File:  [gforth] / gforth / kernel / int.fs
Revision 1.115: download - view: text, annotated - select for diffs
Fri Dec 31 13:24:04 2004 UTC (19 years, 3 months ago) by anton
Branches: MAIN
CVS tags: HEAD
updated copyright years for files changed in 2004

    1: \ definitions needed for interpreter only
    2: 
    3: \ Copyright (C) 1995-2000,2004 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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   20: 
   21: \ \ Revision-Log
   22: 
   23: \       put in seperate file				14sep97jaw 
   24: 
   25: \ \ input stream primitives                       	23feb93py
   26: 
   27: require ./basics.fs 	\ bounds decimal hex ...
   28: require ./io.fs		\ type ...
   29: require ./nio.fs	\ . <# ...
   30: require ./errore.fs	\ .error ...
   31: require kernel/version.fs	\ version-string
   32: require ./../chains.fs
   33: 
   34: has? new-input 0= [IF]
   35: : tib ( -- c-addr ) \ core-ext t-i-b
   36:     \G @i{c-addr} is the address of the Terminal Input Buffer.
   37:     \G OBSOLESCENT: @code{source} superceeds the function of this word.
   38:     >tib @ ;
   39: 
   40: Defer source ( -- c-addr u ) \ core
   41: \ used by dodefer:, must be defer
   42: \G @i{c-addr} is the address of the input buffer and @i{u} is the
   43: \G number of characters in it.
   44: 
   45: : (source) ( -- c-addr u )
   46:     tib #tib @ ;
   47: ' (source) IS source
   48: [THEN]
   49: 
   50: : (word) ( addr1 n1 char -- addr2 n2 )
   51:   dup >r skip 2dup r> scan  nip - ;
   52: 
   53: \ (word) should fold white spaces
   54: \ this is what (parse-white) does
   55: 
   56: \ word parse                                           23feb93py
   57: 
   58: : sword  ( char -- addr len ) \ gforth s-word
   59:     \G Parses like @code{word}, but the output is like @code{parse} output.
   60:     \G @xref{core-idef}.
   61:   \ this word was called PARSE-WORD until 0.3.0, but Open Firmware and
   62:   \ dpANS6 A.6.2.2008 have a word with that name that behaves
   63:   \ differently (like NAME).
   64:   source 2dup >r >r >in @ over min /string
   65:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
   66:   2dup + r> - 1+ r> min >in ! ;
   67: 
   68: : word   ( char "<chars>ccc<char>-- c-addr ) \ core
   69:     \G Skip leading delimiters. Parse @i{ccc}, delimited by
   70:     \G @i{char}, in the parse area. @i{c-addr} is the address of a
   71:     \G transient region containing the parsed string in
   72:     \G counted-string format. If the parse area was empty or
   73:     \G contained no characters other than delimiters, the resulting
   74:     \G string has zero length. A program may replace characters within
   75:     \G the counted string. OBSOLESCENT: the counted string has a
   76:     \G trailing space that is not included in its length.
   77:     sword here place  bl here count + c!  here ;
   78: 
   79: : parse    ( char "ccc<char>" -- c-addr u ) \ core-ext
   80: \G Parse @i{ccc}, delimited by @i{char}, in the parse
   81: \G area. @i{c-addr u} specifies the parsed string within the
   82: \G parse area. If the parse area was empty, @i{u} is 0.
   83:     >r  source  >in @ over min /string  over  swap r>  scan >r
   84:     over - dup r> IF 1+ THEN  >in +! ;
   85: 
   86: \ name                                                 13feb93py
   87: 
   88: [IFUNDEF] (name) \ name might be a primitive
   89: 
   90: : (name) ( -- c-addr count ) \ gforth
   91:     source 2dup >r >r >in @ /string (parse-white)
   92:     2dup + r> - 1+ r> min >in ! ;
   93: \    name count ;
   94: [THEN]
   95: 
   96: : name-too-short? ( c-addr u -- c-addr u )
   97:     dup 0= -&16 and throw ;
   98: 
   99: : name-too-long? ( c-addr u -- c-addr u )
  100:     dup lcount-mask u> -&19 and throw ;
  101: 
  102: \ \ Number parsing					23feb93py
  103: 
  104: \ number? number                                       23feb93py
  105: 
  106: hex
  107: const Create bases   0A , 10 ,   2 ,   0A ,
  108: \                    10   16     2     10
  109: 
  110: \ !! protect BASE saving wrapper against exceptions
  111: : getbase ( addr u -- addr' u' )
  112:     2dup s" 0x" string-prefix? >r
  113:     2dup s" 0X" string-prefix? r> or
  114:     base @ #34 < and if
  115: 	hex 2 /string
  116:     endif
  117:     over c@ [char] # - dup 4 u<
  118:     IF
  119: 	cells bases + @ base ! 1 /string
  120:     ELSE
  121: 	drop
  122:     THEN ;
  123: 
  124: : sign? ( addr u -- addr u flag )
  125:     over c@ [char] - =  dup >r
  126:     IF
  127: 	1 /string
  128:     THEN
  129:     r> ;
  130: 
  131: : s'>unumber? ( addr u -- ud flag )
  132:     \ convert string "C" or "C'" to character code
  133:     dup 0= if
  134: 	false exit
  135:     endif
  136:     char@ s" '" 2swap string-prefix?
  137:     0 swap ;
  138: 
  139: : s>unumber? ( addr u -- ud flag )
  140:     over c@ '' = if
  141: 	1 /string s'>unumber? exit
  142:     endif
  143:     base @ >r  dpl on  getbase
  144:     0. 2swap
  145:     BEGIN ( d addr len )
  146: 	dup >r >number dup
  147:     WHILE \ there are characters left
  148: 	dup r> -
  149:     WHILE \ the last >number parsed something
  150: 	dup 1- dpl ! over c@ [char] . =
  151:     WHILE \ the current char is '.'
  152: 	1 /string
  153:     REPEAT  THEN \ there are unparseable characters left
  154: 	2drop false
  155:     ELSE
  156: 	rdrop 2drop true
  157:     THEN
  158:     r> base ! ;
  159: 
  160: \ ouch, this is complicated; there must be a simpler way - anton
  161: : s>number? ( addr len -- d f )
  162:     \ converts string addr len into d, flag indicates success
  163:     sign? >r
  164:     s>unumber?
  165:     0= IF
  166:         rdrop false
  167:     ELSE \ no characters left, all ok
  168: 	r>
  169: 	IF
  170: 	    dnegate
  171: 	THEN
  172: 	true
  173:     THEN ;
  174: 
  175: : s>number ( addr len -- d )
  176:     \ don't use this, there is no way to tell success
  177:     s>number? drop ;
  178: 
  179: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
  180:     s>number? 0=
  181:     IF
  182: 	2drop false  EXIT
  183:     THEN
  184:     dpl @ dup 0< IF
  185: 	nip
  186:     ELSE
  187: 	1+
  188:     THEN ;
  189: 
  190: : number? ( string -- string 0 / n -1 / d 0> )
  191:     dup >r count snumber? dup if
  192: 	rdrop
  193:     else
  194: 	r> swap
  195:     then ;
  196: 
  197: : number ( string -- d )
  198:     number? ?dup 0= abort" ?"  0<
  199:     IF
  200: 	s>d
  201:     THEN ;
  202: 
  203: \ \ Comments ( \ \G
  204: 
  205: : ( ( compilation 'ccc<close-paren>' -- ; run-time -- ) \ thisone- core,file	paren
  206:     \G ** this will not get annotated. The alias in glocals.fs will instead **
  207:     \G It does not work to use "wordset-" prefix since this file is glossed
  208:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
  209:     [char] ) parse 2drop ; immediate
  210: 
  211: : \ ( compilation 'ccc<newline>' -- ; run-time -- ) \ thisone- core-ext,block-ext backslash
  212:     \G ** this will not get annotated. The alias in glocals.fs will instead ** 
  213:     \G It does not work to use "wordset-" prefix since this file is glossed
  214:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
  215:     [ has? file [IF] ]
  216:     blk @
  217:     IF
  218: 	>in @ c/l / 1+ c/l * >in !
  219: 	EXIT
  220:     THEN
  221:     [ [THEN] ]
  222:     source >in ! drop ; immediate
  223: 
  224: : \G ( compilation 'ccc<newline>' -- ; run-time -- ) \ gforth backslash-gee
  225:     \G Equivalent to @code{\} but used as a tag to annotate definition
  226:     \G comments into documentation.
  227:     POSTPONE \ ; immediate
  228: 
  229: \ \ object oriented search list                         17mar93py
  230: 
  231: \ word list structure:
  232: 
  233: struct
  234:   cell% field find-method   \ xt: ( c_addr u wid -- nt )
  235:   cell% field reveal-method \ xt: ( nt wid -- ) \ used by dofield:, must be field
  236:   cell% field rehash-method \ xt: ( wid -- )	   \ re-initializes a "search-data" (hashtables)
  237:   cell% field hash-method   \ xt: ( wid -- )    \ initializes ""
  238: \   \ !! what else
  239: end-struct wordlist-map-struct
  240: 
  241: struct
  242:   cell% field wordlist-map \ pointer to a wordlist-map-struct
  243:   cell% field wordlist-id \ linked list of words (for WORDS etc.)
  244:   cell% field wordlist-link \ link field to other wordlists
  245:   cell% field wordlist-extend \ wordlist extensions (eg bucket offset)
  246: end-struct wordlist-struct
  247: 
  248: has? f83headerstring [IF]
  249: : f83find      ( addr len wordlist -- nt / false )
  250:     wordlist-id @ (f83find) ;
  251: [ELSE]
  252: : f83find      ( addr len wordlist -- nt / false )
  253:     wordlist-id @ (listlfind) ;
  254: [THEN]
  255: 
  256: : initvoc		( wid -- )
  257:   dup wordlist-map @ hash-method perform ;
  258: 
  259: \ Search list table: find reveal
  260: Create f83search ( -- wordlist-map )
  261:     ' f83find A,  ' drop A,  ' drop A, ' drop A,
  262: 
  263: here G f83search T A, NIL A, NIL A, NIL A,
  264: AValue forth-wordlist \ variable, will be redefined by search.fs
  265: 
  266: AVariable lookup       	forth-wordlist lookup !
  267: \ !! last is user and lookup?! jaw
  268: AVariable current ( -- addr ) \ gforth
  269: \G @code{Variable} -- holds the @i{wid} of the compilation word list.
  270: AVariable voclink	forth-wordlist wordlist-link voclink !
  271: \ lookup AValue context ( -- addr ) \ gforth
  272: Defer context ( -- addr ) \ gforth
  273: \G @code{context} @code{@@} is the @i{wid} of the word list at the
  274: \G top of the search order.
  275: 
  276: ' lookup is context
  277: forth-wordlist current !
  278: 
  279: \ \ header, finding, ticks                              17dec92py
  280: 
  281: \ The constants are defined as 32 bits, but then erased
  282: \ and overwritten by the right ones
  283: 
  284: has? f83headerstring [IF]
  285:     \ to save space, Gforth EC limits words to 31 characters
  286:     $80 constant alias-mask
  287:     $40 constant immediate-mask
  288:     $20 constant restrict-mask
  289:     $1f constant lcount-mask
  290: [ELSE]    
  291: $80000000 constant alias-mask
  292: 1 bits/char 1 - lshift
  293: -1 cells allot  bigendian [IF]   c, 0 1 cells 1- times
  294:                           [ELSE] 0 1 cells 1- times c, [THEN]
  295: $40000000 constant immediate-mask
  296: 1 bits/char 2 - lshift
  297: -1 cells allot  bigendian [IF]   c, 0 1 cells 1- times
  298:                           [ELSE] 0 1 cells 1- times c, [THEN]
  299: $20000000 constant restrict-mask
  300: 1 bits/char 3 - lshift
  301: -1 cells allot  bigendian [IF]   c, 0 1 cells 1- times
  302:                           [ELSE] 0 1 cells 1- times c, [THEN]
  303: $1fffffff constant lcount-mask
  304: 1 bits/char 3 - lshift 1 -
  305: -1 cells allot  bigendian [IF]   c, -1 1 cells 1- times
  306:                           [ELSE] -1 1 cells 1- times c, [THEN]
  307: [THEN]
  308: 
  309: \ higher level parts of find
  310: 
  311: : flag-sign ( f -- 1|-1 )
  312:     \ true becomes 1, false -1
  313:     0= 2* 1+ ;
  314: 
  315: : ticking-compile-only-error ( ... -- )
  316:     -&2048 throw ;
  317: 
  318: : compile-only-error ( ... -- )
  319:     -&14 throw ;
  320: 
  321: : (cfa>int) ( cfa -- xt )
  322: [ has? compiler [IF] ]
  323:     dup interpret/compile?
  324:     if
  325: 	interpret/compile-int @
  326:     then 
  327: [ [THEN] ] ;
  328: 
  329: : (x>int) ( cfa w -- xt )
  330:     \ get interpretation semantics of name
  331:     restrict-mask and
  332:     if
  333: 	drop ['] compile-only-error
  334:     else
  335: 	(cfa>int)
  336:     then ;
  337: 
  338: has? f83headerstring [IF]
  339: : name>string ( nt -- addr count ) \ gforth     head-to-string
  340:     \g @i{addr count} is the name of the word represented by @i{nt}.
  341:     cell+ count lcount-mask and ;
  342: 
  343: : ((name>))  ( nfa -- cfa )
  344:     name>string + cfaligned ;
  345: 
  346: : (name>x) ( nfa -- cfa w )
  347:     \ cfa is an intermediate cfa and w is the flags cell of nfa
  348:     dup ((name>))
  349:     swap cell+ c@ dup alias-mask and 0=
  350:     IF
  351:         swap @ swap
  352:     THEN ;
  353: [ELSE]
  354: : name>string ( nt -- addr count ) \ gforth     head-to-string
  355:     \g @i{addr count} is the name of the word represented by @i{nt}.
  356:     cell+ dup cell+ swap @ lcount-mask and ;
  357: 
  358: : ((name>))  ( nfa -- cfa )
  359:     name>string + cfaligned ;
  360: 
  361: : (name>x) ( nfa -- cfa w )
  362:     \ cfa is an intermediate cfa and w is the flags cell of nfa
  363:     dup ((name>))
  364:     swap cell+ @ dup alias-mask and 0=
  365:     IF
  366:         swap @ swap
  367:     THEN ;
  368: [THEN]
  369: 
  370: : name>int ( nt -- xt ) \ gforth
  371:     \G @i{xt} represents the interpretation semantics of the word
  372:     \G @i{nt}. If @i{nt} has no interpretation semantics (i.e. is
  373:     \G @code{compile-only}), @i{xt} is the execution token for
  374:     \G @code{ticking-compile-only-error}, which performs @code{-2048 throw}.
  375:     (name>x) (x>int) ;
  376: 
  377: : name?int ( nt -- xt ) \ gforth
  378:     \G Like @code{name>int}, but perform @code{-2048 throw} if @i{nt}
  379:     \G has no interpretation semantics.
  380:     (name>x) restrict-mask and
  381:     if
  382: 	ticking-compile-only-error \ does not return
  383:     then
  384:     (cfa>int) ;
  385: 
  386: : (name>comp) ( nt -- w +-1 ) \ gforth
  387:     \G @i{w xt} is the compilation token for the word @i{nt}.
  388:     (name>x) >r 
  389: [ has? compiler [IF] ]
  390:     dup interpret/compile?
  391:     if
  392:         interpret/compile-comp @
  393:     then 
  394: [ [THEN] ]
  395:     r> immediate-mask and flag-sign
  396:     ;
  397: 
  398: : (name>intn) ( nfa -- xt +-1 )
  399:     (name>x) tuck (x>int) ( w xt )
  400:     swap immediate-mask and flag-sign ;
  401: 
  402: const Create ???  0 , 3 , char ? c, char ? c, char ? c,
  403: \ ??? is used by dovar:, must be created/:dovar
  404: 
  405: [IFDEF] forthstart
  406: \ if we have a forthstart we can define head? with it
  407: \ otherwise leave out the head? check
  408: 
  409: : head? ( addr -- f )
  410: \G heuristic check whether addr is a name token; may deliver false
  411: \G positives; addr must be a valid address; returns 1 for
  412: \G particularly unsafe positives
  413:     \ we follow the link fields and check for plausibility; two
  414:     \ iterations should catch most false addresses: on the first
  415:     \ iteration, we may get an xt, on the second a code address (or
  416:     \ some code), which is typically not in the dictionary.
  417:     \ we added a third iteration for working with code and ;code words.
  418:     3 0 do
  419: 	dup dup aligned <> if \ protect @ against unaligned accesses
  420: 	    drop false unloop exit
  421: 	then
  422: 	dup @ dup
  423: 	if ( addr addr1 )
  424: 	    dup rot forthstart within
  425: 	    if \ addr1 is outside forthstart..addr, not a head
  426: 		drop false unloop exit
  427: 	    then ( addr1 )
  428: 	else \ 0 in the link field, no further checks
  429: 	    2drop 1 unloop exit \ this is very unsure, so return 1
  430: 	then
  431:     loop
  432:     \ in dubio pro:
  433:     drop true ;
  434: 
  435: : >head-noprim ( cfa -- nt ) \ gforth  to-head-noprim
  436:     \ also heuristic
  437:     dup forthstart - max-name-length @ float+ cell+ min cell max cell ?do ( cfa )
  438: 	dup i - dup @ [ alias-mask lcount-mask or ] literal
  439: 	[ 1 bits/char 3 - lshift 1 - 1 bits/char 1 - lshift or
  440: 	-1 cells allot bigendian [IF]   c, -1 1 cells 1- times
  441: 	[ELSE] -1 1 cells 1- times c, [THEN] ]
  442: 	and ( cfa len|alias )
  443: 	swap + cell+ cfaligned over alias-mask + =
  444: 	if ( cfa )
  445: 	    dup i - cell - dup head?
  446: 	    if
  447: 		nip unloop exit
  448: 	    then
  449: 	    drop
  450: 	then
  451: 	cell +loop
  452:     drop ??? ( wouldn't 0 be better? ) ;
  453: 
  454: [ELSE]
  455: 
  456: : >head-noprim ( cfa -- nt ) \ gforth  to-head-noprim
  457:     $25 cell do ( cfa )
  458: 	dup i - dup @ [ alias-mask lcount-mask or ] literal
  459: 	[ 1 bits/char 3 - lshift 1 - 1 bits/char 1 - lshift or
  460: 	-1 cells allot bigendian [IF]   c, -1 1 cells 1- times
  461: 	[ELSE] -1 1 cells 1- times c, [THEN] ]
  462: 	and ( cfa len|alias )
  463: 	swap + cell + cfaligned over alias-mask + =
  464: 	if ( cfa ) i - cell - unloop exit
  465: 	then
  466: 	cell +loop
  467:     drop ??? ( wouldn't 0 be better? ) ;
  468: 
  469: [THEN]
  470: 
  471: cell% 2* 0 0 field >body ( xt -- a_addr ) \ core
  472: \G Get the address of the body of the word represented by @i{xt} (the
  473: \G address of the word's data field).
  474: drop drop
  475: 
  476: cell% -2 * 0 0 field body> ( xt -- a_addr )
  477:     drop drop
  478: 
  479: has? standardthreading has? compiler and [IF]
  480: 
  481: ' @ alias >code-address ( xt -- c_addr ) \ gforth
  482: \G @i{c-addr} is the code address of the word @i{xt}.
  483: 
  484: : >does-code ( xt -- a_addr ) \ gforth
  485: \G If @i{xt} is the execution token of a child of a @code{DOES>} word,
  486: \G @i{a-addr} is the start of the Forth code after the @code{DOES>};
  487: \G Otherwise @i{a-addr} is 0.
  488:     dup @ dodoes: = if
  489: 	cell+ @
  490:     else
  491: 	drop 0
  492:     endif ;
  493: 
  494: ' ! alias code-address! ( c_addr xt -- ) \ gforth
  495: \G Create a code field with code address @i{c-addr} at @i{xt}.
  496: 
  497: : does-code! ( a_addr xt -- ) \ gforth
  498: \G Create a code field at @i{xt} for a child of a @code{DOES>}-word;
  499: \G @i{a-addr} is the start of the Forth code after @code{DOES>}.
  500:     dodoes: over ! cell+ ! ;
  501: 
  502: ' drop alias does-handler! ( a_addr -- ) \ gforth
  503: \G Create a @code{DOES>}-handler at address @i{a-addr}. Normally,
  504: \G @i{a-addr} points just behind a @code{DOES>}.
  505: 
  506: 2 cells constant /does-handler ( -- n ) \ gforth
  507: \G The size of a @code{DOES>}-handler (includes possible padding).
  508: 
  509: [THEN]	
  510: 
  511: : (search-wordlist)  ( addr count wid -- nt | false )
  512:     dup wordlist-map @ find-method perform ;
  513: 
  514: : search-wordlist ( c-addr count wid -- 0 | xt +-1 ) \ search
  515:     \G Search the word list identified by @i{wid} for the definition
  516:     \G named by the string at @i{c-addr count}.  If the definition is
  517:     \G not found, return 0. If the definition is found return 1 (if
  518:     \G the definition is immediate) or -1 (if the definition is not
  519:     \G immediate) together with the @i{xt}.  In Gforth, the @i{xt}
  520:     \G returned represents the interpretation semantics.  ANS Forth
  521:     \G does not specify clearly what @i{xt} represents.
  522:     (search-wordlist) dup if
  523: 	(name>intn)
  524:     then ;
  525: 
  526: : find-name ( c-addr u -- nt | 0 ) \ gforth
  527:     \g Find the name @i{c-addr u} in the current search
  528:     \g order. Return its @i{nt}, if found, otherwise 0.
  529:     lookup @ (search-wordlist) ;
  530: 
  531: : sfind ( c-addr u -- 0 / xt +-1  ) \ gforth-obsolete
  532:     find-name dup
  533:     if ( nt )
  534: 	state @
  535: 	if
  536: 	    (name>comp)
  537: 	else
  538: 	    (name>intn)
  539: 	then
  540:    then ;
  541: 
  542: : find ( c-addr -- xt +-1 | c-addr 0 ) \ core,search
  543:     \G Search all word lists in the current search order for the
  544:     \G definition named by the counted string at @i{c-addr}.  If the
  545:     \G definition is not found, return 0. If the definition is found
  546:     \G return 1 (if the definition has non-default compilation
  547:     \G semantics) or -1 (if the definition has default compilation
  548:     \G semantics).  The @i{xt} returned in interpret state represents
  549:     \G the interpretation semantics.  The @i{xt} returned in compile
  550:     \G state represented either the compilation semantics (for
  551:     \G non-default compilation semantics) or the run-time semantics
  552:     \G that the compilation semantics would @code{compile,} (for
  553:     \G default compilation semantics).  The ANS Forth standard does
  554:     \G not specify clearly what the returned @i{xt} represents (and
  555:     \G also talks about immediacy instead of non-default compilation
  556:     \G semantics), so this word is questionable in portable programs.
  557:     \G If non-portability is ok, @code{find-name} and friends are
  558:     \G better (@pxref{Name token}).
  559:     dup count sfind dup
  560:     if
  561: 	rot drop
  562:     then ;
  563: 
  564: \ ticks in interpreter
  565: 
  566: : (') ( "name" -- nt ) \ gforth
  567:     name name-too-short?
  568:     find-name dup 0=
  569:     IF
  570: 	drop -&13 throw
  571:     THEN  ;
  572: 
  573: : '    ( "name" -- xt ) \ core	tick
  574:     \g @i{xt} represents @i{name}'s interpretation
  575:     \g semantics. Perform @code{-14 throw} if the word has no
  576:     \g interpretation semantics.
  577:     (') name?int ;
  578: 
  579: has? compiler 0= [IF]	\ interpreter only version of IS and TO
  580: 
  581: : IS ' >body ! ;
  582: ' IS Alias TO
  583: 
  584: [THEN]
  585: 
  586: \ \ the interpreter loop				  mar92py
  587: 
  588: \ interpret                                            10mar92py
  589: 
  590: Defer parser ( c-addr u -- )
  591: Defer parse-word ( "name" -- c-addr u ) \ gforth
  592: \G Get the next word from the input buffer
  593: ' (name) IS parse-word
  594: 
  595: ' parse-word alias name ( -- c-addr u ) \ gforth-obsolete
  596: \G old name for @code{parse-word}
  597: 
  598: Defer compiler-notfound ( c-addr count -- )
  599: Defer interpreter-notfound ( c-addr count -- )
  600: 
  601: : no.extensions  ( addr u -- )
  602:     2drop -&13 throw ;
  603: ' no.extensions IS compiler-notfound
  604: ' no.extensions IS interpreter-notfound
  605: 
  606: Defer before-word ( -- ) \ gforth
  607: \ called before the text interpreter parses the next word
  608: ' noop IS before-word
  609: 
  610: : interpret1 ( ... -- ... )
  611: [ has? backtrace [IF] ]
  612:     rp@ backtrace-rp0 !
  613: [ [THEN] ]
  614:     BEGIN
  615: 	?stack before-word name dup
  616:     WHILE
  617: 	parser
  618:     REPEAT
  619:     2drop ;
  620:     
  621: : interpret ( ?? -- ?? ) \ gforth
  622:     \ interpret/compile the (rest of the) input buffer
  623: [ has? backtrace [IF] ]
  624:     backtrace-rp0 @ >r	
  625: [ [THEN] ]
  626:     ['] interpret1 catch
  627: [ has? backtrace [IF] ]
  628:     r> backtrace-rp0 !
  629:     [ [THEN] ]
  630:     throw ;
  631: 
  632: \ interpreter                                 	30apr92py
  633: 
  634: \ not the most efficient implementations of interpreter and compiler
  635: : interpreter ( c-addr u -- ) 
  636:     2dup find-name dup
  637:     if
  638: 	nip nip name>int execute
  639:     else
  640: 	drop
  641: 	2dup 2>r snumber?
  642: 	IF
  643: 	    2rdrop
  644: 	ELSE
  645: 	    2r> interpreter-notfound
  646: 	THEN
  647:     then ;
  648: 
  649: ' interpreter  IS  parser
  650: 
  651: \ \ Query Evaluate                                 	07apr93py
  652: 
  653: has? file 0= [IF]
  654: : sourceline# ( -- n )  1 ;
  655: [ELSE]
  656: has? new-input 0= [IF]
  657: Variable #fill-bytes
  658: \G number of bytes read via (read-line) by the last refill
  659: [THEN]
  660: [THEN]
  661: 
  662: has? new-input 0= [IF]
  663: : refill ( -- flag ) \ core-ext,block-ext,file-ext
  664:     \G Attempt to fill the input buffer from the input source.  When
  665:     \G the input source is the user input device, attempt to receive
  666:     \G input into the terminal input device. If successful, make the
  667:     \G result the input buffer, set @code{>IN} to 0 and return true;
  668:     \G otherwise return false. When the input source is a block, add 1
  669:     \G to the value of @code{BLK} to make the next block the input
  670:     \G source and current input buffer, and set @code{>IN} to 0;
  671:     \G return true if the new value of @code{BLK} is a valid block
  672:     \G number, false otherwise. When the input source is a text file,
  673:     \G attempt to read the next line from the file. If successful,
  674:     \G make the result the current input buffer, set @code{>IN} to 0
  675:     \G and return true; otherwise, return false.  A successful result
  676:     \G includes receipt of a line containing 0 characters.
  677:     [ has? file [IF] ]
  678: 	blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
  679: 	[ [THEN] ]
  680:     tib /line
  681:     [ has? file [IF] ]
  682: 	loadfile @ ?dup
  683: 	IF    (read-line) throw #fill-bytes !
  684: 	ELSE
  685: 	    [ [THEN] ]
  686: 	sourceline# 0< IF 2drop false EXIT THEN
  687: 	accept true
  688: 	[ has? file [IF] ]
  689: 	THEN
  690: 	1 loadline +!
  691: 	[ [THEN] ]
  692:     swap #tib ! 0 >in ! ;
  693: 
  694: : query   ( -- ) \ core-ext
  695:     \G Make the user input device the input source. Receive input into
  696:     \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
  697:     \G superceeded by @code{accept}.
  698:     [ has? file [IF] ]
  699: 	blk off loadfile off
  700: 	[ [THEN] ]
  701:     refill drop ;
  702: [THEN]
  703: 
  704: \ save-mem extend-mem
  705: 
  706: has? os [IF]
  707: : save-mem	( addr1 u -- addr2 u ) \ gforth
  708:     \g copy a memory block into a newly allocated region in the heap
  709:     swap >r
  710:     dup allocate throw
  711:     swap 2dup r> -rot move ;
  712: 
  713: : free-mem-var ( addr -- )
  714:     \ addr is the address of a 2variable containing address and size
  715:     \ of a memory range; frees memory and clears the 2variable.
  716:     dup 2@ drop dup
  717:     if ( addr mem-start )
  718: 	free throw
  719: 	0 0 rot 2!
  720:     else
  721: 	2drop
  722:     then ;
  723: 
  724: : extend-mem	( addr1 u1 u -- addr addr2 u2 )
  725:     \ extend memory block allocated from the heap by u aus
  726:     \ the (possibly reallocated) piece is addr2 u2, the extension is at addr
  727:     over >r + dup >r resize throw
  728:     r> over r> + -rot ;
  729: [THEN]
  730: 
  731: \ EVALUATE                                              17may93jaw
  732: 
  733: has? file 0= has? new-input 0= and [IF]
  734: : push-file  ( -- )  r>
  735:   tibstack @ >r  >tib @ >r  #tib @ >r
  736:   >tib @ tibstack @ = IF  r@ tibstack +!  THEN
  737:   tibstack @ >tib ! >in @ >r  >r ;
  738: 
  739: : pop-file   ( throw-code -- throw-code )
  740:   r>
  741:   r> >in !  r> #tib !  r> >tib !  r> tibstack !  >r ;
  742: [THEN]
  743: 
  744: has? new-input 0= [IF]
  745: : evaluate ( c-addr u -- ) \ core,block
  746:     \G Save the current input source specification. Store @code{-1} in
  747:     \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
  748:     \G @code{0} and make the string @i{c-addr u} the input source
  749:     \G and input buffer. Interpret. When the parse area is empty,
  750:     \G restore the input source specification.
  751: [ has? file [IF] ]
  752:     s" *evaluated string*" loadfilename>r
  753: [ [THEN] ]
  754:     push-file #tib ! >tib !
  755:     >in off
  756:     [ has? file [IF] ]
  757: 	blk off loadfile off -1 loadline !
  758: 	[ [THEN] ]
  759:     ['] interpret catch
  760:     pop-file
  761: [ has? file [IF] ]
  762:     r>loadfilename
  763: [ [THEN] ]
  764:     throw ;
  765: [THEN]
  766: 
  767: \ \ Quit                                            	13feb93py
  768: 
  769: Defer 'quit
  770: 
  771: Defer .status
  772: 
  773: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
  774: 
  775: : (quit) ( -- )
  776:     \ exits only through THROW etc.
  777:     BEGIN
  778: 	.status
  779: 	['] cr catch if
  780: 	    >stderr cr ." Can't print to stdout, leaving" cr
  781: 	    \ if stderr does not work either, already DoError causes a hang
  782: 	    2 (bye)
  783: 	endif
  784: 	query interpret prompt
  785:     AGAIN ;
  786: 
  787: ' (quit) IS 'quit
  788: 
  789: \ \ DOERROR (DOERROR)                        		13jun93jaw
  790: 
  791: 8 Constant max-errors
  792: 4 has? file 2 and + Constant /error
  793: Variable error-stack  0 error-stack !
  794: max-errors /error * cells allot
  795: \ format of one cell:
  796: \ source ( addr u )
  797: \ >in
  798: \ line-number
  799: \ Loadfilename ( addr u )
  800: 
  801: : error> ( -- addr u >in line# [addr u] )
  802:     -1 error-stack +!
  803:     error-stack dup @
  804:     /error * cells + cell+
  805:     /error cells bounds DO
  806: 	I @
  807: 	cell +LOOP ;
  808: : >error ( addr u >in line# [addr u] -- )
  809:     error-stack dup @ dup 1+
  810:     max-errors 1- min error-stack !
  811:     /error * cells + cell+
  812:     /error 1- cells bounds swap DO
  813: 	I !
  814: 	-1 cells +LOOP ;
  815: 
  816: : dec. ( n -- ) \ gforth
  817:     \G Display @i{n} as a signed decimal number, followed by a space.
  818:     \ !! not used...
  819:     base @ decimal swap . base ! ;
  820: 
  821: : dec.r ( u n -- ) \ gforth
  822:     \G Display @i{u} as a unsigned decimal number in a field @i{n}
  823:     \G characters wide.
  824:     base @ >r decimal .r r> base ! ;
  825: 
  826: : hex. ( u -- ) \ gforth
  827:     \G Display @i{u} as an unsigned hex number, prefixed with a "$" and
  828:     \G followed by a space.
  829:     \ !! not used...
  830:     [char] $ emit base @ swap hex u. base ! ;
  831: 
  832: : -trailing  ( c_addr u1 -- c_addr u2 ) \ string dash-trailing
  833: \G Adjust the string specified by @i{c-addr, u1} to remove all
  834: \G trailing spaces. @i{u2} is the length of the modified string.
  835:     BEGIN
  836: 	dup
  837:     WHILE
  838: 	1- 2dup + c@ bl <>
  839:     UNTIL  1+  THEN ;
  840: 
  841: DEFER DOERROR
  842: 
  843: has? backtrace [IF]
  844: Defer dobacktrace ( -- )
  845: ' noop IS dobacktrace
  846: [THEN]
  847: 
  848: : .error-string ( throw-code -- )
  849:   dup -2 = 
  850:   IF 	"error @ ?dup IF count type  THEN drop
  851:   ELSE	.error
  852:   THEN ;
  853: 
  854: : umin ( u1 u2 -- u )
  855:     2dup u>
  856:     if
  857: 	swap
  858:     then
  859:     drop ;
  860: 
  861: Defer mark-start
  862: Defer mark-end
  863: 
  864: :noname ." >>>" ; IS mark-start
  865: :noname ." <<<" ; IS mark-end
  866: 
  867: : .error-line ( addr1 u1 n1 -- )
  868:     \ print error ending at char n1 in line addr1 u1
  869:     \ should work with UTF-8 (whitespace check looks ok)
  870:     over umin \ protect against wrong n1
  871:     swap >r ( addr1 n1 R: u1 )
  872:     -trailing 1- \ last non-space
  873:     0 >r  BEGIN \ search for the first non-space
  874: 	2dup + c@ bl >  WHILE
  875: 	r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
  876:     ( addr1 n2 r: u1 namelen )
  877:     2dup type mark-start
  878:     r> -rot r> swap /string ( namelen addr2 u2 )
  879:     >r swap 2dup type mark-end ( addr2 namelen r: u2 )
  880:     r> swap /string type ;
  881: 
  882: : .error-frame ( throwcode addr1 u1 n1 n2 [addr2 u2] -- throwcode )
  883: \ addr2 u2: 	filename of included file - optional
  884: \ n2:		line number
  885: \ n1:		error position in input line
  886: \ addr1 u1:	input line
  887:   cr error-stack @
  888:   IF ( throwcode addr1 u1 n1 n2 [addr2 u2] )
  889: [ has? file [IF] ] \ !! unbalanced stack effect
  890:     ." in file included from "
  891:     type ." :"
  892: [ [THEN] ] ( throwcode addr1 u1 n1 n2 )
  893:     0 dec.r  drop 2drop
  894:   ELSE ( throwcode addr1 u1 n1 n2 [addr2 u2] )
  895: [ has? file [IF] ]
  896:       type ." :"
  897: [ [THEN] ] ( throwcode addr1 u1 n1 n2 )
  898:       dup 0 dec.r ." : " 4 pick .error-string
  899:       IF \ if line# non-zero, there is a line
  900: 	  cr .error-line
  901:       ELSE
  902: 	  2drop drop
  903:       THEN
  904:   THEN ;
  905: 
  906: : (DoError) ( throw-code -- )
  907:   [ has? os [IF] ]
  908:       >stderr
  909:   [ [THEN] ] 
  910:   source >in @ sourceline# [ has? file [IF] ] \ !! unbalanced stack effect
  911:       sourcefilename
  912:   [ [THEN] ] .error-frame
  913:   error-stack @ 0 ?DO
  914:     error>
  915:     .error-frame
  916:   LOOP
  917:   drop 
  918: [ has? backtrace [IF] ]
  919:   dobacktrace
  920: [ [THEN] ]
  921:   normal-dp dpp ! ;
  922: 
  923: ' (DoError) IS DoError
  924: 
  925: : quit ( ?? -- ?? ) \ core
  926:     \G Empty the return stack, make the user input device
  927:     \G the input source, enter interpret state and start
  928:     \G the text interpreter.
  929:     rp0 @ rp! handler off clear-tibstack
  930:     [ has? new-input 0= [IF] ] >tib @ >r [ [THEN] ]
  931:     BEGIN
  932: 	[ has? compiler [IF] ]
  933: 	    [compile] [
  934: 	[ [THEN] ]
  935: 	\ stack depths may be arbitrary here
  936: 	['] 'quit CATCH dup
  937:     WHILE
  938: 	    <# \ reset hold area, or we may get another error
  939: 	    DoError
  940: 	    \ stack depths may be arbitrary still (or again), so clear them
  941: 	    clearstacks
  942: 	    [ has? new-input [IF] ] clear-tibstack
  943: 	    [ [ELSE] ] r@ >tib ! r@ tibstack !
  944: 	    [ [THEN] ]
  945:     REPEAT
  946:     drop [ has? new-input [IF] ] clear-tibstack
  947:     [ [ELSE] ] r> >tib !
  948:     [ [THEN] ] ;
  949: 
  950: \ \ Cold Boot                                    	13feb93py
  951: 
  952: : (bootmessage)
  953:     ." Gforth " version-string type 
  954:     ." , Copyright (C) 1995-2003,2004 Free Software Foundation, Inc." cr
  955:     ." Gforth comes with ABSOLUTELY NO WARRANTY; for details type `license'"
  956: [ has? os [IF] ]
  957:      cr ." Type `bye' to exit"
  958: [ [THEN] ] ;
  959: 
  960: defer bootmessage
  961: defer process-args
  962: 
  963: ' (bootmessage) IS bootmessage
  964: 
  965: Defer 'cold ( -- ) \ gforth  tick-cold
  966: \ hook (deferred word) for things to do right before interpreting the
  967: \ command-line arguments
  968: ' noop IS 'cold
  969: 
  970: 
  971: AVariable init8 NIL init8 !
  972: 
  973: : cold ( -- ) \ gforth
  974: [ has? backtrace [IF] ]
  975:     rp@ backtrace-rp0 !
  976: [ [THEN] ]
  977: [ has? file [IF] ]
  978:     os-cold
  979: [ [THEN] ]
  980:     'cold
  981:     init8 chainperform
  982: [ has? file [IF] ]
  983:     s" *the terminal*" loadfilename 2!
  984:     process-args
  985:     loadline off
  986: [ [THEN] ]
  987:     bootmessage
  988:     quit ;
  989: 
  990: has? new-input 0= [IF]
  991: : clear-tibstack ( -- )
  992: [ has? glocals [IF] ]
  993:     lp@ forthstart 7 cells + @ - 
  994: [ [ELSE] ]
  995:     [ has? os [IF] ]
  996:     r0 @ forthstart 6 cells + @ -
  997:     [ [ELSE] ]
  998:     sp@ $10 cells +
  999:     [ [THEN] ]
 1000: [ [THEN] ]
 1001:     dup >tib ! tibstack ! #tib off >in off ;
 1002: [THEN]
 1003: 
 1004: : boot ( path n **argv argc -- )
 1005:     main-task up!
 1006: [ has? os [IF] ]
 1007:     os-boot
 1008: [ [THEN] ]
 1009:     sp@ sp0 !
 1010: [ has? peephole [IF] ]
 1011:     \ only needed for greedy static superinstruction selection
 1012:     \ primtable prepare-peephole-table TO peeptable
 1013: [ [THEN] ]
 1014: [ has? new-input [IF] ]
 1015:     current-input off
 1016: [ [THEN] ]
 1017:     clear-tibstack
 1018:     rp@ rp0 !
 1019: [ has? floating [IF] ]
 1020:     fp@ fp0 !
 1021: [ [THEN] ]
 1022:     handler off
 1023:     ['] cold catch dup -&2049 <> if \ broken pipe?
 1024: 	DoError cr
 1025:     endif
 1026: [ has? os [IF] ]
 1027:     1 (bye) \ !! determin exit code from throw code?
 1028: [ [THEN] ]
 1029: ;
 1030: 
 1031: has? os [IF]
 1032: : bye ( -- ) \ tools-ext
 1033: [ has? file [IF] ]
 1034:     script? 0= IF  cr  THEN
 1035: [ [ELSE] ]
 1036:     cr
 1037: [ [THEN] ]
 1038:     0 (bye) ;
 1039: [THEN]
 1040: 
 1041: \ **argv may be scanned by the C starter to get some important
 1042: \ information, as -display and -geometry for an X client FORTH
 1043: \ or space and stackspace overrides
 1044: 
 1045: \ 0 arg contains, however, the name of the program.
 1046: 

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