67 lines
1.8 KiB
Forth
67 lines
1.8 KiB
Forth
: H HERE @ ;
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: -^ SWAP - ;
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: +! SWAP OVER @ + SWAP ! ;
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: ALLOT HERE +! ;
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: C, H C! 1 ALLOT ;
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: COMPILE ' LITN ['] , , ; IMMEDIATE
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: BEGIN H ; IMMEDIATE
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: AGAIN COMPILE (bbr) H -^ C, ; IMMEDIATE
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: UNTIL COMPILE SKIP? COMPILE (bbr) H -^ C, ; IMMEDIATE
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: NOT 1 SWAP SKIP? EXIT 0 * ;
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: ( BEGIN LITS ) WORD SCMP NOT UNTIL ; IMMEDIATE
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( Hello, hello, krkrkrkr... do you hear me?
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Ah, voice at last! Some lines above need comments
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BTW: Forth lines limited to 64 cols because of default
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input buffer size in Collapse OS
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COMPILE; Tough one. Get addr of caller word (example above
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(bbr)) and then call LITN on it.
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NOT: a bit convulted because we don't have IF yet )
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: IF ( -- a | a: br cell addr )
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COMPILE SKIP? ( if true, don't branch )
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COMPILE (fbr)
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H ( push a )
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1 ALLOT ( br cell allot )
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; IMMEDIATE
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: THEN ( a -- | a: br cell addr )
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DUP H -^ SWAP ( a-H a )
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C!
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; IMMEDIATE
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: ELSE ( a1 -- a2 | a1: IF cell a2: ELSE cell )
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COMPILE (fbr)
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1 ALLOT
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DUP H -^ SWAP ( a-H a )
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C!
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H 1 - ( push a. -1 for allot offset )
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; IMMEDIATE
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: ? @ . ;
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: VARIABLE CREATE 2 ALLOT ;
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: CONSTANT CREATE H ! DOES> @ ;
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: = CMP NOT ;
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: < CMP 0 1 - = ;
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: > CMP 1 = ;
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: / /MOD SWAP DROP ;
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: MOD /MOD DROP ;
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( In addition to pushing H this compiles 2 >R so that loop variables are sent
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to PS at runtime )
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: DO
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COMPILE SWAP COMPILE >R COMPILE >R
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H
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; IMMEDIATE
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( One could think that we should have a sub word to avoid all these COMPILE,
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but we can't because otherwise it messes with the RS )
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: LOOP
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COMPILE R> 1 LITN COMPILE + COMPILE DUP COMPILE >R
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COMPILE I' COMPILE = COMPILE SKIP? COMPILE (bbr)
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H -^ C,
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COMPILE R> COMPILE DROP COMPILE R> COMPILE DROP
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; IMMEDIATE
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