ID. and WORDS

[rrq/jonesforth.git] / jonesforth.S

diff --git a/jonesforth.S b/jonesforth.S
index 5d1c5834eefc3dfc33bda068fe423ba3fc14fe30..c41cbed029bb72676d7fd5b6a26fb29701138cd0 100644 (file)
--- a/jonesforth.S
+++ b/jonesforth.S
@@ -1,11 +1,11 @@
 /*     A sometimes minimal FORTH compiler and tutorial for Linux / i386 systems. -*- asm -*-
        By Richard W.M. Jones <rich@annexia.org> http://annexia.org/forth
        This is PUBLIC DOMAIN (see public domain release statement below).
-       $Id: jonesforth.S,v 1.22 2007-09-23 19:40:40 rich Exp $
+       $Id: jonesforth.S,v 1.24 2007-09-23 20:06:00 rich Exp $
 
        gcc -m32 -nostdlib -static -Wl,-Ttext,0 -o jonesforth jonesforth.S
 */
-       .set JONES_VERSION,22
+       .set JONES_VERSION,24
 /*
        INTRODUCTION ----------------------------------------------------------------------
 
@@ -579,13 +579,13 @@ cold_start:                       // High-level code without a codeword.
 
        .bss
 /* FORTH return stack. */
-#define RETURN_STACK_SIZE 8192
+       .set RETURN_STACK_SIZE,8192
        .align 4096
        .space RETURN_STACK_SIZE
 return_stack:                  // Initial top of return stack.
 
 /* The user definitions area: space for user-defined words and general memory allocations. */
-#define USER_DEFS_SIZE 16384
+       .set USER_DEFS_SIZE,16384
        .align 4096
 user_defs_start:
        .space USER_DEFS_SIZE
@@ -634,9 +634,9 @@ DOUBLE: .int DOCOL          // codeword
 */
 
 /* Flags - these are discussed later. */
-#define F_IMMED 0x80
-#define F_HIDDEN 0x20
-#define F_LENMASK 0x1f         // length mask
+       .set F_IMMED,0x80
+       .set F_HIDDEN,0x20
+       .set F_LENMASK,0x1f     // length mask
 
        // Store the chain of links.
        .set link,0
@@ -2522,18 +2522,14 @@ buffer:
 )
 : ID.
        4+              ( skip over the link pointer )
-       .S CR
        DUP @b          ( get the flags/length byte )
-       .S CR
-       F_LENMASK .S CR AND     ( mask out the flags - just want the length )
-       .S CR
+       F_LENMASK AND   ( mask out the flags - just want the length )
 
        BEGIN
                DUP 0>          ( length > 0? )
        WHILE
                SWAP 1+         ( addr len -- len addr+1 )
                DUP @b          ( len addr -- len addr char | get the next character)
-               .\" print: \" DUP . CR
                EMIT            ( len addr char -- len addr | and print it)
                SWAP 1-         ( len addr -- addr len-1    | subtract one from length )
        REPEAT
@@ -2545,20 +2541,18 @@ buffer:
 
        The implementation simply iterates backwards from LATEST using the link pointers.
 )
-       (
 : WORDS
        LATEST @        ( start at LATEST dictionary entry )
        BEGIN
-               DUP @ 0<>       ( while link pointer is not null )
+               DUP 0<>         ( while link pointer is not null )
        WHILE
-               
-
-
-
-
+               DUP ID.         ( print the word )
+               SPACE
+               @               ( dereference the link pointer - go to previous word )
        REPEAT
        DROP
-;      )
+       CR
+;
 
 (
        So far we have only allocated words and memory.  FORTH provides a rather primitive method
@@ -2578,11 +2572,13 @@ buffer:
        XXX: Because we wrote VARIABLE to store the variable in memory allocated before the word,
        in the current implementation VARIABLE FOO FORGET FOO will leak 1 cell of memory.
 )
-\\: FORGET
-       
-
+: FORGET
+       WORD FIND       ( find the word, gets the dictionary entry address )
+       DUP @ LATEST !  ( set LATEST to point to the previous word )
+       HERE !          ( and store HERE with the dictionary address )
+;
 
-( While compiling, [COMPILE] WORD compiles WORD if it would otherwise be IMMEDIATE. )
+( While compiling, '[COMPILE] word' compiles 'word' if it would otherwise be IMMEDIATE. )
 : [COMPILE] IMMEDIATE
        WORD            ( get the next word )
        FIND            ( find it in the dictionary )