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Annotation of gforth/interpretation.fs, revision 1.2

1.1       anton       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
1.2     ! anton      23: \ semantics and the interpretation semantics of several words.
        !            24: 
        !            25: require search-order.fs
1.1       anton      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 ;
1.2     ! anton      37: ' interpret-special >body !
1.1       anton      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 : reveal
                     48:     r> set-current ;
1.2     ! anton      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: 
1.1       anton      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