| 1 | \ @(#) condcomp.fth 98/01/26 1.2\r |
| 2 | \ Conditional Compilation support\r |
| 3 | \\r |
| 4 | \ Words: STRINGS= [IF] [ELSE] [THEN] EXISTS?\r |
| 5 | \\r |
| 6 | \ Lifted from X3J14 dpANS-6 document.\r |
| 7 | \r |
| 8 | anew task-condcomp.fth\r |
| 9 | \r |
| 10 | : [ELSE] ( -- )\r |
| 11 | 1\r |
| 12 | BEGIN \ level\r |
| 13 | BEGIN\r |
| 14 | BL WORD \ level $word\r |
| 15 | COUNT DUP \ level adr len len\r |
| 16 | WHILE \ level adr len\r |
| 17 | 2DUP S" [IF]" COMPARE 0=\r |
| 18 | IF \ level adr len\r |
| 19 | 2DROP 1+ \ level'\r |
| 20 | ELSE \ level adr len\r |
| 21 | 2DUP S" [ELSE]"\r |
| 22 | COMPARE 0= \ level adr len flag\r |
| 23 | IF \ level adr len\r |
| 24 | 2DROP 1- DUP IF 1+ THEN \ level'\r |
| 25 | ELSE \ level adr len\r |
| 26 | S" [THEN]" COMPARE 0=\r |
| 27 | IF\r |
| 28 | 1- \ level'\r |
| 29 | THEN\r |
| 30 | THEN\r |
| 31 | THEN\r |
| 32 | ?DUP 0= IF EXIT THEN \ level'\r |
| 33 | REPEAT 2DROP \ level\r |
| 34 | REFILL 0= UNTIL \ level\r |
| 35 | DROP\r |
| 36 | ; IMMEDIATE\r |
| 37 | \r |
| 38 | : [IF] ( flag -- )\r |
| 39 | 0=\r |
| 40 | IF POSTPONE [ELSE]\r |
| 41 | THEN\r |
| 42 | ; IMMEDIATE\r |
| 43 | \r |
| 44 | : [THEN] ( -- )\r |
| 45 | ; IMMEDIATE\r |
| 46 | \r |
| 47 | : EXISTS? ( <name> -- flag , true if defined )\r |
| 48 | bl word find\r |
| 49 | swap drop\r |
| 50 | ; immediate\r |