projects / pforth / blame
| Commit | Line | Data |
|---|---|---|
| 8e9db35f PB |
1 | \ @(#) smart_if.fth 98/01/26 1.2 |
| 2 | \ Smart Conditionals | |
| 3 | \ Allow use of if, do, begin, etc.outside of colon definitions. | |
| 4 | \ | |
| 5 | \ Thanks to Mitch Bradley for the idea. | |
| 6 | \ | |
| 7 | \ Author: Phil Burk | |
| 1a088514 | 8 | \ Copyright 1994 3DO, Phil Burk, Larry Polansky, David Rosenboom |
| 8e9db35f | 9 | \ |
| 1f99f95d S |
10 | \ Permission to use, copy, modify, and/or distribute this |
| 11 | \ software for any purpose with or without fee is hereby granted. | |
| 12 | \ | |
| 13 | \ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL | |
| 14 | \ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED | |
| 15 | \ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL | |
| 16 | \ THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR | |
| 17 | \ CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING | |
| 18 | \ FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF | |
| 19 | \ CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
| 20 | \ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
| 8e9db35f PB |
21 | |
| 22 | anew task-smart_if.fth | |
| 23 | ||
| 24 | variable SMIF-XT \ execution token for conditional code | |
| 25 | variable SMIF-DEPTH \ depth of nested conditionals | |
| 26 | ||
| 27 | : SMIF{ ( -- , if executing, start compiling, setup depth ) | |
| 28 | state @ 0= | |
| 29 | IF | |
| 30 | :noname smif-xt ! | |
| 31 | 1 smif-depth ! | |
| 32 | ELSE | |
| 33 | 1 smif-depth +! | |
| 34 | THEN | |
| 35 | ; | |
| 36 | ||
| 37 | : }SMIF ( -- , unnest, stop compiling, execute code and forget ) | |
| 38 | smif-xt @ | |
| 39 | IF | |
| 40 | -1 smif-depth +! | |
| 41 | smif-depth @ 0 <= | |
| 42 | IF | |
| 43 | postpone ; \ stop compiling | |
| 44 | smif-xt @ execute \ execute conditional code | |
| 45 | smif-xt @ >code dp ! \ forget conditional code | |
| 46 | 0 smif-xt ! \ clear so we don't mess up later | |
| 47 | THEN | |
| 48 | THEN | |
| 49 | ; | |
| 50 | ||
| 51 | \ redefine conditionals to use smart mode | |
| 52 | : IF smif{ postpone if ; immediate | |
| 53 | : DO smif{ postpone do ; immediate | |
| 54 | : ?DO smif{ postpone ?do ; immediate | |
| 55 | : BEGIN smif{ postpone begin ; immediate | |
| 56 | : THEN postpone then }smif ; immediate | |
| 57 | : REPEAT postpone repeat }smif ; immediate | |
| 58 | : UNTIL postpone until }smif ; immediate | |
| 59 | : LOOP postpone loop }smif ; immediate | |
| 60 | : +LOOP postpone +loop }smif ; immediate |