| bb6b2dcd |
1 | \ @(#) case.fth 98/01/26 1.2\r |
| 2 | \ CASE Statement\r |
| 3 | \\r |
| 4 | \ This definition is based upon Wil Baden's assertion that\r |
| 5 | \ >MARK >RESOLVE ?BRANCH etc. are not needed if one has IF ELSE THEN etc.\r |
| 6 | \\r |
| 7 | \ Author: Phil Burk\r |
| 8 | \ Copyright 1994 3DO, Phil Burk, Larry Polansky, Devid Rosenboom\r |
| 9 | \\r |
| 10 | \ The pForth software code is dedicated to the public domain,\r |
| 11 | \ and any third party may reproduce, distribute and modify\r |
| 12 | \ the pForth software code or any derivative works thereof\r |
| 13 | \ without any compensation or license. The pForth software\r |
| 14 | \ code is provided on an "as is" basis without any warranty\r |
| 15 | \ of any kind, including, without limitation, the implied\r |
| 16 | \ warranties of merchantability and fitness for a particular\r |
| 17 | \ purpose and their equivalents under the laws of any jurisdiction.\r |
| 18 | \\r |
| 19 | \ MOD: PLB 6/24/91 Check for missing ENDOF\r |
| 20 | \ MOD: PLB 8/7/91 Add ?OF and RANGEOF\r |
| 21 | \ MOD: PLB 11/2/99 Fixed nesting of CASE. Needed to save of-depth on stack as well as case-depth.\r |
| 22 | \r |
| 23 | anew TASK-CASE\r |
| 24 | \r |
| 25 | variable CASE-DEPTH\r |
| 26 | variable OF-DEPTH\r |
| 27 | \r |
| 28 | : CASE ( n -- , start case statement ) ( -c- case-depth )\r |
| 29 | ?comp\r |
| 30 | of-depth @ 0 of-depth ! \ 11/2/99\r |
| 31 | case-depth @ 0 case-depth ! ( allow nesting )\r |
| 32 | ; IMMEDIATE\r |
| 33 | \r |
| 34 | : ?OF ( n flag -- | n , doit if true ) ( -c- addr )\r |
| 35 | [compile] IF\r |
| 36 | compile drop\r |
| 37 | 1 case-depth +!\r |
| 38 | 1 of-depth +!\r |
| 39 | ; IMMEDIATE\r |
| 40 | \r |
| 41 | : OF ( n t -- | n , doit if match ) ( -c- addr )\r |
| 42 | ?comp\r |
| 43 | compile over compile =\r |
| 44 | [compile] ?OF\r |
| 45 | ; IMMEDIATE\r |
| 46 | \r |
| 47 | : (RANGEOF?) ( n lo hi -- | n flag )\r |
| 48 | >r over ( n lo n ) <=\r |
| 49 | IF\r |
| 50 | dup r> ( n n hi ) <=\r |
| 51 | ELSE\r |
| 52 | rdrop false\r |
| 53 | THEN\r |
| 54 | ;\r |
| 55 | \r |
| 56 | : RANGEOF ( n lo hi -- | n , doit if within ) ( -c- addr )\r |
| 57 | compile (rangeof?)\r |
| 58 | [compile] ?OF\r |
| 59 | ; IMMEDIATE\r |
| 60 | \r |
| 61 | : ENDOF ( -- ) ( addr -c- addr' )\r |
| 62 | [compile] ELSE\r |
| 63 | -1 of-depth +!\r |
| 64 | ; IMMEDIATE\r |
| 65 | \r |
| 66 | : ENDCASE ( n -- ) ( old-case-depth addr' addr' ??? -- )\r |
| 67 | of-depth @\r |
| 68 | IF >newline ." Missing ENDOF in CASE!" cr abort\r |
| 69 | THEN\r |
| 70 | \\r |
| 71 | compile drop\r |
| 72 | case-depth @ 0\r |
| 73 | ?DO [compile] THEN\r |
| 74 | LOOP\r |
| 75 | case-depth !\r |
| 76 | of-depth !\r |
| 77 | ; IMMEDIATE\r |
| 78 | \r |
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