mirror of https://github.com/hsoft/collapseos.git
31 lines
1.0 KiB
Forth
31 lines
1.0 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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: , H ! 2 ALLOT ;
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: C, H C! 1 ALLOT ;
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: NOT 1 SWAP SKIP? EXIT 0 * ;
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: RECURSE R> R> 2 - >R >R EXIT ;
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: ( LIT@ ) WORD SCMP NOT SKIP? RECURSE ; 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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NOT: a bit convulted because we don't have IF yet
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RECURSE: RS TOS is for RECURSE itself, then we have to dig
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one more level to get to RECURSE's parent's caller.
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IF true, skip following (fbr). Also, push br cell ref H,
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to PS )
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: IF ['] SKIP? , ['] (fbr) , H 1 ALLOT ; IMMEDIATE
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( Subtract TOS from H to get offset to write to IF or ELSE's
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br cell )
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: THEN DUP H -^ SWAP C! ; IMMEDIATE
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( write (fbr) addr, allot, then same as THEN )
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: ELSE ['] (fbr) , 1 ALLOT DUP H -^ SWAP C! H 1 - ; 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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