Annotation of gforth/kernel/int.fs, revision 1.64

1.1       pazsan      1: \ definitions needed for interpreter only
                      2: 
1.52      pazsan      3: \ Copyright (C) 1995-2000 Free Software Foundation, Inc.
1.11      anton       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
1.63      anton      19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.11      anton      20: 
1.1       pazsan     21: \ \ Revision-Log
                     22: 
                     23: \       put in seperate file                           14sep97jaw 
                     24: 
                     25: \ \ input stream primitives                            23feb93py
                     26: 
1.33      jwilke     27: require ./basics.fs    \ bounds decimal hex ...
                     28: require ./io.fs                \ type ...
                     29: require ./nio.fs       \ . <# ...
                     30: require ./errore.fs    \ .error ...
1.50      anton      31: require kernel/version.fs      \ version-string
1.33      jwilke     32: require ./../chains.fs
                     33: 
1.64    ! pazsan     34: has? new-input 0= [IF]
1.43      crook      35: : tib ( -- c-addr ) \ core-ext t-i-b
1.40      crook      36:     \G @i{c-addr} is the address of the Terminal Input Buffer.
1.29      crook      37:     \G OBSOLESCENT: @code{source} superceeds the function of this word.
1.1       pazsan     38:     >tib @ ;
                     39: 
1.29      crook      40: Defer source ( -- c-addr u ) \ core
1.1       pazsan     41: \ used by dodefer:, must be defer
1.40      crook      42: \G @i{c-addr} is the address of the input buffer and @i{u} is the
1.29      crook      43: \G number of characters in it.
1.1       pazsan     44: 
1.29      crook      45: : (source) ( -- c-addr u )
1.1       pazsan     46:     tib #tib @ ;
                     47: ' (source) IS source
1.64    ! pazsan     48: [THEN]
1.1       pazsan     49: 
                     50: : (word) ( addr1 n1 char -- addr2 n2 )
                     51:   dup >r skip 2dup r> scan  nip - ;
                     52: 
                     53: \ (word) should fold white spaces
                     54: \ this is what (parse-white) does
                     55: 
                     56: \ word parse                                           23feb93py
                     57: 
1.29      crook      58: : sword  ( char -- addr len ) \ gforth s-word
1.40      crook      59:     \G Parses like @code{word}, but the output is like @code{parse} output.
1.47      anton      60:     \G @xref{core-idef}.
1.3       anton      61:   \ this word was called PARSE-WORD until 0.3.0, but Open Firmware and
                     62:   \ dpANS6 A.6.2.2008 have a word with that name that behaves
                     63:   \ differently (like NAME).
1.1       pazsan     64:   source 2dup >r >r >in @ over min /string
                     65:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
                     66:   2dup + r> - 1+ r> min >in ! ;
                     67: 
1.29      crook      68: : word   ( char "<chars>ccc<char>-- c-addr ) \ core
1.40      crook      69:     \G Skip leading delimiters. Parse @i{ccc}, delimited by
                     70:     \G @i{char}, in the parse area. @i{c-addr} is the address of a
1.29      crook      71:     \G transient region containing the parsed string in
1.40      crook      72:     \G counted-string format. If the parse area was empty or
1.29      crook      73:     \G contained no characters other than delimiters, the resulting
                     74:     \G string has zero length. A program may replace characters within
                     75:     \G the counted string. OBSOLESCENT: the counted string has a
                     76:     \G trailing space that is not included in its length.
                     77:     sword here place  bl here count + c!  here ;
                     78: 
                     79: : parse    ( char "ccc<char>" -- c-addr u ) \ core-ext
1.40      crook      80:     \G Parse @i{ccc}, delimited by @i{char}, in the parse
                     81:     \G area. @i{c-addr u} specifies the parsed string within the
                     82:     \G parse area. If the parse area was empty, @i{u} is 0.
1.29      crook      83:     >r  source  >in @ over min /string  over  swap r>  scan >r
1.1       pazsan     84:   over - dup r> IF 1+ THEN  >in +! ;
                     85: 
                     86: \ name                                                 13feb93py
                     87: 
                     88: [IFUNDEF] (name) \ name might be a primitive
                     89: 
1.40      crook      90: : (name) ( -- c-addr count ) \ gforth
1.1       pazsan     91:     source 2dup >r >r >in @ /string (parse-white)
                     92:     2dup + r> - 1+ r> min >in ! ;
                     93: \    name count ;
                     94: [THEN]
                     95: 
                     96: : name-too-short? ( c-addr u -- c-addr u )
                     97:     dup 0= -&16 and throw ;
                     98: 
                     99: : name-too-long? ( c-addr u -- c-addr u )
                    100:     dup $1F u> -&19 and throw ;
                    101: 
                    102: \ \ Number parsing                                     23feb93py
                    103: 
                    104: \ number? number                                       23feb93py
                    105: 
                    106: hex
                    107: const Create bases   10 ,   2 ,   A , 100 ,
                    108: \                     16     2    10   character
                    109: 
1.18      anton     110: \ !! protect BASE saving wrapper against exceptions
1.1       pazsan    111: : getbase ( addr u -- addr' u' )
                    112:     over c@ [char] $ - dup 4 u<
                    113:     IF
                    114:        cells bases + @ base ! 1 /string
                    115:     ELSE
                    116:        drop
                    117:     THEN ;
                    118: 
1.20      pazsan    119: : sign? ( addr u -- addr u flag )
1.33      jwilke    120:     over c@ [char] - =  dup >r
1.1       pazsan    121:     IF
                    122:        1 /string
                    123:     THEN
1.20      pazsan    124:     r> ;
                    125: 
                    126: : s>unumber? ( addr u -- ud flag )
1.21      pazsan    127:     base @ >r  dpl on  getbase
1.20      pazsan    128:     0. 2swap
1.18      anton     129:     BEGIN ( d addr len )
1.1       pazsan    130:        dup >r >number dup
1.18      anton     131:     WHILE \ there are characters left
1.1       pazsan    132:        dup r> -
1.18      anton     133:     WHILE \ the last >number parsed something
                    134:        dup 1- dpl ! over c@ [char] . =
                    135:     WHILE \ the current char is '.'
1.1       pazsan    136:        1 /string
1.18      anton     137:     REPEAT  THEN \ there are unparseable characters left
1.21      pazsan    138:        2drop false
1.20      pazsan    139:     ELSE
                    140:        rdrop 2drop true
1.21      pazsan    141:     THEN
                    142:     r> base ! ;
1.20      pazsan    143: 
                    144: \ ouch, this is complicated; there must be a simpler way - anton
                    145: : s>number? ( addr len -- d f )
                    146:     \ converts string addr len into d, flag indicates success
1.21      pazsan    147:     sign? >r
1.20      pazsan    148:     s>unumber?
                    149:     0= IF
1.21      pazsan    150:         rdrop false
1.18      anton     151:     ELSE \ no characters left, all ok
1.20      pazsan    152:        r>
1.1       pazsan    153:        IF
                    154:            dnegate
                    155:        THEN
1.18      anton     156:        true
1.21      pazsan    157:     THEN ;
1.1       pazsan    158: 
1.18      anton     159: : s>number ( addr len -- d )
                    160:     \ don't use this, there is no way to tell success
                    161:     s>number? drop ;
                    162: 
1.1       pazsan    163: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
1.18      anton     164:     s>number? 0=
1.1       pazsan    165:     IF
                    166:        2drop false  EXIT
                    167:     THEN
1.18      anton     168:     dpl @ dup 0< IF
1.1       pazsan    169:        nip
1.18      anton     170:     ELSE
                    171:        1+
1.1       pazsan    172:     THEN ;
                    173: 
                    174: : number? ( string -- string 0 / n -1 / d 0> )
                    175:     dup >r count snumber? dup if
                    176:        rdrop
                    177:     else
                    178:        r> swap
                    179:     then ;
                    180: 
                    181: : number ( string -- d )
                    182:     number? ?dup 0= abort" ?"  0<
                    183:     IF
                    184:        s>d
                    185:     THEN ;
                    186: 
                    187: \ \ Comments ( \ \G
                    188: 
1.29      crook     189: : ( ( compilation 'ccc<close-paren>' -- ; run-time -- ) \ thisone- core,file   paren
1.17      crook     190:     \G ** this will not get annotated. The alias in glocals.fs will instead **
1.29      crook     191:     \G It does not work to use "wordset-" prefix since this file is glossed
                    192:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
1.1       pazsan    193:     [char] ) parse 2drop ; immediate
                    194: 
1.51      anton     195: : \ ( compilation 'ccc<newline>' -- ; run-time -- ) \ thisone- core-ext,block-ext backslash
1.29      crook     196:     \G ** this will not get annotated. The alias in glocals.fs will instead ** 
                    197:     \G It does not work to use "wordset-" prefix since this file is glossed
                    198:     \G by cross.fs which doesn't have the same functionalty as makedoc.fs
1.12      pazsan    199:     [ has? file [IF] ]
1.1       pazsan    200:     blk @
                    201:     IF
                    202:        >in @ c/l / 1+ c/l * >in !
                    203:        EXIT
                    204:     THEN
1.12      pazsan    205:     [ [THEN] ]
1.1       pazsan    206:     source >in ! drop ; immediate
                    207: 
1.51      anton     208: : \G ( compilation 'ccc<newline>' -- ; run-time -- ) \ gforth backslash-gee
1.19      crook     209:     \G Equivalent to @code{\} but used as a tag to annotate definition
                    210:     \G comments into documentation.
1.1       pazsan    211:     POSTPONE \ ; immediate
                    212: 
                    213: \ \ object oriented search list                         17mar93py
                    214: 
                    215: \ word list structure:
                    216: 
                    217: struct
                    218:   cell% field find-method   \ xt: ( c_addr u wid -- nt )
                    219:   cell% field reveal-method \ xt: ( nt wid -- ) \ used by dofield:, must be field
                    220:   cell% field rehash-method \ xt: ( wid -- )      \ re-initializes a "search-data" (hashtables)
                    221:   cell% field hash-method   \ xt: ( wid -- )    \ initializes ""
                    222: \   \ !! what else
                    223: end-struct wordlist-map-struct
                    224: 
                    225: struct
1.6       pazsan    226:   cell% field wordlist-map \ pointer to a wordlist-map-struct
1.13      anton     227:   cell% field wordlist-id \ linked list of words (for WORDS etc.)
1.1       pazsan    228:   cell% field wordlist-link \ link field to other wordlists
1.13      anton     229:   cell% field wordlist-extend \ wordlist extensions (eg bucket offset)
1.1       pazsan    230: end-struct wordlist-struct
                    231: 
                    232: : f83find      ( addr len wordlist -- nt / false )
1.6       pazsan    233:     wordlist-id @ (f83find) ;
1.1       pazsan    234: 
                    235: : initvoc              ( wid -- )
                    236:   dup wordlist-map @ hash-method perform ;
                    237: 
                    238: \ Search list table: find reveal
                    239: Create f83search ( -- wordlist-map )
                    240:     ' f83find A,  ' drop A,  ' drop A, ' drop A,
                    241: 
1.6       pazsan    242: here G f83search T A, NIL A, NIL A, NIL A,
1.1       pazsan    243: AValue forth-wordlist \ variable, will be redefined by search.fs
                    244: 
                    245: AVariable lookup               forth-wordlist lookup !
                    246: \ !! last is user and lookup?! jaw
                    247: AVariable current ( -- addr ) \ gforth
1.43      crook     248: \G @code{Variable} -- holds the @i{wid} of the compilation word list.
1.1       pazsan    249: AVariable voclink      forth-wordlist wordlist-link voclink !
1.38      anton     250: \ lookup AValue context ( -- addr ) \ gforth
                    251: Defer context ( -- addr ) \ gforth
1.43      crook     252: \G @code{context} @code{@@} is the @i{wid} of the word list at the
                    253: \G top of the search order.
1.1       pazsan    254: 
1.38      anton     255: ' lookup is context
1.1       pazsan    256: forth-wordlist current !
                    257: 
                    258: \ \ header, finding, ticks                              17dec92py
                    259: 
1.33      jwilke    260: hex
                    261: 80 constant alias-mask \ set when the word is not an alias!
                    262: 40 constant immediate-mask
                    263: 20 constant restrict-mask
1.1       pazsan    264: 
                    265: \ higher level parts of find
                    266: 
                    267: : flag-sign ( f -- 1|-1 )
                    268:     \ true becomes 1, false -1
                    269:     0= 2* 1+ ;
                    270: 
                    271: : compile-only-error ( ... -- )
                    272:     -&14 throw ;
                    273: 
                    274: : (cfa>int) ( cfa -- xt )
                    275: [ has? compiler [IF] ]
                    276:     dup interpret/compile?
                    277:     if
                    278:        interpret/compile-int @
                    279:     then 
                    280: [ [THEN] ] ;
                    281: 
                    282: : (x>int) ( cfa b -- xt )
                    283:     \ get interpretation semantics of name
                    284:     restrict-mask and
                    285:     if
                    286:        drop ['] compile-only-error
                    287:     else
                    288:        (cfa>int)
                    289:     then ;
                    290: 
                    291: : name>string ( nt -- addr count ) \ gforth     head-to-string
1.40      crook     292:     \g @i{addr count} is the name of the word represented by @i{nt}.
1.1       pazsan    293:     cell+ count $1F and ;
                    294: 
                    295: : ((name>))  ( nfa -- cfa )
                    296:     name>string + cfaligned ;
                    297: 
                    298: : (name>x) ( nfa -- cfa b )
                    299:     \ cfa is an intermediate cfa and b is the flags byte of nfa
                    300:     dup ((name>))
                    301:     swap cell+ c@ dup alias-mask and 0=
                    302:     IF
                    303:         swap @ swap
                    304:     THEN ;
                    305: 
                    306: : name>int ( nt -- xt ) \ gforth
1.31      crook     307:     \G @i{xt} represents the interpretation semantics of the word
                    308:     \G @i{nt}. If @i{nt} has no interpretation semantics (i.e. is
                    309:     \G @code{compile-only}), @i{xt} is the execution token for
                    310:     \G @code{compile-only-error}, which performs @code{-14 throw}.
1.1       pazsan    311:     (name>x) (x>int) ;
                    312: 
                    313: : name?int ( nt -- xt ) \ gforth
1.31      crook     314:     \G Like @code{name>int}, but perform @code{-14 throw} if @i{nt}
                    315:     \G has no interpretation semantics.
1.1       pazsan    316:     (name>x) restrict-mask and
                    317:     if
                    318:        compile-only-error \ does not return
                    319:     then
                    320:     (cfa>int) ;
                    321: 
                    322: : (name>comp) ( nt -- w +-1 ) \ gforth
1.31      crook     323:     \G @i{w xt} is the compilation token for the word @i{nt}.
1.1       pazsan    324:     (name>x) >r 
                    325: [ has? compiler [IF] ]
                    326:     dup interpret/compile?
                    327:     if
                    328:         interpret/compile-comp @
                    329:     then 
                    330: [ [THEN] ]
                    331:     r> immediate-mask and flag-sign
                    332:     ;
                    333: 
                    334: : (name>intn) ( nfa -- xt +-1 )
                    335:     (name>x) tuck (x>int) ( b xt )
                    336:     swap immediate-mask and flag-sign ;
                    337: 
1.30      jwilke    338: const Create ???  0 , 3 c, char ? c, char ? c, char ? c,
                    339: \ ??? is used by dovar:, must be created/:dovar
                    340: 
                    341: [IFDEF] forthstart
                    342: \ if we have a forthstart we can define head? with it
                    343: \ otherwise leave out the head? check
                    344: 
1.14      anton     345: : head? ( addr -- f )
                    346:     \G heuristic check whether addr is a name token; may deliver false
                    347:     \G positives; addr must be a valid address
                    348:     \ we follow the link fields and check for plausibility; two
                    349:     \ iterations should catch most false addresses: on the first
                    350:     \ iteration, we may get an xt, on the second a code address (or
                    351:     \ some code), which is typically not in the dictionary.
                    352:     2 0 do
1.41      anton     353:        dup dup aligned <> if \ protect @ against unaligned accesses
                    354:            drop false unloop exit
                    355:        then
1.14      anton     356:        dup @ dup
                    357:        if ( addr addr1 )
                    358:            dup rot forthstart within
                    359:            if \ addr1 is outside forthstart..addr, not a head
                    360:                drop false unloop exit
                    361:            then ( addr1 )
                    362:        else \ 0 in the link field, no further checks
                    363:            2drop true unloop exit
                    364:        then
                    365:     loop
                    366:     \ in dubio pro:
                    367:     drop true ;
                    368: 
1.48      anton     369: : >head-noprim ( cfa -- nt ) \ gforth  to-head-noprim
1.45      pazsan    370:     $25 cell do ( cfa )
1.14      anton     371:        dup i - count $9F and + cfaligned over alias-mask + =
                    372:        if ( cfa )
                    373:            dup i - cell - dup head?
                    374:            if
                    375:                nip unloop exit
                    376:            then
                    377:            drop
                    378:        then
                    379:        cell +loop
                    380:     drop ??? ( wouldn't 0 be better? ) ;
1.1       pazsan    381: 
1.30      jwilke    382: [ELSE]
                    383: 
1.48      anton     384: : >head-noprim ( cfa -- nt ) \ gforth  to-head-noprim
1.45      pazsan    385:     $25 cell do ( cfa )
1.30      jwilke    386:        dup i - count $9F and + cfaligned over alias-mask + =
                    387:        if ( cfa ) i - cell - unloop exit
                    388:        then
                    389:        cell +loop
                    390:     drop ??? ( wouldn't 0 be better? ) ;
                    391: 
                    392: [THEN]
1.1       pazsan    393: 
                    394: : body> 0 >body - ;
                    395: 
1.31      crook     396: : (search-wordlist)  ( addr count wid -- nt | false )
1.1       pazsan    397:     dup wordlist-map @ find-method perform ;
                    398: 
1.31      crook     399: : search-wordlist ( c-addr count wid -- 0 | xt +-1 ) \ search
1.53      anton     400:     \G Search the word list identified by @i{wid} for the definition
                    401:     \G named by the string at @i{c-addr count}.  If the definition is
                    402:     \G not found, return 0. If the definition is found return 1 (if
                    403:     \G the definition is immediate) or -1 (if the definition is not
                    404:     \G immediate) together with the @i{xt}.  In Gforth, the @i{xt}
                    405:     \G returned represents the interpretation semantics.  ANS Forth
                    406:     \G does not specify clearly what @i{xt} represents.
1.1       pazsan    407:     (search-wordlist) dup if
                    408:        (name>intn)
                    409:     then ;
                    410: 
1.31      crook     411: : find-name ( c-addr u -- nt | 0 ) \ gforth
                    412:     \g Find the name @i{c-addr u} in the current search
                    413:     \g order. Return its @i{nt}, if found, otherwise 0.
1.1       pazsan    414:     lookup @ (search-wordlist) ;
                    415: 
                    416: : sfind ( c-addr u -- 0 / xt +-1  ) \ gforth-obsolete
                    417:     find-name dup
                    418:     if ( nt )
                    419:        state @
                    420:        if
                    421:            (name>comp)
                    422:        else
                    423:            (name>intn)
                    424:        then
                    425:    then ;
                    426: 
1.31      crook     427: : find ( c-addr -- xt +-1 | c-addr 0 ) \ core,search
1.53      anton     428:     \G Search all word lists in the current search order for the
                    429:     \G definition named by the counted string at @i{c-addr}.  If the
                    430:     \G definition is not found, return 0. If the definition is found
                    431:     \G return 1 (if the definition has non-default compilation
                    432:     \G semantics) or -1 (if the definition has default compilation
                    433:     \G semantics).  The @i{xt} returned in interpret state represents
                    434:     \G the interpretation semantics.  The @i{xt} returned in compile
                    435:     \G state represented either the compilation semantics (for
                    436:     \G non-default compilation semantics) or the run-time semantics
                    437:     \G that the compilation semantics would @code{compile,} (for
                    438:     \G default compilation semantics).  The ANS Forth standard does
                    439:     \G not specify clearly what the returned @i{xt} represents (and
                    440:     \G also talks about immediacy instead of non-default compilation
                    441:     \G semantics), so this word is questionable in portable programs.
                    442:     \G If non-portability is ok, @code{find-name} and friends are
                    443:     \G better (@pxref{Name token}).
1.1       pazsan    444:     dup count sfind dup
                    445:     if
                    446:        rot drop
                    447:     then ;
                    448: 
1.34      jwilke    449: \ ticks in interpreter
1.1       pazsan    450: 
                    451: : (') ( "name" -- nt ) \ gforth
1.32      anton     452:     name name-too-short?
1.28      anton     453:     find-name dup 0=
1.1       pazsan    454:     IF
1.42      anton     455:        drop -&13 throw
1.1       pazsan    456:     THEN  ;
                    457: 
                    458: : '    ( "name" -- xt ) \ core tick
1.31      crook     459:     \g @i{xt} represents @i{name}'s interpretation
                    460:     \g semantics. Perform @code{-14 throw} if the word has no
1.1       pazsan    461:     \g interpretation semantics.
                    462:     (') name?int ;
1.34      jwilke    463: 
                    464: has? compiler 0= [IF]  \ interpreter only version of IS and TO
                    465: 
                    466: : IS ' >body ! ;
                    467: ' IS Alias TO
                    468: 
                    469: [THEN]
1.1       pazsan    470: 
                    471: \ \ the interpreter loop                                 mar92py
                    472: 
                    473: \ interpret                                            10mar92py
                    474: 
1.37      anton     475: Defer parser ( c-addr u -- )
1.1       pazsan    476: Defer name ( -- c-addr count ) \ gforth
1.55      anton     477: \G Get the next word from the input buffer
1.1       pazsan    478: ' (name) IS name
                    479: Defer compiler-notfound ( c-addr count -- )
                    480: Defer interpreter-notfound ( c-addr count -- )
                    481: 
                    482: : no.extensions  ( addr u -- )
1.42      anton     483:     2drop -&13 throw ;
1.1       pazsan    484: ' no.extensions IS compiler-notfound
                    485: ' no.extensions IS interpreter-notfound
                    486: 
                    487: : interpret ( ?? -- ?? ) \ gforth
                    488:     \ interpret/compile the (rest of the) input buffer
1.33      jwilke    489: [ has? backtrace [IF] ]
1.24      anton     490:     rp@ backtrace-rp0 !
1.33      jwilke    491: [ [THEN] ]
1.1       pazsan    492:     BEGIN
                    493:        ?stack name dup
                    494:     WHILE
                    495:        parser
                    496:     REPEAT
                    497:     2drop ;
                    498: 
                    499: \ interpreter                                  30apr92py
                    500: 
                    501: \ not the most efficient implementations of interpreter and compiler
1.33      jwilke    502: : interpreter ( c-addr u -- ) 
1.1       pazsan    503:     2dup find-name dup
                    504:     if
                    505:        nip nip name>int execute
                    506:     else
                    507:        drop
                    508:        2dup 2>r snumber?
                    509:        IF
                    510:            2rdrop
                    511:        ELSE
                    512:            2r> interpreter-notfound
                    513:        THEN
                    514:     then ;
                    515: 
                    516: ' interpreter  IS  parser
                    517: 
                    518: \ \ Query Evaluate                                     07apr93py
                    519: 
                    520: has? file 0= [IF]
1.12      pazsan    521: : sourceline# ( -- n )  1 ;
1.61      pazsan    522: [ELSE]
1.64    ! pazsan    523: has? new-input 0= [IF]
1.58      pazsan    524: Variable #fill-bytes
                    525: \G number of bytes read via (read-line) by the last refill
1.61      pazsan    526: [THEN]
1.64    ! pazsan    527: [THEN]
1.58      pazsan    528: 
1.64    ! pazsan    529: has? new-input 0= [IF]
1.1       pazsan    530: : refill ( -- flag ) \ core-ext,block-ext,file-ext
1.29      crook     531:     \G Attempt to fill the input buffer from the input source.  When
                    532:     \G the input source is the user input device, attempt to receive
                    533:     \G input into the terminal input device. If successful, make the
                    534:     \G result the input buffer, set @code{>IN} to 0 and return true;
                    535:     \G otherwise return false. When the input source is a block, add 1
                    536:     \G to the value of @code{BLK} to make the next block the input
                    537:     \G source and current input buffer, and set @code{>IN} to 0;
                    538:     \G return true if the new value of @code{BLK} is a valid block
                    539:     \G number, false otherwise. When the input source is a text file,
                    540:     \G attempt to read the next line from the file. If successful,
                    541:     \G make the result the current input buffer, set @code{>IN} to 0
                    542:     \G and return true; otherwise, return false.  A successful result
                    543:     \G includes receipt of a line containing 0 characters.
1.12      pazsan    544:     [ has? file [IF] ]
                    545:        blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
                    546:        [ [THEN] ]
                    547:     tib /line
                    548:     [ has? file [IF] ]
                    549:        loadfile @ ?dup
1.59      pazsan    550:        IF    (read-line) throw #fill-bytes !
1.12      pazsan    551:        ELSE
                    552:            [ [THEN] ]
                    553:        sourceline# 0< IF 2drop false EXIT THEN
                    554:        accept true
                    555:        [ has? file [IF] ]
                    556:        THEN
                    557:        1 loadline +!
                    558:        [ [THEN] ]
                    559:     swap #tib ! 0 >in ! ;
1.1       pazsan    560: 
                    561: : query   ( -- ) \ core-ext
1.29      crook     562:     \G Make the user input device the input source. Receive input into
                    563:     \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
                    564:     \G superceeded by @code{accept}.
1.12      pazsan    565:     [ has? file [IF] ]
                    566:        blk off loadfile off
                    567:        [ [THEN] ]
1.64    ! pazsan    568:     refill drop ;
        !           569: [THEN]
1.1       pazsan    570: 
                    571: \ save-mem extend-mem
                    572: 
                    573: has? os [IF]
                    574: : save-mem     ( addr1 u -- addr2 u ) \ gforth
                    575:     \g copy a memory block into a newly allocated region in the heap
                    576:     swap >r
                    577:     dup allocate throw
                    578:     swap 2dup r> -rot move ;
                    579: 
                    580: : extend-mem   ( addr1 u1 u -- addr addr2 u2 )
                    581:     \ extend memory block allocated from the heap by u aus
                    582:     \ the (possibly reallocated piece is addr2 u2, the extension is at addr
                    583:     over >r + dup >r resize throw
                    584:     r> over r> + -rot ;
                    585: [THEN]
                    586: 
                    587: \ EVALUATE                                              17may93jaw
                    588: 
1.64    ! pazsan    589: has? file 0= has? new-input 0= and [IF]
1.1       pazsan    590: : push-file  ( -- )  r>
1.12      pazsan    591:   tibstack @ >r  >tib @ >r  #tib @ >r
1.1       pazsan    592:   >tib @ tibstack @ = IF  r@ tibstack +!  THEN
                    593:   tibstack @ >tib ! >in @ >r  >r ;
                    594: 
                    595: : pop-file   ( throw-code -- throw-code )
                    596:   r>
1.12      pazsan    597:   r> >in !  r> #tib !  r> >tib !  r> tibstack !  >r ;
1.1       pazsan    598: [THEN]
                    599: 
1.64    ! pazsan    600: has? new-input 0= [IF]
1.29      crook     601: : evaluate ( c-addr u -- ) \ core,block
1.40      crook     602:     \G Save the current input source specification. Store @code{-1} in
                    603:     \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
                    604:     \G @code{0} and make the string @i{c-addr u} the input source
                    605:     \G and input buffer. Interpret. When the parse area is empty,
                    606:     \G restore the input source specification.
1.64    ! pazsan    607: [ has? file [IF] ]
1.56      anton     608:     loadfilename# @ >r
1.60      anton     609:     1 loadfilename# ! \ "*evaluated string*"
1.64    ! pazsan    610: [ [THEN] ]
1.40      crook     611:     push-file #tib ! >tib !
1.29      crook     612:     >in off
                    613:     [ has? file [IF] ]
                    614:        blk off loadfile off -1 loadline !
                    615:        [ [THEN] ]
                    616:     ['] interpret catch
1.56      anton     617:     pop-file
1.64    ! pazsan    618: [ has? file [IF] ]
1.56      anton     619:     r> loadfilename# !
1.64    ! pazsan    620: [ [THEN] ]
1.56      anton     621:     throw ;
1.64    ! pazsan    622: [THEN]
1.1       pazsan    623: 
                    624: \ \ Quit                                               13feb93py
                    625: 
                    626: Defer 'quit
                    627: 
                    628: Defer .status
                    629: 
                    630: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
                    631: 
1.39      anton     632: : (quit) ( -- )
                    633:     \ exits only through THROW etc.
1.42      anton     634: \    sp0 @ cell - handler @ &12 + ! \ !! kludge: fix the stack pointer
1.39      anton     635:     \ stored in the system's CATCH frame, so the stack depth will be 0
                    636:     \ after the next THROW it catches (it may be off due to BOUNCEs or
                    637:     \ because process-args left something on the stack)
                    638:     BEGIN
1.64    ! pazsan    639:        .status cr query interpret prompt
1.39      anton     640:     AGAIN ;
1.1       pazsan    641: 
                    642: ' (quit) IS 'quit
                    643: 
                    644: \ \ DOERROR (DOERROR)                                  13jun93jaw
                    645: 
                    646: 8 Constant max-errors
                    647: Variable error-stack  0 error-stack !
1.64    ! pazsan    648: max-errors has? file [IF] 6 [ELSE] 4 [THEN] * cells allot
1.1       pazsan    649: \ format of one cell:
                    650: \ source ( addr u )
                    651: \ >in
                    652: \ line-number
                    653: \ Loadfilename ( addr u )
                    654: 
1.64    ! pazsan    655: : error> ( -- addr u >in line# [addr u] )
        !           656:     -1 error-stack +!
        !           657:     error-stack dup @
        !           658:     [ has? file [IF] 6 [ELSE] 4 [THEN] ] Literal * cells + cell+
        !           659:     [ has? file [IF] 6 [ELSE] 4 [THEN] ] Literal cells bounds DO
        !           660:        I @
        !           661:        cell +LOOP ;
        !           662: : >error ( addr u >in line# [addr u] -- )
        !           663:     error-stack dup @ dup 1+
        !           664:     max-errors 1- min error-stack !
        !           665:     [ has? file [IF] 6 [ELSE] 4 [THEN] ] Literal * cells + cell+
        !           666:     [ has? file [IF] 6 [ELSE] 4 [THEN] 1- ] Literal cells bounds swap DO
        !           667:        I !
        !           668:        -1 cells +LOOP ;
        !           669: 
1.1       pazsan    670: : dec. ( n -- ) \ gforth
1.40      crook     671:     \G Display @i{n} as a signed decimal number, followed by a space.
                    672:     \ !! not used...
1.1       pazsan    673:     base @ decimal swap . base ! ;
                    674: 
1.23      jwilke    675: : dec.r ( u -- ) \ gforth
1.40      crook     676:     \G Display @i{u} as a unsigned decimal number
1.23      jwilke    677:     base @ decimal swap 0 .r base ! ;
                    678: 
1.1       pazsan    679: : hex. ( u -- ) \ gforth
1.40      crook     680:     \G Display @i{u} as an unsigned hex number, prefixed with a "$" and
1.17      crook     681:     \G followed by a space.
1.40      crook     682:     \ !! not used...
1.33      jwilke    683:     [char] $ emit base @ swap hex u. base ! ;
1.1       pazsan    684: 
                    685: : typewhite ( addr u -- ) \ gforth
1.40      crook     686:     \G Like type, but white space is printed instead of the characters.
1.1       pazsan    687:     bounds ?do
                    688:        i c@ #tab = if \ check for tab
                    689:            #tab
                    690:        else
                    691:            bl
                    692:        then
                    693:        emit
                    694:     loop ;
                    695: 
                    696: DEFER DOERROR
1.33      jwilke    697: 
                    698: has? backtrace [IF]
1.15      anton     699: Defer dobacktrace ( -- )
                    700: ' noop IS dobacktrace
1.33      jwilke    701: [THEN]
1.1       pazsan    702: 
1.23      jwilke    703: : .error-string ( throw-code -- )
                    704:   dup -2 = 
                    705:   IF   "error @ ?dup IF count type  THEN drop
                    706:   ELSE .error
                    707:   THEN ;
                    708: 
1.64    ! pazsan    709: : .error-frame ( throwcode addr1 u1 n1 n2 [addr2 u2] -- throwcode )
        !           710: \ addr2 u2:    filename of included file - optional
1.23      jwilke    711: \ n2:          line number
                    712: \ n1:          error position in input line
                    713: \ addr1 u1:    input line
1.1       pazsan    714:   cr error-stack @
                    715:   IF
1.64    ! pazsan    716: [ has? file [IF] ]
        !           717:     ." in file included from "
        !           718:     type ." :"
        !           719: [ [THEN] ]
        !           720:     dec.r  drop 2drop
1.1       pazsan    721:   ELSE
1.64    ! pazsan    722: [ has? file [IF] ]
        !           723:       type ." :"
        !           724: [ [THEN] ]
        !           725:       dup >r dec.r ." : " 3 pick .error-string
1.57      anton     726:       r> IF \ if line# non-zero, there is a line
                    727:          cr dup 2over type cr drop
                    728:          nip -trailing 1- ( line-start index2 )
                    729:          0 >r  BEGIN
                    730:              2dup + c@ bl >  WHILE
                    731:              r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
                    732:          ( line-start index1 )
                    733:          typewhite
                    734:          r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
                    735:              [char] ^ emit
                    736:          loop
                    737:       ELSE
                    738:          2drop drop
                    739:       THEN
1.23      jwilke    740:   THEN ;
1.1       pazsan    741: 
                    742: : (DoError) ( throw-code -- )
                    743:   [ has? os [IF] ]
1.8       pazsan    744:       >stderr
1.1       pazsan    745:   [ [THEN] ] 
1.64    ! pazsan    746:   source >in @ sourceline# [ has? file [IF] ]
        !           747:       sourcefilename
        !           748:   [ [THEN] ] .error-frame
1.1       pazsan    749:   error-stack @ 0 ?DO
1.64    ! pazsan    750:     error>
1.1       pazsan    751:     .error-frame
                    752:   LOOP
1.33      jwilke    753:   drop 
                    754: [ has? backtrace [IF] ]
                    755:   dobacktrace
                    756: [ [THEN] ]
1.8       pazsan    757:   normal-dp dpp ! ;
1.1       pazsan    758: 
                    759: ' (DoError) IS DoError
                    760: 
                    761: : quit ( ?? -- ?? ) \ core
1.27      crook     762:     \G Empty the return stack, make the user input device
                    763:     \G the input source, enter interpret state and start
                    764:     \G the text interpreter.
1.64    ! pazsan    765:     rp0 @ rp! handler off clear-tibstack
        !           766:     [ has? new-input 0= [IF] ] >tib @ >r [ [THEN] ]
1.1       pazsan    767:     BEGIN
                    768:        [ has? compiler [IF] ]
                    769:        postpone [
                    770:        [ [THEN] ]
                    771:        ['] 'quit CATCH dup
                    772:     WHILE
1.22      anton     773:        <# \ reset hold area, or we may get another error
1.64    ! pazsan    774:        DoError
        !           775:        [ has? new-input [IF] ] clear-tibstack
        !           776:        [ [ELSE] ] r@ >tib ! r@ tibstack !
        !           777:        [ [THEN] ]
1.1       pazsan    778:     REPEAT
1.64    ! pazsan    779:     drop [ has? new-input [IF] ] clear-tibstack
        !           780:     [ [ELSE] ] r> >tib !
        !           781:     [ [THEN] ] ;
1.1       pazsan    782: 
                    783: \ \ Cold Boot                                          13feb93py
                    784: 
                    785: : (bootmessage)
                    786:     ." GForth " version-string type 
1.52      pazsan    787:     ." , Copyright (C) 1995-2000 Free Software Foundation, Inc." cr
1.1       pazsan    788:     ." GForth comes with ABSOLUTELY NO WARRANTY; for details type `license'"
                    789: [ has? os [IF] ]
                    790:      cr ." Type `bye' to exit"
                    791: [ [THEN] ] ;
                    792: 
                    793: defer bootmessage
                    794: defer process-args
                    795: 
                    796: ' (bootmessage) IS bootmessage
                    797: 
1.10      anton     798: Defer 'cold ( -- ) \ gforth  tick-cold
1.1       pazsan    799: \ hook (deferred word) for things to do right before interpreting the
                    800: \ command-line arguments
                    801: ' noop IS 'cold
                    802: 
                    803: 
                    804: Variable init8
                    805: 
                    806: : cold ( -- ) \ gforth
1.44      anton     807: [ has? backtrace [IF] ]
                    808:     rp@ backtrace-rp0 !
                    809: [ [THEN] ]
1.1       pazsan    810: [ has? file [IF] ]
                    811:     pathstring 2@ fpath only-path 
                    812:     init-included-files
                    813: [ [THEN] ]
                    814:     'cold
                    815:     init8 chainperform
                    816: [ has? file [IF] ]
1.62      anton     817:     loadfilename# off
1.8       pazsan    818:     process-args
1.12      pazsan    819:     loadline off
1.1       pazsan    820: [ [THEN] ]
                    821:     bootmessage
1.12      pazsan    822:     quit ;
1.1       pazsan    823: 
1.64    ! pazsan    824: has? new-input 0= [IF]
1.5       anton     825: : clear-tibstack ( -- )
                    826: [ has? glocals [IF] ]
                    827:     lp@ forthstart 7 cells + @ - 
                    828: [ [ELSE] ]
                    829:     [ has? os [IF] ]
1.8       pazsan    830:     r0 @ forthstart 6 cells + @ -
1.5       anton     831:     [ [ELSE] ]
1.16      pazsan    832:     sp@ $10 cells +
1.5       anton     833:     [ [THEN] ]
                    834: [ [THEN] ]
                    835:     dup >tib ! tibstack ! #tib off >in off ;
1.64    ! pazsan    836: [THEN]
1.5       anton     837: 
1.64    ! pazsan    838: : boot ( path n **argv argc -- )
1.1       pazsan    839:     main-task up!
                    840: [ has? os [IF] ]
                    841:     stdout TO outfile-id
1.7       pazsan    842:     stdin  TO infile-id
1.1       pazsan    843: \ !! [ [THEN] ]
                    844: \ !! [ has? file [IF] ]
                    845:     argc ! argv ! pathstring 2!
                    846: [ [THEN] ]
                    847:     sp@ sp0 !
1.64    ! pazsan    848: [ has? new-input [IF] ]
        !           849:     current-input off
        !           850: [ [THEN] ]
1.5       anton     851:     clear-tibstack
1.1       pazsan    852:     rp@ rp0 !
                    853: [ has? floating [IF] ]
                    854:     fp@ fp0 !
                    855: [ [THEN] ]
1.46      anton     856:     handler off
1.8       pazsan    857:     ['] cold catch DoError cr
1.1       pazsan    858: [ has? os [IF] ]
1.35      anton     859:     1 (bye) \ !! determin exit code from throw code?
1.1       pazsan    860: [ [THEN] ]
                    861: ;
                    862: 
                    863: has? os [IF]
                    864: : bye ( -- ) \ tools-ext
                    865: [ has? file [IF] ]
                    866:     script? 0= IF  cr  THEN
                    867: [ [ELSE] ]
                    868:     cr
                    869: [ [THEN] ]
                    870:     0 (bye) ;
                    871: [THEN]
                    872: 
                    873: \ **argv may be scanned by the C starter to get some important
                    874: \ information, as -display and -geometry for an X client FORTH
                    875: \ or space and stackspace overrides
                    876: 
                    877: \ 0 arg contains, however, the name of the program.
                    878: 

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