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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_clear_stream">CLEAR-STREAM</a>  
\r
805 <a href="#p_create">CREATE</a>  
\r
806 <a href="#p_current_wordlist">CURRENT-WORDLIST</a>  </p></div>
\r
807 <div class="paragraph"><p><a href="#p_decimal">DECIMAL</a>  
\r
808 <a href="#p_depth">DEPTH</a>  
\r
809 <a href="#p_digits">DIGITS</a>  
\r
810 <a href="#p_divmod">/MOD</a>  
\r
811 <a href="#p_dfa2tfa">DFA>TFA</a>  
\r
812 <a href="#p_dodoes">doDOES</a>  
\r
813 <a href="#p_does">DOES></a>  
\r
814 <a href="#p_dofasm">doFASM</a>  
\r
815 <a href="#p_doforth">doFORTH</a>  
\r
816 <a href="#p_dostring">doSTRING</a>  
\r
817 <a href="#p_dovalue">doVALUE</a>  
\r
818 <a href="#p_dovariable">doVARIABLE</a>  
\r
819 <a href="#p_drop">DROP</a>  
\r
820 <a href="#p_dup">DUP</a>  </p></div>
\r
821 <div class="paragraph"><p><a href="#p_else">ELSE</a>  
\r
822 <a href="#p_emit">EMIT</a>  
\r
823 <a href="#p_end">END</a>  
\r
824 <a href="#p_erase">ERASE</a>  
\r
825 <a href="#p_evaluate_stream">EVALUATE-STREAM</a>  
\r
826 <a href="#p_execute">EXECUTE</a>  
\r
827 <a href="#p_exit">EXIT</a>  </p></div>
\r
828 <div class="paragraph"><p><a href="#p_false">FALSE</a>  
\r
829 <a href="#p_fdemit">FDEMIT</a>  
\r
830 <a href="#p_fdtell">FDTELL</a>  
\r
831 <a href="#p_find">FIND</a>  
\r
832 <a href="#p_forth">FORTH</a>  </p></div>
\r
833 <div class="paragraph"><p><a href="#p_here">HERE</a>  
\r
834 <a href="#p_hex">HEX</a>  </p></div>
\r
835 <div class="paragraph"><p><a href="#p_if">IF</a>  
\r
836 <a href="#p_ifagain">IFAGAIN</a>  
\r
837 <a href="#p_ifbreak">IFBREAK</a>  
\r
838 <a href="#p_immediate">IMMEDIATE</a>  
\r
839 <a href="#p_input">INPUT</a>  </p></div>
\r
840 <div class="paragraph"><p><a href="#p_literal">LIT</a>  
\r
841 <a href="#p_load_buffer_size">LOAD-BUFFER-SIZE</a>  
\r
842 <a href="#p_load_file">LOAD-FILE</a>  </p></div>
\r
843 <div class="paragraph"><p><a href="#p_args">MAIN-ARGS</a>  
\r
844 <a href="#p_malloc">MALLOC</a>  </p></div>
\r
845 <div class="paragraph"><p><a href="#p_negate">NEGATE</a>  
\r
846 <a href="#p_nip">NIP</a>  
\r
847 <a href="#p_nl">NL</a>  
\r
848 <a href="#p_not">NOT</a>  
\r
849 <a href="#p_number">NUMBER</a>  </p></div>
\r
850 <div class="paragraph"><p><a href="#p_open_file">OPEN-FILE</a>  
\r
851 <a href="#p_or">OR</a>  
\r
852 <a href="#p_over">OVER</a>  </p></div>
\r
853 <div class="paragraph"><p><a href="#p_pad">PAD</a>  
\r
854 <a href="#p_pick">PICK</a>  
\r
855 <a href="#p_program_version">PROGRAM_VERSION</a>  </p></div>
\r
856 <div class="paragraph"><p><a href="#p_quit">QUIT</a>  </p></div>
\r
857 <div class="paragraph"><p><a href="#p_read_stream_char">READ-STREAM-CHAR</a>  
\r
858 <a href="#p_read_word">READ-WORD</a>  
\r
859 <a href="#p_realloc">REALLOC</a>  
\r
860 <a href="#p_roll">ROLL</a>  
\r
861 <a href="#p_rot">ROT</a>  
\r
862 <a href="#p_rbp">RSP</a>  </p></div>
\r
863 <div class="paragraph"><p><a href="#p_sp">SP</a>  
\r
864 <a href="#p_state">STATE</a>  
\r
865 <a href="#p_stdin">STDIN</a>  
\r
866 <a href="#p_stream">STREAM</a>  
\r
867 <a href="#p_stream_nchars">STREAM-NCHARS</a>  
\r
868 <a href="#p_strlen">STRLEN</a>  
\r
869 <a href="#p_strncmp">STRNCMP</a>  
\r
870 <a href="#p_strncpy">STRNCPY</a>  
\r
871 <a href="#p_swap">SWAP</a>  
\r
872 <a href="#p_system">SYSTEM</a>  </p></div>
\r
873 <div class="paragraph"><p><a href="#p_tell">TELL</a>  
\r
874 <a href="#p_dot_temp">.TEMP</a>  
\r
875 <a href="#p_terminate0">TERMINATE0</a>  
\r
876 <a href="#p_tfa2cfa">TFA>CFA</a>  
\r
877 <a href="#p_tfa2dfa">TFA>DFA</a>  
\r
878 <a href="#p_tfa2flags_get">TFA>FLAGS@</a>  
\r
879 <a href="#p_tfa2namez">TFA>NAMEZ</a>  
\r
880 <a href="#p_then">THEN</a>  
\r
881 <a href="#p_this_word">THIS-WORD</a>  
\r
882 <a href="#p_true">TRUE</a>  
\r
883 <a href="#p_tuck">TUCK</a>  </p></div>
\r
884 <div class="paragraph"><p><a href="#p_unstream">UNSTREAM</a>  </p></div>
\r
885 <div class="paragraph"><p><a href="#p_verboseQ">VERBOSE?</a>  </p></div>
\r
886 <div class="paragraph"><p><a href="#p_within">WITHIN</a>  
\r
887 <a href="#p_words">WORDS</a>  </p></div>
\r
888 <div class="paragraph"><p><a href="#p_xor">XOR</a>  </p></div>
\r
889 <div class="paragraph"><p><a href="#p_calltrace">[calltrace]</a>  
\r
890 <a href="#p_setup_signals">[setup_signals]</a>  </p></div>
\r
893 <div class="sect1">
\r
894 <h2 id="_word_descriptions">Word Descriptions</h2>
\r
895 <div class="sectionbody">
\r
896 <div class="paragraph"><p><a id="inline_code"></a></p></div>
\r
897 <div class="sect2">
\r
898 <h3 id="_word_asm">Word: [ASM]</h3>
\r
899 <div class="literalblock">
\r
900 <div class="content">
\r
901 <pre><code>data stack: ( -- )</code></pre>
\r
903 <div class="paragraph"><p>"[ASM]" is a function word that introduces inline assembly in an
\r
904 RRQFORTH definition. Such assembly code may return to subsequence
\r
905 RRQFORTH executon by means of the following instruction sequence:</p></div>
\r
906 <div class="exampleblock">
\r
907 <div class="content">
\r
908 <div class="listingblock">
\r
909 <div class="content">
\r
910 <pre><code> mov rsi,forthcode
\r
913 forthcode:</code></pre>
\r
916 <div class="paragraph"><p>Note that the FORTH compiler does not invoke an assembler so any
\r
917 inline assembly code must be provided in its binary form.</p></div>
\r
918 <div style="text-align:center">
\r
919 _______________________________________________________
\r
921 <div class="paragraph"><p><a id="p_0branch"></a></p></div>
\r
923 <div class="sect2">
\r
924 <h3 id="_word_0branch">Word: 0BRANCH</h3>
\r
925 <div class="literalblock">
\r
926 <div class="content">
\r
927 <pre><code>Data stack: ( v -- )</code></pre>
\r
929 <div class="paragraph"><p>"0BRANCH" is a function word that implements execution conditional by
\r
930 means of optionally adding the subsequent branch offset, or not, to
\r
931 the point of execution. If the value, v, is 0 then the branch offset
\r
932 is added, and otherwise execution continues with the cell following
\r
933 the branch offset in the definition.</p></div>
\r
934 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
935 definition take up a cell of 8 bytes. The offset is relative to the
\r
936 cell address immediately subsequent to the offset cell. In other
\r
937 words, offset 0 is not branching anywhere and an offset of -16 would
\r
938 make a tight loop back to the branch instruction itself. The latter
\r
939 would pull data stack values until and including the first non-zero
\r
941 <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
942 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
943 <div style="text-align:center">
\r
944 _______________________________________________________
\r
946 <div class="paragraph"><p><a id="p_0equal"></a></p></div>
\r
948 <div class="sect2">
\r
949 <h3 id="_word_0">Word: 0=</h3>
\r
950 <div class="literalblock">
\r
951 <div class="content">
\r
952 <pre><code>Data stack: ( v -- 0/-1 )</code></pre>
\r
954 <div class="paragraph"><p>"0=" is a function word that replaces a value with its logical
\r
955 complement; the result is zero if the value non-zero, and the result
\r
956 is non-zero if the value is zero.</p></div>
\r
957 <div class="paragraph"><p>This is the same function as <a href="#p_not">NOT</a>.</p></div>
\r
958 <div style="text-align:center">
\r
959 _______________________________________________________
\r
961 <div class="paragraph"><p><a id="p_0less"></a></p></div>
\r
963 <div class="sect2">
\r
964 <h3 id="_word_0_lt">Word: 0<</h3>
\r
965 <div class="literalblock">
\r
966 <div class="content">
\r
967 <pre><code>Data stack: ( v -- 0/-1 )</code></pre>
\r
969 <div class="paragraph"><p>"0<" is a function word that replaces a value with -1 if the value is
\r
970 less than 0, and 0 otherwise.</p></div>
\r
971 <div class="exampleblock">
\r
972 <div class="content">
\r
973 <div class="sidebarblock">
\r
974 <div class="content">
\r
975 <div class="title">Definition concept for 0<</div>
\r
976 <div class="paragraph"><p>( v — 0/1 ) : 0= 0 SWAP < ;</p></div>
\r
979 <div class="paragraph"><p>See also <a href="#p_swap">SWAP</a> and <a href="#p_lessthan"><</a>.</p></div>
\r
980 <div style="text-align:center">
\r
981 _______________________________________________________
\r
983 <div class="paragraph"><p><a id="p_1branch"></a></p></div>
\r
985 <div class="sect2">
\r
986 <h3 id="_word_1branch">Word: 1BRANCH</h3>
\r
987 <div class="literalblock">
\r
988 <div class="content">
\r
989 <pre><code>Data stack: ( v -- )</code></pre>
\r
991 <div class="paragraph"><p>"1BRANCH" is a function word that implements execution conditional by
\r
992 means of optionally adding the subsequent branch offset, or not, to
\r
993 the point of execution. If the value, v, is non-zero then the branch
\r
994 offset is added, and otherwise execution continues with the cell
\r
995 following the branch offset in the definition.</p></div>
\r
996 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
997 definition take up a cell of 8 bytes. The offset is relative to the
\r
998 cell address immediately subsequent to the offset cell. In other
\r
999 words, offset 0 is not branching anywhere and an offset of -16 would
\r
1000 make a tight loop back to the branch instruction itself. The latter
\r
1001 would pull data stack values until and including the first zero value.</p></div>
\r
1002 <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
1003 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1004 <div style="text-align:center">
\r
1005 _______________________________________________________
\r
1007 <div class="paragraph"><p><a id="p_2drop"></a></p></div>
\r
1009 <div class="sect2">
\r
1010 <h3 id="_word_2drop">Word: 2DROP</h3>
\r
1011 <div class="literalblock">
\r
1012 <div class="content">
\r
1013 <pre><code>Data stack: ( v1 v2 -- )</code></pre>
\r
1015 <div class="paragraph"><p>"2DROP" is a function word that plainly discards the top 2 cells from
\r
1016 the data stack.</p></div>
\r
1017 <div style="text-align:center">
\r
1018 _______________________________________________________
\r
1020 <div class="paragraph"><p><a id="p_2dup"></a></p></div>
\r
1022 <div class="sect2">
\r
1023 <h3 id="_word_2dup">Word: 2DUP</h3>
\r
1024 <div class="literalblock">
\r
1025 <div class="content">
\r
1026 <pre><code>Data stack: ( v1 v2 -- v1 v2 v1 v2 )</code></pre>
\r
1028 <div class="paragraph"><p>"2DUP" is a function word that duplicates the top 2 cells on the data
\r
1030 <div class="exampleblock">
\r
1031 <div class="content">
\r
1032 <div class="sidebarblock">
\r
1033 <div class="content">
\r
1034 <div class="title">Definition concept for 2DUP</div>
\r
1035 <div class="paragraph"><p>( v1 v2 — v1 v2 v1 v2 ) : 2DUP OVER OVER ;</p></div>
\r
1038 <div style="text-align:center">
\r
1039 _______________________________________________________
\r
1041 <div class="paragraph"><p><a id="p_2get"></a></p></div>
\r
1043 <div class="sect2">
\r
1044 <h3 id="_word_2">Word: 2@</h3>
\r
1045 <div class="literalblock">
\r
1046 <div class="content">
\r
1047 <pre><code>Data stack: ( a -- v2 v1 )</code></pre>
\r
1049 <div class="paragraph"><p>"2@" is a function word that pushes the two concecutive values v1 and
\r
1050 v2 from the address a onto the data stack. Value v1 is from address a
\r
1051 and value v2 is from address a + 8.</p></div>
\r
1052 <div style="text-align:center">
\r
1053 _______________________________________________________
\r
1055 <div class="paragraph"><p><a id="p_2over"></a></p></div>
\r
1057 <div class="sect2">
\r
1058 <h3 id="_word_2over">Word: 2OVER</h3>
\r
1059 <div class="literalblock">
\r
1060 <div class="content">
\r
1061 <pre><code>Data stack: ( v1 v2 v3 v4 -- v1 v2 v3 v4 v1 v2 )</code></pre>
\r
1063 <div class="paragraph"><p>"2OVER" is a function word that replicates the second duble-cell pair
\r
1064 onto the top of the data stack. This is similar to <a href="#p_over">OVER</a> but
\r
1065 working with cell pairs rather than single cells.</p></div>
\r
1066 <div class="exampleblock">
\r
1067 <div class="content">
\r
1068 <div class="sidebarblock">
\r
1069 <div class="content">
\r
1070 <div class="title">Definition concept for 2OVER</div>
\r
1071 <div class="paragraph"><p>( v1 v2 v3 v4 — v1 v2 v3 v4 v1 v2 ) : 2OVER 3 PICK 3 PICK ;</p></div>
\r
1074 <div style="text-align:center">
\r
1075 _______________________________________________________
\r
1077 <div class="paragraph"><p><a id="p_2put"></a></p></div>
\r
1079 <div class="sect2">
\r
1080 <h3 id="_word_2_2">Word: 2!</h3>
\r
1081 <div class="literalblock">
\r
1082 <div class="content">
\r
1083 <pre><code>Data stack: ( v2 v1 a -- )</code></pre>
\r
1085 <div class="paragraph"><p>"2!" is a function word that stors two concecutive values v1 and v2 to
\r
1086 the address a from the data stack. Value v1 is stored at address a and
\r
1087 value v2 is stored at address a + 8.</p></div>
\r
1088 <div style="text-align:center">
\r
1089 _______________________________________________________
\r
1091 <div class="paragraph"><p><a id="p_2swap"></a></p></div>
\r
1093 <div class="sect2">
\r
1094 <h3 id="_word_2swap">Word: 2SWAP</h3>
\r
1095 <div class="literalblock">
\r
1096 <div class="content">
\r
1097 <pre><code>Data stack: ( v1 v2 v3 v4 -- v3 v4 v1 v2 )</code></pre>
\r
1099 <div class="paragraph"><p>"2SWAP" is a function word the reorgnizes the top 4 cells swappping
\r
1100 the upper and lower pair. This is similar to <a href="#p_swap">SWAP</a> but
\r
1101 working with cell pairs rather than single cells.</p></div>
\r
1102 <div class="exampleblock">
\r
1103 <div class="content">
\r
1104 <div class="sidebarblock">
\r
1105 <div class="content">
\r
1106 <div class="title">Definition concept for 2SWAP</div>
\r
1107 <div class="paragraph"><p>( v1 v2 v3 v4 — v3 v4 v1 v2 ) : 2SWAP 3 ROLL 3 ROLL ;</p></div>
\r
1110 <div style="text-align:center">
\r
1111 _______________________________________________________
\r
1113 <div class="paragraph"><p><a id="p_Ccomma"></a></p></div>
\r
1115 <div class="sect2">
\r
1116 <h3 id="_word_c">Word: C,</h3>
\r
1117 <div class="literalblock">
\r
1118 <div class="content">
\r
1119 <pre><code>Data stack: ( v -- )</code></pre>
\r
1121 <div class="paragraph"><p>"C," (C-comma) is a function word that puts a byte on the
\r
1122 <a href="#p_here">HERE</a> heap. The least significant byte of the value is put
\r
1123 at the current free head address, which also is incremented.</p></div>
\r
1124 <div class="exampleblock">
\r
1125 <div class="content">
\r
1126 <div class="sidebarblock">
\r
1127 <div class="content">
\r
1128 <div class="title">Definition concept for C,</div>
\r
1129 <div class="paragraph"><p>: C, HERE @ 1 ALLOT C! ; ( v — ; Claim 1 byte and put lsb value there )</p></div>
\r
1132 <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
1133 <a href="#p_allot">ALLOT</a>, <a href="#p_Cput">C!</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1134 <div style="text-align:center">
\r
1135 _______________________________________________________
\r
1137 <div class="paragraph"><p><a id="p_Cget"></a></p></div>
\r
1139 <div class="sect2">
\r
1140 <h3 id="_word_c_2">Word: C@</h3>
\r
1141 <div class="literalblock">
\r
1142 <div class="content">
\r
1143 <pre><code>Data stack: ( a -- v )</code></pre>
\r
1145 <div class="paragraph"><p>"C@" is a function word that pushes the byte value v from the address a.</p></div>
\r
1146 <div style="text-align:center">
\r
1147 _______________________________________________________
\r
1149 <div class="paragraph"><p><a id="p_Cput"></a></p></div>
\r
1151 <div class="sect2">
\r
1152 <h3 id="_word_c_3">Word: C!</h3>
\r
1153 <div class="literalblock">
\r
1154 <div class="content">
\r
1155 <pre><code>Data stack: ( v a -- )</code></pre>
\r
1157 <div class="paragraph"><p>"C!" is a function word that stores the byte value v (the least
\r
1158 significant byte of the cell) at the address a.</p></div>
\r
1159 <div style="text-align:center">
\r
1160 _______________________________________________________
\r
1162 <div class="paragraph"><p><a id="p_Rget"></a></p></div>
\r
1164 <div class="sect2">
\r
1165 <h3 id="_word_r">Word: R@</h3>
\r
1166 <div class="literalblock">
\r
1167 <div class="content">
\r
1168 <pre><code>Data stack: ( -- v ) Return stack: ( v -- v )</code></pre>
\r
1170 <div class="paragraph"><p>"R@" is a function word that "copies" the top return stack value onto
\r
1171 the data stack.</p></div>
\r
1172 <div style="text-align:center">
\r
1173 _______________________________________________________
\r
1175 <div class="paragraph"><p><a id="p_Rgt"></a></p></div>
\r
1177 <div class="sect2">
\r
1178 <h3 id="_word_r_gt">Word: R></h3>
\r
1179 <div class="literalblock">
\r
1180 <div class="content">
\r
1181 <pre><code>Data stack: ( -- v ) Return stack: ( v -- )</code></pre>
\r
1183 <div class="paragraph"><p>"R>" is a function word that "moves" the top return stack value onto
\r
1184 the data stack.</p></div>
\r
1185 <div style="text-align:center">
\r
1186 _______________________________________________________
\r
1188 <div class="paragraph"><p><a id="p_abs"></a></p></div>
\r
1190 <div class="sect2">
\r
1191 <h3 id="_word_abs">Word: ABS</h3>
\r
1192 <div class="literalblock">
\r
1193 <div class="content">
\r
1194 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
1196 <div class="paragraph"><p>"ABS" is a function word that replaces a value with its absolute
\r
1197 value. To that end, the values are 64-bit signed integers.</p></div>
\r
1198 <div style="text-align:center">
\r
1199 _______________________________________________________
\r
1201 <div class="paragraph"><p><a id="p_again"></a></p></div>
\r
1203 <div class="sect2">
\r
1204 <h3 id="_word_again">Word: AGAIN</h3>
\r
1205 <div class="literalblock">
\r
1206 <div class="content">
\r
1207 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
1209 <div class="paragraph"><p>"AGAIN" is an immediate function word that is used together with
\r
1210 <a href="#p_begin">BEGIN</a> and instead of <a href="#p_end">END</a> to implement structured
\r
1211 execution control. AGAIN scans the datastack for the nearest preceding
\r
1212 BEGIN marker and lays out an unconditional branch from this point the
\r
1213 beginning of the block during execution. It thereafter performs the
\r
1214 <a href="#p_end">END</a> compile action to end the block.</p></div>
\r
1215 <div style="text-align:center">
\r
1216 _______________________________________________________
\r
1218 <div class="paragraph"><p><a id="p_allot"></a></p></div>
\r
1220 <div class="sect2">
\r
1221 <h3 id="_word_allot">Word: ALLOT</h3>
\r
1222 <div class="literalblock">
\r
1223 <div class="content">
\r
1224 <pre><code>Data stack: ( n -- )</code></pre>
\r
1226 <div class="paragraph"><p>"ALLOT" is a function word that merely increments the <a href="#p_here">HERE</a>
\r
1227 variable with <code>n</code> so as to claim that amount of the heap.</p></div>
\r
1228 <div class="exampleblock">
\r
1229 <div class="content">
\r
1230 <div class="sidebarblock">
\r
1231 <div class="content">
\r
1232 <div class="title">Defintion concept for ALLOT</div>
\r
1233 <div class="paragraph"><p>( n — ) : ALLOT HERE @ + HERE ! ;</p></div>
\r
1236 <div class="exampleblock">
\r
1237 <div class="content">
\r
1238 <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
1240 <div style="text-align:center">
\r
1241 _______________________________________________________
\r
1243 <div class="paragraph"><p><a id="p_and"></a></p></div>
\r
1245 <div class="sect2">
\r
1246 <h3 id="_word_and">Word: AND</h3>
\r
1247 <div class="literalblock">
\r
1248 <div class="content">
\r
1249 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
1251 <div class="paragraph"><p>"AND" is a function word that replaces a value pair with their bitwise
\r
1252 conjunction; each bit is 1 if the corresponding bits of both operands
\r
1253 are 1 and 0 if not.</p></div>
\r
1254 <div style="text-align:center">
\r
1255 _______________________________________________________
\r
1257 <div class="paragraph"><p><a id="p_args"></a></p></div>
\r
1259 <div class="sect2">
\r
1260 <h3 id="_word_main_args">Word: MAIN-ARGS</h3>
\r
1261 <div class="literalblock">
\r
1262 <div class="content">
\r
1263 <pre><code>Data stack: ( -- p[argv** argc] )</code></pre>
\r
1265 <div class="paragraph"><p>"ARGS" is a value word that holds a pointer to the command line data
\r
1266 block which consists of a count cell followed by that many asciiz
\r
1267 pointers and then a 0 cell.</p></div>
\r
1268 <div class="exampleblock">
\r
1269 <div class="content">
\r
1270 <div class="listingblock">
\r
1271 <div class="title">Usage example 2: the command line argument block</div>
\r
1272 <div class="content">
\r
1273 <pre><code>ARGS -> 8 bytes: count of non-zero asciiz pointers following
\r
1274 8 bytes: command name string
\r
1275 8 bytes: first argument string
\r
1277 8 zero</code></pre>
\r
1280 <div style="text-align:center">
\r
1281 _______________________________________________________
\r
1283 <div class="paragraph"><p><a id="p_base"></a></p></div>
\r
1285 <div class="sect2">
\r
1286 <h3 id="_word_base">Word: BASE</h3>
\r
1287 <div class="literalblock">
\r
1288 <div class="content">
\r
1289 <pre><code>Data stack: ( -- a )</code></pre>
\r
1291 <div class="paragraph"><p>"BASE" is a variable word for the numerical base used by input and
\r
1292 output functions, <a href="#p_number">NUMBER</a> and <a href="#p_dot">[p_dot]</a>, when
\r
1293 translating numbers between cell value form and text form. The
\r
1294 numerical base is set to 10 or 16 by <a href="#p_decimal">DECIMAL</a> and
\r
1295 <a href="#p_hex">HEX</a> respectively, and those are the only two bases currently
\r
1296 supported.</p></div>
\r
1297 <div class="paragraph"><p>See also <a href="#p_digits">DIGITS</a>, which holds the mapping table from
\r
1298 digits to text.</p></div>
\r
1299 <div style="text-align:center">
\r
1300 _______________________________________________________
\r
1302 <div class="paragraph"><p><a id="p_begin"></a></p></div>
\r
1304 <div class="sect2">
\r
1305 <h3 id="_word_begin">Word: BEGIN</h3>
\r
1306 <div class="literalblock">
\r
1307 <div class="content">
\r
1308 <pre><code>Data stack: Compiling: ( -- a 0 )</code></pre>
\r
1310 <div class="paragraph"><p>"BEGIN" is an immediate function word that is used together with
\r
1311 <a href="#p_ifbreak">IFBREAK</a>, <a href="#p_ifagain">IFAGAIN</a> and <a href="#p_end">END</a> to
\r
1312 implement structured execution control. BEGIN simply places the
\r
1313 address for resolving branches back to this point during execution,
\r
1314 and then a 0 as a marker so as to allow for an unknown number of block
\r
1315 exit points.</p></div>
\r
1316 <div class="exampleblock">
\r
1317 <div class="content">
\r
1318 <div class="listingblock">
\r
1319 <div class="title">Usage example 3:</div>
\r
1320 <div class="content">
\r
1321 <pre><code>: WTELL ( tfa -- ; Print word pname )
\r
1322 24 + DUP 8 + SWAP @ TELL SP EMIT
\r
1325 : WORDS ( wordlist -- ; Print all words of word list )
\r
1335 <div style="text-align:center">
\r
1336 _______________________________________________________
\r
1338 <div class="paragraph"><p><a id="p_bracketed_quote"></a></p></div>
\r
1340 <div class="sect2">
\r
1341 <h3 id="_word">Word: [']</h3>
\r
1342 <div class="literalblock">
\r
1343 <div class="content">
\r
1344 <pre><code>Data stack: ( -- cfa ) Input stream: word</code></pre>
\r
1346 <div class="paragraph"><p>"[']" is an immediate function word that reads the next word on the
\r
1347 input stream and pushes its cfa.</p></div>
\r
1348 <div class="exampleblock">
\r
1349 <div class="content">
\r
1350 <div class="sidebarblock">
\r
1351 <div class="content">
\r
1352 <div class="title">Definition concept for [']</div>
\r
1353 <div class="paragraph"><p>: ['] IMMEDIATE ' ;</p></div>
\r
1356 <div style="text-align:center">
\r
1357 _______________________________________________________
\r
1359 <div class="paragraph"><p><a id="p_branch"></a></p></div>
\r
1361 <div class="sect2">
\r
1362 <h3 id="_word_branch">Word: BRANCH</h3>
\r
1363 <div class="literalblock">
\r
1364 <div class="content">
\r
1365 <pre><code>Data stack: ( -- )</code></pre>
\r
1367 <div class="paragraph"><p>"BRANCH" is a function word that implements execution transfer by
\r
1368 means of adding the subsequent branch offset to the point of
\r
1369 execution.</p></div>
\r
1370 <div class="paragraph"><p>Note that the branch offset is a byte count and each FORTH word of a
\r
1371 definition take up a cell of 8 bytes. The offset is relative to the
\r
1372 cell address immediately subsequent to the offset cell. In other
\r
1373 words, offset 0 is not branching anywhere and an offset of -16 would
\r
1374 make a tight loop back to the branch instruction itself. The latter
\r
1375 would pull data stack values until and including the first zero value.</p></div>
\r
1376 <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
1377 <a href="#p_else">ELSE</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1378 <div style="text-align:center">
\r
1379 _______________________________________________________
\r
1381 <div class="paragraph"><p><a id="p_break"></a></p></div>
\r
1383 <div class="sect2">
\r
1384 <h3 id="_word_break">Word: BREAK</h3>
\r
1385 <div class="paragraph"><p>"BREAK" is an immediate function word that lays out an unconditional
\r
1386 branch out of an enclosing xef:p_begin[BEGIN]-<a href="#p_end">END</a> block.
\r
1387 Similar to <a href="#p_ifbreak">IFBREAK</a> it lays out the branch cell
\r
1388 followed by a reserved cell for the branch offset, and inserts the
\r
1389 resolution address just above the required 0 on the data stack.</p></div>
\r
1390 <div class="exampleblock">
\r
1391 <div class="content">
\r
1392 <div class="listingblock">
\r
1393 <div class="title">Usage example 4: unconditional break with a condition.</div>
\r
1394 <div class="content">
\r
1395 <pre><code>: WTELL ( tfa -- ; Print word pname )
\r
1396 24 + DUP 8 + SWAP @ TELL SP EMIT
\r
1399 : WORDS ( wordlist -- ; Print all words of word list )
\r
1401 @ DUP IF DUP WTELL ELSE BREAK THEN
\r
1409 <div class="paragraph"><p>See also <a href="#p_branch">BRANCH</a>, <a href="#p_0branch">0BRANCH</a>,
\r
1410 <a href="#p_1branch">1BRANCH</a>, <a href="#p_if">IF</a>, <a href="#p_else">ELSE</a>,
\r
1411 <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a>.</p></div>
\r
1412 <div style="text-align:center">
\r
1413 _______________________________________________________
\r
1415 <div class="paragraph"><p><a id="p_calltrace"></a></p></div>
\r
1417 <div class="sect2">
\r
1418 <h3 id="_word_calltrace">Word: [calltrace]</h3>
\r
1419 <div class="paragraph"><p>"[calltrace]" is a variable word that ccontains a small assembly
\r
1420 snippet that may be used for debugging when running under <code>gdb</code>.</p></div>
\r
1421 <div style="text-align:center">
\r
1422 _______________________________________________________
\r
1424 <div class="paragraph"><p><a id="p_cfa2flags_get"></a></p></div>
\r
1426 <div class="sect2">
\r
1427 <h3 id="_word_cfa_gt_flags">Word: CFA>FLAGS@</h3>
\r
1428 <div class="literalblock">
\r
1429 <div class="content">
\r
1430 <pre><code>Data stack: ( cfa -- flags )</code></pre>
\r
1432 <div class="paragraph"><p>"CFA>FLAGS@" is a function word that pushes word flags of the given cfa.</p></div>
\r
1433 <div class="exampleblock">
\r
1434 <div class="content">
\r
1435 <div class="sidebarblock">
\r
1436 <div class="content">
\r
1437 <div class="title">Defintion concept for CFA>FLAGS@</div>
\r
1438 <div class="paragraph"><p>: CFA>FLAGS@ 16 - @ 16 + ;</p></div>
\r
1441 <div style="text-align:center">
\r
1442 _______________________________________________________
\r
1444 <div class="paragraph"><p><a id="p_clear_stream"></a></p></div>
\r
1446 <div class="sect2">
\r
1447 <h3 id="_word_clear_stream">Word: CLEAR-STREAM</h3>
\r
1448 <div class="literalblock">
\r
1449 <div class="content">
\r
1450 <pre><code>Data stack: ( stream -- )</code></pre>
\r
1452 <div class="paragraph"><p>"CLEAR-STREAM" is a function word that discards whatever is currently
\r
1453 remaining in the buffer for the stream, so that a subsequent read will
\r
1454 pull in more data from its source.</p></div>
\r
1455 <div class="paragraph"><p>See also <a href="#p_read_stream_char">READ-STREAM-CHAR</a>.</p></div>
\r
1456 <div style="text-align:center">
\r
1457 _______________________________________________________
\r
1459 <div class="paragraph"><p><a id="p_colon"></a></p></div>
\r
1461 <div class="sect2">
\r
1462 <h3 id="_word_3">Word: :</h3>
\r
1463 <div class="literalblock">
\r
1464 <div class="content">
\r
1465 <pre><code>Data stack: ( -- ) Input stream: word</code></pre>
\r
1467 <div class="paragraph"><p>":" (colon) is a function word that starts a new forth definition.
\r
1468 This includes reading the next word for making a new dictionary entry
\r
1469 and setting evaluation state to compiling mode.</p></div>
\r
1470 <div class="exampleblock">
\r
1471 <div class="content">
\r
1472 <div class="sidebarblock">
\r
1473 <div class="content">
\r
1474 <div class="title">Definition concept for :</div>
\r
1475 <div class="paragraph"><p>: : doFORTH READ-WORD CREATE TFA>CFA ! ] ;</p></div>
\r
1478 <div class="paragraph"><p>See also <a href="#p_doforth">doFORTH</a>, <a href="#p_read_word">READ-WORD</a>,
\r
1479 <a href="#p_create">CREATE</a>, <a href="#p_tfa2cfa">TFA>CFA</a>, <a href="#p_put">!</a>,
\r
1480 <a href="#p_left_bracket">]</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1481 <div style="text-align:center">
\r
1482 _______________________________________________________
\r
1484 <div class="paragraph"><p><a id="p_comma"></a></p></div>
\r
1486 <div class="sect2">
\r
1487 <h3 id="_word_4">Word: ,</h3>
\r
1488 <div class="literalblock">
\r
1489 <div class="content">
\r
1490 <pre><code>Data stack: ( v -- )</code></pre>
\r
1492 <div class="paragraph"><p>"," (comma) is a function word that puts a cell value on the
\r
1493 <a href="#p_here">HERE</a> heap.</p></div>
\r
1494 <div class="exampleblock">
\r
1495 <div class="content">
\r
1496 <div class="sidebarblock">
\r
1497 <div class="content">
\r
1498 <div class="title">Definition concept for ,</div>
\r
1499 <div class="paragraph"><p>: , HERE @ 8 ALLOT ! ; ( v — ; Claim 8 bytes and put value there )</p></div>
\r
1502 <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
1503 <a href="#p_allot">ALLOT</a>, <a href="#p_put">!</a> and <a href="#p_semicolon">;</a>.</p></div>
\r
1504 <div style="text-align:center">
\r
1505 _______________________________________________________
\r
1507 <div class="paragraph"><p><a id="p_create"></a></p></div>
\r
1509 <div class="sect2">
\r
1510 <h3 id="_word_create">Word: CREATE</h3>
\r
1511 <div class="literalblock">
\r
1512 <div class="content">
\r
1513 <pre><code>Data stack: ( char* n -- tfa )</code></pre>
\r
1515 <div class="paragraph"><p>"CREATE" is a function word that allocates a "word header" with the
\r
1516 indicated [n:char*] print name, and returns the "TFA" (Token Field
\r
1517 Address) of the word. The header memory layout is as follows:</p></div>
\r
1518 <div class="exampleblock">
\r
1519 <div class="content">
\r
1520 <div class="listingblock">
\r
1521 <div class="title">Layout 1: rrqforth word structure</div>
\r
1522 <div class="content">
\r
1523 <pre><code>struct WORD
\r
1524 TFA 8 link ; tfa of previous word
\r
1525 pCFA 8 cfap ; CFA = Code Field Address of this word
\r
1527 PFA 8 length ; length of pname representation
\r
1528 ? pname ; the pname bytes
\r
1529 1 nul ; a forced nul byte following the pname
\r
1530 pTFA 8 tfap ; TFA = Token Field Address of this word
\r
1531 OFF 8 doff ; entry offset for FORTH level execution
\r
1532 CFA 8 doer ; word execution semantics
\r
1533 DFA 0 content ; DFA = Data Field Address
\r
1534 end_struct</code></pre>
\r
1537 <div class="paragraph"><p>A "word" is generally understod as a marker in memory for some content
\r
1538 as held in the memory space following the DFA (Data Field Address).</p></div>
\r
1539 <div class="paragraph"><p>The words CFA (Code Field Address) is the most important field for
\r
1540 RRQFORTH execution, as holding a jump address to the assembly code
\r
1541 that implements the particular execution semantics for the word.
\r
1542 "CREATE" will assign this as "dovariable", which makes the word push
\r
1543 its DFA when executed. This is changed to "doforth" for RRQFORTH
\r
1544 function words initiated by ":" (aka "COLON") or changed to "dovalue"
\r
1545 for RRQFORTH constants created by "CONSTANT".</p></div>
\r
1546 <div class="exampleblock">
\r
1547 <div class="content">
\r
1548 <div class="sidebarblock">
\r
1549 <div class="content">
\r
1550 <div class="title">Definition concept for CREATE</div>
\r
1551 <div class="paragraph"><p>HERE @ R> ( save tfa on RS )
\r
1552 R@ CURRENT-WORD @ DUP @ , ! ( link in a new word )
\r
1553 DUP 49 + R@ + , ( pCFA )
\r
1556 HERE @ ROT ROT MEMCPY 0 C, ( pname + NUL )
\r
1559 doVARIABLE ( CFA, default semantics )</p></div>
\r
1562 <div class="exampleblock">
\r
1563 <div class="content">
\r
1564 <div class="listingblock">
\r
1565 <div class="title">Usage example 5: a possible definition of CONSTANT</div>
\r
1566 <div class="content">
\r
1567 <pre><code>: CONSTANT READ-WORD CREATE TFA>DFA doVALUE OVER 8 - ! ! ;</code></pre>
\r
1570 <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
1571 <a href="#p_Ccomma">[p_Ccomma]</a>, <a href="#p_current_word">CURRENT-WORD</a>, <a href="#p_dup">DUP</a>,
\r
1572 <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
1573 and <a href="#p_dovariable">doVARIABLE</a>,
\r
1574 as well as <a href="#p_execute">EXECUTE</a>
\r
1575 about the range of "doer" assignments and their meanings.</p></div>
\r
1576 <div style="text-align:center">
\r
1577 _______________________________________________________
\r
1579 <div class="paragraph"><p><a id="p_current_wordlist"></a></p></div>
\r
1581 <div class="sect2">
\r
1582 <h3 id="_word_current_wordlist">Word: CURRENT-WORDLIST</h3>
\r
1583 <div class="literalblock">
\r
1584 <div class="content">
\r
1585 <pre><code>Data stack: ( -- a )</code></pre>
\r
1587 <div class="paragraph"><p>"CURRENT-WORDLIST" is a variable word that points out the DFA of the
\r
1588 current word list word for <a href="#p_find">FIND</a> to use finding words. The
\r
1589 word list word content is as follows:</p></div>
\r
1590 <div class="exampleblock">
\r
1591 <div class="content">
\r
1592 <div class="listingblock">
\r
1593 <div class="title">Layout 2: word list word content</div>
\r
1594 <div class="content">
\r
1595 <pre><code> 8 TFA of latest word in the word list
\r
1596 8 DFA of the/a subsequent word list to search through</code></pre>
\r
1599 <div class="paragraph"><p>Note that word lists are chained by "extension" and in general it ends
\r
1600 with the <a href="#p_forth">FORTH</a> word list. Initially the
\r
1601 <a href="#p_system">SYSTEM</a> word list is the only other word list.</p></div>
\r
1602 <div style="text-align:center">
\r
1603 _______________________________________________________
\r
1605 <div class="paragraph"><p><a id="data_stack"></a></p></div>
\r
1607 <div class="sect2">
\r
1608 <h3 id="_word_data_stack">Word: DATA-STACK</h3>
\r
1609 <div class="literalblock">
\r
1610 <div class="content">
\r
1611 <pre><code>Data stack: ( -- a )</code></pre>
\r
1613 <div class="paragraph"><p>"DATA-STACK" is a variable word that harbours the data stack.</p></div>
\r
1614 <div style="text-align:center">
\r
1615 _______________________________________________________
\r
1617 <div class="paragraph"><p><a id="p_decimal"></a></p></div>
\r
1619 <div class="sect2">
\r
1620 <h3 id="_word_decimal">Word: DECIMAL</h3>
\r
1621 <div class="literalblock">
\r
1622 <div class="content">
\r
1623 <pre><code>Data stack: ( -- )</code></pre>
\r
1625 <div class="paragraph"><p>"DECIMAL" is a function word that sets <a href="#p_base">BASE</a> to 10.</p></div>
\r
1626 <div class="exampleblock">
\r
1627 <div class="content">
\r
1628 <div class="sidebarblock">
\r
1629 <div class="content">
\r
1630 <div class="title">Definition concept for DECIMAL</div>
\r
1631 <div class="paragraph"><p>: DECIMAL 10 BASE ! ;</p></div>
\r
1634 <div style="text-align:center">
\r
1635 _______________________________________________________
\r
1637 <div class="paragraph"><p><a id="p_depth"></a></p></div>
\r
1639 <div class="sect2">
\r
1640 <h3 id="_word_depth">Word: DEPTH</h3>
\r
1641 <div class="literalblock">
\r
1642 <div class="content">
\r
1643 <pre><code>Data stack: ( -- v )</code></pre>
\r
1645 <div class="paragraph"><p>"DEPTH" is a function word that pushes the count of data stack cells
\r
1646 onto the data stack.</p></div>
\r
1647 <div style="text-align:center">
\r
1648 _______________________________________________________
\r
1650 <div class="paragraph"><p><a id="p_dfa2tfa"></a></p></div>
\r
1652 <div class="sect2">
\r
1653 <h3 id="_word_dfa_gt_tfa">Word: DFA>TFA</h3>
\r
1654 <div class="literalblock">
\r
1655 <div class="content">
\r
1656 <pre><code>Data stack: ( dfa -- tfa )</code></pre>
\r
1658 <div class="paragraph"><p>"DFA>TFA" is a function word that pushes word tfa of the given dfa.</p></div>
\r
1659 <div class="exampleblock">
\r
1660 <div class="content">
\r
1661 <div class="sidebarblock">
\r
1662 <div class="content">
\r
1663 <div class="title">Definition concept for DFA>TFA</div>
\r
1664 <div class="paragraph"><p>: DFA>TFA 24 - @ ;</p></div>
\r
1667 <div style="text-align:center">
\r
1668 _______________________________________________________
\r
1670 <div class="paragraph"><p><a id="p_digits"></a></p></div>
\r
1672 <div class="sect2">
\r
1673 <h3 id="_word_digits">Word: DIGITS</h3>
\r
1674 <div class="literalblock">
\r
1675 <div class="content">
\r
1676 <pre><code>Data stack: ( -- a )</code></pre>
\r
1678 <div class="paragraph"><p>"DIGITS" is a variable word that holds the character array for mapping
\r
1679 digit values to characters. It contains the 16 characters 0-9 and a-f.</p></div>
\r
1680 <div style="text-align:center">
\r
1681 _______________________________________________________
\r
1683 <div class="paragraph"><p><a id="p_div"></a></p></div>
\r
1685 <div class="sect2">
\r
1686 <h3 id="_word_5">Word: /</h3>
\r
1687 <div class="literalblock">
\r
1688 <div class="content">
\r
1689 <pre><code>Data stack: ( v1 v2 -- q )</code></pre>
\r
1691 <div class="paragraph"><p>"/" (div) is a function word that replaces a pair of values with the
\r
1692 results of signed integer division of the first, v1, divided by the
\r
1693 second, v2. To that end, the values are 64-bit signed integers. The
\r
1694 result is the integer quotient, q, and the discarded remainder, r,
\r
1695 where q and r are the respectively largest and smallest integers to
\r
1696 satisfy the formula:</p></div>
\r
1697 <div class="literalblock">
\r
1698 <div class="content">
\r
1699 <pre><code> v1 = q * v2 + r</code></pre>
\r
1701 <div style="text-align:center">
\r
1702 _______________________________________________________
\r
1704 <div class="paragraph"><p><a id="p_divmod"></a></p></div>
\r
1706 <div class="sect2">
\r
1707 <h3 id="_word_mod">Word: /MOD</h3>
\r
1708 <div class="literalblock">
\r
1709 <div class="content">
\r
1710 <pre><code>Data stack: ( v1 v2 -- q r )</code></pre>
\r
1712 <div class="paragraph"><p>"/MOD" (div-mod) is a function word that replaces a pair of values
\r
1713 with the results of signed integer division of the first, v1, divided
\r
1714 by the second, v2. To that end, the values are 64-bit signed integers.
\r
1715 The result is the integer quotient, q, and the remainder, r, where q
\r
1716 and r are the respectively largest and smallest integers to satisfy
\r
1717 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_dodoes"></a></p></div>
\r
1727 <div class="sect2">
\r
1728 <h3 id="_word_dodoes">Word: doDOES</h3>
\r
1729 <div class="literalblock">
\r
1730 <div class="content">
\r
1731 <pre><code>Data stack: ( -- a )</code></pre>
\r
1733 <div class="paragraph"><p>"doDOES" is a variable word whose value is the implementation of the
\r
1734 <a href="#p_does">[p_does]</a> execution semantics. This is the same as
\r
1735 <a href="#p_doforth">doFORTH</a> but it starts at an offset into the word
\r
1736 concerned.</p></div>
\r
1737 <div style="text-align:center">
\r
1738 _______________________________________________________
\r
1740 <div class="paragraph"><p><a id="p_does"></a></p></div>
\r
1742 <div class="sect2">
\r
1743 <h3 id="_word_does_gt">WORD: DOES></h3>
\r
1744 <div class="literalblock">
\r
1745 <div class="content">
\r
1746 <pre><code>Data stack: ( -- )</code></pre>
\r
1748 <div class="paragraph"><p>"DOES>" is a function that in execution mode does nothing but in
\r
1749 compilation mode it changes the execution semantics assignments for
\r
1750 the most recent word to use the <code>dodoes</code> sematics with adjustment
\r
1751 offset to the current heap address. I.e., the word being defined will
\r
1752 have its execution start at whatever comes after "DOES>".</p></div>
\r
1753 <div class="exampleblock">
\r
1754 <div class="content">
\r
1755 <div class="sidebarblock">
\r
1756 <div class="content">
\r
1757 <div class="title">Defintion concept for DOES></div>
\r
1758 <div class="paragraph"><p>: DOES> IMMEDIATE
\r
1759 STATE @ != IF ( only for compilation mode )
\r
1760 CURRENT-WORDLIST @ @ TFA>CFA ( cfa of current word )
\r
1761 doDOES OVER ! ( set up doer )
\r
1762 HERE @ OVER 8 + - SWAP 8 - ! ( set up offset
\r
1767 <div class="paragraph"><p>See also
\r
1768 <a href="#p_put">!</a>,
\r
1769 <a href="#p_unequal">!⇒></a>,
\r
1770 <a href="#p_minus">→></a>,
\r
1771 <a href="#p_get">@</a>,
\r
1772 <a href="#p_current_wordlist">CURRENT-WORDLIST</a>,
\r
1773 <a href="#p_here">HERE</a>,
\r
1774 <a href="#p_if">IF</a>,
\r
1775 <a href="#p_immediate">IMMEDIATE</a>,
\r
1776 <a href="#p_over">OVER</a>,
\r
1777 <a href="#p_state">STATE</a>,
\r
1778 <a href="#p_swap">SWAP</a>,
\r
1779 <a href="#p_tfa2cfa">TFA>CFA</a>,
\r
1780 <a href="#p_then">THEN</a>,
\r
1781 <a href="#p_dodoes">doDOES</a>,
\r
1782 as well as <a href="#p_execute">EXECUTE</a>
\r
1783 about the range of "doer" assignments and their meanings.</p></div>
\r
1784 <div style="text-align:center">
\r
1785 _______________________________________________________
\r
1787 <div class="paragraph"><p><a id="p_dofasm"></a></p></div>
\r
1789 <div class="sect2">
\r
1790 <h3 id="_word_dofasm">Word: doFASM</h3>
\r
1791 <div class="literalblock">
\r
1792 <div class="content">
\r
1793 <pre><code>Data stack: ( -- a )</code></pre>
\r
1795 <div class="paragraph"><p>"doFASM" is a variable word whose value is the implementation of the
\r
1796 execution semantics for assembly code content.</p></div>
\r
1797 <div style="text-align:center">
\r
1798 _______________________________________________________
\r
1800 <div class="paragraph"><p><a id="p_doforth"></a></p></div>
\r
1802 <div class="sect2">
\r
1803 <h3 id="_word_doforth">Word: doFORTH</h3>
\r
1804 <div class="literalblock">
\r
1805 <div class="content">
\r
1806 <pre><code>Data stack: ( -- a )</code></pre>
\r
1808 <div class="paragraph"><p>"doFORTH" is a variable word whose value is the implementation of the
\r
1809 RRQFORTH execution semantics.</p></div>
\r
1810 <div style="text-align:center">
\r
1811 _______________________________________________________
\r
1813 <div class="paragraph"><p><a id="p_dostring"></a></p></div>
\r
1815 <div class="sect2">
\r
1816 <h3 id="_word_dostring">Word: doSTRING</h3>
\r
1817 <div class="literalblock">
\r
1818 <div class="content">
\r
1819 <pre><code>Data stack: ( -- a )</code></pre>
\r
1821 <div class="paragraph"><p>"doFASM" is a variable word whose value is the implementation of the
\r
1822 execution semantics for assembly code implemented words. In those
\r
1823 cases the execution leads to the word content.</p></div>
\r
1824 <div class="paragraph"><p>The register context at entry to an assembly code implemented word is
\r
1825 as follows:</p></div>
\r
1826 <div class="listingblock">
\r
1827 <div class="content">
\r
1828 <pre><code> rax = cfa* of word to execute
\r
1829 rsi = cell* in the calling definition, after calling cell
\r
1830 rsp = data stack pointer
\r
1831 rbp = return stack pointer</code></pre>
\r
1833 <div class="paragraph"><p>The assembly code must ensure that <code>rsi</code> is preserved and that <code>rsp</code>
\r
1834 and <code>rbp</code> are used according to their roles.</p></div>
\r
1835 <div style="text-align:center">
\r
1836 _______________________________________________________
\r
1838 <div class="paragraph"><p><a id="p_dot"></a></p></div>
\r
1840 <div class="sect2">
\r
1841 <h3 id="_word_6">Word: .</h3>
\r
1842 <div class="literalblock">
\r
1843 <div class="content">
\r
1844 <pre><code>Data stack: ( v -- )</code></pre>
\r
1846 <div class="paragraph"><p>"." is a function word that prints the top stack value to stdout using
\r
1847 the current <a href="#p_base">BASE</a> (either <a href="#p_decimal">DECIMAL</a> or
\r
1848 <a href="#p_hex">HEX</a>).</p></div>
\r
1849 <div style="text-align:center">
\r
1850 _______________________________________________________
\r
1852 <div class="paragraph"><p><a id="p_dot_temp"></a></p></div>
\r
1854 <div class="sect2">
\r
1855 <h3 id="_word_temp">Word: .TEMP</h3>
\r
1856 <div class="literalblock">
\r
1857 <div class="content">
\r
1858 <pre><code>Data stack: ( v -- char* n )</code></pre>
\r
1860 <div class="paragraph"><p>".TEMP" is a function word that renders a cell value as an integer
\r
1861 using the current <a href="#p_base">BASE</a>, which is either
\r
1862 <a href="#p_decimal">DECIMAL</a> or <a href="#p_hex">HEX</a>. In <a href="#p_decimal">DECIMAL</a>
\r
1863 <a href="#p_base">BASE</a>, a negative value is rendered as such with a leading
\r
1864 minus sign, whereas <a href="#p_hex">HEX</a> <a href="#p_base">BASE</a> rendering is
\r
1865 unsigned.</p></div>
\r
1866 <div style="text-align:center">
\r
1867 _______________________________________________________
\r
1869 <div class="paragraph"><p><a id="p_double_quote"></a></p></div>
\r
1871 <div class="sect2">
\r
1872 <h3 id="_word_7">Word: "</h3>
\r
1873 <div class="literalblock">
\r
1874 <div class="content">
\r
1875 <pre><code>data stack: ( -- char n ) Input stream: ...."</code></pre>
\r
1877 <div class="paragraph"><p>""" (double quote) is a function word that copies the input stream
\r
1878 text up to next double quote to <a href="#p_pad">PAD</a>, and returns the
\r
1879 [n:char*] cell pair for that string.</p></div>
\r
1880 <div style="text-align:center">
\r
1881 _______________________________________________________
\r
1883 <div class="paragraph"><p><a id="p_dovalue"></a></p></div>
\r
1885 <div class="sect2">
\r
1886 <h3 id="_word_dovalue">Word: doVALUE</h3>
\r
1887 <div class="literalblock">
\r
1888 <div class="content">
\r
1889 <pre><code>Data stack: ( -- a )</code></pre>
\r
1891 <div class="paragraph"><p>"doVALUE" is a variable word whose value is the implementation of the
\r
1892 execution semantics for cell values, which are variables with a single
\r
1893 64-bit cell holding the value.</p></div>
\r
1894 <div class="paragraph"><p>The execution of this result in pushing the value:</p></div>
\r
1895 <div class="literalblock">
\r
1896 <div class="content">
\r
1897 <pre><code>Resulting data stack: ( -- v )</code></pre>
\r
1899 <div style="text-align:center">
\r
1900 _______________________________________________________
\r
1902 <div class="paragraph"><p><a id="p_dovariable"></a></p></div>
\r
1904 <div class="sect2">
\r
1905 <h3 id="_word_dovariable">Word: doVARIABLE</h3>
\r
1906 <div class="literalblock">
\r
1907 <div class="content">
\r
1908 <pre><code>Data stack: ( -- a )</code></pre>
\r
1910 <div class="paragraph"><p>"doVARIABLE" is a variable word whose value is the implementation of
\r
1911 the execution semantics for "variables", which basically are markers
\r
1912 into the heap for some number block of memory.</p></div>
\r
1913 <div class="paragraph"><p>The execution of a variable results in pushing its content address:</p></div>
\r
1914 <div class="literalblock">
\r
1915 <div class="content">
\r
1916 <pre><code>Resulting data stack: ( -- a )</code></pre>
\r
1918 <div style="text-align:center">
\r
1919 _______________________________________________________
\r
1921 <div class="paragraph"><p><a id="p_drop"></a></p></div>
\r
1923 <div class="sect2">
\r
1924 <h3 id="_word_drop">Word: DROP</h3>
\r
1925 <div class="literalblock">
\r
1926 <div class="content">
\r
1927 <pre><code>Data stack: ( v -- )</code></pre>
\r
1929 <div class="paragraph"><p>"DROP" is a function word that discards the top stack cell.</p></div>
\r
1930 <div style="text-align:center">
\r
1931 _______________________________________________________
\r
1933 <div class="paragraph"><p><a id="p_dup"></a></p></div>
\r
1935 <div class="sect2">
\r
1936 <h3 id="_word_dup">Word: DUP</h3>
\r
1937 <div class="literalblock">
\r
1938 <div class="content">
\r
1939 <pre><code>Data stack: ( v -- v v )</code></pre>
\r
1941 <div class="paragraph"><p>"DUP" is a function word that duplicates the top stack cell.</p></div>
\r
1942 <div style="text-align:center">
\r
1943 _______________________________________________________
\r
1945 <div class="paragraph"><p><a id="p_else"></a></p></div>
\r
1947 <div class="sect2">
\r
1948 <h3 id="_word_else">Word: ELSE</h3>
\r
1949 <div class="literalblock">
\r
1950 <div class="content">
\r
1951 <pre><code>Data stack: Compiling: ( a -- a )</code></pre>
\r
1953 <div class="paragraph"><p>"ELSE" is an immediate function word that is used together with
\r
1954 <a href="#p_if">IF</a> and <a href="#p_then">THEN</a> to implement structured execution
\r
1955 control. ELSE lays out an unresolved unconditional branch as an ending
\r
1956 for the "then-part" of the structured statement, and it then performs
\r
1957 the branch resolution for the "else-part". To that end it replaces the
\r
1958 stacked address which pin-points the foot address the branch offset to
\r
1959 resolve, so that at execution time there is an appropriate conditional
\r
1960 branch past the "then-part" and the "else-part" of the "structured
\r
1961 statement".</p></div>
\r
1962 <div style="text-align:center">
\r
1963 _______________________________________________________
\r
1965 <div class="paragraph"><p><a id="p_emit"></a></p></div>
\r
1967 <div class="sect2">
\r
1968 <h3 id="_word_emit">Word: EMIT</h3>
\r
1969 <div class="literalblock">
\r
1970 <div class="content">
\r
1971 <pre><code>Data stack: ( c -- )</code></pre>
\r
1973 <div class="paragraph"><p>"EMIT" is a function word that puts the given character code to
\r
1974 standard output (file descriptor 1). The character is the least
\r
1975 significant byte of the top cell.</p></div>
\r
1976 <div style="text-align:center">
\r
1977 _______________________________________________________
\r
1979 <div class="paragraph"><p><a id="p_end"></a></p></div>
\r
1981 <div class="sect2">
\r
1982 <h3 id="_word_end">Word: END</h3>
\r
1983 <div class="literalblock">
\r
1984 <div class="content">
\r
1985 <pre><code>Data stack: Compiling: ( a 0 * -- )</code></pre>
\r
1987 <div class="paragraph"><p>"END" is an immediate function word that is used together with
\r
1988 <a href="#p_begin">BEGIN</a>, <a href="#p_ifbreak">IFBREAK</a> and <a href="#p_ifagain">IFAGAIN</a> to
\r
1989 implement structured execution control. END processes the data stack
\r
1990 to resolve any dangling <a href="#p_ifbreak">IFBREAK</a> branch offset for the
\r
1991 block of the matching <a href="#p_begin">BEGIN</a>.</p></div>
\r
1992 <div style="text-align:center">
\r
1993 _______________________________________________________
\r
1995 <div class="paragraph"><p><a id="p_equal"></a></p></div>
\r
1997 <div class="sect2">
\r
1998 <h3 id="_word_8">Word: =</h3>
\r
1999 <div class="literalblock">
\r
2000 <div class="content">
\r
2001 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2003 <div class="paragraph"><p>"=" is a function word that replaces a pair of values with -1 of the
\r
2004 values are equal, and 0 otherwise.</p></div>
\r
2005 <div style="text-align:center">
\r
2006 _______________________________________________________
\r
2008 <div class="paragraph"><p><a id="p_erase"></a></p></div>
\r
2010 <div class="sect2">
\r
2011 <h3 id="_word_erase">Word: ERASE</h3>
\r
2012 <div class="literalblock">
\r
2013 <div class="content">
\r
2014 <pre><code>Data stack: ( a n -- )</code></pre>
\r
2016 <div class="paragraph"><p>"ERASE" is a function word that stores n NUL bytes at address a an up.</p></div>
\r
2017 <div style="text-align:center">
\r
2018 _______________________________________________________
\r
2020 <div class="paragraph"><p><a id="p_evaluate_stream"></a></p></div>
\r
2022 <div class="sect2">
\r
2023 <h3 id="_word_evaluate_stream">Word: EVALUATE-STREAM</h3>
\r
2024 <div class="literalblock">
\r
2025 <div class="content">
\r
2026 <pre><code>Data stack: ( stream -- ??? 0/1 ) Input stream: ......</code></pre>
\r
2028 <div class="paragraph"><p>"EVALUATE-STREAM" is a function word that reads words separated by
\r
2029 whitespace from the stream until it discovers an unknown word, or the
\r
2030 stream is exhausted. Depending on <a href="#p_state">STATE</a>, the words are
\r
2031 either executed or compiled, and all ther stack and heap effects are
\r
2032 preserved. "EVALUATE-STREAM" returns with an additional 0 or 1 on the
\r
2033 stack to respectively indicate that the last word was unkown, i.e. not
\r
2034 found (<a href="#p_find">FIND</a>) in the current word list
\r
2035 (<a href="#p_current_wordlist">CURRENT-WORDLIST</a>) and not a
\r
2036 <a href="#p_number">NUMBER</a> of the current <a href="#p_base">BASE</a>.</p></div>
\r
2037 <div class="paragraph"><p>Note that numbers in the current <a href="#p_base">BASE</a> are treated as known
\r
2038 words that are parsed into cell values. If interpreting, then the
\r
2039 value is left on the stack. If compiling, then the value is added to
\r
2040 the heap subsequent to first adding <a href="#p_literal">LIT</a>, which is done
\r
2041 so as to make that value be push to the data stack upon a later
\r
2042 execution.</p></div>
\r
2043 <div class="paragraph"><p>In the <a href="#p_decimal">DECIMAL</a> base, the number word may begin with a
\r
2044 minus sign.</p></div>
\r
2045 <div class="paragraph"><p>The words are read and executed one by one, accounting for whether its
\r
2046 a number word or not, whether it is an <a href="#p_immediate">IMMEDIATE</a> word
\r
2047 or not, and whether the state at the time of execution indicates
\r
2048 "compiling" of "interpreting". Immediate words are executed in both
\r
2049 interpreting and compiling state, while other words have their CFA get
\r
2050 added to the heap so as to gain their execution effect upon a later
\r
2051 execution.</p></div>
\r
2052 <div class="paragraph"><p>Note that "EVALUATE-STREAM" keeps the stream (pointer) on the return
\r
2053 stack while reading, parsing and executing.</p></div>
\r
2054 <div class="paragraph"><p>If "EVALUATE-STREAM" ends with 0, then <a href="#p_this_word">THIS-WORD</a> holds
\r
2055 the [n:chars] reference of the offending word in the stream buffer.</p></div>
\r
2056 <div style="text-align:center">
\r
2057 _______________________________________________________
\r
2059 <div class="paragraph"><p><a id="p_execute"></a></p></div>
\r
2061 <div class="sect2">
\r
2062 <h3 id="_word_execute">Word: EXECUTE</h3>
\r
2063 <div class="literalblock">
\r
2064 <div class="content">
\r
2065 <pre><code>Data stack: ( cfa -- )</code></pre>
\r
2067 <div class="paragraph"><p>"EXECUTE" is a function word that transfers the execution to the
\r
2068 indicated "Code Field Address", which typically is the CFA of an
\r
2069 RRQFORTH word with the CFA cell containing a jump address for the code
\r
2070 that implements the execution semnatics of the word.</p></div>
\r
2071 <div class="paragraph"><p>The following execution semantics are predefined:</p></div>
\r
2072 <div class="ulist"><ul>
\r
2075 assembler implemented words constitute their own execution
\r
2081 <a href="#p_doforth">[p_doforth]</a> implements the FORTH machine. This treats the word
\r
2082 content as a succession of cells that hold the cfa pointers for the
\r
2083 words that make of the definition. As is customary in FORTH
\r
2084 machines, the advance through that succession is provided by each
\r
2085 word code ending making an explicit jump to its successor. The
\r
2086 <a href="#p_return_stack">RETURN-STACK</a> serves as a call stack for tracking
\r
2087 the nesting of FORTH executions by saving the "addresses" of the
\r
2093 <a href="#p_dodoes">[p_dodoes]</a> implements the variation of starting the FORTH
\r
2094 execution somewhere within a definition rather than at the
\r
2100 <a href="#p_dostring">[p_dostring]</a>, <a href="#p_dovalue">[p_dovalue]</a> and <a href="#p_dovariable">[p_dovariable]</a> implement
\r
2101 different common ways of using word content other the as FORTH
\r
2106 <div style="text-align:center">
\r
2107 _______________________________________________________
\r
2109 <div class="paragraph"><p><a id="p_exit"></a></p></div>
\r
2111 <div class="sect2">
\r
2112 <h3 id="_word_exit">Word: EXIT</h3>
\r
2113 <div class="literalblock">
\r
2114 <div class="content">
\r
2115 <pre><code>Data stack: ( -- )</code></pre>
\r
2117 <div class="paragraph"><p>"EXIT" is a function word that implements the ending of a FORTH
\r
2118 definition and its threading to the subsequent step of the calling
\r
2119 definition.</p></div>
\r
2120 <div style="text-align:center">
\r
2121 _______________________________________________________
\r
2123 <div class="paragraph"><p><a id="p_false"></a></p></div>
\r
2125 <div class="sect2">
\r
2126 <h3 id="_word_false">Word: FALSE</h3>
\r
2127 <div class="literalblock">
\r
2128 <div class="content">
\r
2129 <pre><code>Data stack: ( -- 0 )</code></pre>
\r
2131 <div class="paragraph"><p>"FALSE" is a value word representing logical false.</p></div>
\r
2132 <div style="text-align:center">
\r
2133 _______________________________________________________
\r
2135 <div class="paragraph"><p><a id="p_fdemit"></a></p></div>
\r
2137 <div class="sect2">
\r
2138 <h3 id="_word_fdemit">Word: FDEMIT</h3>
\r
2139 <div class="literalblock">
\r
2140 <div class="content">
\r
2141 <pre><code>Data stack: ( c fd -- )</code></pre>
\r
2143 <div class="paragraph"><p>"FDEMIT" is a function word that puts the given character code to the
\r
2144 given file descriptor. The character is the least significant byte of
\r
2145 the data stack cell.</p></div>
\r
2146 <div style="text-align:center">
\r
2147 _______________________________________________________
\r
2149 <div class="paragraph"><p><a id="p_fdtell"></a></p></div>
\r
2151 <div class="sect2">
\r
2152 <h3 id="_word_fdtell">Word: FDTELL</h3>
\r
2153 <div class="literalblock">
\r
2154 <div class="content">
\r
2155 <pre><code>Data stack: ( char* n fd -- )</code></pre>
\r
2157 <div class="paragraph"><p>"FDTELL" is a function word that prints a string to the given file
\r
2158 descriptor.</p></div>
\r
2159 <div style="text-align:center">
\r
2160 _______________________________________________________
\r
2162 <div class="paragraph"><p><a id="p_find"></a></p></div>
\r
2164 <div class="sect2">
\r
2165 <h3 id="_word_find">Word: FIND</h3>
\r
2166 <div class="literalblock">
\r
2167 <div class="content">
\r
2168 <pre><code>Data stack: ( char* n -- [ char* n 0 ]/[ tfa ] )</code></pre>
\r
2170 <div class="paragraph"><p>"FIND" is a function word that searches the current word list search
\r
2171 path for the given [n:char*] word, and returns the TFA of the matching
\r
2172 word if any. Otherwise FIND preserves the initial data stack but adds
\r
2173 0 to it.</p></div>
\r
2174 <div class="paragraph"><p>The word is sought starting with the
\r
2175 <a href="#p_current_wordlist">CURRENT-WORDLIST</a> word list, for the first
\r
2176 occurence of a match. If not found, the search continues with the
\r
2177 subsequent word list, and so on.</p></div>
\r
2178 <div class="paragraph"><p>When a word is found, then the data stack is changed by discarding the
\r
2179 [n:char*] double cell string pointer and pushing (only) the TFA of the
\r
2180 matching word instead.</p></div>
\r
2181 <div style="text-align:center">
\r
2182 _______________________________________________________
\r
2184 <div class="paragraph"><p><a id="p_forth"></a></p></div>
\r
2186 <div class="sect2">
\r
2187 <h3 id="_word_forth">Word: FORTH</h3>
\r
2188 <div class="literalblock">
\r
2189 <div class="content">
\r
2190 <pre><code>data stack: ( -- a )</code></pre>
\r
2192 <div class="paragraph"><p>"FORTH" is a variable word for the FORTH word list, which does not
\r
2193 have any subsequent word list.</p></div>
\r
2194 <div style="text-align:center">
\r
2195 _______________________________________________________
\r
2197 <div class="paragraph"><p><a id="p_get"></a></p></div>
\r
2199 <div class="sect2">
\r
2200 <h3 id="_word_9">Word: @</h3>
\r
2201 <div class="literalblock">
\r
2202 <div class="content">
\r
2203 <pre><code>Data stack: ( a -- v )</code></pre>
\r
2205 <div class="paragraph"><p>"@" is a function word that pushes the value v from the address a.</p></div>
\r
2206 <div style="text-align:center">
\r
2207 _______________________________________________________
\r
2209 <div class="paragraph"><p><a id="p_get_n_decrement"></a></p></div>
\r
2211 <div class="sect2">
\r
2212 <h3 id="_word_n">Word: @n--</h3>
\r
2213 <div class="literalblock">
\r
2214 <div class="content">
\r
2215 <pre><code>Data stack: ( a n -- v )</code></pre>
\r
2217 <div class="paragraph"><p>"@n--" is a function word that pushes the value from the address, a,
\r
2218 then decrements the cell at that address by n.</p></div>
\r
2219 <div class="exampleblock">
\r
2220 <div class="content">
\r
2221 <div class="sidebarblock">
\r
2222 <div class="content">
\r
2223 <div class="title">Defintion concept for @n++</div>
\r
2224 <div class="paragraph"><p>: @n++ OVER @ DUP ROT - ROT ! ;</p></div>
\r
2227 <div style="text-align:center">
\r
2228 _______________________________________________________
\r
2230 <div class="paragraph"><p><a id="p_get_n_increment"></a></p></div>
\r
2232 <div class="sect2">
\r
2233 <h3 id="_word_n_2">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 increments 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>( a n — v ) : @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_greaterequal"></a></p></div>
\r
2253 <div class="sect2">
\r
2254 <h3 id="_word_gt">Word: >=</h3>
\r
2255 <div class="literalblock">
\r
2256 <div class="content">
\r
2257 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2259 <div class="paragraph"><p>">=" is a function word that replaces a pair of values with -1 if the
\r
2260 first, v1, is greater than or equal to the second, v1, otherwise 0. To
\r
2261 that end, the values are 64-bit signed integers.</p></div>
\r
2262 <div style="text-align:center">
\r
2263 _______________________________________________________
\r
2265 <div class="paragraph"><p><a id="p_greaterthan"></a></p></div>
\r
2267 <div class="sect2">
\r
2268 <h3 id="_word_gt_2">Word: ></h3>
\r
2269 <div class="literalblock">
\r
2270 <div class="content">
\r
2271 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2273 <div class="paragraph"><p>">" is a function word that replaces a pair of values with -1 if the
\r
2274 first, v1, is greater than the second, v1, otherwise 0. To that end,
\r
2275 the values are 64-bit signed integers.</p></div>
\r
2276 <div style="text-align:center">
\r
2277 _______________________________________________________
\r
2279 <div class="paragraph"><p><a id="p_gtR"></a></p></div>
\r
2281 <div class="sect2">
\r
2282 <h3 id="_word_gt_r">Word: >R</h3>
\r
2283 <div class="literalblock">
\r
2284 <div class="content">
\r
2285 <pre><code>Data stack: ( v -- ) Return stack: ( -- v )</code></pre>
\r
2287 <div class="paragraph"><p>">R" is a function word that "moves" the top data stack value onto the
\r
2288 return stack.</p></div>
\r
2289 <div style="text-align:center">
\r
2290 _______________________________________________________
\r
2292 <div class="paragraph"><p><a id="p_here"></a></p></div>
\r
2294 <div class="sect2">
\r
2295 <h3 id="_word_here">Word: HERE</h3>
\r
2296 <div class="literalblock">
\r
2297 <div class="content">
\r
2298 <pre><code>Data stack: ( -- a )</code></pre>
\r
2300 <div class="paragraph"><p>"HERE" is a variable word that keeps the lowest address of the free
\r
2301 allocation space. It get updated by all words that allocate memory.</p></div>
\r
2302 <div class="exampleblock">
\r
2303 <div class="content">
\r
2304 <div class="sidebarblock">
\r
2305 <div class="content">
\r
2306 <div class="title">allocate 1024 bytes on the heap</div>
\r
2307 <div class="paragraph"><p>1024 HEAP @ + HEAP !</p></div>
\r
2310 <div class="paragraph"><p>See also <a href="#p_allot">ALLOT</a>.</p></div>
\r
2311 <div style="text-align:center">
\r
2312 _______________________________________________________
\r
2314 <div class="paragraph"><p><a id="p_hex"></a></p></div>
\r
2316 <div class="sect2">
\r
2317 <h3 id="_word_hex">Word: HEX</h3>
\r
2318 <div class="literalblock">
\r
2319 <div class="content">
\r
2320 <pre><code>Data stack: ( -- )</code></pre>
\r
2322 <div class="paragraph"><p>"HEX" is a function word that sets <a href="#p_base">BASE</a> to 16, which uses
\r
2323 letters a-f as additional digits. (Uppercase letter are also accepted
\r
2324 on input).</p></div>
\r
2325 <div class="exampleblock">
\r
2326 <div class="content">
\r
2327 <div class="sidebarblock">
\r
2328 <div class="content">
\r
2329 <div class="title">Definition concept for HEX</div>
\r
2330 <div class="paragraph"><p>: HEX 16 BASE ! ;</p></div>
\r
2333 <div style="text-align:center">
\r
2334 _______________________________________________________
\r
2336 <div class="paragraph"><p><a id="p_if"></a></p></div>
\r
2338 <div class="sect2">
\r
2339 <h3 id="_word_if">Word: IF</h3>
\r
2340 <div class="literalblock">
\r
2341 <div class="content">
\r
2342 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2344 <div class="paragraph"><p>"IF" is an immediate function word that is used together with
\r
2345 <a href="#p_else">ELSE</a> and <a href="#p_then">THEN</a> to implement structured execution
\r
2346 control. IF results in layout of a <a href="#p_0branch">0BRANCH</a> instruction
\r
2347 with an unresolved branch offset, and places the address for resolving
\r
2348 this instruction on the datastack. This address will then be resolved
\r
2349 and asssigned by a subsequent <a href="#p_else">ELSE</a> or <a href="#p_then">THEN</a> so
\r
2350 that at execution time there is an appropriate conditional branch past
\r
2351 the "then-part" of the "structured statement".</p></div>
\r
2352 <div style="text-align:center">
\r
2353 _______________________________________________________
\r
2355 <div class="paragraph"><p><a id="p_ifagain"></a></p></div>
\r
2357 <div class="sect2">
\r
2358 <h3 id="_word_ifagain">Word: IFAGAIN</h3>
\r
2359 <div class="literalblock">
\r
2360 <div class="content">
\r
2361 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2363 <div class="paragraph"><p>"IFAGAIN" is an immediate function word that is used together with
\r
2364 <a href="#p_begin">BEGIN</a>, <a href="#p_ifbreak">BREAK</a> and <a href="#p_end">END</a> to implement
\r
2365 structured execution control. IFAGAIN scans the datastack for the
\r
2366 nearest preceding BEGIN marker and lays out a branch from this point
\r
2367 the beginning of the block during execution.</p></div>
\r
2368 <div style="text-align:center">
\r
2369 _______________________________________________________
\r
2371 <div class="paragraph"><p><a id="p_ifbreak"></a></p></div>
\r
2373 <div class="sect2">
\r
2374 <h3 id="_word_ifbreak">Word: IFBREAK</h3>
\r
2375 <div class="literalblock">
\r
2376 <div class="content">
\r
2377 <pre><code>Data stack: Compiling: ( -- a )</code></pre>
\r
2379 <div class="paragraph"><p>"IFBREAK" is an immediate function word that is used together with
\r
2380 <a href="#p_begin">BEGIN</a>, <a href="#p_ifagain">IFAGAIN</a> and <a href="#p_end">END</a> to
\r
2381 implement structured execution control. IFBREAK simply places the
\r
2382 address for resolving branches from this point the end of the block
\r
2383 during execution.</p></div>
\r
2384 <div style="text-align:center">
\r
2385 _______________________________________________________
\r
2387 <div class="paragraph"><p><a id="p_immediate"></a></p></div>
\r
2389 <div class="sect2">
\r
2390 <h3 id="_word_immediate">Word: IMMEDIATE</h3>
\r
2391 <div class="literalblock">
\r
2392 <div class="content">
\r
2393 <pre><code>Data stack: ( -- )</code></pre>
\r
2395 <div class="paragraph"><p>"IMMEDIATE" is an immediate function word that sets the flags field of
\r
2396 the most recent word to 1, thereby making that word an immediate word.</p></div>
\r
2397 <div class="exampleblock">
\r
2398 <div class="content">
\r
2399 <div class="sidebarblock">
\r
2400 <div class="content">
\r
2401 <div class="title">Definition concept for IMMEDIATE</div>
\r
2402 <div class="paragraph"><p>: IMMEDIATE IMMEDIATE 1 CURRENT-WORDLIST @ @ 16 + ! ;</p></div>
\r
2405 <div class="paragraph"><p>See also <a href="#p_colon">:</a>, <a href="#p_current_wordlist">CURRENT-WORDLIST</a>,
\r
2406 <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
2407 <div style="text-align:center">
\r
2408 _______________________________________________________
\r
2410 <div class="paragraph"><p><a id="p_input"></a></p></div>
\r
2412 <div class="sect2">
\r
2413 <h3 id="_word_input">Word: INPUT</h3>
\r
2414 <div class="literalblock">
\r
2415 <div class="content">
\r
2416 <pre><code>Data stack: ( -- a )</code></pre>
\r
2418 <div class="paragraph"><p>"INPUT" is a variable word for the input stream buffer used by
\r
2419 <a href="#p_evaluate_stream">EVALUATE-STREAM</a>.</p></div>
\r
2420 <div style="text-align:center">
\r
2421 _______________________________________________________
\r
2423 <div class="paragraph"><p><a id="p_left_bracket"></a></p></div>
\r
2425 <div class="sect2">
\r
2426 <h3 id="_word_10">Word: [</h3>
\r
2427 <div class="literalblock">
\r
2428 <div class="content">
\r
2429 <pre><code>Data stack: ( -- )</code></pre>
\r
2431 <div class="paragraph"><p>"[" (left bracket) is a function word that sets the stream evaluation
\r
2432 mode to be intepreting. In this mode, words are executed immediately
\r
2433 after parsing, by invoking their "doer".</p></div>
\r
2434 <div class="exampleblock">
\r
2435 <div class="content">
\r
2436 <div class="sidebarblock">
\r
2437 <div class="content">
\r
2438 <div class="title">Definition concept for [</div>
\r
2439 <div class="paragraph"><p>: [ IMMEDIATE 0 STATE ! ;</p></div>
\r
2442 <div style="text-align:center">
\r
2443 _______________________________________________________
\r
2445 <div class="paragraph"><p><a id="p_lessequal"></a></p></div>
\r
2447 <div class="sect2">
\r
2448 <h3 id="_word_lt">Word: <=</h3>
\r
2449 <div class="literalblock">
\r
2450 <div class="content">
\r
2451 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2453 <div class="paragraph"><p>"<=" is a function word that replaces a pair of values with -1 if the
\r
2454 first, v1, is less than or equal to the second, v1, otherwise 0. To
\r
2455 that end, the values are 64-bit signed integers.</p></div>
\r
2456 <div style="text-align:center">
\r
2457 _______________________________________________________
\r
2459 <div class="paragraph"><p><a id="p_lessthan"></a></p></div>
\r
2461 <div class="sect2">
\r
2462 <h3 id="_word_lt_2">Word: <</h3>
\r
2463 <div class="literalblock">
\r
2464 <div class="content">
\r
2465 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
2467 <div class="paragraph"><p>"<" is a function word that replaces a pair of values with -1 if the
\r
2468 first, v1, is less than the second, v1, otherwise 0. To that end, the
\r
2469 values are 64-bit signed integers.</p></div>
\r
2470 <div style="text-align:center">
\r
2471 _______________________________________________________
\r
2473 <div class="paragraph"><p><a id="p_literal"></a></p></div>
\r
2475 <div class="sect2">
\r
2476 <h3 id="_word_lit">Word: LIT</h3>
\r
2477 <div class="literalblock">
\r
2478 <div class="content">
\r
2479 <pre><code>Data stack: ( -- v )</code></pre>
\r
2481 <div class="paragraph"><p>"LIT" is a function word that pushes the cell subsequent and moves
\r
2482 excution past that. The literal value is thus layed out as if a
\r
2483 subsequent CFA pointer in the containing definition, and the LIT
\r
2484 execution will make the execution skip past that and instead contine
\r
2485 with the CFA pointer following the value.</p></div>
\r
2486 <div class="paragraph"><p>It’s not a good idea to use "LIT" interactively.</p></div>
\r
2487 <div class="exampleblock">
\r
2488 <div class="content">
\r
2489 <div class="sidebarblock">
\r
2490 <div class="content">
\r
2491 <div class="title">Definition concept for LIT</div>
\r
2492 <div class="paragraph"><p>: LIT R> DUP 8 + >R @ ;</p></div>
\r
2495 <div style="text-align:center">
\r
2496 _______________________________________________________
\r
2498 <div class="paragraph"><p><a id="p_literal_string"></a></p></div>
\r
2500 <div class="sect2">
\r
2501 <h3 id="_word_s">Word: S"</h3>
\r
2502 <div class="literalblock">
\r
2503 <div class="content">
\r
2504 <pre><code>Data stack: ( -- chars* n )</code></pre>
\r
2506 <div class="paragraph"><p>"S"" is a function word that pushes the [n:char] pointer for a string
\r
2507 inlined subsequently to it in the containing definition. This is
\r
2508 similar to <a href="#p_lit">LIT</a> but for a string literal.</p></div>
\r
2509 <div class="exampleblock">
\r
2510 <div class="content">
\r
2511 <div class="sidebarblock">
\r
2512 <div class="content">
\r
2513 <div class="title">Definition concept for LIT</div>
\r
2514 <div class="paragraph"><p>: LIT R> DUP @ 2DUP + 8 + >R SWAP 8 + SWAP ;</p></div>
\r
2517 <div style="text-align:center">
\r
2518 _______________________________________________________
\r
2520 <div class="paragraph"><p><a id="p_load_buffer_size"></a></p></div>
\r
2522 <div class="sect2">
\r
2523 <h3 id="_word_load_buffer_size">Word: LOAD-BUFFER-SIZE</h3>
\r
2524 <div class="literalblock">
\r
2525 <div class="content">
\r
2526 <pre><code>data stack: ( -- a )</code></pre>
\r
2528 <div class="paragraph"><p>"LOAD-BUFFER-SIZE" is a variable word telling the buffer size in bytes
\r
2529 that <a href="#p_load_file">LOAD-FILE</a> should use.</p></div>
\r
2530 <div style="text-align:center">
\r
2531 _______________________________________________________
\r
2533 <div class="paragraph"><p><a id="p_load_file"></a></p></div>
\r
2535 <div class="sect2">
\r
2536 <h3 id="_word_load_file">Word: LOAD-FILE</h3>
\r
2537 <div class="literalblock">
\r
2538 <div class="content">
\r
2539 <pre><code>data stack: ( chaz* -- * 0/1 )</code></pre>
\r
2541 <div class="paragraph"><p>"LOAD-FILE" is a function word that evaluates a text file. It opens a
\r
2542 file via <a href="#p_open_file">OPEN-FILE</a> and sets up a stream with a
\r
2543 buffer of <a href="#p_load_buffer_size">LOAD-BUFFER-SIZE</a> bytes for
\r
2544 reading it. The stream is passed to
\r
2545 <a href="#p_evaluate_stream">EVALUATE-STREAM</a> for processing its words. Upon
\r
2546 its return the file is closed and the stream memory is reclaimed, and
\r
2547 then the function returns whatever
\r
2548 <a href="#p_evaluate_stream">EVALUATE-STREAM</a> returns.</p></div>
\r
2549 <div style="text-align:center">
\r
2550 _______________________________________________________
\r
2552 <div class="paragraph"><p><a id="p_lparen"></a></p></div>
\r
2554 <div class="sect2">
\r
2555 <h3 id="_word_11">Word: (</h3>
\r
2556 <div class="literalblock">
\r
2557 <div class="content">
\r
2558 <pre><code>Data stack: ( -- )</code></pre>
\r
2560 <div class="paragraph"><p>"(" (left parenthesis) is a function word that scans and ignores words
\r
2561 until the next right parenthesis, or the end of the stream. This is
\r
2562 used for comments in RRQFORTH code.</p></div>
\r
2563 <div class="paragraph"><p>Note that the terminating right parenthesis is a word, i.e. must have
\r
2564 whitespace before and after it.</p></div>
\r
2565 <div style="text-align:center">
\r
2566 _______________________________________________________
\r
2568 <div class="paragraph"><p><a id="p_malloc"></a></p></div>
\r
2570 <div class="sect2">
\r
2571 <h3 id="_word_malloc">Word: MALLOC</h3>
\r
2572 <div class="literalblock">
\r
2573 <div class="content">
\r
2574 <pre><code>Data stack: ( n -- a )</code></pre>
\r
2576 <div class="paragraph"><p>"MALLOC" is a word that allocates memory using mmap of at least n
\r
2577 bytes and returns the lowest address of the allocated block.</p></div>
\r
2578 <div class="paragraph"><p>Note that this makes new page allocations for the process from the
\r
2579 kernel, and the granularity is in pages, i.e. a multiple of 4 kb.</p></div>
\r
2580 <div class="paragraph"><p>The memory is allocated with READ and WRITE access but not EXEC
\r
2581 access, and flagged as PRIVATE, ANONYMOUS and LOCKED. See the "man
\r
2582 page" of mmap for details.</p></div>
\r
2583 <div class="paragraph"><p>See also <a href="#p_stream">STREAM</a></p></div>
\r
2584 <div style="text-align:center">
\r
2585 _______________________________________________________
\r
2587 <div class="paragraph"><p><a id="p_minus"></a></p></div>
\r
2589 <div class="sect2">
\r
2590 <h3 id="_word_12">Word: -</h3>
\r
2591 <div class="literalblock">
\r
2592 <div class="content">
\r
2593 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2595 <div class="paragraph"><p>"-" (minus) is a function word that replaces a pair of values with the
\r
2596 result of reducing the first, v1, with the second, v2. To that end,
\r
2597 the values are 64-bit signed integers.</p></div>
\r
2598 <div style="text-align:center">
\r
2599 _______________________________________________________
\r
2601 <div class="paragraph"><p><a id="p_mult"></a></p></div>
\r
2603 <div class="sect2">
\r
2604 <h3 id="_word_13">Word: *</h3>
\r
2605 <div class="literalblock">
\r
2606 <div class="content">
\r
2607 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2609 <div class="paragraph"><p>"*" is a function word that replaces a pair of values with the result
\r
2610 of multiplying them. To that end, the values are 64-bit signed
\r
2611 integers, and clipping the result to the least signifcant 64 bits.</p></div>
\r
2612 <div style="text-align:center">
\r
2613 _______________________________________________________
\r
2615 <div class="paragraph"><p><a id="p_negate"></a></p></div>
\r
2617 <div class="sect2">
\r
2618 <h3 id="_word_negate">Word: NEGATE</h3>
\r
2619 <div class="literalblock">
\r
2620 <div class="content">
\r
2621 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
2623 <div class="paragraph"><p>"NEGATE" is a function word that replaces a value with its
\r
2624 2’s-complement negation. To that end, the values are 64-bit signed
\r
2625 integers.</p></div>
\r
2626 <div style="text-align:center">
\r
2627 _______________________________________________________
\r
2629 <div class="paragraph"><p><a id="p_nip"></a></p></div>
\r
2631 <div class="sect2">
\r
2632 <h3 id="_word_nip">Word: NIP</h3>
\r
2633 <div class="literalblock">
\r
2634 <div class="content">
\r
2635 <pre><code>Data stack: ( v1 v2 -- v2 )</code></pre>
\r
2637 <div class="paragraph"><p>"NIP" is a function word that discards the second of the top two cells
\r
2638 on the data stack.</p></div>
\r
2639 <div class="exampleblock">
\r
2640 <div class="content">
\r
2641 <div class="sidebarblock">
\r
2642 <div class="content">
\r
2643 <div class="title">Definition concept for NIP</div>
\r
2644 <div class="paragraph"><p>: NIP SWAP DROP ;</p></div>
\r
2647 <div style="text-align:center">
\r
2648 _______________________________________________________
\r
2650 <div class="paragraph"><p><a id="p_nl"></a></p></div>
\r
2652 <div class="sect2">
\r
2653 <h3 id="_word_nl">Word: NL</h3>
\r
2654 <div class="literalblock">
\r
2655 <div class="content">
\r
2656 <pre><code>Data stack: ( -- v )</code></pre>
\r
2658 <div class="paragraph"><p>"NL" is a value word pushing a newline character onto the data stack.</p></div>
\r
2659 <div style="text-align:center">
\r
2660 _______________________________________________________
\r
2662 <div class="paragraph"><p><a id="p_not"></a></p></div>
\r
2664 <div class="sect2">
\r
2665 <h3 id="_word_not">Word: NOT</h3>
\r
2666 <div class="literalblock">
\r
2667 <div class="content">
\r
2668 <pre><code>Data stack: ( v1 -- v2 )</code></pre>
\r
2670 <div class="paragraph"><p>"NOT" is a function word that replaces a value with its bitwise
\r
2671 complement; each bit is zero if non-zero, and non-zero if zero.</p></div>
\r
2672 <div class="paragraph"><p>Compare with <<p_0equal,0⇒>.</p></div>
\r
2673 <div style="text-align:center">
\r
2674 _______________________________________________________
\r
2676 <div class="paragraph"><p><a id="p_number"></a></p></div>
\r
2678 <div class="sect2">
\r
2679 <h3 id="_word_number">Word: NUMBER</h3>
\r
2680 <div class="literalblock">
\r
2681 <div class="content">
\r
2682 <pre><code>Data stack: ( char n -- [ 0 ]/[ v 1 ] )</code></pre>
\r
2684 <div class="paragraph"><p>"NUMBER" is a function word that parses a text number using
\r
2685 <a href="#p_base">BASE</a> as numerical base, then returns the result number and
\r
2686 a 1 on top, or just a 0 if the word didn’t parse.</p></div>
\r
2687 <div class="paragraph"><p>A number consists of, first an optional minus sign, if in
\r
2688 <a href="#p_decimal">DECIMAL</a> base, then digits 0-9 and, if in <a href="#p_hex">HEX</a>
\r
2689 base, letters a-f or A-F for values 10-15. I.e. the normal positive or
\r
2690 negative decimal integers or normal (positive only) hexadecimal
\r
2691 integers.</p></div>
\r
2692 <div style="text-align:center">
\r
2693 _______________________________________________________
\r
2695 <div class="paragraph"><p><a id="p_open_file"></a></p></div>
\r
2697 <div class="sect2">
\r
2698 <h3 id="_word_open_file">Word: OPEN-FILE</h3>
\r
2699 <div class="literalblock">
\r
2700 <div class="content">
\r
2701 <pre><code>Data stack: ( chaz* -- fd )</code></pre>
\r
2703 <div class="paragraph"><p>"OPEN-FILE" is a function word that opens the file named by the zero
\r
2704 terminated character string and returns the file descriptor, or if
\r
2705 less than 0, the system call error code.</p></div>
\r
2706 <div style="text-align:center">
\r
2707 _______________________________________________________
\r
2709 <div class="paragraph"><p><a id="p_or"></a></p></div>
\r
2711 <div class="sect2">
\r
2712 <h3 id="_word_or">Word: OR</h3>
\r
2713 <div class="literalblock">
\r
2714 <div class="content">
\r
2715 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2717 <div class="paragraph"><p>"OR" is a function word that replaces a value pair with their bitwise
\r
2718 disjunction; each bit is 1 if the corresponding bits of any operand
\r
2719 is 1 and 0 if not.</p></div>
\r
2720 <div style="text-align:center">
\r
2721 _______________________________________________________
\r
2723 <div class="paragraph"><p><a id="p_over"></a></p></div>
\r
2725 <div class="sect2">
\r
2726 <h3 id="_word_over">Word: OVER</h3>
\r
2727 <div class="literalblock">
\r
2728 <div class="content">
\r
2729 <pre><code>Data stack: ( v1 v2 -- v1 v2 v1 )</code></pre>
\r
2731 <div class="paragraph"><p>"OVER" is a function word that duplicates the second top stack cell on
\r
2732 the data stack.</p></div>
\r
2733 <div style="text-align:center">
\r
2734 _______________________________________________________
\r
2736 <div class="paragraph"><p><a id="p_pad"></a></p></div>
\r
2738 <div class="sect2">
\r
2739 <h3 id="_word_pad">Word: PAD</h3>
\r
2740 <div class="literalblock">
\r
2741 <div class="content">
\r
2742 <pre><code>Data stack: ( -- a )</code></pre>
\r
2744 <div class="paragraph"><p>"PAD" is a variable word for a 1 kb data space that is used by
\r
2745 <a href="#p_double_quote">[p_double_quote]</a> (only), and otherwise free for temporary use.</p></div>
\r
2746 <div style="text-align:center">
\r
2747 _______________________________________________________
\r
2749 <div class="paragraph"><p><a id="p_pick"></a></p></div>
\r
2751 <div class="sect2">
\r
2752 <h3 id="_word_pick">Word: PICK</h3>
\r
2753 <div class="literalblock">
\r
2754 <div class="content">
\r
2755 <pre><code>Data stack: ( vu...v1 v0 u -- vu...v1 v0 vu )</code></pre>
\r
2757 <div class="paragraph"><p>"PICK" is a function word that pushes the u:th data stack cell down
\r
2758 from top onto the data stack. 0 indicates the top cell making it the
\r
2759 same as <a href="#p_dup">DUP</a>, and 1 indicates the second top cell making it
\r
2760 the same as <a href="#p_over">OVER</a>.</p></div>
\r
2761 <div style="text-align:center">
\r
2762 _______________________________________________________
\r
2764 <div class="paragraph"><p><a id="p_plus"></a></p></div>
\r
2766 <div class="sect2">
\r
2767 <h3 id="_word_43">Word: +</h3>
\r
2768 <div class="literalblock">
\r
2769 <div class="content">
\r
2770 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
2772 <div class="paragraph"><p>"+" (plus) is a function word that replaces a pair of values with the
\r
2773 result of adding them. To that end, the values are 64-bit signed
\r
2774 integers.</p></div>
\r
2775 <div style="text-align:center">
\r
2776 _______________________________________________________
\r
2778 <div class="paragraph"><p><a id="p_program_version"></a></p></div>
\r
2780 <div class="sect2">
\r
2781 <h3 id="_word_program_version">Word: PROGRAM_VERSION</h3>
\r
2782 <div class="literalblock">
\r
2783 <div class="content">
\r
2784 <pre><code>Data stack: ( -- char* length )</code></pre>
\r
2786 <div class="paragraph"><p>"PROGRAM_VERSION" is a string variable hilding the version string.</p></div>
\r
2787 <div style="text-align:center">
\r
2788 _______________________________________________________
\r
2790 <div class="paragraph"><p><a id="p_put"></a></p></div>
\r
2792 <div class="sect2">
\r
2793 <h3 id="_word_14">Word: !</h3>
\r
2794 <div class="literalblock">
\r
2795 <div class="content">
\r
2796 <pre><code>Data stack: ( v a -- )</code></pre>
\r
2798 <div class="paragraph"><p>"!" is a function word that stores the cell value v at the address a.</p></div>
\r
2799 <div style="text-align:center">
\r
2800 _______________________________________________________
\r
2802 <div class="paragraph"><p><a id="p_put_plus"></a></p></div>
\r
2804 <div class="sect2">
\r
2805 <h3 id="_word_15">Word: !+</h3>
\r
2806 <div class="literalblock">
\r
2807 <div class="content">
\r
2808 <pre><code>Data stack: ( a n -- )</code></pre>
\r
2810 <div class="paragraph"><p>"!+" is a function word that adds n to the cell value at a.</p></div>
\r
2811 <div class="exampleblock">
\r
2812 <div class="content">
\r
2813 <div class="sidebarblock">
\r
2814 <div class="content">
\r
2815 <div class="title">definition concept for !+</div>
\r
2816 <div class="paragraph"><p>( a n — ) : !+ OVER @ + SWAP ! ;</p></div>
\r
2819 <div style="text-align:center">
\r
2820 _______________________________________________________
\r
2822 <div class="paragraph"><p><a id="p_quit"></a></p></div>
\r
2824 <div class="sect2">
\r
2825 <h3 id="_word_quit">Word: QUIT</h3>
\r
2826 <div class="literalblock">
\r
2827 <div class="content">
\r
2828 <pre><code>Data stack: ??</code></pre>
\r
2830 <div class="paragraph"><p>"QUIT" is a function word that implements the root execution loop of
\r
2831 RRQFORTH. First it resets the stacks to their original settings, and
\r
2832 thereafter it enters loop of reading words from <a href="#p_stdin">STDIN</a> and
\r
2833 executing them.</p></div>
\r
2834 <div style="text-align:center">
\r
2835 _______________________________________________________
\r
2837 <div class="paragraph"><p><a id="p_quote"></a></p></div>
\r
2839 <div class="sect2">
\r
2840 <h3 id="_word_16">Word: '</h3>
\r
2841 <div class="literalblock">
\r
2842 <div class="content">
\r
2843 <pre><code>data stack: ( -- cfa ) Input stream: word</code></pre>
\r
2845 <div class="paragraph"><p>"'" (single quote) is a function word that reads and find the next
\r
2846 word on the input stream and pushes its cfa.</p></div>
\r
2847 <div style="text-align:center">
\r
2848 _______________________________________________________
\r
2850 <div class="paragraph"><p><a id="p_rbp"></a></p></div>
\r
2852 <div class="sect2">
\r
2853 <h3 id="_word_rsp">Word: RSP</h3>
\r
2854 <div class="literalblock">
\r
2855 <div class="content">
\r
2856 <pre><code>Data stack: ( -- a )</code></pre>
\r
2858 <div class="paragraph"><p>"RSP" is a function word that pushes the return stack pointer value
\r
2859 onto the data stack.</p></div>
\r
2860 <div style="text-align:center">
\r
2861 _______________________________________________________
\r
2863 <div class="paragraph"><p><a id="p_rbpn"></a></p></div>
\r
2865 <div class="sect2">
\r
2866 <h3 id="_word_r_n">Word: R[n]</h3>
\r
2867 <div class="literalblock">
\r
2868 <div class="content">
\r
2869 <pre><code>Data stack: ( n -- a )</code></pre>
\r
2871 <div class="paragraph"><p>"R[n]" is a function word that pushes the address for the n:th cell on
\r
2872 the top return stack value onto the data stack.</p></div>
\r
2873 <div class="exampleblock">
\r
2874 <div class="content">
\r
2875 <div class="sidebarblock">
\r
2876 <div class="content">
\r
2877 <div class="title">Defintion concept for R[n]</div>
\r
2878 <div class="paragraph"><p>( n — a ) : R[n] 8 * RSP + ;</p></div>
\r
2881 <div style="text-align:center">
\r
2882 _______________________________________________________
\r
2884 <div class="paragraph"><p><a id="p_read_stream_char"></a></p></div>
\r
2886 <div class="sect2">
\r
2887 <h3 id="_word_read_stream_char">Word: READ-STREAM-CHAR</h3>
\r
2888 <div class="literalblock">
\r
2889 <div class="content">
\r
2890 <pre><code>Data stack: ( stream -- c )</code></pre>
\r
2892 <div class="paragraph"><p>"READ-STREAM-CHAR" is a function word that gets the next character
\r
2893 from the given stream buffer, possibly refilling the buffer if it is
\r
2894 backed by a file descriptor. The refill is done by a SYS_READ call
\r
2895 when more characters are needed. The next character is pushed on the
\r
2896 stack, unless the stream is exhausted in which case the -1 is pushed
\r
2897 instead.</p></div>
\r
2898 <div class="paragraph"><p>See also <a href="#p_stream">STREAM</a>.</p></div>
\r
2899 <div style="text-align:center">
\r
2900 _______________________________________________________
\r
2902 <div class="paragraph"><p><a id="p_read_word"></a></p></div>
\r
2904 <div class="sect2">
\r
2905 <h3 id="_word_read_word">Word: READ-WORD</h3>
\r
2906 <div class="literalblock">
\r
2907 <div class="content">
\r
2908 <pre><code>Data stack: ( stream -- char* n )</code></pre>
\r
2910 <div class="paragraph"><p>"READ-WORD" is a function word that "reads" the next whitespace
\r
2911 separated word from the given stream and returns the [n:char*] duoble
\r
2912 cell pointer for it. The characters of the word are copied to
\r
2913 <a href="#p_pad">PAD</a>, and there is a limit of 1024 characters.</p></div>
\r
2914 <div class="paragraph"><p>At the end of the stream READ-WORD returns 0 length.</p></div>
\r
2915 <div class="exampleblock">
\r
2916 <div class="title">Special syntax 1: Whitespace</div>
\r
2917 <div class="content">
\r
2918 <div class="paragraph"><p>All character codes less or equal to 32 are regarded as "whitespace".</p></div>
\r
2920 <div class="exampleblock">
\r
2921 <div class="title">Special syntax 2: Rest-of-line comment</div>
\r
2922 <div class="content">
\r
2923 <div class="paragraph"><p>The "#" character following whitespace starts a line comment and the
\r
2924 rest of the line is ignored. Note that this is also recognised with
\r
2925 <a href="#p_lparen">parethesis commenting</a>.</p></div>
\r
2927 <div style="text-align:center">
\r
2928 _______________________________________________________
\r
2930 <div class="paragraph"><p><a id="p_realloc"></a></p></div>
\r
2932 <div class="sect2">
\r
2933 <h3 id="_word_realloc">Word: REALLOC</h3>
\r
2934 <div class="literalblock">
\r
2935 <div class="content">
\r
2936 <pre><code>Data stack: ( a m n -- a )</code></pre>
\r
2938 <div class="paragraph"><p>"REALLOC" is a word that reallocates memory using mremap of address a
\r
2939 of size m to be size n bytes and returns the lowest address of the
\r
2940 allocated block.</p></div>
\r
2941 <div class="paragraph"><p>Note that this makes new page allocations for the process from the
\r
2942 kernel, and the granularity is in pages, i.e. a multiple of 4 kb.</p></div>
\r
2943 <div class="paragraph"><p>The memory is reampped using the MREMAP_MAYMOVE flag,</p></div>
\r
2944 <div class="paragraph"><p>See also <a href="#p_malloc">MALLOC</a></p></div>
\r
2945 <div style="text-align:center">
\r
2946 _______________________________________________________
\r
2948 <div class="paragraph"><p>compile.asm: WORD p_right_bracket,<em>]</em>,fasm</p></div>
\r
2949 <div class="paragraph"><p><a id="p_right_bracket"></a></p></div>
\r
2951 <div class="sect2">
\r
2952 <h3 id="_word_17">Word: ]</h3>
\r
2953 <div class="literalblock">
\r
2954 <div class="content">
\r
2955 <pre><code>Data stack: ( -- )</code></pre>
\r
2957 <div class="paragraph"><p>"]" (right bracket) is a function word that sets the stream evaluation
\r
2958 mode to be compiling. In this mode words parsed into CFA pointers
\r
2959 which are placed on the heap in the given order, unless the word is
\r
2960 flagged as <a href="#p_immediate">IMMEDIATE</a> or a <a href="#p_number">NUMBER</a>. An
\r
2961 immediate word is executed immediately, and a number is parsed and
\r
2962 left on the stack.</p></div>
\r
2963 <div class="paragraph"><p>Note that a word is parsed as a number only if it is not found in the
\r
2964 wordlist; i.e., the word list may contain definitions for numbers.</p></div>
\r
2965 <div class="exampleblock">
\r
2966 <div class="content">
\r
2967 <div class="sidebarblock">
\r
2968 <div class="content">
\r
2969 <div class="title">Definition concept for ]</div>
\r
2970 <div class="paragraph"><p>: ] 1 STATE ! ;</p></div>
\r
2973 <div style="text-align:center">
\r
2974 _______________________________________________________
\r
2976 <div class="paragraph"><p><a id="p_roll"></a></p></div>
\r
2978 <div class="sect2">
\r
2979 <h3 id="_word_roll">Word: ROLL</h3>
\r
2980 <div class="literalblock">
\r
2981 <div class="content">
\r
2982 <pre><code>Data stack: ( vu...v1 v0 u -- ...v1 v0 vu )</code></pre>
\r
2984 <div class="paragraph"><p>"ROLL" is a function word that "moves" the u:th data stack cell down
\r
2985 from top onto the data stack while discarding it. 0 indicates the top
\r
2986 cell; 1 indicates the second top cell making it the same as
\r
2987 <a href="#p_swap">SWAP</a>; 2 indicates the third top cell making it the same as
\r
2988 <a href="#p_rot">ROT</a>.</p></div>
\r
2989 <div style="text-align:center">
\r
2990 _______________________________________________________
\r
2992 <div class="paragraph"><p><a id="p_rot"></a></p></div>
\r
2994 <div class="sect2">
\r
2995 <h3 id="_word_rot">Word: ROT</h3>
\r
2996 <div class="literalblock">
\r
2997 <div class="content">
\r
2998 <pre><code>Data stack: ( v1 v2 v3 -- v2 v3 v1 )</code></pre>
\r
3000 <div class="paragraph"><p>"ROT" is a function word that "rotates" the top three data stack cells
\r
3001 such that the third becomes the first while the second becomes third
\r
3002 and the first becomes the second.</p></div>
\r
3003 <div class="paragraph"><p>See also <a href="#p_roll">ROLL</a>.</p></div>
\r
3004 <div style="text-align:center">
\r
3005 _______________________________________________________
\r
3007 <div class="paragraph"><p><a id="p_semicolon"></a></p></div>
\r
3009 <div class="sect2">
\r
3010 <h3 id="_word_18">Word: ;</h3>
\r
3011 <div class="literalblock">
\r
3012 <div class="content">
\r
3013 <pre><code>Data stack: ( -- )</code></pre>
\r
3015 <div class="paragraph"><p>";" (semi-colon) is a function word that ends a new forth definition
\r
3016 by means of adding an <a href="#p_exit">EXIT</a></p></div>
\r
3017 <div class="exampleblock">
\r
3018 <div class="content">
\r
3019 <div class="sidebarblock">
\r
3020 <div class="content">
\r
3021 <div class="title">Definition concept for ;</div>
\r
3022 <div class="paragraph"><p>: ; IMMEDIATE ' EXIT , ;</p></div>
\r
3025 <div style="text-align:center">
\r
3026 _______________________________________________________
\r
3028 <div class="paragraph"><p><a id="p_setup_signals"></a></p></div>
\r
3030 <div class="sect2">
\r
3031 <h3 id="_word_p_setup_signals">Word: [p_setup_signals]</h3>
\r
3032 <div class="literalblock">
\r
3033 <div class="content">
\r
3034 <pre><code>Data stack: ( -- a )</code></pre>
\r
3036 <div class="paragraph"><p>"[p_setup_signals]" is a variable word that contains the assembly code
\r
3037 sniippet for setting up the signal handling. rrqforth handles SEGV by
\r
3038 restarting the interpreter loop on <a href="#p_stdin">STDIN</a>.</p></div>
\r
3039 <div style="text-align:center">
\r
3040 _______________________________________________________
\r
3042 <div class="paragraph"><p><a id="p_shift_left"></a></p></div>
\r
3044 <div class="sect2">
\r
3045 <h3 id="_word_lt_lt">Word: <<</h3>
\r
3046 <div class="literalblock">
\r
3047 <div class="content">
\r
3048 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3050 <div class="paragraph"><p>"<<" is a function word that shifts value v1 n steps left (i.e.
\r
3051 "moving" bits towards more significant bits) to form value v2.</p></div>
\r
3052 <div style="text-align:center">
\r
3053 _______________________________________________________
\r
3055 <div class="paragraph"><p><a id="p_shift_right"></a></p></div>
\r
3057 <div class="sect2">
\r
3058 <h3 id="_word_gt_gt">Word: >></h3>
\r
3059 <div class="literalblock">
\r
3060 <div class="content">
\r
3061 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3063 <div class="paragraph"><p>">>" is a function word that shifts value v1 n steps right (i.e.
\r
3064 "moving" bits towards less significant bits) to form value v2.</p></div>
\r
3065 <div style="text-align:center">
\r
3066 _______________________________________________________
\r
3068 <div class="paragraph"><p><a id="p_shift_signed_right"></a></p></div>
\r
3070 <div class="sect2">
\r
3071 <h3 id="_word_s_gt_gt">Word: s>></h3>
\r
3072 <div class="literalblock">
\r
3073 <div class="content">
\r
3074 <pre><code>Data stack: ( v1 n -- v2 )</code></pre>
\r
3076 <div class="paragraph"><p>"s>>" is a function word that shifts value v1 n steps right (i.e.
\r
3077 "moving" bits towards less significant bits) to form value v2, but
\r
3078 preserving (and copying) the sign bit.</p></div>
\r
3079 <div style="text-align:center">
\r
3080 _______________________________________________________
\r
3082 <div class="paragraph"><p><a id="p_sp"></a></p></div>
\r
3084 <div class="sect2">
\r
3085 <h3 id="_word_sp">Word: SP</h3>
\r
3086 <div class="literalblock">
\r
3087 <div class="content">
\r
3088 <pre><code>Data stack: ( -- v )</code></pre>
\r
3090 <div class="paragraph"><p>"SP" is a value word pushing a space character onto the data stack.</p></div>
\r
3091 <div style="text-align:center">
\r
3092 _______________________________________________________
\r
3094 <div class="paragraph"><p><a id="p_state"></a></p></div>
\r
3096 <div class="sect2">
\r
3097 <h3 id="_word_state">Word: STATE</h3>
\r
3098 <div class="literalblock">
\r
3099 <div class="content">
\r
3100 <pre><code>Data stack: ( -- a )</code></pre>
\r
3102 <div class="paragraph"><p>"STATE" is a variable word marking whether the stream evaluator is in
\r
3103 compiling mode (1) or interpreting (0) mode.</p></div>
\r
3104 <div style="text-align:center">
\r
3105 _______________________________________________________
\r
3107 <div class="paragraph"><p><a id="p_stdin"></a></p></div>
\r
3109 <div class="sect2">
\r
3110 <h3 id="_word_stdin">Word: STDIN</h3>
\r
3111 <div class="literalblock">
\r
3112 <div class="content">
\r
3113 <pre><code>Data stack: ( -- stream )</code></pre>
\r
3115 <div class="paragraph"><p>"STDIN" is a value word referring to the stream buffer for the
\r
3116 standard input file descriptor.</p></div>
\r
3117 <div style="text-align:center">
\r
3118 _______________________________________________________
\r
3120 <div class="paragraph"><p><a id="p_stream"></a></p></div>
\r
3122 <div class="sect2">
\r
3123 <h3 id="_word_stream">Word: STREAM</h3>
\r
3124 <div class="literalblock">
\r
3125 <div class="content">
\r
3126 <pre><code>Data stack: ( fd size -- addr ) or ( block -1 -- addr )</code></pre>
\r
3128 <div class="paragraph"><p>"STREAM" is a function word that sets up a buffer for an input file
\r
3129 descriptor or for a memory block (of size+data).</p></div>
\r
3130 <div class="sect3">
\r
3131 <h4 id="_file_descriptor_backed_stream">File descriptor backed STREAM</h4>
\r
3132 <div class="paragraph"><p>A file descriptor backed STREAM gains a buffer of the given size
\r
3133 prefixed by a 32 byte STREAM header of the following layout:</p></div>
\r
3134 <div class="exampleblock">
\r
3135 <div class="content">
\r
3136 <div class="listingblock">
\r
3137 <div class="title">Layout 3: file descriptor stream</div>
\r
3138 <div class="content">
\r
3139 <pre><code> 8 bytes = size of buffer (excluding the 32 byte header)
\r
3140 8 bytes source file descriptor
\r
3141 8 bytes current fill
\r
3142 8 current read position</code></pre>
\r
3146 <div class="sect3">
\r
3147 <h4 id="_memory_block_backed_stream">Memory block backed STREAM</h4>
\r
3148 <div class="paragraph"><p>A memory block stream is only the header (though allocated via
\r
3149 <a href="#p_malloc">MALLOC</a> which reserves a full kernel page) with the
\r
3150 following layout:</p></div>
\r
3151 <div class="exampleblock">
\r
3152 <div class="content">
\r
3153 <div class="listingblock">
\r
3154 <div class="title">Layout 4: memory block stream</div>
\r
3155 <div class="content">
\r
3156 <pre><code> 8 bytes = block address
\r
3157 8 -1 (indicates memory block)
\r
3158 8 size of block (taken from the block's first 8 bytes)
\r
3159 8 current read position</code></pre>
\r
3162 <div style="text-align:center">
\r
3163 _______________________________________________________
\r
3165 <div class="paragraph"><p><a id="p_stream_nchars"></a></p></div>
\r
3168 <div class="sect2">
\r
3169 <h3 id="_word_stream_nchars">Word: STREAM-NCHARS</h3>
\r
3170 <div class="literalblock">
\r
3171 <div class="content">
\r
3172 <pre><code>Data stack: ( stream -- n )</code></pre>
\r
3174 <div class="paragraph"><p>"STREAM-NCHARS" is a function word that scans ahead in the stream
\r
3175 buffer for the next non-whitespace character, and returns its position
\r
3176 relative to the end of the buffer. This is done without changing the
\r
3177 stream (or filling it by reading the backing file).</p></div>
\r
3178 <div style="text-align:center">
\r
3179 _______________________________________________________
\r
3181 <div class="paragraph"><p><a id="p_strlen"></a></p></div>
\r
3183 <div class="sect2">
\r
3184 <h3 id="_word_strlen">Word: STRLEN</h3>
\r
3185 <div class="literalblock">
\r
3186 <div class="content">
\r
3187 <pre><code>Data stack: ( s -- n )</code></pre>
\r
3189 <div class="paragraph"><p>"STRLEN" is a function words that counts how many bytes there are from
\r
3190 s to the first NUL byte and returns that count, n, not including the
\r
3191 NUL byte.</p></div>
\r
3192 <div style="text-align:center">
\r
3193 _______________________________________________________
\r
3195 <div class="paragraph"><p><a id="p_strncmp"></a></p></div>
\r
3197 <div class="sect2">
\r
3198 <h3 id="_word_strncmp">Word: STRNCMP</h3>
\r
3199 <div class="literalblock">
\r
3200 <div class="content">
\r
3201 <pre><code>Data stack: ( s1 s2 n -- v )</code></pre>
\r
3203 <div class="paragraph"><p>"STRNCMP" is a function words that compares up to n characters of
\r
3204 character sequences s1 and s2, and returns the difference of the first
\r
3205 differing characters, as in <code>s2[i] - s1[i]</code>, or 0 if all n characters
\r
3206 are the same.</p></div>
\r
3207 <div class="paragraph"><p>I.e., the value v is less than 0 if string [n:s1] is alpha-numerically
\r
3209 v is greater than 0 if [n:s1] is greater than [n:s2],
\r
3210 and v is 0 if [n:s1] and [n:s2] are equal.</p></div>
\r
3211 <div style="text-align:center">
\r
3212 _______________________________________________________
\r
3214 <div class="paragraph"><p><a id="p_strncpy"></a></p></div>
\r
3216 <div class="sect2">
\r
3217 <h3 id="_word_strncpy">Word: STRNCPY</h3>
\r
3218 <div class="literalblock">
\r
3219 <div class="content">
\r
3220 <pre><code>Data stack: ( s1 s2 n -- )</code></pre>
\r
3222 <div class="paragraph"><p>"STRNCPY" is a function words that copies n bytes of byte sequence s1
\r
3224 <div style="text-align:center">
\r
3225 _______________________________________________________
\r
3227 <div class="paragraph"><p><a id="p_swap"></a></p></div>
\r
3229 <div class="sect2">
\r
3230 <h3 id="_word_swap">Word: SWAP</h3>
\r
3231 <div class="literalblock">
\r
3232 <div class="content">
\r
3233 <pre><code>Data stack: ( v1 v2 -- v2 v1 )</code></pre>
\r
3235 <div class="paragraph"><p>"SWAP" is a function word the swaps the top two data stack cells.</p></div>
\r
3236 <div style="text-align:center">
\r
3237 _______________________________________________________
\r
3239 <div class="paragraph"><p><a id="p_system"></a></p></div>
\r
3241 <div class="sect2">
\r
3242 <h3 id="_word_system">Word: SYSTEM</h3>
\r
3243 <div class="literalblock">
\r
3244 <div class="content">
\r
3245 <pre><code>Data value: ( -- a )</code></pre>
\r
3247 <div class="paragraph"><p>"SYSTEM" is a variable that holds the word list data for the system
\r
3248 calls. This is set up as separate word list from <a href="#p_forth">FORTH</a>
\r
3249 merely as a matter of segregation.</p></div>
\r
3250 <div style="text-align:center">
\r
3251 _______________________________________________________
\r
3253 <div class="paragraph"><p><a id="p_tell"></a></p></div>
\r
3255 <div class="sect2">
\r
3256 <h3 id="_word_tell">Word: TELL</h3>
\r
3257 <div class="literalblock">
\r
3258 <div class="content">
\r
3259 <pre><code>Data stack: ( char* n -- )</code></pre>
\r
3261 <div class="paragraph"><p>"TELL" is a function word that prints a string to stdout (file
\r
3262 descriptor 1).</p></div>
\r
3263 <div style="text-align:center">
\r
3264 _______________________________________________________
\r
3266 <div class="paragraph"><p><a id="p_terminate0"></a></p></div>
\r
3268 <div class="sect2">
\r
3269 <h3 id="_word_terminate0">Word: TERMINATE0</h3>
\r
3270 <div class="literalblock">
\r
3271 <div class="content">
\r
3272 <pre><code>Data stack: ( -- )</code></pre>
\r
3274 <div class="paragraph"><p>"TERMINATE0" is a function word that terminates the program with exit
\r
3276 <div style="text-align:center">
\r
3277 _______________________________________________________
\r
3279 <div class="paragraph"><p><a id="p_tfa2cfa"></a></p></div>
\r
3281 <div class="sect2">
\r
3282 <h3 id="_word_tfa_gt_cfa">Word: TFA>CFA</h3>
\r
3283 <div class="literalblock">
\r
3284 <div class="content">
\r
3285 <pre><code>Data stack: ( tfa -- cfa )</code></pre>
\r
3287 <div class="paragraph"><p>"TFA>CFA" is a function word that pushes word cfa of the given tfa.</p></div>
\r
3288 <div class="exampleblock">
\r
3289 <div class="content">
\r
3290 <div class="sidebarblock">
\r
3291 <div class="content">
\r
3292 <div class="title">Definition concept for TFA>CFA</div>
\r
3293 <div class="paragraph"><p>: TFA>CFA 8 + @ ;</p></div>
\r
3296 <div style="text-align:center">
\r
3297 _______________________________________________________
\r
3299 <div class="paragraph"><p><a id="p_tfa2dfa"></a></p></div>
\r
3301 <div class="sect2">
\r
3302 <h3 id="_word_tfa_gt_dfa">Word: TFA>DFA</h3>
\r
3303 <div class="literalblock">
\r
3304 <div class="content">
\r
3305 <pre><code>Data stack: ( tfa -- dfa )</code></pre>
\r
3307 <div class="paragraph"><p>"TFA>DFA" is a function word that pushes word dfa of the given tfa.</p></div>
\r
3308 <div class="exampleblock">
\r
3309 <div class="content">
\r
3310 <div class="sidebarblock">
\r
3311 <div class="content">
\r
3312 <div class="title">Definition concept for TFA>DFA</div>
\r
3313 <div class="paragraph"><p>: TFA>DFA TFA>CFA 8 + ;</p></div>
\r
3316 <div style="text-align:center">
\r
3317 _______________________________________________________
\r
3319 <div class="paragraph"><p><a id="p_tfa2flags_get"></a></p></div>
\r
3321 <div class="sect2">
\r
3322 <h3 id="_word_tfa_gt_flags">Word: TFA>FLAGS@</h3>
\r
3323 <div class="literalblock">
\r
3324 <div class="content">
\r
3325 <pre><code>Data stack: ( tfa -- flags )</code></pre>
\r
3327 <div class="paragraph"><p>"TFA>FLAGS@" is a function word that pushes word flags of the given tfa.</p></div>
\r
3328 <div class="exampleblock">
\r
3329 <div class="content">
\r
3330 <div class="sidebarblock">
\r
3331 <div class="content">
\r
3332 <div class="title">Defintion concept for TFA>FLAGS@</div>
\r
3333 <div class="paragraph"><p>: TFA>FLAGS@ 16 + @ ;</p></div>
\r
3336 <div style="text-align:center">
\r
3337 _______________________________________________________
\r
3339 <div class="paragraph"><p><a id="p_tfa2namez"></a></p></div>
\r
3341 <div class="sect2">
\r
3342 <h3 id="_word_tfa_gt_namez">Word: TFA>NAMEZ</h3>
\r
3343 <div class="literalblock">
\r
3344 <div class="content">
\r
3345 <pre><code>Data stack: ( tfa -- char* )</code></pre>
\r
3347 <div class="paragraph"><p>"TFA>NAMEZ" is a function word that pushes changes a tfa pointer to a
\r
3348 pointer to the word pname’s character sequence, which is zero
\r
3349 terminated as well as preceded by a length cell.</p></div>
\r
3350 <div class="exampleblock">
\r
3351 <div class="content">
\r
3352 <div class="sidebarblock">
\r
3353 <div class="content">
\r
3354 <div class="title">Defintion concept for TFA>NAMEZ</div>
\r
3355 <div class="paragraph"><p>: TFA>NAMEZ 32 + ;</p></div>
\r
3358 <div style="text-align:center">
\r
3359 _______________________________________________________
\r
3361 <div class="paragraph"><p><a id="p_then"></a></p></div>
\r
3363 <div class="sect2">
\r
3364 <h3 id="_word_then">Word: THEN</h3>
\r
3365 <div class="literalblock">
\r
3366 <div class="content">
\r
3367 <pre><code>Data stack: Compiling: ( a -- )</code></pre>
\r
3369 <div class="paragraph"><p>"THEN" is an immediate function word that is used together with
\r
3370 <a href="#p_if">IF</a> and <a href="#p_else">ELSE</a> to implement structured execution
\r
3371 control. THEN performs the branch resolution for the stacked address
\r
3372 which pinpoints the foot address the branch offset to resolve, so that
\r
3373 at execution time there is an appropriate conditional branch past the
\r
3374 "then-part" or the "else-part" of the "structured statement".</p></div>
\r
3375 <div style="text-align:center">
\r
3376 _______________________________________________________
\r
3378 <div class="paragraph"><p><a id="p_this_word"></a></p></div>
\r
3380 <div class="sect2">
\r
3381 <h3 id="_word_this_word">Word: THIS-WORD</h3>
\r
3382 <div class="literalblock">
\r
3383 <div class="content">
\r
3384 <pre><code>Data stack: ( -- a )</code></pre>
\r
3386 <div class="paragraph"><p>"THIS-WORD" is a variable word used in
\r
3387 <a href="#p_evaluate_stream:EVALUATE-STREAM">[p_evaluate_stream:EVALUATE-STREAM]</a> as cache for the [n:char*]
\r
3388 values of the successive words being evaluated. This typically points
\r
3389 into the input stream buffer and remain valid until further stream
\r
3390 buffering functions are used.</p></div>
\r
3391 <div style="text-align:center">
\r
3392 _______________________________________________________
\r
3394 <div class="paragraph"><p><a id="p_true"></a></p></div>
\r
3396 <div class="sect2">
\r
3397 <h3 id="_word_true">Word: TRUE</h3>
\r
3398 <div class="literalblock">
\r
3399 <div class="content">
\r
3400 <pre><code>Data stack: ( -- -1 )</code></pre>
\r
3402 <div class="paragraph"><p>"TRUE" is a value word representing logical true.</p></div>
\r
3403 <div style="text-align:center">
\r
3404 _______________________________________________________
\r
3406 <div class="paragraph"><p><a id="p_tuck"></a></p></div>
\r
3408 <div class="sect2">
\r
3409 <h3 id="_word_tuck">Word: TUCK</h3>
\r
3410 <div class="literalblock">
\r
3411 <div class="content">
\r
3412 <pre><code>Data stack ( v1 v2 -- v2 v1 v2 )</code></pre>
\r
3414 <div class="paragraph"><p>"TUCK" is a function word that "inserts" the top cell below the second
\r
3415 cell on the data stack.</p></div>
\r
3416 <div class="exampleblock">
\r
3417 <div class="content">
\r
3418 <div class="sidebarblock">
\r
3419 <div class="content">
\r
3420 <div class="title">Definition concept for TUCK</div>
\r
3421 <div class="paragraph"><p>: TUCK SWAP OVER ;</p></div>
\r
3424 <div style="text-align:center">
\r
3425 _______________________________________________________
\r
3427 <div class="paragraph"><p><a id="p_unequal"></a></p></div>
\r
3429 <div class="sect2">
\r
3430 <h3 id="_word_19">Word: !=</h3>
\r
3431 <div class="literalblock">
\r
3432 <div class="content">
\r
3433 <pre><code>Data stack: ( v1 v2 -- 0/-1 )</code></pre>
\r
3435 <div class="paragraph"><p>"!=" is a function word that replaces a pair of values with -1 of the
\r
3436 values are unequal, and 0 otherwise.</p></div>
\r
3437 <div style="text-align:center">
\r
3438 _______________________________________________________
\r
3440 <div class="paragraph"><p><a id="p_unstream"></a></p></div>
\r
3442 <div class="sect2">
\r
3443 <h3 id="_word_unstream">Word: UNSTREAM</h3>
\r
3444 <div class="literalblock">
\r
3445 <div class="content">
\r
3446 <pre><code>Data stack: ( stream* -- )</code></pre>
\r
3448 <div class="paragraph"><p>"UNSTREAM" is a function word that releases the memory allocated for a
\r
3449 stream, and closes the associated file if it’s a file stream.</p></div>
\r
3450 <div class="sect3">
\r
3451 <h4 id="_file_descriptor_backed_stream_2">File descriptor backed stream</h4>
\r
3452 <div class="paragraph"><p>This kind of stream has the stream header as a prefix within the
\r
3453 allocated memory. Thus, stream* is the base address for the memory to
\r
3454 reclaim, and the size of this is determined from the cell at (stream*
\r
3455 + 16) plus the 32 bytes head itself.</p></div>
\r
3457 <div class="sect3">
\r
3458 <h4 id="_memory_block_backed_stream_2">Memory block backed STREAM</h4>
\r
3459 <div class="paragraph"><p>This kind of stream has a separate header which points at the memory
\r
3460 area to reclaim. The cell at stream* is the base address, and the cell
\r
3461 at (stream* + 16) is its size.</p></div>
\r
3462 <div style="text-align:center">
\r
3463 _______________________________________________________
\r
3465 <div class="paragraph"><p><a id="p_verboseQ"></a></p></div>
\r
3468 <div class="sect2">
\r
3469 <h3 id="_word_verbose">Word: VERBOSE?</h3>
\r
3470 <div class="literalblock">
\r
3471 <div class="content">
\r
3472 <pre><code>Data stack: ( -- a )</code></pre>
\r
3474 <div class="paragraph"><p>"VERBOSE?" is a variable word that is assigned at start up to -1 or 0
\r
3475 signify whether or not the command line arguments includes "-v". When
\r
3476 non-zero (i.e. running rrqforth with "-v") the evaluation loop is more
\r
3477 verbose.</p></div>
\r
3478 <div style="text-align:center">
\r
3479 _______________________________________________________
\r
3481 <div class="paragraph"><p><a id="p_within"></a></p></div>
\r
3483 <div class="sect2">
\r
3484 <h3 id="_word_within">Word: WITHIN</h3>
\r
3485 <div class="literalblock">
\r
3486 <div class="content">
\r
3487 <pre><code>Data stack: ( v lo hi -- 0/-1</code></pre>
\r
3489 <div class="paragraph"><p>"WITHIN" is a function word that replaces a triple of values with -1
\r
3490 of the the first, v, is within the value range spanned by the second,
\r
3491 lo, inclusive and third, hi, exclusive.</p></div>
\r
3492 <div class="exampleblock">
\r
3493 <div class="content">
\r
3494 <div class="sidebarblock">
\r
3495 <div class="content">
\r
3496 <div class="title">Definition concept for WITHIN</div>
\r
3497 <div class="paragraph"><p>: WITHIN 2 PICK > ROT ROT ⇐ AND ;</p></div>
\r
3500 <div style="text-align:center">
\r
3501 _______________________________________________________
\r
3503 <div class="paragraph"><p><a id="p_words"></a></p></div>
\r
3505 <div class="sect2">
\r
3506 <h3 id="_word_words">Word: WORDS</h3>
\r
3507 <div class="literalblock">
\r
3508 <div class="content">
\r
3509 <pre><code>Data stack: ( wl -- )</code></pre>
\r
3511 <div class="paragraph"><p>"WORDS" is a function word that prints all words of teh given word
\r
3512 list to stdout (file descriptor 1).</p></div>
\r
3513 <div style="text-align:center">
\r
3514 _______________________________________________________
\r
3516 <div class="paragraph"><p><a id="p_xor"></a></p></div>
\r
3518 <div class="sect2">
\r
3519 <h3 id="_word_xor">Word: XOR</h3>
\r
3520 <div class="literalblock">
\r
3521 <div class="content">
\r
3522 <pre><code>Data stack: ( v1 v2 -- v3 )</code></pre>
\r
3524 <div class="paragraph"><p>"XOR" is a function word that replaces a value pair with their bitwise
\r
3525 exclusion; each bit is 1 if the corresponding bits of the two operands
\r
3526 differ and 0 if not.</p></div>
\r
3527 <div style="text-align:center">
\r
3528 _______________________________________________________
\r
3530 <div class="paragraph"><p><a id="return_stack"></a></p></div>
\r
3532 <div class="sect2">
\r
3533 <h3 id="_word_return_stack">Word: RETURN-STACK</h3>
\r
3534 <div class="literalblock">
\r
3535 <div class="content">
\r
3536 <pre><code>Data stack: ( -- a )</code></pre>
\r
3538 <div class="paragraph"><p>"RETURN-STACK" is a variable word harbouring the return stack.</p></div>
\r
3542 <div class="sect1">
\r
3543 <h2 id="_system_calls">System calls</h2>
\r
3544 <div class="sectionbody">
\r
3545 <div class="paragraph"><p>RRQFORTH includes function wrapping for all "Linux syscalls", which
\r
3546 generally are described in their "man pages. This wrapping takes the
\r
3547 arguments fro the data stack in reverse order, i.e. the first argument
\r
3548 is deepest.</p></div>
\r
3549 <div class="paragraph"><p>Use <code>SYSTEM WORDS</code> to get a list of all (321) available syscalls.</p></div>
\r
3553 <div id="footnotes"><hr /></div>
\r
3555 <div id="footer-text">
\r
3557 2021-06-05 20:46:13 AEST
\r
projects / rrq / rrqforth.git / blob