File:  [gforth] / gforth / Attic / interpretation.fs
Revision 1.3: download - view: text, annotated - select for diffs
Mon May 13 16:36:59 1996 UTC (26 years, 1 month ago) by anton
Branches: MAIN
CVS tags: HEAD
eliminated state-smartness in ;code and sfnumber
immediate-flag is now $40 and restrict-flag $20
HEADER now stores the compilation wordlist in the header and
	REVEAL reveals into that wordlist
assorted cleanups

    1: \ Interpretation semantics
    2: 
    3: \ Copyright (C) 1996 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation; either version 2
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program; if not, write to the Free Software
   19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: 
   22: \ This file defines a mechanism for specifying special interpretation
   23: \ semantics and the interpretation semantics of several words.
   24: 
   25: require search-order.fs
   26: 
   27: table constant interpretation-semantics
   28: 
   29: :noname ( c-addr u word-ident -- )
   30:     \ word-ident is currently an xt, but it might be the nfa
   31:     sp@ cell interpretation-semantics search-wordlist
   32:     if ( c-addr u word-ident xt )
   33: 	nip nip nip execute
   34:     else
   35: 	defers interpret-special
   36:     endif ;
   37: ' interpret-special >body !
   38: 
   39: : interpretation: ( -- colon-sys ) \ gforth
   40:     \G make the last word one with special interpretation semantics and
   41:     \G start the (colon) definition of these semantics.
   42:     \ !! fix reveal such that it is not necessary to do it before the
   43:     \    set-current
   44:     restrict
   45:     lastcfa cell nextname \ !! use nfa instead of cfa
   46:     get-current >r
   47:     interpretation-semantics set-current :
   48:     r> set-current ;
   49: 
   50: \ !! split notfound and sfnumber in a compiler and an interpreter part?
   51: 
   52: \ ' [']
   53: 
   54: \ !! or keep it state-smart?
   55: ' [char] Alias Ascii immediate
   56: interpretation: ( "char" -- c )
   57:     \ currently also the interpretation semantics of [char]
   58:     char ;
   59: 
   60: \ [I]
   61: 
   62: \ the following interpretation semantics definitions restrict the
   63: \ preceeding word. However, this does not matter because these
   64: \ restricted words are in interpretation-semantics and are never
   65: \ interpreted like regular words.
   66: 
   67: \ we cannot use s" interpretively yet (to make a string for (sfind), so:
   68: ' S" lastcfa !
   69: interpretation: ( "ccc<">" -- c-addr u )
   70:     [char] " parse
   71:     /line min >r s"-buffer r@ cmove
   72:     s"-buffer r> ;
   73: 
   74: ' ." lastcfa !
   75: interpretation: ( "ccc<">" -- )
   76:     [char] " parse type ;
   77: 
   78: ' does> lastcfa !
   79: interpretation: ( -- colon-sys ) ( name execution: -- addr )
   80:     align dodoes, here !does ]
   81:     defstart :-hook ;
   82: 
   83: ' is lastcfa !
   84: interpretation: ( addr "name" -- )
   85:     ' >body ! ;
   86: 
   87: ' what's lastcfa !
   88: interpretation: ( "name" -- addr )
   89:     ' >body @ ;
   90: 
   91: 
   92: \ : foo
   93: \     ." compilation semantics" ; immediate
   94: \ interpretation:
   95: \     ." interpretation semantics" ;
   96: 
   97: \ foo			\ interpretation semantics ok
   98: \ : xxx foo ;		\ compilation semantics ok
   99: \ : yyy postpone foo ;	\ ok
  100: \ yyy			\ compilation semantics ok

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