Annotation of gforth/kernal.fs, revision 1.11

1.1       anton       1: \ KERNAL.FS    ANS figFORTH kernal                     17dec92py
                      2: \ $ID:
                      3: \ Idea and implementation: Bernd Paysan (py)
                      4: \ Copyright 1992 by the ANSI figForth Development Group
                      5: 
                      6: \ Log:  ', '- usw. durch [char] ... ersetzt
                      7: \       man sollte die unterschiedlichen zahlensysteme
                      8: \       mit $ und & zumindest im interpreter weglassen
                      9: \       schon erledigt!
                     10: \       11may93jaw
                     11: \ name>         0= nicht vorhanden              17may93jaw
                     12: \               nfa can be lfa or nfa!
                     13: \ find          splited into find and (find)
                     14: \               (find) for later use            17may93jaw
                     15: \ search        replaced by lookup because
                     16: \               it is a word of the string wordset
                     17: \                                               20may93jaw
                     18: \ postpone      added immediate                 21may93jaw
                     19: \ to            added immediate                 07jun93jaw
                     20: \ cfa, header   put "here lastcfa !" in
                     21: \               cfa, this is more logical
                     22: \               and noname: works wothout
                     23: \               extra "here lastcfa !"          08jun93jaw
                     24: \ (parse-white) thrown out
                     25: \ refill        added outer trick
                     26: \               to show there is something
                     27: \               going on                        09jun93jaw
                     28: \ leave ?leave  somebody forgot UNLOOP!!!       09jun93jaw
                     29: \ leave ?leave  unloop thrown out
                     30: \               unloop after loop is used       10jun93jaw
                     31: 
                     32: HEX
                     33: 
                     34: \ Bit string manipulation                              06oct92py
                     35: 
                     36: Create bits  80 c, 40 c, 20 c, 10 c, 8 c, 4 c, 2 c, 1 c,
                     37: DOES> ( n -- )  + c@ ;
                     38: 
                     39: : >bit  ( addr n -- c-addr mask )  8 /mod rot + swap bits ;
                     40: : +bit  ( addr n -- )  >bit over c@ or swap c! ;
                     41: 
                     42: : relinfo ( -- addr )  forthstart dup @ + ;
                     43: : >rel  ( addr -- n )  forthstart - ;
                     44: : relon ( addr -- )  relinfo swap >rel cell / +bit ;
                     45: 
                     46: \ here allot , c, A,                                   17dec92py
                     47: 
1.5       anton      48: : dp   ( -- addr )  dpp @ ;
1.1       anton      49: : here  ( -- here )  dp @ ;
                     50: : allot ( n -- )     dp +! ;
                     51: : c,    ( c -- )     here 1 chars allot c! ;
                     52: : ,     ( x -- )     here cell allot  ! ;
                     53: : 2,    ( w1 w2 -- ) \ general
                     54:     here 2 cells allot 2! ;
                     55: 
                     56: : aligned ( addr -- addr' )
                     57:   [ cell 1- ] Literal + [ -1 cells ] Literal and ;
                     58: : align ( -- )          here dup aligned swap ?DO  bl c,  LOOP ;
                     59: 
1.8       anton      60: : faligned ( addr -- f-addr )
                     61:   [ 1 floats 1- ] Literal + [ -1 floats ] Literal and ;
                     62: 
                     63: : falign ( -- )
                     64:   here dup faligned swap
                     65:   ?DO
                     66:       bl c,
                     67:   LOOP ;
                     68: 
                     69: 
                     70: 
1.1       anton      71: : A!    ( addr1 addr2 -- )  dup relon ! ;
                     72: : A,    ( addr -- )     here cell allot A! ;
                     73: 
                     74: \ on off                                               23feb93py
                     75: 
                     76: : on  ( addr -- )  true  swap ! ;
                     77: : off ( addr -- )  false swap ! ;
                     78: 
                     79: \ name> found                                          17dec92py
                     80: 
                     81: : (name>)  ( nfa -- cfa )    count  $1F and  +  aligned ;
1.9       pazsan     82: : name>    ( nfa -- cfa )    cell+
1.1       anton      83:   dup  (name>) swap  c@ $80 and 0= IF  @ THEN ;
                     84: 
                     85: : found ( nfa -- cfa n )  cell+
                     86:   dup c@ >r  (name>) r@ $80 and  0= IF  @       THEN
1.9       pazsan     87:                   -1 r@ $40 and     IF  1-      THEN
                     88:                      r> $20 and     IF  negate  THEN  ;
1.1       anton      89: 
                     90: \ (find)                                               17dec92py
                     91: 
                     92: \ : (find) ( addr count nfa1 -- nfa2 / false )
                     93: \   BEGIN  dup  WHILE  dup >r
                     94: \          cell+ count $1F and dup >r 2over r> =
                     95: \          IF  -text  0= IF  2drop r> EXIT  THEN
                     96: \          ELSE  2drop drop  THEN  r> @
                     97: \   REPEAT nip nip ;
                     98: 
                     99: \ place bounds                                         13feb93py
                    100: 
                    101: : place  ( addr len to -- ) over >r  rot over 1+  r> move c! ;
                    102: : bounds ( beg count -- end beg )  over + swap ;
                    103: 
                    104: \ input stream primitives                              23feb93py
                    105: 
                    106: : tib   >tib @ ;
                    107: Defer source
                    108: : (source) ( -- addr count ) tib #tib @ ;
                    109: ' (source) IS source
                    110: 
                    111: \ (word)                                               22feb93py
                    112: 
                    113: : scan   ( addr1 n1 char -- addr2 n2 )  >r
                    114:   BEGIN  dup  WHILE  over c@ r@ <>  WHILE  1 /string
                    115:   REPEAT  THEN  rdrop ;
                    116: : skip   ( addr1 n1 char -- addr2 n2 )  >r
                    117:   BEGIN  dup  WHILE  over c@ r@  =  WHILE  1 /string
                    118:   REPEAT  THEN  rdrop ;
                    119: 
                    120: : (word) ( addr1 n1 char -- addr2 n2 )
                    121:   dup >r skip 2dup r> scan  nip - ;
                    122: 
                    123: \ (word) should fold white spaces
                    124: \ this is what (parse-white) does
                    125: 
                    126: \ word parse                                           23feb93py
                    127: 
                    128: : parse-word  ( char -- addr len )
                    129:   source 2dup >r >r >in @ /string
                    130:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
                    131:   2dup + r> - 1+ r> min >in ! ;
                    132: : word   ( char -- addr )
                    133:   parse-word here place  bl here count + c!  here ;
                    134: 
                    135: : parse    ( char -- addr len )
                    136:   >r  source  >in @ /string  over  swap r>  scan >r
                    137:   over - dup r> IF 1+ THEN  >in +! ;
                    138: 
                    139: \ name                                                 13feb93py
                    140: 
                    141: : capitalize ( addr -- addr )
                    142:   dup count chars bounds
                    143:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
                    144: : (name)  ( -- addr )  bl word ;
1.7       pazsan    145: : (cname) ( -- addr )  bl word capitalize ;
1.1       anton     146: 
                    147: \ Literal                                              17dec92py
                    148: 
1.8       anton     149: : Literal  ( n -- )  state @ IF postpone lit  , THEN ;
1.1       anton     150:                                                       immediate
1.8       anton     151: : ALiteral ( n -- )  state @ IF postpone lit A, THEN ;
1.1       anton     152:                                                       immediate
                    153: 
                    154: : char   ( 'char' -- n )  bl word char+ c@ ;
                    155: : [char] ( 'char' -- n )  char postpone Literal ; immediate
                    156: ' [char] Alias Ascii immediate
                    157: 
                    158: : (compile) ( -- )  r> dup cell+ >r @ A, ;
                    159: : postpone ( "name" -- )
                    160:   name find dup 0= abort" Can't compile "
                    161:   0> IF  A,  ELSE  postpone (compile) A,  THEN ;
                    162:                                              immediate restrict
                    163: 
                    164: \ Use (compile) for the old behavior of compile!
                    165: 
                    166: \ digit?                                               17dec92py
                    167: 
                    168: : digit?   ( char -- digit true/ false )
1.8       anton     169:   base @ $100 =
                    170:   IF
                    171:     true EXIT
                    172:   THEN
1.1       anton     173:   toupper [char] 0 - dup 9 u> IF
                    174:     [ 'A '9 1 + -  ] literal -
                    175:     dup 9 u<= IF
                    176:       drop false EXIT
                    177:     THEN
                    178:   THEN
                    179:   dup base @ u>= IF
                    180:     drop false EXIT
                    181:   THEN
                    182:   true ;
                    183: 
                    184: : accumulate ( +d0 addr digit - +d1 addr )
                    185:   swap >r swap  base @  um* drop rot  base @  um* d+ r> ;
                    186: : >number ( d addr count -- d addr count )
                    187:   0 ?DO  count digit? WHILE  accumulate  LOOP 0
                    188:   ELSE  1- I' I - UNLOOP  THEN ;
                    189: 
                    190: \ number? number                                       23feb93py
                    191: 
                    192: Create bases   10 ,   2 ,   A , 100 ,
                    193: \              16     2    10   Zeichen
                    194: \ !! this saving and restoring base is an abomination! - anton
                    195: : getbase ( addr u -- addr' u' )  over c@ [char] $ - dup 4 u<
                    196:   IF  cells bases + @ base ! 1 /string  ELSE  drop  THEN ;
                    197: : number?  ( string -- string 0 / n -1 )  base @ >r
                    198:   dup count over c@ [char] - = dup >r  IF 1 /string  THEN
                    199:   getbase  dpl on  0 0 2swap
                    200:   BEGIN  dup >r >number dup  WHILE  dup r> -  WHILE
                    201:          dup dpl ! over c@ [char] . =  WHILE
                    202:          1 /string
                    203:   REPEAT  THEN  2drop 2drop rdrop false r> base ! EXIT  THEN
                    204:   2drop rot drop rdrop r> IF dnegate THEN
                    205:   dpl @ dup 0< IF  nip  THEN  r> base ! ;
                    206: : s>d ( n -- d ) dup 0< ;
                    207: : number ( string -- d )
                    208:   number? ?dup 0= abort" ?"  0< IF s>d THEN ;
                    209: 
                    210: \ space spaces ud/mod                                  21mar93py
                    211: decimal
                    212: Create spaces  bl 80 times \ times from target compiler! 11may93jaw
                    213: DOES>   ( u -- )  swap
                    214:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
                    215: hex
                    216: : space   1 spaces ;
                    217: 
                    218: : ud/mod ( ud1 u2 -- urem udquot )  >r 0 r@ um/mod r> swap >r
                    219:                                     um/mod r> ;
                    220: 
                    221: : pad    ( -- addr )
                    222:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
                    223: 
                    224: \ hold <# #> sign # #s                                 25jan92py
                    225: 
                    226: : hold    ( char -- )         pad cell - -1 chars over +! @ c! ;
                    227: 
                    228: : <#                          pad cell - dup ! ;
                    229: 
                    230: : #>      ( 64b -- addr +n )  2drop pad cell - dup @ tuck - ;
                    231: 
                    232: : sign    ( n -- )            0< IF  [char] - hold  THEN ;
                    233: 
                    234: : #       ( +d1 -- +d2 )    base @ 2 max ud/mod rot 9 over <
                    235:   IF [ char A char 9 - 1- ] Literal +  THEN  [char] 0 + hold ;
                    236: 
                    237: : #s      ( +d -- 0 0 )         BEGIN  # 2dup d0=  UNTIL ;
                    238: 
                    239: \ print numbers                                        07jun92py
                    240: 
                    241: : d.r      >r tuck  dabs  <# #s  rot sign #>
                    242:            r> over - spaces  type ;
                    243: 
                    244: : ud.r     >r <# #s #> r> over - spaces type ;
                    245: 
                    246: : .r       >r s>d r> d.r ;
                    247: : u.r      0 swap ud.r ;
                    248: 
                    249: : d.       0 d.r space ;
                    250: : ud.      0 ud.r space ;
                    251: 
                    252: : .        s>d d. ;
                    253: : u.       0 ud. ;
                    254: 
                    255: \ catch throw                                          23feb93py
                    256: \ bounce                                                08jun93jaw
                    257: 
                    258: \ !! allow the user to add rollback actions    anton
                    259: \ !! use a separate exception stack?           anton
                    260: 
1.5       anton     261: : lp@ ( -- addr )
                    262:  laddr# [ 0 , ] ;
                    263: 
1.1       anton     264: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
1.5       anton     265:   >r sp@ r> swap >r       \ don't count xt! jaw
                    266:   fp@ >r
                    267:   lp@ >r
                    268:   handler @ >r
                    269:   rp@ handler !
                    270:   execute
1.6       pazsan    271:   r> handler ! rdrop rdrop rdrop 0 ;
                    272: 
1.5       anton     273: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
1.10      anton     274:     ?DUP IF
                    275:        [ here 4 cells ! ]
                    276:        handler @ rp!
                    277:        r> handler !
                    278:        r> lp!
                    279:        r> fp!
                    280:        r> swap >r sp! r>
                    281:     THEN ;
1.6       pazsan    282: 
1.1       anton     283: \ Bouncing is very fine,
                    284: \ programming without wasting time...   jaw
1.5       anton     285: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym )
                    286: \ a throw without data or fp stack restauration
                    287:   ?DUP IF
                    288:     handler @ rp!
                    289:     r> handler !
                    290:     r> lp!
                    291:     rdrop
                    292:     rdrop
                    293:   THEN ;
1.1       anton     294: 
                    295: \ ?stack                                               23feb93py
                    296: 
                    297: : ?stack ( ?? -- ?? )  sp@ s0 @ > IF  -4 throw  THEN ;
                    298: \ ?stack should be code -- it touches an empty stack!
                    299: 
                    300: \ interpret                                            10mar92py
                    301: 
                    302: Defer parser
                    303: Defer name      ' (name) IS name
                    304: Defer notfound
                    305: 
1.2       pazsan    306: : no.extensions  ( string -- )  IF  &-13 bounce  THEN ;
1.1       anton     307: 
                    308: ' no.extensions IS notfound
                    309: 
                    310: : interpret
                    311:   BEGIN  ?stack name dup c@  WHILE  parser  REPEAT drop ;
                    312: 
                    313: \ interpreter compiler                                 30apr92py
                    314: 
                    315: : interpreter  ( name -- ) find ?dup
                    316:   IF  1 and  IF execute  EXIT THEN  -&14 throw  THEN
                    317:   number? 0= IF  notfound THEN ;
                    318: 
                    319: ' interpreter  IS  parser
                    320: 
                    321: : compiler     ( name -- ) find  ?dup
                    322:   IF  0> IF  execute EXIT THEN compile, EXIT THEN number? dup
                    323:   IF  0> IF  swap postpone Literal  THEN  postpone Literal
1.2       pazsan    324:   ELSE  drop notfound  THEN ;
1.1       anton     325: 
                    326: : [     ['] interpreter  IS parser state off ; immediate
                    327: : ]     ['] compiler     IS parser state on  ;
                    328: 
1.8       anton     329: \ locals stuff needed for control structures
                    330: 
                    331: : compile-lp+! ( n -- )
                    332:     dup negate locals-size +!
                    333:     0 over = if
                    334:     else -4 over = if postpone -4lp+!
                    335:     else  8 over = if postpone  8lp+!
                    336:     else 16 over = if postpone 16lp+!
                    337:     else postpone lp+!# dup ,
                    338:     then then then then drop ;
                    339: 
                    340: : adjust-locals-size ( n -- )
                    341:     \ sets locals-size to n and generates an appropriate lp+!
                    342:     locals-size @ swap - compile-lp+! ;
                    343: 
                    344: 
                    345: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
                    346: AConstant locals-list \ acts like a variable that contains
1.10      anton     347:                      \ a linear list of locals names
1.8       anton     348: 
                    349: 
                    350: variable dead-code \ true if normal code at "here" would be dead
                    351: 
                    352: : unreachable ( -- )
                    353: \ declares the current point of execution as unreachable
                    354:  dead-code on ;
                    355: 
                    356: \ locals list operations
                    357: 
                    358: : common-list ( list1 list2 -- list3 )
                    359: \ list1 and list2 are lists, where the heads are at higher addresses than
                    360: \ the tail. list3 is the largest sublist of both lists.
                    361:  begin
                    362:    2dup u<>
                    363:  while
                    364:    2dup u>
                    365:    if
                    366:      swap
                    367:    then
                    368:    @
                    369:  repeat
                    370:  drop ;
                    371: 
                    372: : sub-list? ( list1 list2 -- f )
                    373: \ true iff list1 is a sublist of list2
                    374:  begin
                    375:    2dup u<
                    376:  while
                    377:    @
                    378:  repeat
                    379:  = ;
                    380: 
                    381: : list-size ( list -- u )
                    382: \ size of the locals frame represented by list
                    383:  0 ( list n )
                    384:  begin
                    385:    over 0<>
                    386:  while
                    387:    over
1.11    ! pazsan    388:    name> >body @ max
1.8       anton     389:    swap @ swap ( get next )
                    390:  repeat
                    391:  faligned nip ;
                    392: 
                    393: : set-locals-size-list ( list -- )
                    394:  dup locals-list !
                    395:  list-size locals-size ! ;
                    396: 
                    397: : check-begin ( list -- )
                    398: \ warn if list is not a sublist of locals-list
                    399:  locals-list @ sub-list? 0= if
                    400:    \ !! print current position
                    401:    ." compiler was overly optimistic about locals at a BEGIN" cr
                    402:    \ !! print assumption and reality
                    403:  then ;
                    404: 
                    405: \ Control Flow Stack
                    406: \ orig, etc. have the following structure:
                    407: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
                    408: \ address (of the branch or the instruction to be branched to) (second)
                    409: \ locals-list (valid at address) (third)
                    410: 
                    411: \ types
                    412: 0 constant defstart
                    413: 1 constant live-orig
                    414: 2 constant dead-orig
                    415: 3 constant dest \ the loopback branch is always assumed live
                    416: 4 constant do-dest
                    417: 5 constant scopestart
                    418: 
                    419: : def? ( n -- )
                    420:     defstart <> abort" unstructured " ;
                    421: 
                    422: : orig? ( n -- )
                    423:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
                    424: 
                    425: : dest? ( n -- )
                    426:  dest <> abort" expected dest " ;
                    427: 
                    428: : do-dest? ( n -- )
                    429:  do-dest <> abort" expected do-dest " ;
                    430: 
                    431: : scope? ( n -- )
                    432:  scopestart <> abort" expected scope " ;
                    433: 
                    434: : non-orig? ( n -- )
                    435:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
                    436: 
                    437: : cs-item? ( n -- )
                    438:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
                    439: 
                    440: 3 constant cs-item-size
                    441: 
                    442: : CS-PICK ( ... u -- ... destu )
                    443:  1+ cs-item-size * 1- >r
                    444:  r@ pick  r@ pick  r@ pick
                    445:  rdrop
                    446:  dup non-orig? ;
                    447: 
                    448: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
                    449:  1+ cs-item-size * 1- >r
                    450:  r@ roll r@ roll r@ roll
                    451:  rdrop
                    452:  dup cs-item? ; 
                    453: 
                    454: : cs-push-part ( -- list addr )
                    455:  locals-list @ here ;
                    456: 
                    457: : cs-push-orig ( -- orig )
                    458:  cs-push-part dead-code @
                    459:  if
                    460:    dead-orig
                    461:  else
                    462:    live-orig
                    463:  then ;   
                    464: 
1.1       anton     465: \ Structural Conditionals                              12dec92py
                    466: 
                    467: : ?struc      ( flag -- )       abort" unstructured " ;
                    468: : sys?        ( sys -- )        dup 0= ?struc ;
1.8       anton     469: : >mark ( -- orig )
                    470:  cs-push-orig 0 , ;
                    471: : >resolve    ( addr -- )        here over - swap ! ;
                    472: : <resolve    ( addr -- )        here - , ;
1.1       anton     473: 
1.8       anton     474: : BUT       1 cs-roll ;                      immediate restrict
                    475: : YET       0 cs-pick ;                       immediate restrict
1.1       anton     476: 
                    477: \ Structural Conditionals                              12dec92py
                    478: 
1.8       anton     479: : AHEAD ( -- orig )
                    480:  POSTPONE branch >mark unreachable ; immediate restrict
                    481: 
                    482: : IF ( -- orig )
                    483:  POSTPONE ?branch >mark ; immediate restrict
                    484: 
1.1       anton     485: : ?DUP-IF \ general
                    486: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
                    487: \ better handled by tools like stack checkers
1.8       anton     488:     POSTPONE ?dup POSTPONE if ;       immediate restrict
1.1       anton     489: : ?DUP-NOT-IF \ general
1.8       anton     490:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
                    491: 
                    492: : THEN ( orig -- )
                    493:     dup orig?
                    494:     dead-code @
                    495:     if
                    496:        dead-orig =
                    497:        if
                    498:            >resolve drop
                    499:        else
                    500:            >resolve set-locals-size-list dead-code off
                    501:        then
                    502:     else
                    503:        dead-orig =
                    504:        if
                    505:            >resolve drop
                    506:        else \ both live
                    507:            over list-size adjust-locals-size
                    508:            >resolve
                    509:            locals-list @ common-list dup list-size adjust-locals-size
                    510:            locals-list !
                    511:        then
                    512:     then ; immediate restrict
                    513: 
1.1       anton     514: ' THEN alias ENDIF immediate restrict \ general
                    515: \ Same as "THEN". This is what you use if your program will be seen by
                    516: \ people who have not been brought up with Forth (or who have been
                    517: \ brought up with fig-Forth).
                    518: 
1.8       anton     519: : ELSE ( orig1 -- orig2 )
                    520:     POSTPONE ahead
                    521:     1 cs-roll
                    522:     POSTPONE then ; immediate restrict
                    523: 
                    524: 
                    525: : BEGIN ( -- dest )
                    526:     dead-code @ if
                    527:        \ set up an assumption of the locals visible here
                    528:        \ currently we just take the top cs-item
                    529:        \ it would be more intelligent to take the top orig
                    530:        \   but that can be arranged by the user
                    531:        dup defstart <> if
                    532:            dup cs-item?
                    533:            2 pick
                    534:        else
                    535:            0
                    536:        then
                    537:        set-locals-size-list
                    538:     then
                    539:     cs-push-part dest
                    540:     dead-code off ; immediate restrict
                    541: 
                    542: \ AGAIN (the current control flow joins another, earlier one):
                    543: \ If the dest-locals-list is not a subset of the current locals-list,
                    544: \ issue a warning (see below). The following code is generated:
                    545: \ lp+!# (current-local-size - dest-locals-size)
                    546: \ branch <begin>
                    547: : AGAIN ( dest -- )
                    548:     dest?
                    549:     over list-size adjust-locals-size
                    550:     POSTPONE branch
                    551:     <resolve
                    552:     check-begin
                    553:     unreachable ; immediate restrict
                    554: 
                    555: \ UNTIL (the current control flow may join an earlier one or continue):
                    556: \ Similar to AGAIN. The new locals-list and locals-size are the current
                    557: \ ones. The following code is generated:
                    558: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
                    559: : until-like ( list addr xt1 xt2 -- )
                    560:     \ list and addr are a fragment of a cs-item
                    561:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
                    562:     >r >r
                    563:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
                    564:        r> drop r> compile,
                    565:        swap <resolve ( list adjustment ) ,
                    566:     else ( list dest-addr adjustment )
                    567:        drop
                    568:        r> compile, <resolve
                    569:        r> drop
                    570:     then ( list )
                    571:     check-begin ;
                    572: 
                    573: : UNTIL ( dest -- )
                    574:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
                    575: 
                    576: : WHILE ( dest -- orig dest )
                    577:     POSTPONE if
                    578:     1 cs-roll ; immediate restrict
                    579: 
                    580: : REPEAT ( orig dest -- )
                    581:     POSTPONE again
                    582:     POSTPONE then ; immediate restrict
                    583: 
                    584: 
                    585: \ counted loops
                    586: 
                    587: \ leave poses a little problem here
                    588: \ we have to store more than just the address of the branch, so the
                    589: \ traditional linked list approach is no longer viable.
                    590: \ This is solved by storing the information about the leavings in a
1.9       pazsan    591: \ special stack.
1.8       anton     592: 
                    593: \ !! remove the fixed size limit. 'Tis not hard.
                    594: 20 constant leave-stack-size
1.9       pazsan    595: create leave-stack  60 cells allot
                    596: Avariable leave-sp  leave-stack 3 cells + leave-sp !
1.8       anton     597: 
                    598: : clear-leave-stack ( -- )
                    599:     leave-stack leave-sp ! ;
                    600: 
                    601: \ : leave-empty? ( -- f )
                    602: \  leave-sp @ leave-stack = ;
                    603: 
                    604: : >leave ( orig -- )
                    605:     \ push on leave-stack
                    606:     leave-sp @
                    607:     dup [ leave-stack 60 cells + ] Aliteral
                    608:     >= abort" leave-stack full"
                    609:     tuck ! cell+
                    610:     tuck ! cell+
                    611:     tuck ! cell+
                    612:     leave-sp ! ;
                    613: 
                    614: : leave> ( -- orig )
                    615:     \ pop from leave-stack
                    616:     leave-sp @
1.9       pazsan    617:     dup leave-stack <= IF
                    618:        drop 0 0 0  EXIT  THEN
1.8       anton     619:     cell - dup @ swap
                    620:     cell - dup @ swap
                    621:     cell - dup @ swap
                    622:     leave-sp ! ;
                    623: 
1.9       pazsan    624: : DONE ( orig -- )  drop >r drop
1.8       anton     625:     \ !! the original done had ( addr -- )
                    626:     begin
                    627:        leave>
1.9       pazsan    628:        over r@ u>=
1.8       anton     629:     while
                    630:        POSTPONE then
                    631:     repeat
1.9       pazsan    632:     >leave rdrop ; immediate restrict
1.8       anton     633: 
                    634: : LEAVE ( -- )
                    635:     POSTPONE ahead
1.9       pazsan    636:     >leave ; immediate restrict
1.8       anton     637: 
                    638: : ?LEAVE ( -- )
                    639:     POSTPONE 0= POSTPONE if
1.9       pazsan    640:     >leave ; immediate restrict
1.8       anton     641: 
                    642: : DO ( -- do-sys )
                    643:     POSTPONE (do)
                    644:     POSTPONE begin drop do-dest
1.9       pazsan    645:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     646: 
                    647: : ?DO ( -- do-sys )
1.9       pazsan    648:     ( 0 0 0 >leave )
1.8       anton     649:     POSTPONE (?do)
                    650:     >mark >leave
1.9       pazsan    651:     POSTPONE begin drop do-dest ; immediate restrict
1.8       anton     652: 
                    653: : FOR ( -- do-sys )
                    654:     POSTPONE (for)
                    655:     POSTPONE begin drop do-dest
1.9       pazsan    656:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     657: 
                    658: \ LOOP etc. are just like UNTIL
                    659: 
                    660: : loop-like ( do-sys xt1 xt2 -- )
1.9       pazsan    661:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
1.8       anton     662:     until-like  POSTPONE done  POSTPONE unloop ;
                    663: 
                    664: : LOOP ( do-sys -- )
1.9       pazsan    665:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
1.8       anton     666: 
                    667: : +LOOP ( do-sys -- )
1.9       pazsan    668:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
1.8       anton     669: 
                    670: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
                    671: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
                    672: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
                    673: \ negative increments.
                    674: : S+LOOP ( do-sys -- )
1.9       pazsan    675:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
1.5       anton     676: 
1.8       anton     677: : NEXT ( do-sys -- )
1.9       pazsan    678:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
1.1       anton     679: 
                    680: \ Structural Conditionals                              12dec92py
                    681: 
1.8       anton     682: : EXIT ( -- )
                    683:     0 adjust-locals-size
                    684:     POSTPONE ;s
                    685:     unreachable ; immediate restrict
1.1       anton     686: 
1.8       anton     687: : ?EXIT ( -- )
                    688:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
1.1       anton     689: 
                    690: \ Strings                                              22feb93py
                    691: 
                    692: : ," ( "string"<"> -- ) [char] " parse
                    693:   here over char+ allot  place align ;
                    694: : "lit ( -- addr )
                    695:   r> r> dup count + aligned >r swap >r ;               restrict
                    696: : (.")     "lit count type ;                           restrict
                    697: : (S")     "lit count ;                                restrict
                    698: : SLiteral postpone (S") here over char+ allot  place align ;
                    699:                                              immediate restrict
                    700: : S"       [char] " parse  state @ IF  postpone SLiteral  THEN ;
                    701:                                              immediate
                    702: : ."       state @  IF    postpone (.") ,"  align
                    703:                     ELSE  [char] " parse type  THEN  ;  immediate
                    704: : (        [char] ) parse 2drop ;                       immediate
                    705: : \        source >in ! drop ;                          immediate
                    706: 
                    707: \ error handling                                       22feb93py
                    708: \ 'abort thrown out!                                   11may93jaw
                    709: 
                    710: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
                    711:                 rdrop ;
                    712: : abort"        postpone (abort") ," ;        immediate restrict
                    713: 
                    714: \ Header states                                        23feb93py
                    715: 
1.10      anton     716: : flag! ( 8b -- )
                    717:     last @ dup 0= abort" last word was headerless"
                    718:     cell+ tuck c@ xor swap c! ;
1.1       anton     719: : immediate     $20 flag! ;
1.9       pazsan    720: : restrict      $40 flag! ;
                    721: \ ' noop alias restrict
1.1       anton     722: 
                    723: \ Header                                               23feb93py
                    724: 
                    725: \ input-stream, nextname and noname are quite ugly (passing
                    726: \ information through global variables), but they are useful for dealing
                    727: \ with existing/independent defining words
                    728: 
                    729: defer header
                    730: 
                    731: : name,  ( "name" -- )
1.10      anton     732:     name c@
                    733:     dup $1F u> &-19 and throw ( is name too long? )
                    734:     1+ chars allot align ;
1.1       anton     735: : input-stream-header ( "name" -- )
                    736:     \ !! this is f83-implementation-dependent
                    737:     align here last !  -1 A,
                    738:     name, $80 flag! ;
                    739: 
                    740: : input-stream ( -- )  \ general
                    741: \ switches back to getting the name from the input stream ;
                    742:     ['] input-stream-header IS header ;
                    743: 
                    744: ' input-stream-header IS header
                    745: 
                    746: \ !! make that a 2variable
1.5       anton     747: create nextname-buffer 32 chars allot
1.1       anton     748: 
                    749: : nextname-header ( -- )
                    750:     \ !! f83-implementation-dependent
1.5       anton     751:     nextname-buffer count
1.1       anton     752:     align here last ! -1 A,
                    753:     dup c,  here swap chars  dup allot  move  align
                    754:     $80 flag!
                    755:     input-stream ;
                    756: 
                    757: \ the next name is given in the string
                    758: : nextname ( c-addr u -- ) \ general
1.10      anton     759:     dup $1F u> &-19 and throw ( is name too long? )
1.5       anton     760:     nextname-buffer c! ( c-addr )
                    761:     nextname-buffer count move
1.1       anton     762:     ['] nextname-header IS header ;
                    763: 
                    764: : noname-header ( -- )
                    765:     0 last !
                    766:     input-stream ;
                    767: 
                    768: : noname ( -- ) \ general
                    769: \ the next defined word remains anonymous. The xt of that word is given by lastxt
                    770:     ['] noname-header IS header ;
                    771: 
                    772: : lastxt ( -- xt ) \ general
                    773: \ 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
                    774:     lastcfa @ ;
                    775: 
                    776: : Alias    ( cfa "name" -- )
                    777:   Header reveal , $80 flag! ;
                    778: 
                    779: : name>string ( nfa -- addr count )
                    780:  cell+ count $1F and ;
                    781: 
1.9       pazsan    782: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
1.1       anton     783: : >name ( cfa -- nfa )
                    784:  $21 cell do
                    785:    dup i - count $9F and + aligned over $80 + = if
                    786:      i - cell - unloop exit
                    787:    then
                    788:  cell +loop
                    789:  drop ??? ( wouldn't 0 be better? ) ;
                    790: 
                    791: \ indirect threading                                   17mar93py
                    792: 
                    793: : cfa,     ( code-address -- )
                    794:     here lastcfa !
                    795:     here  0 A, 0 ,  code-address! ;
                    796: : compile, ( xt -- )           A, ;
                    797: : !does    ( addr -- )         lastcfa @ does-code! ;
                    798: : (;code)  ( R: addr -- )      r> /does-handler + !does ;
                    799: : dodoes,  ( -- )
                    800:   here /does-handler allot does-handler! ;
                    801: 
                    802: \ direct threading is implementation dependent
                    803: 
1.4       pazsan    804: : Create    Header reveal [ :dovar ] Literal cfa, ;
1.1       anton     805: 
                    806: \ DOES>                                                17mar93py
                    807: 
1.5       anton     808: : DOES>  ( compilation: -- )
                    809:     state @
                    810:     IF
                    811:        ;-hook postpone (;code) dodoes,
                    812:     ELSE
                    813:        dodoes, here !does 0 ]
                    814:     THEN 
                    815:     :-hook ; immediate
1.1       anton     816: 
                    817: \ Create Variable User Constant                        17mar93py
                    818: 
                    819: : Variable  Create 0 , ;
                    820: : AVariable Create 0 A, ;
                    821: : 2VARIABLE ( "name" -- ) \ double
                    822:     create 0 , 0 , ;
                    823:     
                    824: : User      Variable ;
                    825: : AUser     AVariable ;
                    826: 
1.4       pazsan    827: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
1.1       anton     828: : Constant  (Constant) , ;
                    829: : AConstant (Constant) A, ;
1.5       anton     830: 
                    831: : 2CONSTANT
                    832:     create ( w1 w2 "name" -- )
                    833:         2,
                    834:     does> ( -- w1 w2 )
                    835:         2@ ;
1.1       anton     836:     
                    837: \ IS Defer What's Defers TO                            24feb93py
                    838: 
1.5       anton     839: : Defer
                    840:   Create ( -- ) 
                    841:     ['] noop A,
                    842:   DOES> ( ??? )
                    843:     @ execute ;
1.1       anton     844: 
                    845: : IS ( addr "name" -- )
                    846:     ' >body
                    847:     state @
                    848:     IF    postpone ALiteral postpone !  
                    849:     ELSE  !
                    850:     THEN ;  immediate
                    851: ' IS Alias TO immediate
                    852: 
                    853: : What's ( "name" -- addr )  ' >body
                    854:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
                    855:                                              immediate
                    856: : Defers ( "name" -- )  ' >body @ compile, ;
                    857:                                              immediate restrict
                    858: 
                    859: \ : ;                                                  24feb93py
                    860: 
1.5       anton     861: defer :-hook ( sys1 -- sys2 )
                    862: defer ;-hook ( sys2 -- sys1 )
                    863: 
1.8       anton     864: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
1.5       anton     865: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
1.1       anton     866:   immediate restrict
1.5       anton     867: 
1.10      anton     868: : :noname ( -- xt colon-sys )
                    869:     0 last !
                    870:     here [ :docol ] Literal cfa, 0 ] :-hook ;
1.1       anton     871: 
                    872: \ Search list handling                                 23feb93py
                    873: 
                    874: AVariable current
                    875: 
                    876: : last?   ( -- false / nfa nfa )    last @ ?dup ;
1.5       anton     877: : (reveal) ( -- )
                    878:   last?
                    879:   IF
                    880:       dup @ 0<
                    881:       IF
                    882:        current @ @ over ! current @ !
                    883:       ELSE
                    884:        drop
                    885:       THEN
                    886:   THEN ;
1.1       anton     887: 
                    888: \ object oriented search list                          17mar93py
                    889: 
1.5       anton     890: \ word list structure:
                    891: \ struct
1.7       pazsan    892: \   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
1.5       anton     893: \   1 cells: field reveal-method \ xt: ( -- )
1.7       pazsan    894: \   1 cells: field rehash-method \ xt: ( wid -- )
1.5       anton     895: \   \ !! what else
                    896: \ end-struct wordlist-map-struct
                    897: 
                    898: \ struct
                    899: \   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
                    900: \   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
1.7       pazsan    901: \   1 cells: field wordlist-link \ link field to other wordlists
                    902: \   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
1.5       anton     903: \ end-struct wordlist-struct
                    904: 
1.7       pazsan    905: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
                    906: : f83casefind  ( addr len wordlist -- nfa / false )  @ (f83casefind) ;
1.5       anton     907: 
1.1       anton     908: \ Search list table: find reveal
1.7       pazsan    909: Create f83search       ' f83casefind A,  ' (reveal) A,  ' drop A,
                    910: 
                    911: : caps-name       ['] (cname) IS name  ['] f83find     f83search ! ;
                    912: : case-name       ['] (name)  IS name  ['] f83casefind f83search ! ;
                    913: : case-sensitive  ['] (name)  IS name  ['] f83find     f83search ! ;
                    914: 
1.1       anton     915: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
                    916: AVariable search       G forth-wordlist search T !
                    917: G forth-wordlist current T !
                    918: 
                    919: : (search-wordlist)  ( addr count wid -- nfa / false )
1.7       pazsan    920:   dup ( @ swap ) cell+ @ @ execute ;
1.1       anton     921: 
                    922: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
                    923:   (search-wordlist) dup  IF  found  THEN ;
                    924: 
                    925: Variable warnings  G -1 warnings T !
                    926: 
                    927: : check-shadow  ( addr count wid -- )
                    928: \ prints a warning if the string is already present in the wordlist
                    929: \ !! should be refined so the user can suppress the warnings
                    930:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
                    931:    ." redefined " name>string 2dup type
                    932:    compare 0<> if
                    933:      ."  with " type
                    934:    else
                    935:      2drop
                    936:    then
                    937:    space space EXIT
                    938:  then
                    939:  2drop 2drop ;
                    940: 
                    941: : find   ( addr -- cfa +-1 / string false )  dup
                    942:   count search @ search-wordlist  dup IF  rot drop  THEN ;
                    943: 
                    944: : reveal ( -- )
                    945:  last? if
                    946:    name>string current @ check-shadow
                    947:  then
                    948:  current @ cell+ @ cell+ @ execute ;
1.7       pazsan    949: 
                    950: : rehash  ( wid -- )  dup cell+ @ cell+ cell+ @ execute ;
1.1       anton     951: 
                    952: : '    ( "name" -- addr )  name find 0= no.extensions ;
                    953: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
                    954: \ Input                                                13feb93py
                    955: 
                    956: 07 constant #bell
                    957: 08 constant #bs
                    958: 7F constant #del
                    959: 0D constant #cr                \ the newline key code
                    960: 0A constant #lf
                    961: 
                    962: : bell  #bell emit ;
                    963: 
                    964: : backspaces  0 ?DO  #bs emit  LOOP ;
                    965: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
                    966:   over 3 pick 2 pick chars /string ;
                    967: : type-rest ( span addr pos1 -- span addr pos1 back )
                    968:   >string tuck type ;
                    969: : (del)  ( max span addr pos1 -- max span addr pos2 )
                    970:   1- >string over 1+ -rot move
                    971:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
                    972: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
                    973:   >r >string over 1+ swap move 2dup chars + r> swap c!
                    974:   rot 1+ -rot type-rest 1- backspaces 1+ ;
                    975: : ?del ( max span addr pos1 -- max span addr pos2 0 )
                    976:   dup  IF  (del)  THEN  0 ;
                    977: : (ret)  type-rest drop true space ;
                    978: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
                    979: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
                    980: 
                    981: Create crtlkeys
                    982:   ] false false back  false  false false forw  false
                    983:     ?del  false (ret) false  false (ret) false false
                    984:     false false false false  false false false false
                    985:     false false false false  false false false false [
                    986: 
                    987: : decode ( max span addr pos1 key -- max span addr pos2 flag )
                    988:   dup #del = IF  drop #bs  THEN  \ del is rubout
                    989:   dup bl <   IF  cells crtlkeys + @ execute  EXIT  THEN
                    990:   >r 2over = IF  rdrop bell 0 EXIT  THEN
                    991:   r> (ins) 0 ;
                    992: 
                    993: \ decode should better use a table for control key actions
                    994: \ to define keyboard bindings later
                    995: 
                    996: : accept   ( addr len -- len )
                    997:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
                    998: \ this allows to edit given strings
                    999:          ELSE  0  THEN rot over
                   1000:   BEGIN  key decode  UNTIL
                   1001:   2drop nip ;
                   1002: 
                   1003: \ Output                                               13feb93py
                   1004: 
                   1005: DEFER type      \ defer type for a output buffer or fast
                   1006:                 \ screen write
                   1007: 
1.9       pazsan   1008: \ : (type) ( addr len -- )
                   1009: \   bounds ?DO  I c@ emit  LOOP ;
1.1       anton    1010: 
                   1011: ' (TYPE) IS Type
                   1012: 
1.9       pazsan   1013: DEFER Emit
1.1       anton    1014: 
1.9       pazsan   1015: ' (Emit) IS Emit
1.1       anton    1016: 
                   1017: \ : form  ( -- rows cols )  &24 &80 ;
                   1018: \ form should be implemented using TERMCAPS or CURSES
                   1019: \ : rows  form drop ;
                   1020: \ : cols  form nip  ;
                   1021: 
                   1022: \ Query                                                07apr93py
                   1023: 
                   1024: : refill ( -- flag )
                   1025:   tib /line
                   1026:   loadfile @ ?dup
                   1027:   IF    dup file-position throw linestart 2!
                   1028:         read-line throw
                   1029:   ELSE  linestart @ IF 2drop false EXIT THEN
                   1030:         accept true
                   1031:   THEN
                   1032:   1 loadline +!
1.10      anton    1033:   swap #tib ! 0 >in ! ;
1.1       anton    1034: 
1.10      anton    1035: : Query  ( -- )  0 loadfile ! refill drop ;
1.1       anton    1036: 
                   1037: \ File specifiers                                       11jun93jaw
                   1038: 
                   1039: 
                   1040: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
                   1041: \ 2 c, here char r c, char + c, 0 c,
                   1042: \ 2 c, here char w c, char + c, 0 c, align
                   1043: 4 Constant w/o
                   1044: 2 Constant r/w
                   1045: 0 Constant r/o
                   1046: 
                   1047: \ BIN WRITE-LINE                                        11jun93jaw
                   1048: 
                   1049: \ : bin           dup 1 chars - c@
                   1050: \                 r/o 4 chars + over - dup >r swap move r> ;
                   1051: 
                   1052: : bin  1+ ;
                   1053: 
                   1054: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
                   1055:                            \ or not unix environments if
                   1056:                            \ bin is not selected
                   1057: 
                   1058: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
                   1059:                 nl$ count r> write-file ;
                   1060: 
                   1061: \ include-file                                         07apr93py
                   1062: 
                   1063: : include-file ( i*x fid -- j*x )
                   1064:   linestart @ >r loadline @ >r loadfile @ >r
                   1065:   blk @ >r >tib @ >r  #tib @ dup >r  >in @ >r
                   1066: 
                   1067:   >tib +! loadfile !
                   1068:   0 loadline ! blk off
                   1069:   BEGIN  refill  WHILE  interpret  REPEAT
                   1070:   loadfile @ close-file throw
                   1071: 
                   1072:   r> >in !  r> #tib !  r> >tib ! r> blk !
                   1073:   r> loadfile ! r> loadline ! r> linestart ! ;
                   1074: 
                   1075: : included ( i*x addr u -- j*x )
1.10      anton    1076:     loadfilename 2@ >r >r
                   1077:     dup allocate throw over loadfilename 2!
                   1078:     over loadfilename 2@ move
                   1079:     r/o open-file throw include-file
                   1080:     \ don't free filenames; they don't take much space
                   1081:     \ and are used for debugging
                   1082:     r> r> loadfilename 2! ;
1.1       anton    1083: 
                   1084: \ HEX DECIMAL                                           2may93jaw
                   1085: 
                   1086: : decimal a base ! ;
                   1087: : hex     10 base ! ;
                   1088: 
                   1089: \ DEPTH                                                 9may93jaw
                   1090: 
                   1091: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
                   1092: 
                   1093: \ INCLUDE                                               9may93jaw
                   1094: 
1.6       pazsan   1095: : include  ( "file" -- )
                   1096:   bl word count included ;
1.1       anton    1097: 
                   1098: \ RECURSE                                               17may93jaw
                   1099: 
1.10      anton    1100: : recurse ( -- )
                   1101:     lastxt compile, ; immediate restrict
                   1102: : recursive ( -- )
                   1103:     reveal ; immediate
1.1       anton    1104: 
                   1105: \ */MOD */                                              17may93jaw
                   1106: 
                   1107: : */mod >r m* r> sm/rem ;
                   1108: 
                   1109: : */ */mod nip ;
                   1110: 
                   1111: \ EVALUATE                                              17may93jaw
                   1112: 
                   1113: : evaluate ( c-addr len -- )
                   1114:   linestart @ >r loadline @ >r loadfile @ >r
                   1115:   blk @ >r >tib @ >r  #tib @ dup >r  >in @ >r
                   1116: 
                   1117:   >tib +! dup #tib ! >tib @ swap move
                   1118:   >in off blk off loadfile off -1 linestart !
                   1119: 
                   1120:   BEGIN  interpret  >in @ #tib @ u>= UNTIL
                   1121: 
                   1122:   r> >in !  r> #tib !  r> >tib ! r> blk !
                   1123:   r> loadfile ! r> loadline ! r> linestart ! ;
                   1124: 
                   1125: 
                   1126: : abort -1 throw ;
                   1127: 
                   1128: \+ environment? true ENV" CORE"
                   1129: \ core wordset is now complete!
                   1130: 
                   1131: \ Quit                                                 13feb93py
                   1132: 
                   1133: Defer 'quit
                   1134: Defer .status
                   1135: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
                   1136: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
                   1137: ' (quit) IS 'quit
                   1138: 
                   1139: \ DOERROR (DOERROR)                                     13jun93jaw
                   1140: 
1.10      anton    1141: : dec. ( n -- )
                   1142:     \ print value in decimal representation
                   1143:     base @ decimal swap . base ! ;
                   1144: 
                   1145: : typewhite ( addr u -- )
                   1146:     \ like type, but white space is printed instead of the characters
                   1147:     0 ?do
                   1148:        dup i + c@ 9 = if \ check for tab
                   1149:            9
                   1150:        else
                   1151:            bl
                   1152:        then
                   1153:        emit
                   1154:     loop
                   1155:     drop ;
                   1156: 
1.1       anton    1157: DEFER DOERROR
                   1158: 
                   1159: : (DoError) ( throw-code -- )
1.10      anton    1160:     LoadFile @
                   1161:     IF
                   1162:        cr loadfilename 2@ type ." :" Loadline @ dec.
                   1163:     THEN
                   1164:     cr source type cr
                   1165:     source drop >in @ -trailing ( throw-code line-start index2 )
                   1166:     here c@ 1F min dup >r - 0 max ( throw-code line-start index1 )
                   1167:     typewhite
                   1168:     r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
                   1169:        ." ^"
                   1170:     loop
                   1171:     dup -2 =
                   1172:     IF 
                   1173:        "error @ ?dup
                   1174:        IF
                   1175:            cr count type 
                   1176:        THEN
                   1177:        drop
                   1178:     ELSE
                   1179:        .error
                   1180:     THEN
                   1181:     normal-dp dpp ! ;
1.1       anton    1182: 
                   1183: ' (DoError) IS DoError
                   1184: 
                   1185: : quit   r0 @ rp! handler off >tib @ >r
1.5       anton    1186:   BEGIN
                   1187:     postpone [
                   1188:     ['] 'quit CATCH dup
                   1189:   WHILE
                   1190:     DoError r@ >tib !
                   1191:   REPEAT
                   1192:   drop r> >tib ! ;
1.1       anton    1193: 
                   1194: \ Cold                                                 13feb93py
                   1195: 
                   1196: \ : .name ( name -- ) cell+ count $1F and type space ;
                   1197: \ : words  listwords @
                   1198: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
                   1199: 
                   1200: : >len  ( cstring -- addr n )  100 0 scan 0 swap 100 - /string ;
                   1201: : arg ( n -- addr count )  cells argv @ + @ >len ;
                   1202: : #!       postpone \ ;  immediate
                   1203: 
                   1204: Variable env
                   1205: Variable argv
                   1206: Variable argc
                   1207: 
                   1208: : get-args ( -- )  #tib off
                   1209:   argc @ 1 ?DO  I arg 2dup source + swap move
                   1210:                 #tib +! drop  bl source + c! 1 #tib +!  LOOP
                   1211:   >in off #tib @ 0<> #tib +! ;
                   1212: 
                   1213: : script? ( -- flag )  0 arg 1 arg dup 3 pick - /string compare 0= ;
                   1214: 
1.5       anton    1215: : cold ( -- )  
1.10      anton    1216:     argc @ 1 >
                   1217:     IF  script?
                   1218:        IF
                   1219:            1 arg ['] included
                   1220:        ELSE
                   1221:            get-args ['] interpret
                   1222:        THEN
                   1223:        catch ?dup
                   1224:        IF
                   1225:            dup >r DoError cr r> (bye)
                   1226:        THEN
                   1227:     THEN
                   1228:     cr ." GNU Forth 0.0alpha, Copyright (C) 1994 Free Software Foundation"
                   1229:     cr ." GNU Forth comes with ABSOLUTELY NO WARRANTY; for details type `license'" 
                   1230:     cr quit ;
1.1       anton    1231: 
                   1232: : boot ( **env **argv argc -- )
1.4       pazsan   1233:   argc ! argv ! env !  main-task up!
1.1       anton    1234:   sp@ dup s0 ! $10 + >tib ! rp@ r0 !  fp@ f0 !  cold ;
                   1235: 
                   1236: : bye  cr 0 (bye) ;
                   1237: 
                   1238: \ **argv may be scanned by the C starter to get some important
                   1239: \ information, as -display and -geometry for an X client FORTH
                   1240: \ or space and stackspace overrides
                   1241: 
                   1242: \ 0 arg contains, however, the name of the program.

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