</p></div>
\r
3024 <div class="paragraph"><p>See also <a href="#p_roll">ROLL</a>.</p></div>
\r
3025 <div style="text-align:center">
\r
3026 _______________________________________________________
\r
3028 <div class="paragraph"><p><a id="p_semicolon"></a></p></div>
\r
3030 <div class="sect2">
\r
3031 <h3 id="_word_18">Word: ;</h3>
\r
3032 <div class="literalblock">
\r
3033 <div class="content">
\r
3034 <pre><code>Data stack: ( -- )</code></pre>
\r
3036 <div class="paragraph"><p>";" (semi-colon) is a function word that ends a new forth definition
\r
3037 by means of adding an <a href="#p_exit">EXIT</a></p></div>
\r
3038 <div class="exampleblock">
\r
3039 <div class="content">
\r
3040 <div class="sidebarblock">
\r
3041 <div class="content">
\r
3042 <div class="title">Definition concept for ;</div>
\r
3043 <div class="paragraph"><p>: ; IMMEDIATE ' EXIT , ;</p></div>
\r
3046 <div style="text-align:center">
\r
3047 _______________________________________________________
\r
3049 <div class="paragraph"><p><a id="p_setup_signals"></a></p></div>
\r
3051 <div class="sect2">
\r
3052 <h3 id="_word_p_setup_signals">Word: [p_setup_signals]</h3>
\r
3053 <div class="literalblock">
\r
3054 <div class="content">
\r
3055 <pre><code>Data stack: ( -- a )</code></pre>
\r
3057 <div class="paragraph"><p>"[p_setup_signals]" is a variable word that contains the assembly code
\r
3058 sniippet for setting up the signal handling. rrqforth handles SEGV by
\r
3059 restarting the interpreter loop on <a href="#p_stdin">STDIN</a>.</p></div>
\r
3060 <div style="text-align:center">
\r
3061 _______________________________________________________
\r
3063 <div class="paragraph"><p><a id="p_shift_left"></a></p></div>
\r
3065 <div class="sect2">
\r
3066 <h3 id="_word_lt_lt">Word: <<</h3>
\r
3067 <div class="literalblock">
\r
3068 <div class="content">
\r
3069 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3071 <div class="paragraph"><p>"<<" is a function word that shifts value v1 n steps left (i.e.
\r
3072 "moving" bits towards more significant bits) to form value v2.</p></div>
\r
3073 <div style="text-align:center">
\r
3074 _______________________________________________________
\r
3076 <div class="paragraph"><p><a id="p_shift_right"></a></p></div>
\r
3078 <div class="sect2">
\r
3079 <h3 id="_word_gt_gt">Word: >></h3>
\r
3080 <div class="literalblock">
\r
3081 <div class="content">
\r
3082 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3084 <div class="paragraph"><p>">>" is a function word that shifts value v1 n steps right (i.e.
\r
3085 "moving" bits towards less significant bits) to form value v2.</p></div>
\r
3086 <div style="text-align:center">
\r
3087 _______________________________________________________
\r
3089 <div class="paragraph"><p><a id="p_shift_signed_right"></a></p></div>
\r
3091 <div class="sect2">
\r
3092 <h3 id="_word_s_gt_gt">Word: s>></h3>
\r
3093 <div class="literalblock">
\r
3094 <div class="content">
\r
3095 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3097 <div class="paragraph"><p>"s>>" is a function word that shifts value v1 n steps right (i.e.
\r
3098 "moving" bits towards less significant bits) to form value v2, but
\r
3099 preserving (and copying) the sign bit.</p></div>
\r
3100 <div style="text-align:center">
\r
3101 _______________________________________________________
\r
3103 <div class="paragraph"><p><a id="p_sp"></a></p></div>
\r
3105 <div class="sect2">
\r
3106 <h3 id="_word_sp">Word: SP</h3>
\r
3107 <div class="literalblock">
\r
3108 <div class="content">
\r
3109 <pre><code>Data stack: ( -- v )</code></pre>
\r
3111 <div class="paragraph"><p>"SP" is a value word pushing a space character onto the data stack.</p></div>
\r
3112 <div style="text-align:center">
\r
3113 _______________________________________________________
\r
3115 <div class="paragraph"><p><a id="p_state"></a></p></div>
\r
3117 <div class="sect2">
\r
3118 <h3 id="_word_state">Word: STATE</h3>
\r
3119 <div class="literalblock">
\r
3120 <div class="content">
\r
3121 <pre><code>Data stack: ( -- a )</code></pre>
\r
3123 <div class="paragraph"><p>"STATE" is a variable word marking whether the stream evaluator is in
\r
3124 compiling mode (1) or interpreting (0) mode.</p></div>
\r
3125 <div style="text-align:center">
\r
3126 _______________________________________________________
\r
3128 <div class="paragraph"><p><a id="p_stdin"></a></p></div>
\r
3130 <div class="sect2">
\r
3131 <h3 id="_word_stdin">Word: STDIN</h3>
\r
3132 <div class="literalblock">
\r
3133 <div class="content">
\r
3134 <pre><code>Data stack: ( -- stream )</code></pre>
\r
3136 <div class="paragraph"><p>"STDIN" is a value word referring to the stream buffer for the
\r
3137 standard input file descriptor.</p></div>
\r
3138 <div style="text-align:center">
\r
3139 _______________________________________________________
\r
3141 <div class="paragraph"><p><a id="p_stream"></a></p></div>
\r
3143 <div class="sect2">
\r
3144 <h3 id="_word_stream">Word: STREAM</h3>
\r
3145 <div class="literalblock">
\r
3146 <div class="content">
\r
3147 <pre><code>Data stack: ( fd size -- addr ) or ( block -1 -- addr )</code></pre>
\r
3149 <div class="paragraph"><p>"STREAM" is a function word that sets up a buffer for an input file
\r
3150 descriptor or for a memory block (of size+data).</p></div>
\r
3151 <div class="sect3">
\r
3152 <h4 id="_file_descriptor_backed_stream">File descriptor backed STREAM</h4>
\r
3153 <div class="paragraph"><p>A file descriptor backed STREAM gains a buffer of the given size
\r
3154 prefixed by a 32 byte STREAM header of the following layout:</p></div>
\r
3155 <div class="exampleblock">
\r
3156 <div class="content">
\r
3157 <div class="listingblock">
\r
3158 <div class="title">Layout 3: file descriptor stream</div>
\r
3159 <div class="content">
\r
3160 <pre><code> 8 bytes = size of buffer (excluding the 32 byte header)
\r
3161 8 bytes source file descriptor
\r
3162 8 bytes current fill
\r
3163 8 current read position</code></pre>
\r
3167 <div class="sect3">
\r
3168 <h4 id="_memory_block_backed_stream">Memory block backed STREAM</h4>
\r
3169 <div class="paragraph"><p>A memory block stream is only the header (though allocated via
\r
3170 <a href="#p_malloc">MALLOC</a> which reserves a full kernel page) with the
\r
3171 following layout:</p></div>
\r
3172 <div class="exampleblock">
\r
3173 <div class="content">
\r
3174 <div class="listingblock">
\r
3175 <div class="title">Layout 4: memory block stream</div>
\r
3176 <div class="content">
\r
3177 <pre><code> 8 bytes = block address
\r
3178 8 -1 (indicates memory block)
\r
3179 8 size of block (taken from the block's first 8 bytes)
\r
3180 8 current read position</code></pre>
\r
3183 <div style="text-align:center">
\r
3184 _______________________________________________________
\r
3186 <div class="paragraph"><p><a id="p_stream_nchars"></a></p></div>
\r
3189 <div class="sect2">
\r
3190 <h3 id="_word_stream_nchars">Word: STREAM-NCHARS</h3>
\r
3191 <div class="literalblock">
\r
3192 <div class="content">
\r
3193 <pre><code>Data stack: ( stream -- n )</code></pre>
\r
3195 <div class="paragraph"><p>"STREAM-NCHARS" is a function word that scans ahead in the stream
\r
3196 buffer for the next non-whitespace character, and returns its position
\r
3197 relative to the end of the buffer. This is done without changing the
\r
3198 stream (or filling it by reading the backing file).</p></div>
\r
3199 <div style="text-align:center">
\r
3200 _______________________________________________________
\r
3202 <div class="paragraph"><p><a id="p_strlen"></a></p></div>
\r
3204 <div class="sect2">
\r
3205 <h3 id="_word_strlen">Word: STRLEN</h3>
\r
3206 <div class="literalblock">
\r
3207 <div class="content">
\r
3208 <pre><code>Data stack: ( s -- n )</code></pre>
\r
3210 <div class="paragraph"><p>"STRLEN" is a function words that counts how many bytes there are from
\r
3211 s to the first NUL byte and returns that count, n, not including the
\r
3212 NUL byte.</p></div>
\r
3213 <div style="text-align:center">
\r
3214 _______________________________________________________
\r
3216 <div class="paragraph"><p><a id="p_strncmp"></a></p></div>
\r
3218 <div class="sect2">
\r
3219 <h3 id="_word_strncmp">Word: STRNCMP</h3>
\r
3220 <div class="literalblock">
\r
3221 <div class="content">
\r
3222 <pre><code>Data stack: ( s1 s2 n -- v )</code></pre>
\r
3224 <div class="paragraph"><p>"STRNCMP" is a function words that compares up to n characters of
\r
3225 character sequences s1 and s2, and returns the difference of the first
\r
3226 differing characters, as in <code>s2[i] - s1[i]</code>, or 0 if all n characters
\r
3227 are the same.</p></div>
\r
3228 <div class="paragraph"><p>I.e., the value v is less than 0 if string [n:s1] is alpha-numerically
\r
3230 v is greater than 0 if [n:s1] is greater than [n:s2],
\r
3231 and v is 0 if [n:s1] and [n:s2] are equal.</p></div>
\r
3232 <div style="text-align:center">
\r
3233 _______________________________________________________
\r
3235 <div class="paragraph"><p><a id="p_strncpy"></a></p></div>
\r
3237 <div class="sect2">
\r
3238 <h3 id="_word_strncpy">Word: STRNCPY</h3>
\r
3239 <div class="literalblock">
\r
3240 <div class="content">
\r
3241 <pre><code>Data stack: ( s1 s2 n -- )</code></pre>
\r
3243 <div class="paragraph"><p>"STRNCPY" is a function words that copies n bytes of byte sequence s1
\r
3245 <div style="text-align:center">
\r
3246 _______________________________________________________
\r
3248 <div class="paragraph"><p><a id="p_swap"></a></p></div>
\r
3250 <div class="sect2">
\r
3251 <h3 id="_word_swap">Word: SWAP</h3>
\r
3252 <div class="literalblock">
\r
3253 <div class="content">
\r
3254 <pre><code>Data stack: ( v1 v2 -- v2 v1 )</code></pre>
\r
3256 <div class="paragraph"><p>"SWAP" is a function word the swaps the top two data stack cells.</p></div>
\r
3257 <div style="text-align:center">
\r
3258 _______________________________________________________
\r
3260 <div class="paragraph"><p><a id="p_system"></a></p></div>
\r
3262 <div class="sect2">
\r
3263 <h3 id="_word_system">Word: SYSTEM</h3>
\r
3264 <div class="literalblock">
\r
3265 <div class="content">
\r
3266 <pre><code>Data value: ( -- a )</code></pre>
\r
3268 <div class="paragraph"><p>"SYSTEM" is a variable that holds the word list data for the system
\r
3269 calls. This is set up as separate word list from <a href="#p_forth">FORTH</a>
\r
3270 merely as a matter of segregation.</p></div>
\r
3271 <div style="text-align:center">
\r
3272 _______________________________________________________
\r
3274 <div class="paragraph"><p><a id="p_tell"></a></p></div>
\r
3276 <div class="sect2">
\r
3277 <h3 id="_word_tell">Word: TELL</h3>
\r
3278 <div class="literalblock">
\r
3279 <div class="content">
\r
3280 <pre><code>Data stack: ( char* n -- )</code></pre>
\r
3282 <div class="paragraph"><p>"TELL" is a function word that prints a string to stdout (file
\r
3283 descriptor 1).</p></div>
\r
3284 <div style="text-align:center">
\r
3285 _______________________________________________________
\r
3287 <div class="paragraph"><p><a id="p_terminate0"></a></p></div>
\r
3289 <div class="sect2">
\r
3290 <h3 id="_word_terminate0">Word: TERMINATE0</h3>
\r
3291 <div class="literalblock">
\r
3292 <div class="content">
\r
3293 <pre><code>Data stack: ( -- )</code></pre>
\r
3295 <div class="paragraph"><p>"TERMINATE0" is a function word that terminates the program with exit
\r
3297 <div style="text-align:center">
\r
3298 _______________________________________________________
\r
3300 <div class="paragraph"><p><a id="p_tfa2cfa"></a></p></div>
\r
3302 <div class="sect2">
\r
3303 <h3 id="_word_tfa_gt_cfa">Word: TFA>CFA</h3>
\r
3304 <div class="literalblock">
\r
3305 <div class="content">
\r
3306 <pre><code>Data stack: ( tfa -- cfa )</code></pre>
\r
3308 <div class="paragraph"><p>"TFA>CFA" is a function word that pushes word cfa of the given tfa.</p></div>
\r
3309 <div class="exampleblock">
\r
3310 <div class="content">
\r
3311 <div class="sidebarblock">
\r
3312 <div class="content">
\r
3313 <div class="title">Definition concept for TFA>CFA</div>
\r
3314 <div class="paragraph"><p>: TFA>CFA 8 + @ ;</p></div>
\r
3317 <div style="text-align:center">
\r
3318 _______________________________________________________
\r
3320 <div class="paragraph"><p><a id="p_tfa2dfa"></a></p></div>
\r
3322 <div class="sect2">
\r
3323 <h3 id="_word_tfa_gt_dfa">Word: TFA>DFA</h3>
\r
3324 <div class="literalblock">
\r
3325 <div class="content">
\r
3326 <pre><code>Data stack: ( tfa -- dfa )</code></pre>
\r
3328 <div class="paragraph"><p>"TFA>DFA" is a function word that pushes word dfa of the given tfa.</p></div>
\r
3329 <div class="exampleblock">
\r
3330 <div class="content">
\r
3331 <div class="sidebarblock">
\r
3332 <div class="content">
\r
3333 <div class="title">Definition concept for TFA>DFA</div>
\r
3334 <div class="paragraph"><p>: TFA>DFA TFA>CFA 8 + ;</p></div>
\r
3337 <div style="text-align:center">
\r
3338 _______________________________________________________
\r
3340 <div class="paragraph"><p><a id="p_tfa2flags_get"></a></p></div>
\r
3342 <div class="sect2">
\r
3343 <h3 id="_word_tfa_gt_flags">Word: TFA>FLAGS@</h3>
\r
3344 <div class="literalblock">
\r
3345 <div class="content">
\r
3346 <pre><code>Data stack: ( tfa -- flags )</code></pre>
\r
3348 <div class="paragraph"><p>"TFA>FLAGS@" is a function word that pushes word flags of the given tfa.</p></div>
\r
3349 <div class="exampleblock">
\r
3350 <div class="content">
\r
3351 <div class="sidebarblock">
\r
3352 <div class="content">
\r
3353 <div class="title">Defintion concept for TFA>FLAGS@</div>
\r
3354 <div class="paragraph"><p>: TFA>FLAGS@ 16 + @ ;</p></div>
\r
3357 <div style="text-align:center">
\r
3358 _______________________________________________________
\r
3360 <div class="paragraph"><p><a id="p_tfa2namez"></a></p></div>
\r
3362 <div class="sect2">
\r
3363 <h3 id="_word_tfa_gt_namez">Word: TFA>NAMEZ</h3>
\r
3364 <div class="literalblock">
\r
3365 <div class="content">
\r
3366 <pre><code>Data stack: ( tfa -- char* )</code></pre>
\r
3368 <div class="paragraph"><p>"TFA>NAMEZ" is a function word that pushes changes a tfa pointer to a
\r
3369 pointer to the word pname’s character sequence, which is zero
\r
3370 terminated as well as preceded by a length cell.</p></div>
\r
3371 <div class="exampleblock">
\r
3372 <div class="content">
\r
3373 <div class="sidebarblock">
\r
3374 <div class="content">
\r
3375 <div class="title">Defintion concept for TFA>NAMEZ</div>
\r
3376 <div class="paragraph"><p>: TFA>NAMEZ 32 + ;</p></div>
\r
3379 <div style="text-align:center">
\r
3380 _______________________________________________________
\r
3382 <div class="paragraph"><p><a id="p_then"></a></p></div>
\r
3384 <div class="sect2">
\r
3385 <h3 id="_word_then">Word: THEN</h3>
\r
3386 <div class="literalblock">
\r
3387 <div class="content">
\r
3388 <pre><code>Data stack: Compiling: ( a -- )</code></pre>
\r
3390 <div class="paragraph"><p>"THEN" is an immediate function word that is used together with
\r
3391 <a href="#p_if">IF</a> and <a href="#p_else">ELSE</a> to implement structured execution
\r
3392 control. THEN performs the branch resolution for the stacked address
\r
3393 which pinpoints the foot address the branch offset to resolve, so that
\r
3394 at execution time there is an appropriate conditional branch past the
\r
3395 "then-part" or the "else-part" of the "structured statement".</p></div>
\r
3396 <div style="text-align:center">
\r
3397 _______________________________________________________
\r
3399 <div class="paragraph"><p><a id="p_this_word"></a></p></div>
\r
3401 <div class="sect2">
\r
3402 <h3 id="_word_this_word">Word: THIS-WORD</h3>
\r
3403 <div class="literalblock">
\r
3404 <div class="content">
\r
3405 <pre><code>Data stack: ( -- a )</code></pre>
\r
3407 <div class="paragraph"><p>"THIS-WORD" is a variable word used in
\r
3408 <a href="#p_evaluate_stream:EVALUATE-STREAM">[p_evaluate_stream:EVALUATE-STREAM]</a> as cache for the [n:char*]
\r
3409 values of the successive words being evaluated. This typically points
\r
3410 into the input stream buffer and remain valid until further stream
\r
3411 buffering functions are used.</p></div>
\r
3412 <div style="text-align:center">
\r
3413 _______________________________________________________
\r
3415 <div class="paragraph"><p><a id="p_true"></a></p></div>
\r
3417 <div class="sect2">
\r
3418 <h3 id="_word_true">Word: TRUE</h3>
\r
3419 <div class="literalblock">
\r
3420 <div class="content">
\r
3421 <pre><code>Data stack: ( -- -1 )</code></pre>
\r
3423 <div class="paragraph"><p>"TRUE" is a value word representing logical true.</p></div>
\r
3424 <div style="text-align:center">
\r
3425 _______________________________________________________
\r
3427 <div class="paragraph"><p><a id="p_tuck"></a></p></div>
\r
3429 <div class="sect2">
\r
3430 <h3 id="_word_tuck">Word: TUCK</h3>
\r
3431 <div class="literalblock">
\r
3432 <div class="content">
\r
3433 <pre><code>Data stack ( v1 v2 -- v2 v1 v2 )</code></pre>
\r
3435 <div class="paragraph"><p>"TUCK" is a function word that "inserts" the top cell below the second
\r
3436 cell on the data stack.</p></div>
\r
3437 <div class="exampleblock">
\r
3438 <div class="content">
\r
3439 <div class="sidebarblock">
\r
3440 <div class="content">
\r
3441 <div class="title">Definition concept for TUCK</div>
\r
3442 <div class="paragraph"><p>: TUCK SWAP OVER ;</p></div>
\r
3445 <div style="text-align:center">
\r
3446 _______________________________________________________
\r
3448 <div class="paragraph"><p><a id="p_unequal"></a></p></div>
\r
3450 <div class="sect2">
\r
3451 <h3 id="_word_19">Word: !=</h3>
\r
3452 <div class="literalblock">
\r
3453 <div class="content">
\r
3454 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
3456 <div class="paragraph"><p>"!=" is a function word that replaces a pair of values with -1 of the
\r
3457 values are unequal, and 0 otherwise.</p></div>
\r
3458 <div style="text-align:center">
\r
3459 _______________________________________________________
\r
3461 <div class="paragraph"><p><a id="p_unstream"></a></p></div>
\r
3463 <div class="sect2">
\r
3464 <h3 id="_word_unstream">Word: UNSTREAM</h3>
\r
3465 <div class="literalblock">
\r
3466 <div class="content">
\r
3467 <pre><code>Data stack: ( stream* -- )</code></pre>
\r
3469 <div class="paragraph"><p>"UNSTREAM" is a function word that releases the memory allocated for a
\r
3470 stream, and closes the associated file if it’s a file stream.</p></div>
\r
3471 <div class="sect3">
\r
3472 <h4 id="_file_descriptor_backed_stream_2">File descriptor backed stream</h4>
\r
3473 <div class="paragraph"><p>This kind of stream has the stream header as a prefix within the
\r
3474 allocated memory. Thus, stream* is the base address for the memory to
\r
3475 reclaim, and the size of this is determined from the cell at (stream*
\r
3476 + 16) plus the 32 bytes head itself.</p></div>
\r
3478 <div class="sect3">
\r
3479 <h4 id="_memory_block_backed_stream_2">Memory block backed STREAM</h4>
\r
3480 <div class="paragraph"><p>This kind of stream has a separate header which points at the memory
\r
3481 area to reclaim. The cell at stream* is the base address, and the cell
\r
3482 at (stream* + 16) is its size.</p></div>
\r
3483 <div style="text-align:center">
\r
3484 _______________________________________________________
\r
3486 <div class="paragraph"><p><a id="p_verboseQ"></a></p></div>
\r
3489 <div class="sect2">
\r
3490 <h3 id="_word_verbose">Word: VERBOSE?</h3>
\r
3491 <div class="literalblock">
\r
3492 <div class="content">
\r
3493 <pre><code>Data stack: ( -- a )</code></pre>
\r
3495 <div class="paragraph"><p>"VERBOSE?" is a variable word that is assigned at start up to -1 or 0
\r
3496 signify whether or not the command line arguments includes "-v". When
\r
3497 non-zero (i.e. running rrqforth with "-v") the evaluation loop is more
\r
3498 verbose.</p></div>
\r
3499 <div style="text-align:center">
\r
3500 _______________________________________________________
\r
3502 <div class="paragraph"><p><a id="p_within"></a></p></div>
\r
3504 <div class="sect2">
\r
3505 <h3 id="_word_within">Word: WITHIN</h3>
\r
3506 <div class="literalblock">
\r
3507 <div class="content">
\r
3508 <pre><code>Data stack: ( v lo hi -- 0/-1</code></pre>
\r
3510 <div class="paragraph"><p>"WITHIN" is a function word that replaces a triple of values with -1
\r
3511 of the the first, v, is within the value range spanned by the second,
\r
3512 lo, inclusive and third, hi, exclusive.</p></div>
\r
3513 <div class="exampleblock">
\r
3514 <div class="content">
\r
3515 <div class="sidebarblock">
\r
3516 <div class="content">
\r
3517 <div class="title">Definition concept for WITHIN</div>
\r
3518 <div class="paragraph"><p>: WITHIN 2 PICK > ROT ROT ⇐ AND ;</p></div>
\r
3521 <div style="text-align:center">
\r
3522 _______________________________________________________
\r
3524 <div class="paragraph"><p><a id="p_words"></a></p></div>
\r
3526 <div class="sect2">
\r
3527 <h3 id="_word_words">Word: WORDS</h3>
\r
3528 <div class="literalblock">
\r
3529 <div class="content">
\r
3530 <pre><code>Data stack: ( wl -- )</code></pre>
\r
3532 <div class="paragraph"><p>"WORDS" is a function word that prints all words of teh given word
\r
3533 list to stdout (file descriptor 1).</p></div>
\r
3534 <div style="text-align:center">
\r
3535 _______________________________________________________
\r
3537 <div class="paragraph"><p><a id="p_xor"></a></p></div>
\r
3539 <div class="sect2">
\r
3540 <h3 id="_word_xor">Word: XOR</h3>
\r
3541 <div class="literalblock">
\r
3542 <div class="content">
\r
3543 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
3545 <div class="paragraph"><p>"XOR" is a function word that replaces a value pair with their bitwise
\r
3546 exclusion; each bit is 1 if the corresponding bits of the two operands
\r
3547 differ and 0 if not.</p></div>
\r
3548 <div style="text-align:center">
\r
3549 _______________________________________________________
\r
3551 <div class="paragraph"><p><a id="return_stack"></a></p></div>
\r
3553 <div class="sect2">
\r
3554 <h3 id="_word_return_stack">Word: RETURN-STACK</h3>
\r
3555 <div class="literalblock">
\r
3556 <div class="content">
\r
3557 <pre><code>Data stack: ( -- a )</code></pre>
\r
3559 <div class="paragraph"><p>"RETURN-STACK" is a variable word harbouring the return stack.</p></div>
\r
3563 <div class="sect1">
\r
3564 <h2 id="_system_calls">System calls</h2>
\r
3565 <div class="sectionbody">
\r
3566 <div class="paragraph"><p>RRQFORTH includes function wrapping for all "Linux syscalls", which
\r
3567 generally are described in their "man pages. This wrapping takes the
\r
3568 arguments fro the data stack in reverse order, i.e. the first argument
\r
3569 is deepest.</p></div>
\r
3570 <div class="paragraph"><p>Use <code>SYSTEM WORDS</code> to get a list of all (321) available syscalls.</p></div>
\r
3574 <div id="footnotes"><hr /></div>
\r
3576 <div id="footer-text">
\r
3578 2021-06-06 09:36:53 AEST
\r
projects / rrq / rrqforth.git / blob