File:  [gforth] / gforth / kernel / toolsext.fs
Revision 1.29: download - view: text, annotated - select for diffs
Fri Jul 20 19:34:27 2012 UTC (9 years, 2 months ago) by pazsan
Branches: MAIN
CVS tags: HEAD
Refactoring for libgforth

    1: \ Copyright (C) 1995,1998,2000,2003,2005,2007,2009,2010 Free Software Foundation, Inc.
    2: 
    3: \ This file is part of Gforth.
    4: 
    5: \ Gforth is free software; you can redistribute it and/or
    6: \ modify it under the terms of the GNU General Public License
    7: \ as published by the Free Software Foundation, either version 3
    8: \ of the License, or (at your option) any later version.
    9: 
   10: \ This program is distributed in the hope that it will be useful,
   11: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   12: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   13: \ GNU General Public License for more details.
   14: 
   15: \ You should have received a copy of the GNU General Public License
   16: \ along with this program. If not, see http://www.gnu.org/licenses/.
   17: 
   18: Warnings off
   19: 
   20: Variable countif
   21: 
   22: : dummy ;  immediate
   23: : >exec  >r ; restrict ( :-)
   24: : scanIF   f83find  dup 0=  IF  drop ['] dummy >head-noprim  THEN  ;
   25: 
   26: Create [struct]-search    ' scanIF A,  ' (reveal) A,  ' drop A, ' drop A,
   27: Create [struct]-voc       [struct]-search A,
   28:                           NIL A,       NIL A,       NIL A,
   29: 
   30: : ?if  countif @ 0<
   31:   IF  [ [struct]-voc 3 cells + ] ALiteral @ lookup !  THEN ;
   32: 
   33: UNLOCK  Tlast @ TNIL Tlast !  LOCK
   34: \ last @  0 last !
   35: 
   36: : [IF]
   37:   1 countif +! ?if ;       immediate
   38: : [THEN]
   39:   -1 countif +! ?if ;       immediate
   40: : [ELSE]
   41:   postpone [THEN] postpone [IF] ; immediate
   42: 
   43: ' [IF]   Alias [IFDEF]               immediate
   44: ' [IF]   Alias [IFUNDEF]             immediate
   45: ' [THEN] Alias [ENDIF]               immediate
   46: ' [IF]   Alias [BEGIN]               immediate
   47: ' [IF]   Alias [WHILE]               immediate
   48: ' [THEN] Alias [UNTIL]               immediate
   49: ' [THEN] Alias [AGAIN]               immediate
   50: ' [IF]   Alias [DO]                  immediate
   51: ' [IF]   Alias [?DO]                 immediate
   52: ' [THEN] Alias [LOOP]                immediate
   53: ' [THEN] Alias [+LOOP]               immediate
   54: : [REPEAT]  postpone [AGAIN] postpone [THEN] ;
   55:                                      immediate
   56: \ The following was too smart for its own good; consider "postpone (".
   57: \ Moreover, ANS Forth specifies that the next [THEN] ends an [IF]
   58: \ (even if its in a '( ... )').
   59: 
   60: \ ' ( Alias (                          immediate ( keep fontify happy)
   61: \ ' \ Alias \                          immediate
   62: 
   63: UNLOCK Tlast @ swap Tlast ! LOCK
   64: \ last @ swap last !
   65: 1 cells - [struct]-voc cell+ !
   66: 
   67: \ Interpretative Structuren                            30apr92py
   68: 
   69: : [defined] ( "<spaces>name" -- flag )   parse-name find-name 0<> ; immediate
   70:   \G returns true if name is found in current search order
   71: ' [defined] alias defined immediate
   72: : [undefined] ( "<spaces>name" -- flag ) postpone [defined] 0= ; immediate
   73:   \G returns false if name is found in current search order
   74: 
   75: : [IF] ( flag -- ) \ tools-ext bracket-if
   76:   \G If flag is @code{TRUE} do nothing (and therefore
   77:   \G execute subsequent words as normal). If flag is @code{FALSE},
   78:   \G parse and discard words from the parse
   79:   \G area (refilling it if necessary using
   80:   \G @code{REFILL}) including nested instances of @code{[IF]}..
   81:   \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
   82:   \G until the balancing @code{[ELSE]} or @code{[THEN]} has been
   83:   \G parsed and discarded. Immediate word.
   84:        0= IF  countif off
   85:               lookup @ [ [struct]-voc 3 cells + ] ALiteral !
   86: 	      [struct]-voc lookup !
   87:           THEN ;                                      immediate
   88: 
   89: : [IFDEF] ( "<spaces>name" -- ) \ gforth bracket-if-def
   90:   \G If name is found in the current search-order, behave like
   91:   \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
   92:   \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
   93:   postpone [defined]    postpone [IF] ;                 immediate
   94: 
   95: : [IFUNDEF] ( "<spaces>name" -- ) \ gforth bracket-if-un-def
   96:   \G If name is not found in the current search-order, behave like
   97:   \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
   98:   \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
   99:   postpone [defined] 0= postpone [IF] ;                 immediate
  100: 
  101: : [ELSE]  ( -- ) \ tools-ext bracket-else
  102:   \G Parse and discard words from the parse
  103:   \G area (refilling it if necessary using
  104:   \G @code{REFILL}) including nested instances of @code{[IF]}..
  105:   \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
  106:   \G until the balancing @code{[THEN]} has been parsed and discarded.
  107:   \G @code{[ELSE]} only gets executed if the balancing @code{[IF]}
  108:   \G was @code{TRUE}; if it was @code{FALSE}, @code{[IF]} would
  109:   \G have parsed and discarded the @code{[ELSE]}, leaving the
  110:   \G subsequent words to be executed as normal.
  111:   \G Immediate word.
  112:   0 postpone [IF] ;                                   immediate
  113: 
  114: : [THEN] ( -- ) \ tools-ext bracket-then
  115:   \G Do nothing; used as a marker for other words to parse
  116:   \G and discard up to. Immediate word.
  117:   ;                                                   immediate
  118: 
  119: : [ENDIF] ( -- ) \ gforth bracket-end-if
  120:   \G Do nothing; synonym for @code{[THEN]}
  121:   ;                                                   immediate
  122: 
  123: \ Structs for interpreter                              28nov92py
  124: 
  125: User (i)
  126: 
  127: : [DO]  ( n-limit n-index -- ) \ gforth bracket-do
  128:   >in @ -rot
  129:   DO   I (i) ! dup >r >in ! interpret r> swap +LOOP  drop ;
  130:                                                       immediate
  131: 
  132: : [?DO] ( n-limit n-index -- ) \ gforth bracket-question-do
  133:   2dup = IF 2drop postpone [ELSE] ELSE postpone [DO] THEN ;
  134:                                                       immediate
  135: 
  136: : [+LOOP] ( n -- ) \ gforth bracket-question-plus-loop
  137:   rdrop lp+ ;                                         immediate
  138: 
  139: : [LOOP] ( -- ) \ gforth bracket-loop
  140:   1 rdrop lp+ ;                                       immediate
  141: 
  142: : [FOR] ( n -- ) \ gforth bracket-for
  143:   0 swap postpone [DO] ;                              immediate
  144: 
  145: : [NEXT] ( n -- ) \ gforth bracket-next
  146:   -1 rdrop lp+ ;                                      immediate
  147: 
  148: :noname (i) @ ;
  149: :noname (i) @ postpone Literal ;
  150: interpret/compile: [I] ( -- n ) \ gforth bracket-i
  151: 
  152: : [BEGIN] ( -- ) \ gforth bracket-begin
  153:   >in @ >r BEGIN r@ >in ! interpret UNTIL rdrop lp+ ; immediate
  154: 
  155: ' [+LOOP]  Alias [UNTIL] ( flag -- ) \ gforth bracket-until
  156:                                                       immediate
  157: 
  158: : [REPEAT]  ( -- ) \ gforth bracket-repeat
  159:   false rdrop lp+ ;                                   immediate
  160: 
  161: ' [REPEAT] Alias [AGAIN] ( -- ) \ gforth bracket-again
  162:                                                       immediate
  163: 
  164: : [WHILE]   ( flag -- ) \ gforth bracket-while
  165:   0= IF   postpone [ELSE] true rdrop lp+ 1 countif +!  THEN ;
  166:                                                       immediate
  167: 
  168: \ Warnings on

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