File:  [gforth] / gforth / Attic / interpretation.fs
Revision 1.2: download - view: text, annotated - select for diffs
Thu May 9 18:13:00 1996 UTC (23 years, 2 months ago) by anton
Branches: MAIN
CVS tags: HEAD
changed most state-smart words into words with interpretation: behaviour.
added postponetest.fs to "make test"
made HashTable into a value (for speed)
replaced 'flag!' by lastflags, cset, creset, ctoggle

\ Interpretation semantics

\ Copyright (C) 1996 Free Software Foundation, Inc.

\ This file is part of Gforth.

\ Gforth is free software; you can redistribute it and/or
\ modify it under the terms of the GNU General Public License
\ as published by the Free Software Foundation; either version 2
\ of the License, or (at your option) any later version.

\ This program is distributed in the hope that it will be useful,
\ but WITHOUT ANY WARRANTY; without even the implied warranty of
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
\ GNU General Public License for more details.

\ You should have received a copy of the GNU General Public License
\ along with this program; if not, write to the Free Software
\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.


\ This file defines a mechanism for specifying special interpretation
\ semantics and the interpretation semantics of several words.

require search-order.fs

table constant interpretation-semantics

:noname ( c-addr u word-ident -- )
    \ word-ident is currently an xt, but it might be the nfa
    sp@ cell interpretation-semantics search-wordlist
    if ( c-addr u word-ident xt )
	nip nip nip execute
    else
	defers interpret-special
    endif ;
' interpret-special >body !

: interpretation: ( -- colon-sys ) \ gforth
    \G make the last word one with special interpretation semantics and
    \G start the (colon) definition of these semantics.
    \ !! fix reveal such that it is not necessary to do it before the
    \    set-current
    restrict
    lastcfa cell nextname \ !! use nfa instead of cfa
    get-current >r
    interpretation-semantics set-current : reveal
    r> set-current ;

\ !! split notfound and sfnumber in a compiler and an interpreter part?

\ ' [']

\ !! or keep it state-smart?
' [char] Alias Ascii immediate
interpretation: ( "char" -- c )
    \ currently also the interpretation semantics of [char]
    char ;

\ [I]

\ the following interpretation semantics definitions restrict the
\ preceeding word. However, this does not matter because these
\ restricted words are in interpretation-semantics and are never
\ interpreted like regular words.

\ we cannot use s" interpretively yet (to make a string for (sfind), so:
' S" lastcfa !
interpretation: ( "ccc<">" -- c-addr u )
    [char] " parse
    /line min >r s"-buffer r@ cmove
    s"-buffer r> ;

' ." lastcfa !
interpretation: ( "ccc<">" -- )
    [char] " parse type ;

' does> lastcfa !
interpretation: ( -- colon-sys ) ( name execution: -- addr )
    align dodoes, here !does ]
    defstart :-hook ;

' is lastcfa !
interpretation: ( addr "name" -- )
    ' >body ! ;

' what's lastcfa !
interpretation: ( "name" -- addr )
    ' >body @ ;


\ : foo
\     ." compilation semantics" ; immediate
\ interpretation:
\     ." interpretation semantics" ;

\ foo			\ interpretation semantics ok
\ : xxx foo ;		\ compilation semantics ok
\ : yyy postpone foo ;	\ ok
\ yyy			\ compilation semantics ok

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