Annotation of gforth/kernel.fs, revision 1.1

1.1     ! pazsan      1: \ kernel.fs    GForth kernel                        17dec92py
        !             2: 
        !             3: \ Copyright (C) 1995 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: \ Idea and implementation: Bernd Paysan (py)
        !            22: 
        !            23: \ Log:  ', '- usw. durch [char] ... ersetzt
        !            24: \       man sollte die unterschiedlichen zahlensysteme
        !            25: \       mit $ und & zumindest im interpreter weglassen
        !            26: \       schon erledigt!
        !            27: \       11may93jaw
        !            28: \ name>         0= nicht vorhanden              17may93jaw
        !            29: \               nfa can be lfa or nfa!
        !            30: \ find          splited into find and (find)
        !            31: \               (find) for later use            17may93jaw
        !            32: \ search        replaced by lookup because
        !            33: \               it is a word of the string wordset
        !            34: \                                               20may93jaw
        !            35: \ postpone      added immediate                 21may93jaw
        !            36: \ to            added immediate                 07jun93jaw
        !            37: \ cfa, header   put "here lastcfa !" in
        !            38: \               cfa, this is more logical
        !            39: \               and noname: works wothout
        !            40: \               extra "here lastcfa !"          08jun93jaw
        !            41: \ (parse-white) thrown out
        !            42: \ refill        added outer trick
        !            43: \               to show there is something
        !            44: \               going on                        09jun93jaw
        !            45: \ leave ?leave  somebody forgot UNLOOP!!!       09jun93jaw
        !            46: \ leave ?leave  unloop thrown out
        !            47: \               unloop after loop is used       10jun93jaw
        !            48: 
        !            49: HEX
        !            50: 
        !            51: \ labels for some code addresses
        !            52: 
        !            53: : docon: ( -- addr )   \ gforth
        !            54:     \ the code address of a @code{CONSTANT}
        !            55:     ['] bl >code-address ;
        !            56: 
        !            57: : docol: ( -- addr )   \ gforth
        !            58:     \ the code address of a colon definition
        !            59:     ['] docon: >code-address ;
        !            60: 
        !            61: : dovar: ( -- addr )   \ gforth
        !            62:     \ the code address of a @code{CREATE}d word
        !            63:     ['] udp >code-address ;
        !            64: 
        !            65: : douser: ( -- addr )  \ gforth
        !            66:     \ the code address of a @code{USER} variable
        !            67:     ['] s0 >code-address ;
        !            68: 
        !            69: : dodefer: ( -- addr ) \ gforth
        !            70:     \ the code address of a @code{defer}ed word
        !            71:     ['] source >code-address ;
        !            72: 
        !            73: : dofield: ( -- addr ) \ gforth
        !            74:     \ the code address of a @code{field}
        !            75:     ['] reveal-method >code-address ;
        !            76: 
        !            77: NIL AConstant NIL \ gforth
        !            78: 
        !            79: \ Bit string manipulation                              06oct92py
        !            80: 
        !            81: \ Create bits  80 c, 40 c, 20 c, 10 c, 8 c, 4 c, 2 c, 1 c,
        !            82: \ DOES> ( n -- )  + c@ ;
        !            83: 
        !            84: \ : >bit  ( addr n -- c-addr mask )  8 /mod rot + swap bits ;
        !            85: \ : +bit  ( addr n -- )  >bit over c@ or swap c! ;
        !            86: 
        !            87: \ : relinfo ( -- addr )  forthstart dup @ + !!bug!! ;
        !            88: \ : >rel  ( addr -- n )  forthstart - ;
        !            89: \ : relon ( addr -- )  relinfo swap >rel cell / +bit ;
        !            90: 
        !            91: \ here allot , c, A,                                   17dec92py
        !            92: 
        !            93: : dp   ( -- addr ) \ gforth
        !            94:     dpp @ ;
        !            95: : here  ( -- here ) \ core
        !            96:     dp @ ;
        !            97: : allot ( n -- ) \ core
        !            98:     dp +! ;
        !            99: : c,    ( c -- ) \ core
        !           100:     here 1 chars allot c! ;
        !           101: : ,     ( x -- ) \ core
        !           102:     here cell allot  ! ;
        !           103: : 2,   ( w1 w2 -- ) \ gforth
        !           104:     here 2 cells allot 2! ;
        !           105: 
        !           106: \ : aligned ( addr -- addr' ) \ core
        !           107: \     [ cell 1- ] Literal + [ -1 cells ] Literal and ;
        !           108: : align ( -- ) \ core
        !           109:     here dup aligned swap ?DO  bl c,  LOOP ;
        !           110: 
        !           111: \ : faligned ( addr -- f-addr ) \ float
        !           112: \     [ 1 floats 1- ] Literal + [ -1 floats ] Literal and ;
        !           113: 
        !           114: : falign ( -- ) \ float
        !           115:     here dup faligned swap
        !           116:     ?DO
        !           117:        bl c,
        !           118:     LOOP ;
        !           119: 
        !           120: \ !! this is machine-dependent, but works on all but the strangest machines
        !           121: ' faligned Alias maxaligned ( addr1 -- addr2 ) \ gforth
        !           122: ' falign Alias maxalign ( -- ) \ gforth
        !           123: 
        !           124: \ !! machine-dependent and won't work if "0 >body" <> "0 >body maxaligned"
        !           125: ' maxaligned Alias cfaligned ( addr1 -- addr2 ) \ gforth
        !           126: \ the code field is aligned if its body is maxaligned
        !           127: ' maxalign Alias cfalign ( -- ) \ gforth
        !           128: 
        !           129: : chars ( n1 -- n2 ) \ core
        !           130: ; immediate
        !           131: 
        !           132: 
        !           133: \ : A!    ( addr1 addr2 -- ) \ gforth
        !           134: \    dup relon ! ;
        !           135: \ : A,    ( addr -- ) \ gforth
        !           136: \    here cell allot A! ;
        !           137: ' ! alias A! ( addr1 addr2 -- ) \ gforth
        !           138: ' , alias A, ( addr -- ) \ gforth 
        !           139: 
        !           140: 
        !           141: \ on off                                               23feb93py
        !           142: 
        !           143: : on  ( addr -- ) \ gforth
        !           144:     true  swap ! ;
        !           145: : off ( addr -- ) \ gforth
        !           146:     false swap ! ;
        !           147: 
        !           148: \ dabs roll                                           17may93jaw
        !           149: 
        !           150: : dabs ( d1 -- d2 ) \ double
        !           151:     dup 0< IF dnegate THEN ;
        !           152: 
        !           153: : roll  ( x0 x1 .. xn n -- x1 .. xn x0 ) \ core-ext
        !           154:   dup 1+ pick >r
        !           155:   cells sp@ cell+ dup cell+ rot move drop r> ;
        !           156: 
        !           157: \ name> found                                          17dec92py
        !           158: 
        !           159: $80 constant alias-mask \ set when the word is not an alias!
        !           160: $40 constant immediate-mask
        !           161: $20 constant restrict-mask
        !           162: 
        !           163: : ((name>))  ( nfa -- cfa )
        !           164:     name>string +  cfaligned ;
        !           165: 
        !           166: : (name>x) ( nfa -- cfa b )
        !           167:     \ cfa is an intermediate cfa and b is the flags byte of nfa
        !           168:     dup ((name>))
        !           169:     swap cell+ c@ dup alias-mask and 0=
        !           170:     IF
        !           171:        swap @ swap
        !           172:     THEN ;
        !           173: 
        !           174: \ place bounds                                         13feb93py
        !           175: 
        !           176: : place  ( addr len to -- ) \ gforth
        !           177:     over >r  rot over 1+  r> move c! ;
        !           178: : bounds ( beg count -- end beg ) \ gforth
        !           179:     over + swap ;
        !           180: 
        !           181: : save-mem     ( addr1 u -- addr2 u ) \ gforth
        !           182:     \ copy a memory block into a newly allocated region in the heap
        !           183:     swap >r
        !           184:     dup allocate throw
        !           185:     swap 2dup r> -rot move ;
        !           186: 
        !           187: : extend-mem   ( addr1 u1 u -- addr addr2 u2 )
        !           188:     \ extend memory block allocated from the heap by u aus
        !           189:     \ the (possibly reallocated piece is addr2 u2, the extension is at addr
        !           190:     over >r + dup >r resize throw
        !           191:     r> over r> + -rot ;
        !           192: 
        !           193: \ input stream primitives                              23feb93py
        !           194: 
        !           195: : tib ( -- c-addr ) \ core-ext
        !           196:     \ obsolescent
        !           197:     >tib @ ;
        !           198: Defer source ( -- addr count ) \ core
        !           199: \ used by dodefer:, must be defer
        !           200: : (source) ( -- addr count )
        !           201:     tib #tib @ ;
        !           202: ' (source) IS source
        !           203: 
        !           204: \ (word)                                               22feb93py
        !           205: 
        !           206: : scan   ( addr1 n1 char -- addr2 n2 ) \ gforth
        !           207:     \ skip all characters not equal to char
        !           208:     >r
        !           209:     BEGIN
        !           210:        dup
        !           211:     WHILE
        !           212:        over c@ r@ <>
        !           213:     WHILE
        !           214:        1 /string
        !           215:     REPEAT  THEN
        !           216:     rdrop ;
        !           217: : skip   ( addr1 n1 char -- addr2 n2 ) \ gforth
        !           218:     \ skip all characters equal to char
        !           219:     >r
        !           220:     BEGIN
        !           221:        dup
        !           222:     WHILE
        !           223:        over c@ r@  =
        !           224:     WHILE
        !           225:        1 /string
        !           226:     REPEAT  THEN
        !           227:     rdrop ;
        !           228: 
        !           229: : (word) ( addr1 n1 char -- addr2 n2 )
        !           230:   dup >r skip 2dup r> scan  nip - ;
        !           231: 
        !           232: \ (word) should fold white spaces
        !           233: \ this is what (parse-white) does
        !           234: 
        !           235: \ word parse                                           23feb93py
        !           236: 
        !           237: : parse-word  ( char -- addr len ) \ gforth
        !           238:   source 2dup >r >r >in @ over min /string
        !           239:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
        !           240:   2dup + r> - 1+ r> min >in ! ;
        !           241: : word   ( char -- addr ) \ core
        !           242:   parse-word here place  bl here count + c!  here ;
        !           243: 
        !           244: : parse    ( char -- addr len ) \ core-ext
        !           245:   >r  source  >in @ over min /string  over  swap r>  scan >r
        !           246:   over - dup r> IF 1+ THEN  >in +! ;
        !           247: 
        !           248: \ name                                                 13feb93py
        !           249: 
        !           250: : capitalize ( addr len -- addr len ) \ gforth
        !           251:   2dup chars chars bounds
        !           252:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
        !           253: : (name) ( -- c-addr count )
        !           254:     source 2dup >r >r >in @ /string (parse-white)
        !           255:     2dup + r> - 1+ r> min >in ! ;
        !           256: \    name count ;
        !           257: 
        !           258: : name-too-short? ( c-addr u -- c-addr u )
        !           259:     dup 0= -&16 and throw ;
        !           260: 
        !           261: : name-too-long? ( c-addr u -- c-addr u )
        !           262:     dup $1F u> -&19 and throw ;
        !           263: 
        !           264: \ Literal                                              17dec92py
        !           265: 
        !           266: : Literal  ( compilation n -- ; run-time -- n ) \ core
        !           267:     postpone lit  , ; immediate restrict
        !           268: : ALiteral ( compilation addr -- ; run-time -- addr ) \ gforth
        !           269:     postpone lit A, ; immediate restrict
        !           270: 
        !           271: : char   ( 'char' -- n ) \ core
        !           272:     bl word char+ c@ ;
        !           273: : [char] ( compilation 'char' -- ; run-time -- n )
        !           274:     char postpone Literal ; immediate restrict
        !           275: 
        !           276: : (compile) ( -- ) \ gforth
        !           277:     r> dup cell+ >r @ compile, ;
        !           278: 
        !           279: \ not the most efficient implementation of POSTPONE, but simple
        !           280: : POSTPONE ( -- ) \ core
        !           281:     COMP' swap POSTPONE aliteral compile, ; immediate restrict
        !           282: 
        !           283: : interpret/compile: ( interp-xt comp-xt "name" -- )
        !           284:     Create immediate swap A, A,
        !           285: DOES>
        !           286:     abort" executed primary cfa of an interpret/compile: word" ;
        !           287: \    state @ IF  cell+  THEN  perform ;
        !           288: 
        !           289: \ Use (compile) for the old behavior of compile!
        !           290: 
        !           291: \ digit?                                               17dec92py
        !           292: 
        !           293: : digit?   ( char -- digit true/ false ) \ gforth
        !           294:   base @ $100 =
        !           295:   IF
        !           296:     true EXIT
        !           297:   THEN
        !           298:   toupper [char] 0 - dup 9 u> IF
        !           299:     [ 'A '9 1 + -  ] literal -
        !           300:     dup 9 u<= IF
        !           301:       drop false EXIT
        !           302:     THEN
        !           303:   THEN
        !           304:   dup base @ u>= IF
        !           305:     drop false EXIT
        !           306:   THEN
        !           307:   true ;
        !           308: 
        !           309: : accumulate ( +d0 addr digit - +d1 addr )
        !           310:   swap >r swap  base @  um* drop rot  base @  um* d+ r> ;
        !           311: 
        !           312: : >number ( d addr count -- d addr count ) \ core
        !           313:     0
        !           314:     ?DO
        !           315:        count digit?
        !           316:     WHILE
        !           317:        accumulate
        !           318:     LOOP
        !           319:         0
        !           320:     ELSE
        !           321:        1- I' I -
        !           322:        UNLOOP
        !           323:     THEN ;
        !           324: 
        !           325: \ number? number                                       23feb93py
        !           326: 
        !           327: Create bases   10 ,   2 ,   A , 100 ,
        !           328: \              16     2    10   Zeichen
        !           329: \ !! this saving and restoring base is an abomination! - anton
        !           330: : getbase ( addr u -- addr' u' )
        !           331:     over c@ [char] $ - dup 4 u<
        !           332:     IF
        !           333:        cells bases + @ base ! 1 /string
        !           334:     ELSE
        !           335:        drop
        !           336:     THEN ;
        !           337: : s>number ( addr len -- d )
        !           338:     base @ >r  dpl on
        !           339:     over c@ '- =  dup >r
        !           340:     IF
        !           341:        1 /string
        !           342:     THEN
        !           343:     getbase  dpl on  0 0 2swap
        !           344:     BEGIN
        !           345:        dup >r >number dup
        !           346:     WHILE
        !           347:        dup r> -
        !           348:     WHILE
        !           349:        dup dpl ! over c@ [char] . =
        !           350:     WHILE
        !           351:        1 /string
        !           352:     REPEAT  THEN
        !           353:         2drop rdrop dpl off
        !           354:     ELSE
        !           355:        2drop rdrop r>
        !           356:        IF
        !           357:            dnegate
        !           358:        THEN
        !           359:     THEN
        !           360:     r> base ! ;
        !           361: 
        !           362: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
        !           363:     s>number dpl @ 0=
        !           364:     IF
        !           365:        2drop false  EXIT
        !           366:     THEN
        !           367:     dpl @ dup 0> 0= IF
        !           368:        nip
        !           369:     THEN ;
        !           370: : number? ( string -- string 0 / n -1 / d 0> )
        !           371:     dup >r count snumber? dup if
        !           372:        rdrop
        !           373:     else
        !           374:        r> swap
        !           375:     then ;
        !           376: : s>d ( n -- d ) \ core                s-to-d
        !           377:     dup 0< ;
        !           378: : number ( string -- d )
        !           379:     number? ?dup 0= abort" ?"  0<
        !           380:     IF
        !           381:        s>d
        !           382:     THEN ;
        !           383: 
        !           384: \ space spaces ud/mod                                  21mar93py
        !           385: decimal
        !           386: Create spaces ( u -- ) \ core
        !           387: bl 80 times \ times from target compiler! 11may93jaw
        !           388: DOES>   ( u -- )
        !           389:     swap
        !           390:     0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
        !           391: Create backspaces
        !           392: 08 80 times \ times from target compiler! 11may93jaw
        !           393: DOES>   ( u -- )
        !           394:     swap
        !           395:     0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
        !           396: hex
        !           397: : space ( -- ) \ core
        !           398:     1 spaces ;
        !           399: 
        !           400: : ud/mod ( ud1 u2 -- urem udquot ) \ gforth
        !           401:     >r 0 r@ um/mod r> swap >r
        !           402:     um/mod r> ;
        !           403: 
        !           404: : pad    ( -- addr ) \ core-ext
        !           405:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
        !           406: 
        !           407: \ hold <# #> sign # #s                                 25jan92py
        !           408: 
        !           409: : hold    ( char -- ) \ core
        !           410:     pad cell - -1 chars over +! @ c! ;
        !           411: 
        !           412: : <# ( -- ) \ core     less-number-sign
        !           413:     pad cell - dup ! ;
        !           414: 
        !           415: : #>      ( xd -- addr u ) \ core      number-sign-greater
        !           416:     2drop pad cell - dup @ tuck - ;
        !           417: 
        !           418: : sign    ( n -- ) \ core
        !           419:     0< IF  [char] - hold  THEN ;
        !           420: 
        !           421: : #       ( ud1 -- ud2 ) \ core                number-sign
        !           422:     base @ 2 max ud/mod rot 9 over <
        !           423:     IF
        !           424:        [ char A char 9 - 1- ] Literal +
        !           425:     THEN
        !           426:     [char] 0 + hold ;
        !           427: 
        !           428: : #s      ( +d -- 0 0 ) \ core number-sign-s
        !           429:     BEGIN
        !           430:        # 2dup d0=
        !           431:     UNTIL ;
        !           432: 
        !           433: \ print numbers                                        07jun92py
        !           434: 
        !           435: : d.r ( d n -- ) \ double      d-dot-r
        !           436:     >r tuck  dabs  <# #s  rot sign #>
        !           437:     r> over - spaces  type ;
        !           438: 
        !           439: : ud.r ( ud n -- ) \ gforth    u-d-dot-r
        !           440:     >r <# #s #> r> over - spaces type ;
        !           441: 
        !           442: : .r ( n1 n2 -- ) \ core-ext   dot-r
        !           443:     >r s>d r> d.r ;
        !           444: : u.r ( u n -- )  \ core-ext   u-dot-r
        !           445:     0 swap ud.r ;
        !           446: 
        !           447: : d. ( d -- ) \ double d-dot
        !           448:     0 d.r space ;
        !           449: : ud. ( ud -- ) \ gforth       u-d-dot
        !           450:     0 ud.r space ;
        !           451: 
        !           452: : . ( n -- ) \ core    dot
        !           453:     s>d d. ;
        !           454: : u. ( u -- ) \ core   u-dot
        !           455:     0 ud. ;
        !           456: 
        !           457: \ catch throw                                          23feb93py
        !           458: \ bounce                                                08jun93jaw
        !           459: 
        !           460: \ !! allow the user to add rollback actions    anton
        !           461: \ !! use a separate exception stack?           anton
        !           462: 
        !           463: : lp@ ( -- addr ) \ gforth     l-p-fetch
        !           464:  laddr# [ 0 , ] ;
        !           465: 
        !           466: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error ) \ exception
        !           467:   >r sp@ r> swap >r       \ don't count xt! jaw
        !           468:   fp@ >r
        !           469:   lp@ >r
        !           470:   handler @ >r
        !           471:   rp@ handler !
        !           472:   execute
        !           473:   r> handler ! rdrop rdrop rdrop 0 ;
        !           474: 
        !           475: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error ) \ exception
        !           476:     ?DUP IF
        !           477:        [ here 9 cells ! ]
        !           478:        handler @ rp!
        !           479:        r> handler !
        !           480:        r> lp!
        !           481:        r> fp!
        !           482:        r> swap >r sp! r>
        !           483:     THEN ;
        !           484: 
        !           485: \ Bouncing is very fine,
        !           486: \ programming without wasting time...   jaw
        !           487: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym ) \ gforth
        !           488: \ a throw without data or fp stack restauration
        !           489:   ?DUP IF
        !           490:     handler @ rp!
        !           491:     r> handler !
        !           492:     r> lp!
        !           493:     rdrop
        !           494:     rdrop
        !           495:   THEN ;
        !           496: 
        !           497: \ ?stack                                               23feb93py
        !           498: 
        !           499: : ?stack ( ?? -- ?? ) \ gforth
        !           500:     sp@ s0 @ > IF    -4 throw  THEN
        !           501:     fp@ f0 @ > IF  -&45 throw  THEN  ;
        !           502: \ ?stack should be code -- it touches an empty stack!
        !           503: 
        !           504: \ interpret                                            10mar92py
        !           505: 
        !           506: Defer parser
        !           507: Defer name ( -- c-addr count ) \ gforth
        !           508: \ get the next word from the input buffer
        !           509: ' (name) IS name
        !           510: Defer compiler-notfound ( c-addr count -- )
        !           511: Defer interpreter-notfound ( c-addr count -- )
        !           512: 
        !           513: : no.extensions  ( addr u -- )
        !           514:     2drop -&13 bounce ;
        !           515: ' no.extensions IS compiler-notfound
        !           516: ' no.extensions IS interpreter-notfound
        !           517: 
        !           518: : compile-only-error ( ... -- )
        !           519:     -&14 throw ;
        !           520: 
        !           521: : interpret ( ?? -- ?? ) \ gforth
        !           522:     \ interpret/compile the (rest of the) input buffer
        !           523:     BEGIN
        !           524:        ?stack name dup
        !           525:     WHILE
        !           526:        parser
        !           527:     REPEAT
        !           528:     2drop ;
        !           529: 
        !           530: \ interpreter compiler                                 30apr92py
        !           531: 
        !           532: \ not the most efficient implementations of interpreter and compiler
        !           533: : interpreter ( c-addr u -- ) 
        !           534:     2dup find-name dup
        !           535:     if
        !           536:        nip nip name>int execute
        !           537:     else
        !           538:        drop
        !           539:        2dup 2>r snumber?
        !           540:        IF
        !           541:            2rdrop
        !           542:        ELSE
        !           543:            2r> interpreter-notfound
        !           544:        THEN
        !           545:     then ;
        !           546: 
        !           547: : compiler ( c-addr u -- )
        !           548:     2dup find-name dup
        !           549:     if ( c-addr u nfa )
        !           550:        nip nip name>comp execute
        !           551:     else
        !           552:        drop
        !           553:        2dup snumber? dup
        !           554:        IF
        !           555:            0>
        !           556:            IF
        !           557:                swap postpone Literal
        !           558:            THEN
        !           559:            postpone Literal
        !           560:            2drop
        !           561:        ELSE
        !           562:            drop compiler-notfound
        !           563:        THEN
        !           564:     then ;
        !           565: 
        !           566: ' interpreter  IS  parser
        !           567: 
        !           568: : [ ( -- ) \ core      left-bracket
        !           569:     ['] interpreter  IS parser state off ; immediate
        !           570: : ] ( -- ) \ core      right-bracket
        !           571:     ['] compiler     IS parser state on  ;
        !           572: 
        !           573: \ locals stuff needed for control structures
        !           574: 
        !           575: : compile-lp+! ( n -- ) \ gforth       compile-l-p-plus-store
        !           576:     dup negate locals-size +!
        !           577:     0 over = if
        !           578:     else -1 cells  over = if postpone lp-
        !           579:     else  1 floats over = if postpone lp+
        !           580:     else  2 floats over = if postpone lp+2
        !           581:     else postpone lp+!# dup ,
        !           582:     then then then then drop ;
        !           583: 
        !           584: : adjust-locals-size ( n -- ) \ gforth
        !           585:     \ sets locals-size to n and generates an appropriate lp+!
        !           586:     locals-size @ swap - compile-lp+! ;
        !           587: 
        !           588: 
        !           589: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
        !           590: AConstant locals-list \ acts like a variable that contains
        !           591:                      \ a linear list of locals names
        !           592: 
        !           593: 
        !           594: variable dead-code \ true if normal code at "here" would be dead
        !           595: variable backedge-locals
        !           596:     \ contains the locals list that BEGIN will assume to be live on
        !           597:     \ the back edge if the BEGIN is unreachable from above. Set by
        !           598:     \ ASSUME-LIVE, reset by UNREACHABLE.
        !           599: 
        !           600: : UNREACHABLE ( -- ) \ gforth
        !           601:     \ declares the current point of execution as unreachable
        !           602:     dead-code on
        !           603:     0 backedge-locals ! ; immediate
        !           604: 
        !           605: : ASSUME-LIVE ( orig -- orig ) \ gforth
        !           606:     \ used immediatly before a BEGIN that is not reachable from
        !           607:     \ above.  causes the BEGIN to assume that the same locals are live
        !           608:     \ as at the orig point
        !           609:     dup orig?
        !           610:     2 pick backedge-locals ! ; immediate
        !           611:     
        !           612: \ locals list operations
        !           613: 
        !           614: : common-list ( list1 list2 -- list3 ) \ gforth-internal
        !           615: \ list1 and list2 are lists, where the heads are at higher addresses than
        !           616: \ the tail. list3 is the largest sublist of both lists.
        !           617:  begin
        !           618:    2dup u<>
        !           619:  while
        !           620:    2dup u>
        !           621:    if
        !           622:      swap
        !           623:    then
        !           624:    @
        !           625:  repeat
        !           626:  drop ;
        !           627: 
        !           628: : sub-list? ( list1 list2 -- f ) \ gforth-internal
        !           629: \ true iff list1 is a sublist of list2
        !           630:  begin
        !           631:    2dup u<
        !           632:  while
        !           633:    @
        !           634:  repeat
        !           635:  = ;
        !           636: 
        !           637: : list-size ( list -- u ) \ gforth-internal
        !           638: \ size of the locals frame represented by list
        !           639:  0 ( list n )
        !           640:  begin
        !           641:    over 0<>
        !           642:  while
        !           643:    over
        !           644:    ((name>)) >body @ max
        !           645:    swap @ swap ( get next )
        !           646:  repeat
        !           647:  faligned nip ;
        !           648: 
        !           649: : set-locals-size-list ( list -- )
        !           650:  dup locals-list !
        !           651:  list-size locals-size ! ;
        !           652: 
        !           653: : check-begin ( list -- )
        !           654: \ warn if list is not a sublist of locals-list
        !           655:  locals-list @ sub-list? 0= if
        !           656:    \ !! print current position
        !           657:    ." compiler was overly optimistic about locals at a BEGIN" cr
        !           658:    \ !! print assumption and reality
        !           659:  then ;
        !           660: 
        !           661: \ Control Flow Stack
        !           662: \ orig, etc. have the following structure:
        !           663: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
        !           664: \ address (of the branch or the instruction to be branched to) (second)
        !           665: \ locals-list (valid at address) (third)
        !           666: 
        !           667: \ types
        !           668: 0 constant defstart
        !           669: 1 constant live-orig
        !           670: 2 constant dead-orig
        !           671: 3 constant dest \ the loopback branch is always assumed live
        !           672: 4 constant do-dest
        !           673: 5 constant scopestart
        !           674: 
        !           675: : def? ( n -- )
        !           676:     defstart <> abort" unstructured " ;
        !           677: 
        !           678: : orig? ( n -- )
        !           679:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
        !           680: 
        !           681: : dest? ( n -- )
        !           682:  dest <> abort" expected dest " ;
        !           683: 
        !           684: : do-dest? ( n -- )
        !           685:  do-dest <> abort" expected do-dest " ;
        !           686: 
        !           687: : scope? ( n -- )
        !           688:  scopestart <> abort" expected scope " ;
        !           689: 
        !           690: : non-orig? ( n -- )
        !           691:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
        !           692: 
        !           693: : cs-item? ( n -- )
        !           694:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
        !           695: 
        !           696: 3 constant cs-item-size
        !           697: 
        !           698: : CS-PICK ( ... u -- ... destu ) \ tools-ext
        !           699:  1+ cs-item-size * 1- >r
        !           700:  r@ pick  r@ pick  r@ pick
        !           701:  rdrop
        !           702:  dup non-orig? ;
        !           703: 
        !           704: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu ) \ tools-ext
        !           705:  1+ cs-item-size * 1- >r
        !           706:  r@ roll r@ roll r@ roll
        !           707:  rdrop
        !           708:  dup cs-item? ; 
        !           709: 
        !           710: : cs-push-part ( -- list addr )
        !           711:  locals-list @ here ;
        !           712: 
        !           713: : cs-push-orig ( -- orig )
        !           714:  cs-push-part dead-code @
        !           715:  if
        !           716:    dead-orig
        !           717:  else
        !           718:    live-orig
        !           719:  then ;   
        !           720: 
        !           721: \ Structural Conditionals                              12dec92py
        !           722: 
        !           723: : ?struc      ( flag -- )       abort" unstructured " ;
        !           724: : sys?        ( sys -- )        dup 0= ?struc ;
        !           725: : >mark ( -- orig )
        !           726:  cs-push-orig 0 , ;
        !           727: : >resolve    ( addr -- )        here over - swap ! ;
        !           728: : <resolve    ( addr -- )        here - , ;
        !           729: 
        !           730: : BUT
        !           731:     1 cs-roll ;                      immediate restrict
        !           732: : YET
        !           733:     0 cs-pick ;                       immediate restrict
        !           734: 
        !           735: \ Structural Conditionals                              12dec92py
        !           736: 
        !           737: : AHEAD ( compilation -- orig ; run-time -- ) \ tools-ext
        !           738:     POSTPONE branch  >mark  POSTPONE unreachable ; immediate restrict
        !           739: 
        !           740: : IF ( compilation -- orig ; run-time f -- ) \ core
        !           741:  POSTPONE ?branch >mark ; immediate restrict
        !           742: 
        !           743: : ?DUP-IF ( compilation -- orig ; run-time n -- n| ) \ gforth  question-dupe-if
        !           744: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
        !           745: \ better handled by tools like stack checkers. Besides, it's faster.
        !           746:     POSTPONE ?dup-?branch >mark ;       immediate restrict
        !           747: 
        !           748: : ?DUP-0=-IF ( compilation -- orig ; run-time n -- n| ) \ gforth       question-dupe-zero-equals-if
        !           749:     POSTPONE ?dup-0=-?branch >mark ;       immediate restrict
        !           750: 
        !           751: : then-like ( orig -- addr )
        !           752:     swap -rot dead-orig =
        !           753:     if
        !           754:         drop
        !           755:     else
        !           756:         dead-code @
        !           757:         if
        !           758:            set-locals-size-list dead-code off
        !           759:        else \ both live
        !           760:            dup list-size adjust-locals-size
        !           761:            locals-list @ common-list dup list-size adjust-locals-size
        !           762:            locals-list !
        !           763:        then
        !           764:     then ;
        !           765: 
        !           766: : THEN ( compilation orig -- ; run-time -- ) \ core
        !           767:     dup orig?  then-like  >resolve ; immediate restrict
        !           768: 
        !           769: ' THEN alias ENDIF ( compilation orig -- ; run-time -- ) \ gforth
        !           770: immediate restrict
        !           771: \ Same as "THEN". This is what you use if your program will be seen by
        !           772: \ people who have not been brought up with Forth (or who have been
        !           773: \ brought up with fig-Forth).
        !           774: 
        !           775: : ELSE ( compilation orig1 -- orig2 ; run-time f -- ) \ core
        !           776:     POSTPONE ahead
        !           777:     1 cs-roll
        !           778:     POSTPONE then ; immediate restrict
        !           779: 
        !           780: 
        !           781: : BEGIN ( compilation -- dest ; run-time -- ) \ core
        !           782:     dead-code @ if
        !           783:        \ set up an assumption of the locals visible here.  if the
        !           784:        \ users want something to be visible, they have to declare
        !           785:        \ that using ASSUME-LIVE
        !           786:        backedge-locals @ set-locals-size-list
        !           787:     then
        !           788:     cs-push-part dest
        !           789:     dead-code off ; immediate restrict
        !           790: 
        !           791: \ AGAIN (the current control flow joins another, earlier one):
        !           792: \ If the dest-locals-list is not a subset of the current locals-list,
        !           793: \ issue a warning (see below). The following code is generated:
        !           794: \ lp+!# (current-local-size - dest-locals-size)
        !           795: \ branch <begin>
        !           796: 
        !           797: : again-like ( dest -- addr )
        !           798:     over list-size adjust-locals-size
        !           799:     swap check-begin  POSTPONE unreachable ;
        !           800: 
        !           801: : AGAIN ( compilation dest -- ; run-time -- ) \ core-ext
        !           802:     dest? again-like  POSTPONE branch  <resolve ; immediate restrict
        !           803: 
        !           804: \ UNTIL (the current control flow may join an earlier one or continue):
        !           805: \ Similar to AGAIN. The new locals-list and locals-size are the current
        !           806: \ ones. The following code is generated:
        !           807: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
        !           808: : until-like ( list addr xt1 xt2 -- )
        !           809:     \ list and addr are a fragment of a cs-item
        !           810:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
        !           811:     >r >r
        !           812:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
        !           813:        r> drop r> compile,
        !           814:        swap <resolve ( list adjustment ) ,
        !           815:     else ( list dest-addr adjustment )
        !           816:        drop
        !           817:        r> compile, <resolve
        !           818:        r> drop
        !           819:     then ( list )
        !           820:     check-begin ;
        !           821: 
        !           822: : UNTIL ( compilation dest -- ; run-time f -- ) \ core
        !           823:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
        !           824: 
        !           825: : WHILE ( compilation dest -- orig dest ; run-time f -- ) \ core
        !           826:     POSTPONE if
        !           827:     1 cs-roll ; immediate restrict
        !           828: 
        !           829: : REPEAT ( compilation orig dest -- ; run-time -- ) \ core
        !           830:     POSTPONE again
        !           831:     POSTPONE then ; immediate restrict
        !           832: 
        !           833: 
        !           834: \ counted loops
        !           835: 
        !           836: \ leave poses a little problem here
        !           837: \ we have to store more than just the address of the branch, so the
        !           838: \ traditional linked list approach is no longer viable.
        !           839: \ This is solved by storing the information about the leavings in a
        !           840: \ special stack.
        !           841: 
        !           842: \ !! remove the fixed size limit. 'Tis not hard.
        !           843: 20 constant leave-stack-size
        !           844: create leave-stack  60 cells allot
        !           845: Avariable leave-sp  leave-stack 3 cells + leave-sp !
        !           846: 
        !           847: : clear-leave-stack ( -- )
        !           848:     leave-stack leave-sp ! ;
        !           849: 
        !           850: \ : leave-empty? ( -- f )
        !           851: \  leave-sp @ leave-stack = ;
        !           852: 
        !           853: : >leave ( orig -- )
        !           854:     \ push on leave-stack
        !           855:     leave-sp @
        !           856:     dup [ leave-stack 60 cells + ] Aliteral
        !           857:     >= abort" leave-stack full"
        !           858:     tuck ! cell+
        !           859:     tuck ! cell+
        !           860:     tuck ! cell+
        !           861:     leave-sp ! ;
        !           862: 
        !           863: : leave> ( -- orig )
        !           864:     \ pop from leave-stack
        !           865:     leave-sp @
        !           866:     dup leave-stack <= IF
        !           867:        drop 0 0 0  EXIT  THEN
        !           868:     cell - dup @ swap
        !           869:     cell - dup @ swap
        !           870:     cell - dup @ swap
        !           871:     leave-sp ! ;
        !           872: 
        !           873: : DONE ( compilation orig -- ; run-time -- ) \ gforth
        !           874:     \ !! the original done had ( addr -- )
        !           875:     drop >r drop
        !           876:     begin
        !           877:        leave>
        !           878:        over r@ u>=
        !           879:     while
        !           880:        POSTPONE then
        !           881:     repeat
        !           882:     >leave rdrop ; immediate restrict
        !           883: 
        !           884: : LEAVE ( compilation -- ; run-time loop-sys -- ) \ core
        !           885:     POSTPONE ahead
        !           886:     >leave ; immediate restrict
        !           887: 
        !           888: : ?LEAVE ( compilation -- ; run-time f | f loop-sys -- ) \ gforth      question-leave
        !           889:     POSTPONE 0= POSTPONE if
        !           890:     >leave ; immediate restrict
        !           891: 
        !           892: : DO ( compilation -- do-sys ; run-time w1 w2 -- loop-sys ) \ core
        !           893:     POSTPONE (do)
        !           894:     POSTPONE begin drop do-dest
        !           895:     ( 0 0 0 >leave ) ; immediate restrict
        !           896: 
        !           897: : ?do-like ( -- do-sys )
        !           898:     ( 0 0 0 >leave )
        !           899:     >mark >leave
        !           900:     POSTPONE begin drop do-dest ;
        !           901: 
        !           902: : ?DO ( compilation -- do-sys ; run-time w1 w2 -- | loop-sys ) \ core-ext      question-do
        !           903:     POSTPONE (?do) ?do-like ; immediate restrict
        !           904: 
        !           905: : +DO ( compilation -- do-sys ; run-time n1 n2 -- | loop-sys ) \ gforth        plus-do
        !           906:     POSTPONE (+do) ?do-like ; immediate restrict
        !           907: 
        !           908: : U+DO ( compilation -- do-sys ; run-time u1 u2 -- | loop-sys )        \ gforth        u-plus-do
        !           909:     POSTPONE (u+do) ?do-like ; immediate restrict
        !           910: 
        !           911: : -DO ( compilation -- do-sys ; run-time n1 n2 -- | loop-sys ) \ gforth        minus-do
        !           912:     POSTPONE (-do) ?do-like ; immediate restrict
        !           913: 
        !           914: : U-DO ( compilation -- do-sys ; run-time u1 u2 -- | loop-sys )        \ gforth        u-minus-do
        !           915:     POSTPONE (u-do) ?do-like ; immediate restrict
        !           916: 
        !           917: : FOR ( compilation -- do-sys ; run-time u -- loop-sys )       \ gforth
        !           918:     POSTPONE (for)
        !           919:     POSTPONE begin drop do-dest
        !           920:     ( 0 0 0 >leave ) ; immediate restrict
        !           921: 
        !           922: \ LOOP etc. are just like UNTIL
        !           923: 
        !           924: : loop-like ( do-sys xt1 xt2 -- )
        !           925:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
        !           926:     until-like  POSTPONE done  POSTPONE unloop ;
        !           927: 
        !           928: : LOOP ( compilation do-sys -- ; run-time loop-sys1 -- | loop-sys2 )   \ core
        !           929:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
        !           930: 
        !           931: : +LOOP ( compilation do-sys -- ; run-time loop-sys1 n -- | loop-sys2 )        \ core  plus-loop
        !           932:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
        !           933: 
        !           934: \ !! should the compiler warn about +DO..-LOOP?
        !           935: : -LOOP ( compilation do-sys -- ; run-time loop-sys1 u -- | loop-sys2 )        \ gforth        minus-loop
        !           936:  ['] (-loop) ['] (-loop)-lp+!# loop-like ; immediate restrict
        !           937: 
        !           938: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
        !           939: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
        !           940: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
        !           941: \ negative increments.
        !           942: : S+LOOP ( compilation do-sys -- ; run-time loop-sys1 n -- | loop-sys2 )       \ gforth        s-plus-loop
        !           943:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
        !           944: 
        !           945: : NEXT ( compilation do-sys -- ; run-time loop-sys1 -- | loop-sys2 ) \ gforth
        !           946:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
        !           947: 
        !           948: \ Structural Conditionals                              12dec92py
        !           949: 
        !           950: : EXIT ( compilation -- ; run-time nest-sys -- ) \ core
        !           951:     0 adjust-locals-size
        !           952:     POSTPONE ;s
        !           953:     POSTPONE unreachable ; immediate restrict
        !           954: 
        !           955: : ?EXIT ( -- ) ( compilation -- ; run-time nest-sys f -- | nest-sys ) \ gforth
        !           956:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
        !           957: 
        !           958: \ Strings                                              22feb93py
        !           959: 
        !           960: : ," ( "string"<"> -- ) [char] " parse
        !           961:   here over char+ allot  place align ;
        !           962: : "lit ( -- addr )
        !           963:   r> r> dup count + aligned >r swap >r ;
        !           964: : (.")     "lit count type ;
        !           965: : (S")     "lit count ;
        !           966: : SLiteral ( Compilation c-addr1 u ; run-time -- c-addr2 u ) \ string
        !           967:     postpone (S") here over char+ allot  place align ;
        !           968:                                              immediate restrict
        !           969: : ( ( compilation 'ccc<close-paren>' -- ; run-time -- ) \ core,file    paren
        !           970:     BEGIN
        !           971:        >in @ [char] ) parse nip >in @ rot - =
        !           972:     WHILE
        !           973:        loadfile @ IF
        !           974:            refill 0= abort" missing ')' in paren comment"
        !           975:        THEN
        !           976:     REPEAT ;                       immediate
        !           977: : \ ( -- ) \ core-ext backslash
        !           978:     blk @
        !           979:     IF
        !           980:        >in @ c/l / 1+ c/l * >in !
        !           981:        EXIT
        !           982:     THEN
        !           983:     source >in ! drop ; immediate
        !           984: 
        !           985: : \G ( -- ) \ gforth backslash
        !           986:     POSTPONE \ ; immediate
        !           987: 
        !           988: \ error handling                                       22feb93py
        !           989: \ 'abort thrown out!                                   11may93jaw
        !           990: 
        !           991: : (abort")
        !           992:     "lit >r
        !           993:     IF
        !           994:        r> "error ! -2 throw
        !           995:     THEN
        !           996:     rdrop ;
        !           997: : abort" ( compilation 'ccc"' -- ; run-time f -- ) \ core,exception-ext        abort-quote
        !           998:     postpone (abort") ," ;        immediate restrict
        !           999: 
        !          1000: \ Header states                                        23feb93py
        !          1001: 
        !          1002: : cset ( bmask c-addr -- )
        !          1003:     tuck c@ or swap c! ; 
        !          1004: : creset ( bmask c-addr -- )
        !          1005:     tuck c@ swap invert and swap c! ; 
        !          1006: : ctoggle ( bmask c-addr -- )
        !          1007:     tuck c@ xor swap c! ; 
        !          1008: 
        !          1009: : lastflags ( -- c-addr )
        !          1010:     \ the address of the flags byte in the last header
        !          1011:     \ aborts if the last defined word was headerless
        !          1012:     last @ dup 0= abort" last word was headerless" cell+ ;
        !          1013: 
        !          1014: : immediate     immediate-mask lastflags cset ;
        !          1015: : restrict      restrict-mask lastflags cset ;
        !          1016: 
        !          1017: \ Header                                               23feb93py
        !          1018: 
        !          1019: \ input-stream, nextname and noname are quite ugly (passing
        !          1020: \ information through global variables), but they are useful for dealing
        !          1021: \ with existing/independent defining words
        !          1022: 
        !          1023: defer (header)
        !          1024: defer header ( -- ) \ gforth
        !          1025: ' (header) IS header
        !          1026: 
        !          1027: : string, ( c-addr u -- ) \ gforth
        !          1028:     \ puts down string as cstring
        !          1029:     dup c, here swap chars dup allot move ;
        !          1030: 
        !          1031: : header, ( c-addr u -- ) \ gforth
        !          1032:     name-too-long?
        !          1033:     align here last !
        !          1034:     current @ 1 or A,  \ link field; before revealing, it contains the
        !          1035:                        \ tagged reveal-into wordlist
        !          1036:     string, cfalign
        !          1037:     alias-mask lastflags cset ;
        !          1038: 
        !          1039: : input-stream-header ( "name" -- )
        !          1040:     name name-too-short? header, ;
        !          1041: : input-stream ( -- )  \ general
        !          1042: \ switches back to getting the name from the input stream ;
        !          1043:     ['] input-stream-header IS (header) ;
        !          1044: 
        !          1045: ' input-stream-header IS (header)
        !          1046: 
        !          1047: \ !! make that a 2variable
        !          1048: create nextname-buffer 32 chars allot
        !          1049: 
        !          1050: : nextname-header ( -- )
        !          1051:     nextname-buffer count header,
        !          1052:     input-stream ;
        !          1053: 
        !          1054: \ the next name is given in the string
        !          1055: : nextname ( c-addr u -- ) \ gforth
        !          1056:     name-too-long?
        !          1057:     nextname-buffer c! ( c-addr )
        !          1058:     nextname-buffer count move
        !          1059:     ['] nextname-header IS (header) ;
        !          1060: 
        !          1061: : noname-header ( -- )
        !          1062:     0 last ! cfalign
        !          1063:     input-stream ;
        !          1064: 
        !          1065: : noname ( -- ) \ gforth
        !          1066: \ the next defined word remains anonymous. The xt of that word is given by lastxt
        !          1067:     ['] noname-header IS (header) ;
        !          1068: 
        !          1069: : lastxt ( -- xt ) \ gforth
        !          1070: \ xt is the execution token of the last word defined. The main purpose of this word is to get the xt of words defined using noname
        !          1071:     lastcfa @ ;
        !          1072: 
        !          1073: : Alias    ( cfa "name" -- ) \ gforth
        !          1074:     Header reveal
        !          1075:     alias-mask lastflags creset
        !          1076:     dup A, lastcfa ! ;
        !          1077: 
        !          1078: : name>string ( nfa -- addr count ) \ gforth   name-to-string
        !          1079:  cell+ count $1F and ;
        !          1080: 
        !          1081: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
        !          1082: : >name ( cfa -- nfa ) \ gforth        to-name
        !          1083:  $21 cell do
        !          1084:    dup i - count $9F and + cfaligned over alias-mask + = if
        !          1085:      i - cell - unloop exit
        !          1086:    then
        !          1087:  cell +loop
        !          1088:  drop ??? ( wouldn't 0 be better? ) ;
        !          1089: 
        !          1090: \ threading                                   17mar93py
        !          1091: 
        !          1092: : cfa,     ( code-address -- )  \ gforth       cfa-comma
        !          1093:     here
        !          1094:     dup lastcfa !
        !          1095:     0 A, 0 ,  code-address! ;
        !          1096: : compile, ( xt -- )   \ core-ext      compile-comma
        !          1097:     A, ;
        !          1098: : !does    ( addr -- ) \ gforth        store-does
        !          1099:     lastxt does-code! ;
        !          1100: : (does>)  ( R: addr -- )
        !          1101:     r> /does-handler + !does ;
        !          1102: : dodoes,  ( -- )
        !          1103:   here /does-handler allot does-handler! ;
        !          1104: 
        !          1105: : Create ( "name" -- ) \ core
        !          1106:     Header reveal dovar: cfa, ;
        !          1107: 
        !          1108: \ Create Variable User Constant                        17mar93py
        !          1109: 
        !          1110: : Variable ( "name" -- ) \ core
        !          1111:     Create 0 , ;
        !          1112: : AVariable ( "name" -- ) \ gforth
        !          1113:     Create 0 A, ;
        !          1114: : 2VARIABLE ( "name" -- ) \ double
        !          1115:     create 0 , 0 , ;
        !          1116:     
        !          1117: : User ( "name" -- ) \ gforth
        !          1118:     Variable ;
        !          1119: : AUser ( "name" -- ) \ gforth
        !          1120:     AVariable ;
        !          1121: 
        !          1122: : (Constant)  Header reveal docon: cfa, ;
        !          1123: : Constant ( w "name" -- ) \ core
        !          1124:     (Constant) , ;
        !          1125: : AConstant ( addr "name" -- ) \ gforth
        !          1126:     (Constant) A, ;
        !          1127: 
        !          1128: : 2Constant ( w1 w2 "name" -- ) \ double
        !          1129:     Create ( w1 w2 "name" -- )
        !          1130:         2,
        !          1131:     DOES> ( -- w1 w2 )
        !          1132:         2@ ;
        !          1133:     
        !          1134: \ IS Defer What's Defers TO                            24feb93py
        !          1135: 
        !          1136: : Defer ( "name" -- ) \ gforth
        !          1137:     \ !! shouldn't it be initialized with abort or something similar?
        !          1138:     Header Reveal dodefer: cfa,
        !          1139:     ['] noop A, ;
        !          1140: \     Create ( -- ) 
        !          1141: \      ['] noop A,
        !          1142: \     DOES> ( ??? )
        !          1143: \      perform ;
        !          1144: 
        !          1145: : Defers ( "name" -- ) \ gforth
        !          1146:     ' >body @ compile, ; immediate
        !          1147: 
        !          1148: \ : ;                                                  24feb93py
        !          1149: 
        !          1150: defer :-hook ( sys1 -- sys2 )
        !          1151: defer ;-hook ( sys2 -- sys1 )
        !          1152: 
        !          1153: : : ( "name" -- colon-sys ) \ core     colon
        !          1154:     Header docol: cfa, defstart ] :-hook ;
        !          1155: : ; ( compilation colon-sys -- ; run-time nest-sys ) \ core    semicolon
        !          1156:     ;-hook ?struc postpone exit reveal postpone [ ; immediate restrict
        !          1157: 
        !          1158: : :noname ( -- xt colon-sys ) \ core-ext       colon-no-name
        !          1159:     0 last !
        !          1160:     cfalign here docol: cfa, 0 ] :-hook ;
        !          1161: 
        !          1162: \ Search list handling                                 23feb93py
        !          1163: 
        !          1164: AVariable current ( -- addr ) \ gforth
        !          1165: 
        !          1166: : last?   ( -- false / nfa nfa )
        !          1167:     last @ ?dup ;
        !          1168: : (reveal) ( nfa wid -- )
        !          1169:     ( wid>wordlist-id ) dup >r
        !          1170:     @ over ( name>link ) ! 
        !          1171:     r> ! ;
        !          1172: 
        !          1173: \ object oriented search list                          17mar93py
        !          1174: 
        !          1175: \ word list structure:
        !          1176: 
        !          1177: struct
        !          1178:   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
        !          1179:   1 cells: field reveal-method \ xt: ( nfa wid -- ) \ used by dofield:, must be field
        !          1180:   1 cells: field rehash-method \ xt: ( wid -- )
        !          1181: \   \ !! what else
        !          1182: end-struct wordlist-map-struct
        !          1183: 
        !          1184: struct
        !          1185:   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
        !          1186:   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
        !          1187:   1 cells: field wordlist-link \ link field to other wordlists
        !          1188:   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
        !          1189: end-struct wordlist-struct
        !          1190: 
        !          1191: : f83find      ( addr len wordlist -- nfa / false )
        !          1192:     ( wid>wordlist-id ) @ (f83find) ;
        !          1193: 
        !          1194: \ Search list table: find reveal
        !          1195: Create f83search ( -- wordlist-map )
        !          1196:     ' f83find A,  ' (reveal) A,  ' drop A,
        !          1197: 
        !          1198: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
        !          1199: AVariable lookup       G forth-wordlist lookup T !
        !          1200: G forth-wordlist current T !
        !          1201: 
        !          1202: \ higher level parts of find
        !          1203: 
        !          1204: ( struct )
        !          1205: 0 >body cell
        !          1206:   1 cells: field interpret/compile-int
        !          1207:   1 cells: field interpret/compile-comp
        !          1208: end-struct interpret/compile-struct
        !          1209: 
        !          1210: : interpret/compile? ( xt -- flag )
        !          1211:     >does-code ['] S" >does-code = ;
        !          1212: 
        !          1213: : (cfa>int) ( cfa -- xt )
        !          1214:     dup interpret/compile?
        !          1215:     if
        !          1216:        interpret/compile-int @
        !          1217:     then ;
        !          1218: 
        !          1219: : (x>int) ( cfa b -- xt )
        !          1220:     \ get interpretation semantics of name
        !          1221:     restrict-mask and
        !          1222:     if
        !          1223:        drop ['] compile-only-error
        !          1224:     else
        !          1225:        (cfa>int)
        !          1226:     then ;
        !          1227: 
        !          1228: : name>int ( nfa -- xt ) \ gforth
        !          1229:     (name>x) (x>int) ;
        !          1230: 
        !          1231: : name?int ( nfa -- xt ) \ gforth
        !          1232:     \ like name>int, but throws an error if compile-only
        !          1233:     (name>x) restrict-mask and
        !          1234:     if
        !          1235:        compile-only-error \ does not return
        !          1236:     then
        !          1237:     (cfa>int) ;
        !          1238: 
        !          1239: : name>comp ( nfa -- w xt ) \ gforth
        !          1240:     \ get compilation semantics of name
        !          1241:     (name>x) >r dup interpret/compile?
        !          1242:     if
        !          1243:        interpret/compile-comp @
        !          1244:     then
        !          1245:     r> immediate-mask and if
        !          1246:        ['] execute
        !          1247:     else
        !          1248:        ['] compile,
        !          1249:     then ;
        !          1250: 
        !          1251: : (search-wordlist)  ( addr count wid -- nfa / false )
        !          1252:     dup wordlist-map @ find-method perform ;
        !          1253: 
        !          1254: : flag-sign ( f -- 1|-1 )
        !          1255:     \ true becomes 1, false -1
        !          1256:     0= 2* 1+ ;
        !          1257: 
        !          1258: : (name>intn) ( nfa -- xt +-1 )
        !          1259:     (name>x) tuck (x>int) ( b xt )
        !          1260:     swap immediate-mask and flag-sign ;
        !          1261: 
        !          1262: : search-wordlist ( addr count wid -- 0 / xt +-1 ) \ search
        !          1263:     \ xt is the interpretation semantics
        !          1264:     (search-wordlist) dup if
        !          1265:        (name>intn)
        !          1266:     then ;
        !          1267: 
        !          1268: : find-name ( c-addr u -- nfa/0 )
        !          1269:     lookup @ (search-wordlist) ;
        !          1270: 
        !          1271: : sfind ( c-addr u -- 0 / xt +-1  ) \ gforth-obsolete
        !          1272:     find-name dup
        !          1273:     if ( nfa )
        !          1274:        state @
        !          1275:        if
        !          1276:            name>comp ['] execute = flag-sign
        !          1277:        else
        !          1278:            (name>intn)
        !          1279:        then
        !          1280:     then ;
        !          1281: 
        !          1282: : find ( c-addr -- xt +-1 / c-addr 0 ) \ core
        !          1283:     dup count sfind dup
        !          1284:     if
        !          1285:        rot drop
        !          1286:     then ;
        !          1287: 
        !          1288: : (') ( "name" -- nfa ) \ gforth
        !          1289:     name find-name dup 0=
        !          1290:     IF
        !          1291:        drop -&13 bounce
        !          1292:     THEN  ;
        !          1293: 
        !          1294: : [(')]  ( compilation "name" -- ; run-time -- nfa ) \ gforth  bracket-paren-tick
        !          1295:     (') postpone ALiteral ; immediate restrict
        !          1296: 
        !          1297: : '    ( "name" -- xt ) \ core tick
        !          1298:     (') name?int ;
        !          1299: : [']  ( compilation "name" -- ; run-time -- xt ) \ core       bracket-tick
        !          1300:     ' postpone ALiteral ; immediate restrict
        !          1301: 
        !          1302: : COMP'    ( "name" -- w xt ) \ gforth c-tick
        !          1303:     (') name>comp ;
        !          1304: : [COMP']  ( compilation "name" -- ; run-time -- w xt ) \ gforth       bracket-comp-tick
        !          1305:     COMP' swap POSTPONE Aliteral POSTPONE ALiteral ; immediate restrict
        !          1306: 
        !          1307: \ reveal words
        !          1308: 
        !          1309: Variable warnings ( -- addr ) \ gforth
        !          1310: G -1 warnings T !
        !          1311: 
        !          1312: : check-shadow  ( addr count wid -- )
        !          1313: \ prints a warning if the string is already present in the wordlist
        !          1314:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
        !          1315:    ." redefined " name>string 2dup type
        !          1316:    compare 0<> if
        !          1317:      ."  with " type
        !          1318:    else
        !          1319:      2drop
        !          1320:    then
        !          1321:    space space EXIT
        !          1322:  then
        !          1323:  2drop 2drop ;
        !          1324: 
        !          1325: : reveal ( -- ) \ gforth
        !          1326:     last?
        !          1327:     if \ the last word has a header
        !          1328:        dup ( name>link ) @ 1 and
        !          1329:        if \ it is still hidden
        !          1330:            dup ( name>link ) @ 1 xor           ( nfa wid )
        !          1331:            2dup >r name>string r> check-shadow ( nfa wid )
        !          1332:            dup wordlist-map @ reveal-method perform
        !          1333:        then
        !          1334:     then ;
        !          1335: 
        !          1336: : rehash  ( wid -- )
        !          1337:     dup wordlist-map @ rehash-method perform ;
        !          1338: 
        !          1339: \ Input                                                13feb93py
        !          1340: 
        !          1341: 07 constant #bell ( -- c ) \ gforth
        !          1342: 08 constant #bs ( -- c ) \ gforth
        !          1343: 09 constant #tab ( -- c ) \ gforth
        !          1344: 7F constant #del ( -- c ) \ gforth
        !          1345: 0D constant #cr   ( -- c ) \ gforth
        !          1346: \ the newline key code
        !          1347: 0C constant #ff ( -- c ) \ gforth
        !          1348: 0A constant #lf ( -- c ) \ gforth
        !          1349: 
        !          1350: : bell  #bell emit ;
        !          1351: : cr ( -- ) \ core
        !          1352:     \ emit a newline
        !          1353:     #lf ( sic! ) emit ;
        !          1354: 
        !          1355: \ : backspaces  0 ?DO  #bs emit  LOOP ;
        !          1356: 
        !          1357: : (ins) ( max span addr pos1 key -- max span addr pos2 )
        !          1358:     >r 2dup + r@ swap c! r> emit 1+ rot 1+ -rot ;
        !          1359: : (bs) ( max span addr pos1 -- max span addr pos2 flag )
        !          1360:     dup IF
        !          1361:        #bs emit bl emit #bs emit 1- rot 1- -rot
        !          1362:     THEN false ;
        !          1363: : (ret)  true space ;
        !          1364: 
        !          1365: Create ctrlkeys
        !          1366:   ] false false false false  false false false false
        !          1367:     (bs)  false (ret) false  false (ret) false false
        !          1368:     false false false false  false false false false
        !          1369:     false false false false  false false false false [
        !          1370: 
        !          1371: defer insert-char
        !          1372: ' (ins) IS insert-char
        !          1373: defer everychar
        !          1374: ' noop IS everychar
        !          1375: 
        !          1376: : decode ( max span addr pos1 key -- max span addr pos2 flag )
        !          1377:   everychar
        !          1378:   dup #del = IF  drop #bs  THEN  \ del is rubout
        !          1379:   dup bl <   IF  cells ctrlkeys + perform  EXIT  THEN
        !          1380:   >r 2over = IF  rdrop bell 0 EXIT  THEN
        !          1381:   r> insert-char 0 ;
        !          1382: 
        !          1383: : accept   ( addr len -- len ) \ core
        !          1384:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
        !          1385: \ this allows to edit given strings
        !          1386:          ELSE  0  THEN rot over
        !          1387:   BEGIN  key decode  UNTIL
        !          1388:   2drop nip ;
        !          1389: 
        !          1390: \ Output                                               13feb93py
        !          1391: 
        !          1392: : (type) ( c-addr u -- ) \ gforth
        !          1393:     outfile-id write-file drop \ !! use ?DUP-IF THROW ENDIF instead of DROP ?
        !          1394: ;
        !          1395: 
        !          1396: Defer type ( c-addr u -- ) \ core
        !          1397: \ defer type for a output buffer or fast
        !          1398: \ screen write
        !          1399: 
        !          1400: ' (type) IS Type
        !          1401: 
        !          1402: : (emit) ( c -- ) \ gforth
        !          1403:     outfile-id emit-file drop \ !! use ?DUP-IF THROW ENDIF instead of DROP ?
        !          1404: ;
        !          1405: 
        !          1406: Defer emit ( c -- ) \ core
        !          1407: ' (Emit) IS Emit
        !          1408: 
        !          1409: Defer key ( -- c ) \ core
        !          1410: ' (key) IS key
        !          1411: 
        !          1412: \ Query                                                07apr93py
        !          1413: 
        !          1414: : refill ( -- flag ) \ core-ext,block-ext,file-ext
        !          1415:   blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
        !          1416:   tib /line
        !          1417:   loadfile @ ?dup
        !          1418:   IF    read-line throw
        !          1419:   ELSE  sourceline# 0< IF 2drop false EXIT THEN
        !          1420:         accept true
        !          1421:   THEN
        !          1422:   1 loadline +!
        !          1423:   swap #tib ! 0 >in ! ;
        !          1424: 
        !          1425: : Query  ( -- ) \ core-ext
        !          1426:     \ obsolescent
        !          1427:     loadfile off  blk off  refill drop ;
        !          1428: 
        !          1429: \ File specifiers                                       11jun93jaw
        !          1430: 
        !          1431: 
        !          1432: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
        !          1433: \ 2 c, here char r c, char + c, 0 c,
        !          1434: \ 2 c, here char w c, char + c, 0 c, align
        !          1435: 4 Constant w/o ( -- fam ) \ file       w-o
        !          1436: 2 Constant r/w ( -- fam ) \ file       r-w
        !          1437: 0 Constant r/o ( -- fam ) \ file       r-o
        !          1438: 
        !          1439: \ BIN WRITE-LINE                                        11jun93jaw
        !          1440: 
        !          1441: \ : bin           dup 1 chars - c@
        !          1442: \                 r/o 4 chars + over - dup >r swap move r> ;
        !          1443: 
        !          1444: : bin ( fam1 -- fam2 ) \ file
        !          1445:     1 or ;
        !          1446: 
        !          1447: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
        !          1448:                            \ or not unix environments if
        !          1449:                            \ bin is not selected
        !          1450: 
        !          1451: : write-line ( c-addr u fileid -- ior ) \ file
        !          1452:     dup >r write-file
        !          1453:     ?dup IF
        !          1454:        r> drop EXIT
        !          1455:     THEN
        !          1456:     nl$ count r> write-file ;
        !          1457: 
        !          1458: \ include-file                                         07apr93py
        !          1459: 
        !          1460: : push-file  ( -- )  r>
        !          1461:   sourceline# >r  loadfile @ >r
        !          1462:   blk @ >r  tibstack @ >r  >tib @ >r  #tib @ >r
        !          1463:   >tib @ tibstack @ = IF  r@ tibstack +!  THEN
        !          1464:   tibstack @ >tib ! >in @ >r  >r ;
        !          1465: 
        !          1466: : pop-file   ( throw-code -- throw-code )
        !          1467:   dup IF
        !          1468:          source >in @ sourceline# sourcefilename
        !          1469:         error-stack dup @ dup 1+
        !          1470:         max-errors 1- min error-stack !
        !          1471:         6 * cells + cell+
        !          1472:         5 cells bounds swap DO
        !          1473:                            I !
        !          1474:         -1 cells +LOOP
        !          1475:   THEN
        !          1476:   r>
        !          1477:   r> >in !  r> #tib !  r> >tib !  r> tibstack !  r> blk !
        !          1478:   r> loadfile ! r> loadline !  >r ;
        !          1479: 
        !          1480: : read-loop ( i*x -- j*x )
        !          1481:   BEGIN  refill  WHILE  interpret  REPEAT ;
        !          1482: 
        !          1483: : include-file ( i*x fid -- j*x ) \ file
        !          1484:   push-file  loadfile !
        !          1485:   0 loadline ! blk off  ['] read-loop catch
        !          1486:   loadfile @ close-file swap 2dup or
        !          1487:   pop-file  drop throw throw ;
        !          1488: 
        !          1489: create pathfilenamebuf 256 chars allot \ !! make this grow on demand
        !          1490: 
        !          1491: \ : check-file-prefix  ( addr len -- addr' len' flag )
        !          1492: \   dup 0=                    IF  true EXIT  THEN 
        !          1493: \   over c@ '/ =              IF  true EXIT  THEN 
        !          1494: \   over 2 S" ./" compare 0=  IF  true EXIT  THEN 
        !          1495: \   over 3 S" ../" compare 0= IF  true EXIT  THEN
        !          1496: \   over 2 S" ~/" compare 0=
        !          1497: \   IF     1 /string
        !          1498: \          S" HOME" getenv tuck pathfilenamebuf swap move
        !          1499: \          2dup + >r pathfilenamebuf + swap move
        !          1500: \          pathfilenamebuf r> true
        !          1501: \   ELSE   false
        !          1502: \   THEN ;
        !          1503: 
        !          1504: : absolut-path? ( addr u -- flag ) \ gforth
        !          1505:     \ a path is absolute, if it starts with a / or a ~ (~ expansion),
        !          1506:     \ or if it is in the form ./* or ../*, extended regexp: [/~]|./|../
        !          1507:     \ Pathes simply containing a / are not absolute!
        !          1508:     over c@ '/ = >r
        !          1509:     over c@ '~ = >r
        !          1510:     2dup 2 min S" ./" compare 0= >r
        !          1511:          3 min S" ../" compare 0=
        !          1512:     r> r> r> or or or ;
        !          1513: \   [char] / scan nip 0<> ;    
        !          1514: 
        !          1515: : open-path-file ( c-addr1 u1 -- file-id c-addr2 u2 ) \ gforth
        !          1516:     \ opens a file for reading, searching in the path for it (unless
        !          1517:     \ the filename contains a slash); c-addr2 u2 is the full filename
        !          1518:     \ (valid until the next call); if the file is not found (or in
        !          1519:     \ case of other errors for each try), -38 (non-existant file) is
        !          1520:     \ thrown. Opening for other access modes makes little sense, as
        !          1521:     \ the path will usually contain dirs that are only readable for
        !          1522:     \ the user
        !          1523:     \ !! use file-status to determine access mode?
        !          1524:     2dup absolut-path?
        !          1525:     if \ the filename contains a slash
        !          1526:        2dup r/o open-file throw ( c-addr1 u1 file-id )
        !          1527:        -rot >r pathfilenamebuf r@ cmove ( file-id R: u1 )
        !          1528:        pathfilenamebuf r> EXIT
        !          1529:     then
        !          1530:     pathdirs 2@ 0
        !          1531: \    check-file-prefix 0= 
        !          1532: \    IF  pathdirs 2@ 0
        !          1533:     ?DO ( c-addr1 u1 dirnamep )
        !          1534:        dup >r 2@ dup >r pathfilenamebuf swap cmove ( addr u )
        !          1535:        2dup pathfilenamebuf r@ chars + swap cmove ( addr u )
        !          1536:        pathfilenamebuf over r> + dup >r r/o open-file 0=
        !          1537:        IF ( addr u file-id )
        !          1538:            nip nip r> rdrop 0 LEAVE
        !          1539:        THEN
        !          1540:        rdrop drop r> cell+ cell+
        !          1541:     LOOP
        !          1542: \    ELSE   2dup open-file throw -rot  THEN 
        !          1543:     0<> -&38 and throw ( file-id u2 )
        !          1544:     pathfilenamebuf swap ;
        !          1545: 
        !          1546: create included-files 0 , 0 , ( pointer to and count of included files )
        !          1547: here ," the terminal" dup c@ swap 1 + swap , A, here 2 cells -
        !          1548: create image-included-files  1 , A, ( pointer to and count of included files )
        !          1549: \ included-files points to ALLOCATEd space, while image-included-files
        !          1550: \ points to ALLOTed objects, so it survives a save-system
        !          1551: 
        !          1552: : loadfilename ( -- a-addr )
        !          1553:     \ a-addr 2@ produces the current file name ( c-addr u )
        !          1554:     included-files 2@ drop loadfilename# @ 2* cells + ;
        !          1555: 
        !          1556: : sourcefilename ( -- c-addr u ) \ gforth
        !          1557:     \ the name of the source file which is currently the input
        !          1558:     \ source.  The result is valid only while the file is being
        !          1559:     \ loaded.  If the current input source is no (stream) file, the
        !          1560:     \ result is undefined.
        !          1561:     loadfilename 2@ ;
        !          1562: 
        !          1563: : sourceline# ( -- u ) \ gforth                sourceline-number
        !          1564:     \ the line number of the line that is currently being interpreted
        !          1565:     \ from a (stream) file. The first line has the number 1. If the
        !          1566:     \ current input source is no (stream) file, the result is
        !          1567:     \ undefined.
        !          1568:     loadline @ ;
        !          1569: 
        !          1570: : init-included-files ( -- )
        !          1571:     image-included-files 2@ 2* cells save-mem drop ( addr )
        !          1572:     image-included-files 2@ nip included-files 2! ;
        !          1573: 
        !          1574: : included? ( c-addr u -- f ) \ gforth
        !          1575:     \ true, iff filename c-addr u is in included-files
        !          1576:     included-files 2@ 0
        !          1577:     ?do ( c-addr u addr )
        !          1578:        dup >r 2@ 2over compare 0=
        !          1579:        if
        !          1580:            2drop rdrop unloop
        !          1581:            true EXIT
        !          1582:        then
        !          1583:        r> cell+ cell+
        !          1584:     loop
        !          1585:     2drop drop false ;
        !          1586: 
        !          1587: : add-included-file ( c-addr u -- ) \ gforth
        !          1588:     \ add name c-addr u to included-files
        !          1589:     included-files 2@ 2* cells 2 cells extend-mem
        !          1590:     2/ cell / included-files 2!
        !          1591:     2! ;
        !          1592: \    included-files 2@ tuck 1+ 2* cells resize throw
        !          1593: \    swap 2dup 1+ included-files 2!
        !          1594: \    2* cells + 2! ;
        !          1595: 
        !          1596: : included1 ( i*x file-id c-addr u -- j*x ) \ gforth
        !          1597:     \ include the file file-id with the name given by c-addr u
        !          1598:     loadfilename# @ >r
        !          1599:     save-mem add-included-file ( file-id )
        !          1600:     included-files 2@ nip 1- loadfilename# !
        !          1601:     ['] include-file catch
        !          1602:     r> loadfilename# !
        !          1603:     throw ;
        !          1604:     
        !          1605: : included ( i*x addr u -- j*x ) \ file
        !          1606:     open-path-file included1 ;
        !          1607: 
        !          1608: : required ( i*x addr u -- j*x ) \ gforth
        !          1609:     \ include the file with the name given by addr u, if it is not
        !          1610:     \ included already. Currently this works by comparing the name of
        !          1611:     \ the file (with path) against the names of earlier included
        !          1612:     \ files; however, it would probably be better to fstat the file,
        !          1613:     \ and compare the device and inode. The advantages would be: no
        !          1614:     \ problems with several paths to the same file (e.g., due to
        !          1615:     \ links) and we would catch files included with include-file and
        !          1616:     \ write a require-file.
        !          1617:     open-path-file 2dup included?
        !          1618:     if
        !          1619:        2drop close-file throw
        !          1620:     else
        !          1621:        included1
        !          1622:     then ;
        !          1623: 
        !          1624: \ HEX DECIMAL                                           2may93jaw
        !          1625: 
        !          1626: : decimal ( -- ) \ core
        !          1627:     a base ! ;
        !          1628: : hex ( -- ) \ core-ext
        !          1629:     10 base ! ;
        !          1630: 
        !          1631: \ DEPTH                                                 9may93jaw
        !          1632: 
        !          1633: : depth ( -- +n ) \ core
        !          1634:     sp@ s0 @ swap - cell / ;
        !          1635: : clearstack ( ... -- )
        !          1636:     s0 @ sp! ;
        !          1637: 
        !          1638: \ INCLUDE                                               9may93jaw
        !          1639: 
        !          1640: : include  ( "file" -- ) \ gforth
        !          1641:   name included ;
        !          1642: 
        !          1643: : require  ( "file" -- ) \ gforth
        !          1644:   name required ;
        !          1645: 
        !          1646: \ RECURSE                                               17may93jaw
        !          1647: 
        !          1648: : recurse ( compilation -- ; run-time ?? -- ?? ) \ core
        !          1649:     lastxt compile, ; immediate restrict
        !          1650: ' reveal alias recursive ( -- ) \ gforth
        !          1651:        immediate
        !          1652: 
        !          1653: \ */MOD */                                              17may93jaw
        !          1654: 
        !          1655: \ !! I think */mod should have the same rounding behaviour as / - anton
        !          1656: : */mod ( n1 n2 n3 -- n4 n5 ) \ core   star-slash-mod
        !          1657:     >r m* r> sm/rem ;
        !          1658: 
        !          1659: : */ ( n1 n2 n3 -- n4 ) \ core star-slash
        !          1660:     */mod nip ;
        !          1661: 
        !          1662: \ EVALUATE                                              17may93jaw
        !          1663: 
        !          1664: : evaluate ( c-addr len -- ) \ core,block
        !          1665:   push-file  #tib ! >tib !
        !          1666:   >in off blk off loadfile off -1 loadline !
        !          1667:   ['] interpret catch
        !          1668:   pop-file throw ;
        !          1669: 
        !          1670: : abort ( ?? -- ?? ) \ core,exception-ext
        !          1671:     -1 throw ;
        !          1672: 
        !          1673: \+ environment? true ENV" CORE"
        !          1674: \ core wordset is now complete!
        !          1675: 
        !          1676: \ Quit                                                 13feb93py
        !          1677: 
        !          1678: Defer 'quit
        !          1679: Defer .status
        !          1680: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
        !          1681: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
        !          1682: ' (quit) IS 'quit
        !          1683: 
        !          1684: \ DOERROR (DOERROR)                                     13jun93jaw
        !          1685: 
        !          1686: 8 Constant max-errors
        !          1687: Variable error-stack  0 error-stack !
        !          1688: max-errors 6 * cells allot
        !          1689: \ format of one cell:
        !          1690: \ source ( addr u )
        !          1691: \ >in
        !          1692: \ line-number
        !          1693: \ Loadfilename ( addr u )
        !          1694: 
        !          1695: : dec. ( n -- ) \ gforth
        !          1696:     \ print value in decimal representation
        !          1697:     base @ decimal swap . base ! ;
        !          1698: 
        !          1699: : hex. ( u -- ) \ gforth
        !          1700:     \ print value as unsigned hex number
        !          1701:     '$ emit base @ swap hex u. base ! ;
        !          1702: 
        !          1703: : typewhite ( addr u -- ) \ gforth
        !          1704:     \ like type, but white space is printed instead of the characters
        !          1705:     bounds ?do
        !          1706:        i c@ 9 = if \ check for tab
        !          1707:            9
        !          1708:        else
        !          1709:            bl
        !          1710:        then
        !          1711:        emit
        !          1712:     loop ;
        !          1713: 
        !          1714: DEFER DOERROR
        !          1715: 
        !          1716: : .error-frame ( addr1 u1 n1 n2 addr2 u2 -- )
        !          1717:   cr error-stack @
        !          1718:   IF
        !          1719:      ." in file included from "
        !          1720:      type ." :" dec.  drop 2drop
        !          1721:   ELSE
        !          1722:      type ." :" dec.
        !          1723:      cr dup 2over type cr drop
        !          1724:      nip -trailing 1- ( line-start index2 )
        !          1725:      0 >r  BEGIN
        !          1726:                   2dup + c@ bl >  WHILE
        !          1727:                  r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
        !          1728:      ( line-start index1 )
        !          1729:      typewhite
        !          1730:      r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
        !          1731:                   [char] ^ emit
        !          1732:      loop
        !          1733:   THEN
        !          1734: ;
        !          1735: 
        !          1736: : (DoError) ( throw-code -- )
        !          1737:   sourceline# IF
        !          1738:                source >in @ sourceline# 0 0 .error-frame
        !          1739:   THEN
        !          1740:   error-stack @ 0 ?DO
        !          1741:     -1 error-stack +!
        !          1742:     error-stack dup @ 6 * cells + cell+
        !          1743:     6 cells bounds DO
        !          1744:       I @
        !          1745:     cell +LOOP
        !          1746:     .error-frame
        !          1747:   LOOP
        !          1748:   dup -2 =
        !          1749:   IF 
        !          1750:      "error @ ?dup
        !          1751:      IF
        !          1752:         cr count type 
        !          1753:      THEN
        !          1754:      drop
        !          1755:   ELSE
        !          1756:      .error
        !          1757:   THEN
        !          1758:   normal-dp dpp ! ;
        !          1759: 
        !          1760: ' (DoError) IS DoError
        !          1761: 
        !          1762: : quit ( ?? -- ?? ) \ core
        !          1763:     r0 @ rp! handler off >tib @ >r
        !          1764:     BEGIN
        !          1765:        postpone [
        !          1766:        ['] 'quit CATCH dup
        !          1767:     WHILE
        !          1768:        DoError r@ >tib ! r@ tibstack !
        !          1769:     REPEAT
        !          1770:     drop r> >tib ! ;
        !          1771: 
        !          1772: \ Cold                                                 13feb93py
        !          1773: 
        !          1774: \ : .name ( name -- ) name>string type space ;
        !          1775: \ : words  listwords @
        !          1776: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
        !          1777: 
        !          1778: : cstring>sstring  ( cstring -- addr n ) \ gforth      cstring-to-sstring
        !          1779:     -1 0 scan 0 swap 1+ /string ;
        !          1780: : arg ( n -- addr count ) \ gforth
        !          1781:     cells argv @ + @ cstring>sstring ;
        !          1782: : #!       postpone \ ;  immediate
        !          1783: 
        !          1784: Create pathstring 2 cells allot \ string
        !          1785: Create pathdirs   2 cells allot \ dir string array, pointer and count
        !          1786: Variable argv
        !          1787: Variable argc
        !          1788: 
        !          1789: 0 Value script? ( -- flag )
        !          1790: 
        !          1791: : process-path ( addr1 u1 -- addr2 u2 )
        !          1792:     \ addr1 u1 is a path string, addr2 u2 is an array of dir strings
        !          1793:     align here >r
        !          1794:     BEGIN
        !          1795:        over >r [char] : scan
        !          1796:        over r> tuck - ( rest-str this-str )
        !          1797:        dup
        !          1798:        IF
        !          1799:            2dup 1- chars + c@ [char] / <>
        !          1800:            IF
        !          1801:                2dup chars + [char] / swap c!
        !          1802:                1+
        !          1803:            THEN
        !          1804:            2,
        !          1805:        ELSE
        !          1806:            2drop
        !          1807:        THEN
        !          1808:        dup
        !          1809:     WHILE
        !          1810:        1 /string
        !          1811:     REPEAT
        !          1812:     2drop
        !          1813:     here r> tuck - 2 cells / ;
        !          1814: 
        !          1815: : do-option ( addr1 len1 addr2 len2 -- n )
        !          1816:     2swap
        !          1817:     2dup s" -e"         compare  0= >r
        !          1818:     2dup s" --evaluate" compare  0= r> or
        !          1819:     IF  2drop dup >r ['] evaluate catch
        !          1820:        ?dup IF  dup >r DoError r> negate (bye)  THEN
        !          1821:        r> >tib +!  2 EXIT  THEN
        !          1822:     ." Unknown option: " type cr 2drop 1 ;
        !          1823: 
        !          1824: : process-args ( -- )
        !          1825:     >tib @ >r
        !          1826:     argc @ 1
        !          1827:     ?DO
        !          1828:        I arg over c@ [char] - <>
        !          1829:        IF
        !          1830:            required 1
        !          1831:        ELSE
        !          1832:            I 1+ argc @ =  IF  s" "  ELSE  I 1+ arg  THEN
        !          1833:            do-option
        !          1834:        THEN
        !          1835:     +LOOP
        !          1836:     r> >tib ! ;
        !          1837: 
        !          1838: Defer 'cold ' noop IS 'cold
        !          1839: 
        !          1840: : cold ( -- ) \ gforth
        !          1841:     stdout TO outfile-id
        !          1842:     pathstring 2@ process-path pathdirs 2!
        !          1843:     init-included-files
        !          1844:     'cold
        !          1845:     argc @ 1 >
        !          1846:     IF
        !          1847:        true to script?
        !          1848:        ['] process-args catch ?dup
        !          1849:        IF
        !          1850:            dup >r DoError cr r> negate (bye)
        !          1851:        THEN
        !          1852:        cr
        !          1853:     THEN
        !          1854:     false to script?
        !          1855:     ." GForth " version-string type ." , Copyright (C) 1994-1996 Free Software Foundation, Inc." cr
        !          1856:     ." GForth comes with ABSOLUTELY NO WARRANTY; for details type `license'" cr
        !          1857:     ." Type `bye' to exit"
        !          1858:     loadline off quit ;
        !          1859: 
        !          1860: : license ( -- ) \ gforth
        !          1861:  cr
        !          1862:  ." This program is free software; you can redistribute it and/or modify" cr
        !          1863:  ." it under the terms of the GNU General Public License as published by" cr
        !          1864:  ." the Free Software Foundation; either version 2 of the License, or" cr
        !          1865:  ." (at your option) any later version." cr cr
        !          1866: 
        !          1867:  ." This program is distributed in the hope that it will be useful," cr
        !          1868:  ." but WITHOUT ANY WARRANTY; without even the implied warranty of" cr
        !          1869:  ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" cr
        !          1870:  ." GNU General Public License for more details." cr cr
        !          1871: 
        !          1872:  ." You should have received a copy of the GNU General Public License" cr
        !          1873:  ." along with this program; if not, write to the Free Software" cr
        !          1874:  ." Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA." cr ;
        !          1875: 
        !          1876: : boot ( path **argv argc -- )
        !          1877:   argc ! argv ! cstring>sstring pathstring 2!  main-task up!
        !          1878:   sp@ dup s0 ! $10 + dup >tib ! tibstack ! #tib off >in off
        !          1879:   rp@ r0 !  fp@ f0 !  ['] cold catch DoError bye ;
        !          1880: 
        !          1881: : bye ( -- ) \ tools-ext
        !          1882:     script? 0= IF  cr  THEN  0 (bye) ;
        !          1883: 
        !          1884: \ **argv may be scanned by the C starter to get some important
        !          1885: \ information, as -display and -geometry for an X client FORTH
        !          1886: \ or space and stackspace overrides
        !          1887: 
        !          1888: \ 0 arg contains, however, the name of the program.
        !          1889: 
        !          1890: 

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