collapseos/apps/forth/core.fth
Virgil Dupras d60ea4cb30 forth: Forth-ify RECURSE
This comes with RS-modifying words. Also, this commit separates ";" from "EXIT",
allowing EXIT to be used in definitions (was needed for RECURSE).
2020-03-13 16:40:55 -04:00

18 lines
417 B
Forth

: H HERE @ ;
: -^ SWAP - ;
: ? @ . ;
: +! SWAP OVER @ + SWAP ! ;
: ALLOT HERE +! ;
: VARIABLE CREATE 2 ALLOT ;
: CONSTANT CREATE H ! DOES> @ ;
: , H ! 2 ALLOT ;
: C, H C! 1 ALLOT ;
: IF ['] (fbr?) , H 0 C, ; IMMEDIATE
: THEN DUP H -^ SWAP C! ; IMMEDIATE
: ELSE ['] (fbr) , 0 C, DUP H -^ SWAP C! H 1 - ; IMMEDIATE
: NOT IF 0 ELSE 1 THEN ;
: = CMP NOT ;
: < CMP 0 1 - = ;
: > CMP 1 = ;
: RECURSE R> R> 2 - >R >R EXIT ;