File:  [gforth] / gforth / kernel / int.fs
Revision 1.42: download - view: text, annotated - select for diffs
Sat Nov 20 12:12:54 1999 UTC (24 years, 4 months ago) by anton
Branches: MAIN
CVS tags: HEAD
took exception handling out of the kernel into exceptions.fs
added inline exception handling (TRY...RECOVER...ENDTRY)
added exception handling without affecting sp or fp (PROTECT...ENDPROTECT)

    1: \ definitions needed for interpreter only
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998 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: \ \ 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: : tib ( -- c-addr ) \ core-ext
   35:     \G @i{c-addr} is the address of the Terminal Input Buffer.
   36:     \G OBSOLESCENT: @code{source} superceeds the function of this word.
   37:     >tib @ ;
   38: 
   39: Defer source ( -- c-addr u ) \ core
   40: \ used by dodefer:, must be defer
   41: \G @i{c-addr} is the address of the input buffer and @i{u} is the
   42: \G number of characters in it.
   43: 
   44: : (source) ( -- c-addr u )
   45:     tib #tib @ ;
   46: ' (source) IS source
   47: 
   48: : (word) ( addr1 n1 char -- addr2 n2 )
   49:   dup >r skip 2dup r> scan  nip - ;
   50: 
   51: \ (word) should fold white spaces
   52: \ this is what (parse-white) does
   53: 
   54: \ word parse                                           23feb93py
   55: 
   56: : sword  ( char -- addr len ) \ gforth s-word
   57:     \G Parses like @code{word}, but the output is like @code{parse} output.
   58:     \G @xref{core-idef}
   59:   \ this word was called PARSE-WORD until 0.3.0, but Open Firmware and
   60:   \ dpANS6 A.6.2.2008 have a word with that name that behaves
   61:   \ differently (like NAME).
   62:   source 2dup >r >r >in @ over min /string
   63:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
   64:   2dup + r> - 1+ r> min >in ! ;
   65: 
   66: : word   ( char "<chars>ccc<char>-- c-addr ) \ core
   67:     \G Skip leading delimiters. Parse @i{ccc}, delimited by
   68:     \G @i{char}, in the parse area. @i{c-addr} is the address of a
   69:     \G transient region containing the parsed string in
   70:     \G counted-string format. If the parse area was empty or
   71:     \G contained no characters other than delimiters, the resulting
   72:     \G string has zero length. A program may replace characters within
   73:     \G the counted string. OBSOLESCENT: the counted string has a
   74:     \G trailing space that is not included in its length.
   75:     sword here place  bl here count + c!  here ;
   76: 
   77: : parse    ( char "ccc<char>" -- c-addr u ) \ core-ext
   78:     \G Parse @i{ccc}, delimited by @i{char}, in the parse
   79:     \G area. @i{c-addr u} specifies the parsed string within the
   80:     \G parse area. If the parse area was empty, @i{u} is 0.
   81:     >r  source  >in @ over min /string  over  swap r>  scan >r
   82:   over - dup r> IF 1+ THEN  >in +! ;
   83: 
   84: \ name                                                 13feb93py
   85: 
   86: [IFUNDEF] (name) \ name might be a primitive
   87: 
   88: : (name) ( -- c-addr count ) \ gforth
   89:     source 2dup >r >r >in @ /string (parse-white)
   90:     2dup + r> - 1+ r> min >in ! ;
   91: \    name count ;
   92: [THEN]
   93: 
   94: : name-too-short? ( c-addr u -- c-addr u )
   95:     dup 0= -&16 and throw ;
   96: 
   97: : name-too-long? ( c-addr u -- c-addr u )
   98:     dup $1F u> -&19 and throw ;
   99: 
  100: \ \ Number parsing					23feb93py
  101: 
  102: \ number? number                                       23feb93py
  103: 
  104: hex
  105: const Create bases   10 ,   2 ,   A , 100 ,
  106: \                     16     2    10   character
  107: 
  108: \ !! protect BASE saving wrapper against exceptions
  109: : getbase ( addr u -- addr' u' )
  110:     over c@ [char] $ - dup 4 u<
  111:     IF
  112: 	cells bases + @ base ! 1 /string
  113:     ELSE
  114: 	drop
  115:     THEN ;
  116: 
  117: : sign? ( addr u -- addr u flag )
  118:     over c@ [char] - =  dup >r
  119:     IF
  120: 	1 /string
  121:     THEN
  122:     r> ;
  123: 
  124: : s>unumber? ( addr u -- ud flag )
  125:     base @ >r  dpl on  getbase
  126:     0. 2swap
  127:     BEGIN ( d addr len )
  128: 	dup >r >number dup
  129:     WHILE \ there are characters left
  130: 	dup r> -
  131:     WHILE \ the last >number parsed something
  132: 	dup 1- dpl ! over c@ [char] . =
  133:     WHILE \ the current char is '.'
  134: 	1 /string
  135:     REPEAT  THEN \ there are unparseable characters left
  136: 	2drop false
  137:     ELSE
  138: 	rdrop 2drop true
  139:     THEN
  140:     r> base ! ;
  141: 
  142: \ ouch, this is complicated; there must be a simpler way - anton
  143: : s>number? ( addr len -- d f )
  144:     \ converts string addr len into d, flag indicates success
  145:     sign? >r
  146:     s>unumber?
  147:     0= IF
  148:         rdrop false
  149:     ELSE \ no characters left, all ok
  150: 	r>
  151: 	IF
  152: 	    dnegate
  153: 	THEN
  154: 	true
  155:     THEN ;
  156: 
  157: : s>number ( addr len -- d )
  158:     \ don't use this, there is no way to tell success
  159:     s>number? drop ;
  160: 
  161: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
  162:     s>number? 0=
  163:     IF
  164: 	2drop false  EXIT
  165:     THEN
  166:     dpl @ dup 0< IF
  167: 	nip
  168:     ELSE
  169: 	1+
  170:     THEN ;
  171: 
  172: : number? ( string -- string 0 / n -1 / d 0> )
  173:     dup >r count snumber? dup if
  174: 	rdrop
  175:     else
  176: 	r> swap
  177:     then ;
  178: 
  179: : number ( string -- d )
  180:     number? ?dup 0= abort" ?"  0<
  181:     IF
  182: 	s>d
  183:     THEN ;
  184: 
  185: \ \ Comments ( \ \G
  186: 
  187: : ( ( compilation 'ccc<close-paren>' -- ; run-time -- ) \ thisone- core,file	paren
  188:     \G ** this will not get annotated. The alias in glocals.fs will instead **
  189:     \G It does not work to use "wordset-" prefix since this file is glossed
  190:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
  191:     [char] ) parse 2drop ; immediate
  192: 
  193: : \ ( -- ) \ thisone- core-ext,block-ext backslash
  194:     \G ** this will not get annotated. The alias in glocals.fs will instead ** 
  195:     \G It does not work to use "wordset-" prefix since this file is glossed
  196:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
  197:     [ has? file [IF] ]
  198:     blk @
  199:     IF
  200: 	>in @ c/l / 1+ c/l * >in !
  201: 	EXIT
  202:     THEN
  203:     [ [THEN] ]
  204:     source >in ! drop ; immediate
  205: 
  206: : \G ( -- ) \ gforth backslash-gee
  207:     \G Equivalent to @code{\} but used as a tag to annotate definition
  208:     \G comments into documentation.
  209:     POSTPONE \ ; immediate
  210: 
  211: \ \ object oriented search list                         17mar93py
  212: 
  213: \ word list structure:
  214: 
  215: struct
  216:   cell% field find-method   \ xt: ( c_addr u wid -- nt )
  217:   cell% field reveal-method \ xt: ( nt wid -- ) \ used by dofield:, must be field
  218:   cell% field rehash-method \ xt: ( wid -- )	   \ re-initializes a "search-data" (hashtables)
  219:   cell% field hash-method   \ xt: ( wid -- )    \ initializes ""
  220: \   \ !! what else
  221: end-struct wordlist-map-struct
  222: 
  223: struct
  224:   cell% field wordlist-map \ pointer to a wordlist-map-struct
  225:   cell% field wordlist-id \ linked list of words (for WORDS etc.)
  226:   cell% field wordlist-link \ link field to other wordlists
  227:   cell% field wordlist-extend \ wordlist extensions (eg bucket offset)
  228: end-struct wordlist-struct
  229: 
  230: : f83find      ( addr len wordlist -- nt / false )
  231:     wordlist-id @ (f83find) ;
  232: 
  233: : initvoc		( wid -- )
  234:   dup wordlist-map @ hash-method perform ;
  235: 
  236: \ Search list table: find reveal
  237: Create f83search ( -- wordlist-map )
  238:     ' f83find A,  ' drop A,  ' drop A, ' drop A,
  239: 
  240: here G f83search T A, NIL A, NIL A, NIL A,
  241: AValue forth-wordlist \ variable, will be redefined by search.fs
  242: 
  243: AVariable lookup       	forth-wordlist lookup !
  244: \ !! last is user and lookup?! jaw
  245: AVariable current ( -- addr ) \ gforth
  246: \G @code{Variable} -- holds the wid of the current compilation word list.
  247: AVariable voclink	forth-wordlist wordlist-link voclink !
  248: \ lookup AValue context ( -- addr ) \ gforth
  249: Defer context ( -- addr ) \ gforth
  250: \G @code{context} @code{@@} is the wid of the word list at the
  251: \G top of the search order stack.
  252: 
  253: ' lookup is context
  254: forth-wordlist current !
  255: 
  256: \ \ header, finding, ticks                              17dec92py
  257: 
  258: hex
  259: 80 constant alias-mask \ set when the word is not an alias!
  260: 40 constant immediate-mask
  261: 20 constant restrict-mask
  262: 
  263: \ higher level parts of find
  264: 
  265: : flag-sign ( f -- 1|-1 )
  266:     \ true becomes 1, false -1
  267:     0= 2* 1+ ;
  268: 
  269: : compile-only-error ( ... -- )
  270:     -&14 throw ;
  271: 
  272: : (cfa>int) ( cfa -- xt )
  273: [ has? compiler [IF] ]
  274:     dup interpret/compile?
  275:     if
  276: 	interpret/compile-int @
  277:     then 
  278: [ [THEN] ] ;
  279: 
  280: : (x>int) ( cfa b -- xt )
  281:     \ get interpretation semantics of name
  282:     restrict-mask and
  283:     if
  284: 	drop ['] compile-only-error
  285:     else
  286: 	(cfa>int)
  287:     then ;
  288: 
  289: : name>string ( nt -- addr count ) \ gforth     head-to-string
  290:     \g @i{addr count} is the name of the word represented by @i{nt}.
  291:     cell+ count $1F and ;
  292: 
  293: : ((name>))  ( nfa -- cfa )
  294:     name>string + cfaligned ;
  295: 
  296: : (name>x) ( nfa -- cfa b )
  297:     \ cfa is an intermediate cfa and b is the flags byte of nfa
  298:     dup ((name>))
  299:     swap cell+ c@ dup alias-mask and 0=
  300:     IF
  301:         swap @ swap
  302:     THEN ;
  303: 
  304: : name>int ( nt -- xt ) \ gforth
  305:     \G @i{xt} represents the interpretation semantics of the word
  306:     \G @i{nt}. If @i{nt} has no interpretation semantics (i.e. is
  307:     \G @code{compile-only}), @i{xt} is the execution token for
  308:     \G @code{compile-only-error}, which performs @code{-14 throw}.
  309:     (name>x) (x>int) ;
  310: 
  311: : name?int ( nt -- xt ) \ gforth
  312:     \G Like @code{name>int}, but perform @code{-14 throw} if @i{nt}
  313:     \G has no interpretation semantics.
  314:     (name>x) restrict-mask and
  315:     if
  316: 	compile-only-error \ does not return
  317:     then
  318:     (cfa>int) ;
  319: 
  320: : (name>comp) ( nt -- w +-1 ) \ gforth
  321:     \G @i{w xt} is the compilation token for the word @i{nt}.
  322:     (name>x) >r 
  323: [ has? compiler [IF] ]
  324:     dup interpret/compile?
  325:     if
  326:         interpret/compile-comp @
  327:     then 
  328: [ [THEN] ]
  329:     r> immediate-mask and flag-sign
  330:     ;
  331: 
  332: : (name>intn) ( nfa -- xt +-1 )
  333:     (name>x) tuck (x>int) ( b xt )
  334:     swap immediate-mask and flag-sign ;
  335: 
  336: const Create ???  0 , 3 c, char ? c, char ? c, char ? c,
  337: \ ??? is used by dovar:, must be created/:dovar
  338: 
  339: [IFDEF] forthstart
  340: \ if we have a forthstart we can define head? with it
  341: \ otherwise leave out the head? check
  342: 
  343: : head? ( addr -- f )
  344:     \G heuristic check whether addr is a name token; may deliver false
  345:     \G positives; addr must be a valid address
  346:     \ we follow the link fields and check for plausibility; two
  347:     \ iterations should catch most false addresses: on the first
  348:     \ iteration, we may get an xt, on the second a code address (or
  349:     \ some code), which is typically not in the dictionary.
  350:     2 0 do
  351: 	dup dup aligned <> if \ protect @ against unaligned accesses
  352: 	    drop false unloop exit
  353: 	then
  354: 	dup @ dup
  355: 	if ( addr addr1 )
  356: 	    dup rot forthstart within
  357: 	    if \ addr1 is outside forthstart..addr, not a head
  358: 		drop false unloop exit
  359: 	    then ( addr1 )
  360: 	else \ 0 in the link field, no further checks
  361: 	    2drop true unloop exit
  362: 	then
  363:     loop
  364:     \ in dubio pro:
  365:     drop true ;
  366: 
  367: : >head ( cfa -- nt ) \ gforth  to-head
  368:     $21 cell do ( cfa )
  369: 	dup i - count $9F and + cfaligned over alias-mask + =
  370: 	if ( cfa )
  371: 	    dup i - cell - dup head?
  372: 	    if
  373: 		nip unloop exit
  374: 	    then
  375: 	    drop
  376: 	then
  377: 	cell +loop
  378:     drop ??? ( wouldn't 0 be better? ) ;
  379: 
  380: [ELSE]
  381: 
  382: : >head ( cfa -- nt ) \ gforth  to-head
  383:     $21 cell do ( cfa )
  384: 	dup i - count $9F and + cfaligned over alias-mask + =
  385: 	if ( cfa ) i - cell - unloop exit
  386: 	then
  387: 	cell +loop
  388:     drop ??? ( wouldn't 0 be better? ) ;
  389: 
  390: [THEN]
  391: 
  392: ' >head ALIAS >name
  393: 
  394: : body> 0 >body - ;
  395: 
  396: : (search-wordlist)  ( addr count wid -- nt | false )
  397:     dup wordlist-map @ find-method perform ;
  398: 
  399: : search-wordlist ( c-addr count wid -- 0 | xt +-1 ) \ search
  400:     \G Search the word list identified by @i{wid}
  401:     \G for the definition named by the string at @i{c-addr count}.
  402:     \G If the definition is not found, return 0. If the definition
  403:     \G is found return 1 (if the definition is immediate) or -1
  404:     \G (if the definition is not immediate) together with the @i{xt}.
  405:     \G The @i{xt} returned represents the interpretation semantics.
  406:     (search-wordlist) dup if
  407: 	(name>intn)
  408:     then ;
  409: 
  410: : find-name ( c-addr u -- nt | 0 ) \ gforth
  411:     \g Find the name @i{c-addr u} in the current search
  412:     \g order. Return its @i{nt}, if found, otherwise 0.
  413:     lookup @ (search-wordlist) ;
  414: 
  415: : sfind ( c-addr u -- 0 / xt +-1  ) \ gforth-obsolete
  416:     find-name dup
  417:     if ( nt )
  418: 	state @
  419: 	if
  420: 	    (name>comp)
  421: 	else
  422: 	    (name>intn)
  423: 	then
  424:    then ;
  425: 
  426: : find ( c-addr -- xt +-1 | c-addr 0 ) \ core,search
  427:     \G Search all word lists in the current search order
  428:     \G for the definition named by the counted string at @i{c-addr}.
  429:     \G If the definition is not found, return 0. If the definition
  430:     \G is found return 1 (if the definition is immediate) or -1
  431:     \G (if the definition is not immediate) together with the @i{xt}.
  432:     dup count sfind dup
  433:     if
  434: 	rot drop
  435:     then ;
  436: 
  437: \ ticks in interpreter
  438: 
  439: : (') ( "name" -- nt ) \ gforth
  440:     name name-too-short?
  441:     find-name dup 0=
  442:     IF
  443: 	drop -&13 throw
  444:     THEN  ;
  445: 
  446: : '    ( "name" -- xt ) \ core	tick
  447:     \g @i{xt} represents @i{name}'s interpretation
  448:     \g semantics. Perform @code{-14 throw} if the word has no
  449:     \g interpretation semantics.
  450:     (') name?int ;
  451: 
  452: has? compiler 0= [IF]	\ interpreter only version of IS and TO
  453: 
  454: : IS ' >body ! ;
  455: ' IS Alias TO
  456: 
  457: [THEN]
  458: 
  459: \ \ the interpreter loop				  mar92py
  460: 
  461: \ interpret                                            10mar92py
  462: 
  463: Defer parser ( c-addr u -- )
  464: Defer name ( -- c-addr count ) \ gforth
  465: \ get the next word from the input buffer
  466: ' (name) IS name
  467: Defer compiler-notfound ( c-addr count -- )
  468: Defer interpreter-notfound ( c-addr count -- )
  469: 
  470: : no.extensions  ( addr u -- )
  471:     2drop -&13 throw ;
  472: ' no.extensions IS compiler-notfound
  473: ' no.extensions IS interpreter-notfound
  474: 
  475: : interpret ( ?? -- ?? ) \ gforth
  476:     \ interpret/compile the (rest of the) input buffer
  477: [ has? backtrace [IF] ]
  478:     rp@ backtrace-rp0 !
  479: [ [THEN] ]
  480:     BEGIN
  481: 	?stack name dup
  482:     WHILE
  483: 	parser
  484:     REPEAT
  485:     2drop ;
  486: 
  487: \ interpreter                                 	30apr92py
  488: 
  489: \ not the most efficient implementations of interpreter and compiler
  490: : interpreter ( c-addr u -- ) 
  491:     2dup find-name dup
  492:     if
  493: 	nip nip name>int execute
  494:     else
  495: 	drop
  496: 	2dup 2>r snumber?
  497: 	IF
  498: 	    2rdrop
  499: 	ELSE
  500: 	    2r> interpreter-notfound
  501: 	THEN
  502:     then ;
  503: 
  504: ' interpreter  IS  parser
  505: 
  506: \ \ Query Evaluate                                 	07apr93py
  507: 
  508: has? file 0= [IF]
  509: : sourceline# ( -- n )  1 ;
  510: [THEN]
  511: 
  512: : refill ( -- flag ) \ core-ext,block-ext,file-ext
  513:     \G Attempt to fill the input buffer from the input source.  When
  514:     \G the input source is the user input device, attempt to receive
  515:     \G input into the terminal input device. If successful, make the
  516:     \G result the input buffer, set @code{>IN} to 0 and return true;
  517:     \G otherwise return false. When the input source is a block, add 1
  518:     \G to the value of @code{BLK} to make the next block the input
  519:     \G source and current input buffer, and set @code{>IN} to 0;
  520:     \G return true if the new value of @code{BLK} is a valid block
  521:     \G number, false otherwise. When the input source is a text file,
  522:     \G attempt to read the next line from the file. If successful,
  523:     \G make the result the current input buffer, set @code{>IN} to 0
  524:     \G and return true; otherwise, return false.  A successful result
  525:     \G includes receipt of a line containing 0 characters.
  526:     [ has? file [IF] ]
  527: 	blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
  528: 	[ [THEN] ]
  529:     tib /line
  530:     [ has? file [IF] ]
  531: 	loadfile @ ?dup
  532: 	IF    read-line throw
  533: 	ELSE
  534: 	    [ [THEN] ]
  535: 	sourceline# 0< IF 2drop false EXIT THEN
  536: 	accept true
  537: 	[ has? file [IF] ]
  538: 	THEN
  539: 	1 loadline +!
  540: 	[ [THEN] ]
  541:     swap #tib ! 0 >in ! ;
  542: 
  543: : query   ( -- ) \ core-ext
  544:     \G Make the user input device the input source. Receive input into
  545:     \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
  546:     \G superceeded by @code{accept}.
  547:     [ has? file [IF] ]
  548: 	blk off loadfile off
  549: 	[ [THEN] ]
  550:     tib /line accept #tib ! 0 >in ! ;
  551: 
  552: \ save-mem extend-mem
  553: 
  554: has? os [IF]
  555: : save-mem	( addr1 u -- addr2 u ) \ gforth
  556:     \g copy a memory block into a newly allocated region in the heap
  557:     swap >r
  558:     dup allocate throw
  559:     swap 2dup r> -rot move ;
  560: 
  561: : extend-mem	( addr1 u1 u -- addr addr2 u2 )
  562:     \ extend memory block allocated from the heap by u aus
  563:     \ the (possibly reallocated piece is addr2 u2, the extension is at addr
  564:     over >r + dup >r resize throw
  565:     r> over r> + -rot ;
  566: [THEN]
  567: 
  568: \ EVALUATE                                              17may93jaw
  569: 
  570: has? file 0= [IF]
  571: : push-file  ( -- )  r>
  572:   tibstack @ >r  >tib @ >r  #tib @ >r
  573:   >tib @ tibstack @ = IF  r@ tibstack +!  THEN
  574:   tibstack @ >tib ! >in @ >r  >r ;
  575: 
  576: : pop-file   ( throw-code -- throw-code )
  577:   r>
  578:   r> >in !  r> #tib !  r> >tib !  r> tibstack !  >r ;
  579: [THEN]
  580: 
  581: : evaluate ( c-addr u -- ) \ core,block
  582:     \G Save the current input source specification. Store @code{-1} in
  583:     \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
  584:     \G @code{0} and make the string @i{c-addr u} the input source
  585:     \G and input buffer. Interpret. When the parse area is empty,
  586:     \G restore the input source specification.
  587:     push-file #tib ! >tib !
  588:     >in off
  589:     [ has? file [IF] ]
  590: 	blk off loadfile off -1 loadline !
  591: 	[ [THEN] ]
  592:     ['] interpret catch
  593:     pop-file throw ;
  594: 
  595: \ \ Quit                                            	13feb93py
  596: 
  597: Defer 'quit
  598: 
  599: Defer .status
  600: 
  601: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
  602: 
  603: : (Query)  ( -- )
  604:     [ has? file [IF] ]
  605: 	loadfile off  blk off loadline off
  606: 	[ [THEN] ]
  607:     refill drop ;
  608: 
  609: : (quit) ( -- )
  610:     \ exits only through THROW etc.
  611: \    sp0 @ cell - handler @ &12 + ! \ !! kludge: fix the stack pointer
  612:     \ stored in the system's CATCH frame, so the stack depth will be 0
  613:     \ after the next THROW it catches (it may be off due to BOUNCEs or
  614:     \ because process-args left something on the stack)
  615:     BEGIN
  616: 	.status cr (query) interpret prompt
  617:     AGAIN ;
  618: 
  619: ' (quit) IS 'quit
  620: 
  621: \ \ DOERROR (DOERROR)                        		13jun93jaw
  622: 
  623: 8 Constant max-errors
  624: Variable error-stack  0 error-stack !
  625: max-errors 6 * cells allot
  626: \ format of one cell:
  627: \ source ( addr u )
  628: \ >in
  629: \ line-number
  630: \ Loadfilename ( addr u )
  631: 
  632: : dec. ( n -- ) \ gforth
  633:     \G Display @i{n} as a signed decimal number, followed by a space.
  634:     \ !! not used...
  635:     base @ decimal swap . base ! ;
  636: 
  637: : dec.r ( u -- ) \ gforth
  638:     \G Display @i{u} as a unsigned decimal number
  639:     base @ decimal swap 0 .r base ! ;
  640: 
  641: : hex. ( u -- ) \ gforth
  642:     \G Display @i{u} as an unsigned hex number, prefixed with a "$" and
  643:     \G followed by a space.
  644:     \ !! not used...
  645:     [char] $ emit base @ swap hex u. base ! ;
  646: 
  647: : typewhite ( addr u -- ) \ gforth
  648:     \G Like type, but white space is printed instead of the characters.
  649:     bounds ?do
  650: 	i c@ #tab = if \ check for tab
  651: 	    #tab
  652: 	else
  653: 	    bl
  654: 	then
  655: 	emit
  656:     loop ;
  657: 
  658: DEFER DOERROR
  659: 
  660: has? backtrace [IF]
  661: Defer dobacktrace ( -- )
  662: ' noop IS dobacktrace
  663: [THEN]
  664: 
  665: : .error-string ( throw-code -- )
  666:   dup -2 = 
  667:   IF 	"error @ ?dup IF count type  THEN drop
  668:   ELSE	.error
  669:   THEN ;
  670: 
  671: : .error-frame ( throwcode addr1 u1 n1 n2 addr2 u2 -- throwcode )
  672: \ addr2 u2: 	filename of included file
  673: \ n2:		line number
  674: \ n1:		error position in input line
  675: \ addr1 u1:	input line
  676: 
  677:   cr error-stack @
  678:   IF
  679:      ." in file included from "
  680:      type ." :" dec.r  drop 2drop
  681:   ELSE
  682:      type ." :" dec.r ." : " 3 pick .error-string cr
  683:      dup 2over type cr drop
  684:      nip -trailing 1- ( line-start index2 )
  685:      0 >r  BEGIN
  686:                   2dup + c@ bl >  WHILE
  687: 		  r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
  688:      ( line-start index1 )
  689:      typewhite
  690:      r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
  691:                   [char] ^ emit
  692:      loop
  693:   THEN ;
  694: 
  695: : (DoError) ( throw-code -- )
  696:   [ has? os [IF] ]
  697:       >stderr
  698:   [ [THEN] ] 
  699:   sourceline# IF
  700:       source >in @ sourceline# 0 0 .error-frame
  701:   THEN
  702:   error-stack @ 0 ?DO
  703:     -1 error-stack +!
  704:     error-stack dup @ 6 * cells + cell+
  705:     6 cells bounds DO
  706:       I @
  707:     cell +LOOP
  708:     .error-frame
  709:   LOOP
  710:   drop 
  711: [ has? backtrace [IF] ]
  712:   dobacktrace
  713: [ [THEN] ]
  714:   normal-dp dpp ! ;
  715: 
  716: ' (DoError) IS DoError
  717: 
  718: : quit ( ?? -- ?? ) \ core
  719:     \G Empty the return stack, make the user input device
  720:     \G the input source, enter interpret state and start
  721:     \G the text interpreter.
  722:     rp0 @ rp! handler off clear-tibstack >tib @ >r
  723:     BEGIN
  724: 	[ has? compiler [IF] ]
  725: 	postpone [
  726: 	[ [THEN] ]
  727: 	['] 'quit CATCH dup
  728:     WHILE
  729: 	<# \ reset hold area, or we may get another error
  730: 	DoError r@ >tib ! r@ tibstack !
  731:     REPEAT
  732:     drop r> >tib ! ;
  733: 
  734: \ \ Cold Boot                                    	13feb93py
  735: 
  736: : (bootmessage)
  737:     ." GForth " version-string type 
  738:     ." , Copyright (C) 1998 Free Software Foundation, Inc." cr
  739:     ." GForth comes with ABSOLUTELY NO WARRANTY; for details type `license'"
  740: [ has? os [IF] ]
  741:      cr ." Type `bye' to exit"
  742: [ [THEN] ] ;
  743: 
  744: defer bootmessage
  745: defer process-args
  746: 
  747: ' (bootmessage) IS bootmessage
  748: 
  749: Defer 'cold ( -- ) \ gforth  tick-cold
  750: \ hook (deferred word) for things to do right before interpreting the
  751: \ command-line arguments
  752: ' noop IS 'cold
  753: 
  754: 
  755: Variable init8
  756: 
  757: : cold ( -- ) \ gforth
  758: [ has? file [IF] ]
  759:     pathstring 2@ fpath only-path 
  760:     init-included-files
  761: [ [THEN] ]
  762:     'cold
  763:     init8 chainperform
  764: [ has? file [IF] ]
  765:     process-args
  766:     loadline off
  767: [ [THEN] ]
  768:     bootmessage
  769:     quit ;
  770: 
  771: : clear-tibstack ( -- )
  772: [ has? glocals [IF] ]
  773:     lp@ forthstart 7 cells + @ - 
  774: [ [ELSE] ]
  775:     [ has? os [IF] ]
  776:     r0 @ forthstart 6 cells + @ -
  777:     [ [ELSE] ]
  778:     sp@ $10 cells +
  779:     [ [THEN] ]
  780: [ [THEN] ]
  781:     dup >tib ! tibstack ! #tib off >in off ;
  782: 
  783: : boot ( path **argv argc -- )
  784:     main-task up!
  785: [ has? os [IF] ]
  786:     stdout TO outfile-id
  787:     stdin  TO infile-id
  788: \ !! [ [THEN] ]
  789: \ !! [ has? file [IF] ]
  790:     argc ! argv ! pathstring 2!
  791: [ [THEN] ]
  792:     sp@ sp0 !
  793:     clear-tibstack
  794:     rp@ rp0 !
  795: [ has? floating [IF] ]
  796:     fp@ fp0 !
  797: [ [THEN] ]
  798:     ['] cold catch DoError cr
  799: [ has? os [IF] ]
  800:     1 (bye) \ !! determin exit code from throw code?
  801: [ [THEN] ]
  802: ;
  803: 
  804: has? os [IF]
  805: : bye ( -- ) \ tools-ext
  806: [ has? file [IF] ]
  807:     script? 0= IF  cr  THEN
  808: [ [ELSE] ]
  809:     cr
  810: [ [THEN] ]
  811:     0 (bye) ;
  812: [THEN]
  813: 
  814: \ **argv may be scanned by the C starter to get some important
  815: \ information, as -display and -geometry for an X client FORTH
  816: \ or space and stackspace overrides
  817: 
  818: \ 0 arg contains, however, the name of the program.
  819: 

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