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jwilke
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1.1
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\ Structural Conditionals, based on branches 12dec92py |
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\ Copyright (C) 1995,1996,1997 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
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\ Gforth is free software; you can redistribute it and/or |
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\ modify it under the terms of the GNU General Public License |
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\ as published by the Free Software Foundation; either version 2 |
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\ of the License, or (at your option) any later version. |
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\ This program is distributed in the hope that it will be useful, |
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\ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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\ GNU General Public License for more details. |
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\ You should have received a copy of the GNU General Public License |
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\ along with this program; if not, write to the Free Software |
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\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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: ?struc ( flag -- ) abort" unstructured " ; |
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: sys? ( sys -- ) dup 0= ?struc ; |
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: >mark ( -- sys ) here 0 , ; |
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: >resolve ( sys -- ) here over - swap ! ; |
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: <resolve ( sys -- ) here - , ; |
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: BUT sys? swap ; immediate restrict |
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: YET sys? dup ; immediate restrict |
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\ Structural Conditionals 12dec92py |
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: AHEAD compile branch >mark ; immediate restrict |
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: IF compile ?branch >mark ; immediate restrict |
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: THEN sys? dup @ ?struc >resolve ; immediate restrict |
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: ELSE sys? compile AHEAD swap compile THEN ; |
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immediate restrict |
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' THEN Alias ENDIF immediate restrict |
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: BEGIN here ; immediate restrict |
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: WHILE sys? compile IF swap ; immediate restrict |
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: AGAIN sys? compile branch <resolve ; immediate restrict |
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: UNTIL sys? compile ?branch <resolve ; immediate restrict |
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: REPEAT over 0= ?struc compile AGAIN compile THEN ; |
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immediate restrict |
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