Annotation of gforth/kernal.fs, revision 1.14

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 ;
1.12      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 ;
1.12      pazsan    197: : s>number ( addr len -- d )  base @ >r  dpl on
                    198:   over c@ '- =  dup >r  IF  1 /string  THEN
1.1       anton     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
1.12      pazsan    203:   REPEAT  THEN  2drop rdrop dpl off  ELSE
                    204:   2drop rdrop r> IF  dnegate  THEN
                    205:   THEN r> base ! ;
                    206: : number? ( string -- string 0 / n -1 / d 0> )
                    207:   dup count s>number dpl @ 0= IF  2drop false  EXIT  THEN
                    208:   rot drop dpl @ dup 0> 0= IF  nip  THEN ;
1.1       anton     209: : s>d ( n -- d ) dup 0< ;
                    210: : number ( string -- d )
                    211:   number? ?dup 0= abort" ?"  0< IF s>d THEN ;
                    212: 
                    213: \ space spaces ud/mod                                  21mar93py
                    214: decimal
                    215: Create spaces  bl 80 times \ times from target compiler! 11may93jaw
                    216: DOES>   ( u -- )  swap
                    217:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
                    218: hex
                    219: : space   1 spaces ;
                    220: 
                    221: : ud/mod ( ud1 u2 -- urem udquot )  >r 0 r@ um/mod r> swap >r
                    222:                                     um/mod r> ;
                    223: 
                    224: : pad    ( -- addr )
                    225:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
                    226: 
                    227: \ hold <# #> sign # #s                                 25jan92py
                    228: 
                    229: : hold    ( char -- )         pad cell - -1 chars over +! @ c! ;
                    230: 
                    231: : <#                          pad cell - dup ! ;
                    232: 
                    233: : #>      ( 64b -- addr +n )  2drop pad cell - dup @ tuck - ;
                    234: 
                    235: : sign    ( n -- )            0< IF  [char] - hold  THEN ;
                    236: 
                    237: : #       ( +d1 -- +d2 )    base @ 2 max ud/mod rot 9 over <
                    238:   IF [ char A char 9 - 1- ] Literal +  THEN  [char] 0 + hold ;
                    239: 
                    240: : #s      ( +d -- 0 0 )         BEGIN  # 2dup d0=  UNTIL ;
                    241: 
                    242: \ print numbers                                        07jun92py
                    243: 
                    244: : d.r      >r tuck  dabs  <# #s  rot sign #>
                    245:            r> over - spaces  type ;
                    246: 
                    247: : ud.r     >r <# #s #> r> over - spaces type ;
                    248: 
                    249: : .r       >r s>d r> d.r ;
                    250: : u.r      0 swap ud.r ;
                    251: 
                    252: : d.       0 d.r space ;
                    253: : ud.      0 ud.r space ;
                    254: 
                    255: : .        s>d d. ;
                    256: : u.       0 ud. ;
                    257: 
                    258: \ catch throw                                          23feb93py
                    259: \ bounce                                                08jun93jaw
                    260: 
                    261: \ !! allow the user to add rollback actions    anton
                    262: \ !! use a separate exception stack?           anton
                    263: 
1.5       anton     264: : lp@ ( -- addr )
                    265:  laddr# [ 0 , ] ;
                    266: 
1.1       anton     267: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
1.5       anton     268:   >r sp@ r> swap >r       \ don't count xt! jaw
                    269:   fp@ >r
                    270:   lp@ >r
                    271:   handler @ >r
                    272:   rp@ handler !
                    273:   execute
1.6       pazsan    274:   r> handler ! rdrop rdrop rdrop 0 ;
                    275: 
1.5       anton     276: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
1.10      anton     277:     ?DUP IF
                    278:        [ here 4 cells ! ]
                    279:        handler @ rp!
                    280:        r> handler !
                    281:        r> lp!
                    282:        r> fp!
                    283:        r> swap >r sp! r>
                    284:     THEN ;
1.6       pazsan    285: 
1.1       anton     286: \ Bouncing is very fine,
                    287: \ programming without wasting time...   jaw
1.5       anton     288: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym )
                    289: \ a throw without data or fp stack restauration
                    290:   ?DUP IF
                    291:     handler @ rp!
                    292:     r> handler !
                    293:     r> lp!
                    294:     rdrop
                    295:     rdrop
                    296:   THEN ;
1.1       anton     297: 
                    298: \ ?stack                                               23feb93py
                    299: 
                    300: : ?stack ( ?? -- ?? )  sp@ s0 @ > IF  -4 throw  THEN ;
                    301: \ ?stack should be code -- it touches an empty stack!
                    302: 
                    303: \ interpret                                            10mar92py
                    304: 
                    305: Defer parser
                    306: Defer name      ' (name) IS name
                    307: Defer notfound
                    308: 
1.12      pazsan    309: : no.extensions  ( string -- )  IF  -&13 bounce  THEN ;
1.1       anton     310: 
                    311: ' no.extensions IS notfound
                    312: 
                    313: : interpret
                    314:   BEGIN  ?stack name dup c@  WHILE  parser  REPEAT drop ;
                    315: 
                    316: \ interpreter compiler                                 30apr92py
                    317: 
                    318: : interpreter  ( name -- ) find ?dup
                    319:   IF  1 and  IF execute  EXIT THEN  -&14 throw  THEN
                    320:   number? 0= IF  notfound THEN ;
                    321: 
                    322: ' interpreter  IS  parser
                    323: 
                    324: : compiler     ( name -- ) find  ?dup
                    325:   IF  0> IF  execute EXIT THEN compile, EXIT THEN number? dup
                    326:   IF  0> IF  swap postpone Literal  THEN  postpone Literal
1.2       pazsan    327:   ELSE  drop notfound  THEN ;
1.1       anton     328: 
                    329: : [     ['] interpreter  IS parser state off ; immediate
                    330: : ]     ['] compiler     IS parser state on  ;
                    331: 
1.8       anton     332: \ locals stuff needed for control structures
                    333: 
                    334: : compile-lp+! ( n -- )
                    335:     dup negate locals-size +!
                    336:     0 over = if
                    337:     else -4 over = if postpone -4lp+!
                    338:     else  8 over = if postpone  8lp+!
                    339:     else 16 over = if postpone 16lp+!
                    340:     else postpone lp+!# dup ,
                    341:     then then then then drop ;
                    342: 
                    343: : adjust-locals-size ( n -- )
                    344:     \ sets locals-size to n and generates an appropriate lp+!
                    345:     locals-size @ swap - compile-lp+! ;
                    346: 
                    347: 
                    348: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
                    349: AConstant locals-list \ acts like a variable that contains
1.10      anton     350:                      \ a linear list of locals names
1.8       anton     351: 
                    352: 
                    353: variable dead-code \ true if normal code at "here" would be dead
                    354: 
                    355: : unreachable ( -- )
                    356: \ declares the current point of execution as unreachable
                    357:  dead-code on ;
                    358: 
                    359: \ locals list operations
                    360: 
                    361: : common-list ( list1 list2 -- list3 )
                    362: \ list1 and list2 are lists, where the heads are at higher addresses than
                    363: \ the tail. list3 is the largest sublist of both lists.
                    364:  begin
                    365:    2dup u<>
                    366:  while
                    367:    2dup u>
                    368:    if
                    369:      swap
                    370:    then
                    371:    @
                    372:  repeat
                    373:  drop ;
                    374: 
                    375: : sub-list? ( list1 list2 -- f )
                    376: \ true iff list1 is a sublist of list2
                    377:  begin
                    378:    2dup u<
                    379:  while
                    380:    @
                    381:  repeat
                    382:  = ;
                    383: 
                    384: : list-size ( list -- u )
                    385: \ size of the locals frame represented by list
                    386:  0 ( list n )
                    387:  begin
                    388:    over 0<>
                    389:  while
                    390:    over
1.11      pazsan    391:    name> >body @ max
1.8       anton     392:    swap @ swap ( get next )
                    393:  repeat
                    394:  faligned nip ;
                    395: 
                    396: : set-locals-size-list ( list -- )
                    397:  dup locals-list !
                    398:  list-size locals-size ! ;
                    399: 
                    400: : check-begin ( list -- )
                    401: \ warn if list is not a sublist of locals-list
                    402:  locals-list @ sub-list? 0= if
                    403:    \ !! print current position
                    404:    ." compiler was overly optimistic about locals at a BEGIN" cr
                    405:    \ !! print assumption and reality
                    406:  then ;
                    407: 
                    408: \ Control Flow Stack
                    409: \ orig, etc. have the following structure:
                    410: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
                    411: \ address (of the branch or the instruction to be branched to) (second)
                    412: \ locals-list (valid at address) (third)
                    413: 
                    414: \ types
                    415: 0 constant defstart
                    416: 1 constant live-orig
                    417: 2 constant dead-orig
                    418: 3 constant dest \ the loopback branch is always assumed live
                    419: 4 constant do-dest
                    420: 5 constant scopestart
                    421: 
                    422: : def? ( n -- )
                    423:     defstart <> abort" unstructured " ;
                    424: 
                    425: : orig? ( n -- )
                    426:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
                    427: 
                    428: : dest? ( n -- )
                    429:  dest <> abort" expected dest " ;
                    430: 
                    431: : do-dest? ( n -- )
                    432:  do-dest <> abort" expected do-dest " ;
                    433: 
                    434: : scope? ( n -- )
                    435:  scopestart <> abort" expected scope " ;
                    436: 
                    437: : non-orig? ( n -- )
                    438:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
                    439: 
                    440: : cs-item? ( n -- )
                    441:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
                    442: 
                    443: 3 constant cs-item-size
                    444: 
                    445: : CS-PICK ( ... u -- ... destu )
                    446:  1+ cs-item-size * 1- >r
                    447:  r@ pick  r@ pick  r@ pick
                    448:  rdrop
                    449:  dup non-orig? ;
                    450: 
                    451: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
                    452:  1+ cs-item-size * 1- >r
                    453:  r@ roll r@ roll r@ roll
                    454:  rdrop
                    455:  dup cs-item? ; 
                    456: 
                    457: : cs-push-part ( -- list addr )
                    458:  locals-list @ here ;
                    459: 
                    460: : cs-push-orig ( -- orig )
                    461:  cs-push-part dead-code @
                    462:  if
                    463:    dead-orig
                    464:  else
                    465:    live-orig
                    466:  then ;   
                    467: 
1.1       anton     468: \ Structural Conditionals                              12dec92py
                    469: 
                    470: : ?struc      ( flag -- )       abort" unstructured " ;
                    471: : sys?        ( sys -- )        dup 0= ?struc ;
1.8       anton     472: : >mark ( -- orig )
                    473:  cs-push-orig 0 , ;
                    474: : >resolve    ( addr -- )        here over - swap ! ;
                    475: : <resolve    ( addr -- )        here - , ;
1.1       anton     476: 
1.8       anton     477: : BUT       1 cs-roll ;                      immediate restrict
                    478: : YET       0 cs-pick ;                       immediate restrict
1.1       anton     479: 
                    480: \ Structural Conditionals                              12dec92py
                    481: 
1.8       anton     482: : AHEAD ( -- orig )
                    483:  POSTPONE branch >mark unreachable ; immediate restrict
                    484: 
                    485: : IF ( -- orig )
                    486:  POSTPONE ?branch >mark ; immediate restrict
                    487: 
1.1       anton     488: : ?DUP-IF \ general
                    489: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
                    490: \ better handled by tools like stack checkers
1.8       anton     491:     POSTPONE ?dup POSTPONE if ;       immediate restrict
1.14    ! anton     492: : ?DUP-0=-IF \ general
1.8       anton     493:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
                    494: 
                    495: : THEN ( orig -- )
                    496:     dup orig?
                    497:     dead-code @
                    498:     if
                    499:        dead-orig =
                    500:        if
                    501:            >resolve drop
                    502:        else
                    503:            >resolve set-locals-size-list dead-code off
                    504:        then
                    505:     else
                    506:        dead-orig =
                    507:        if
                    508:            >resolve drop
                    509:        else \ both live
                    510:            over list-size adjust-locals-size
                    511:            >resolve
                    512:            locals-list @ common-list dup list-size adjust-locals-size
                    513:            locals-list !
                    514:        then
                    515:     then ; immediate restrict
                    516: 
1.1       anton     517: ' THEN alias ENDIF immediate restrict \ general
                    518: \ Same as "THEN". This is what you use if your program will be seen by
                    519: \ people who have not been brought up with Forth (or who have been
                    520: \ brought up with fig-Forth).
                    521: 
1.8       anton     522: : ELSE ( orig1 -- orig2 )
                    523:     POSTPONE ahead
                    524:     1 cs-roll
                    525:     POSTPONE then ; immediate restrict
                    526: 
                    527: 
                    528: : BEGIN ( -- dest )
                    529:     dead-code @ if
                    530:        \ set up an assumption of the locals visible here
                    531:        \ currently we just take the top cs-item
                    532:        \ it would be more intelligent to take the top orig
                    533:        \   but that can be arranged by the user
                    534:        dup defstart <> if
                    535:            dup cs-item?
                    536:            2 pick
                    537:        else
                    538:            0
                    539:        then
                    540:        set-locals-size-list
                    541:     then
                    542:     cs-push-part dest
                    543:     dead-code off ; immediate restrict
                    544: 
                    545: \ AGAIN (the current control flow joins another, earlier one):
                    546: \ If the dest-locals-list is not a subset of the current locals-list,
                    547: \ issue a warning (see below). The following code is generated:
                    548: \ lp+!# (current-local-size - dest-locals-size)
                    549: \ branch <begin>
                    550: : AGAIN ( dest -- )
                    551:     dest?
                    552:     over list-size adjust-locals-size
                    553:     POSTPONE branch
                    554:     <resolve
                    555:     check-begin
                    556:     unreachable ; immediate restrict
                    557: 
                    558: \ UNTIL (the current control flow may join an earlier one or continue):
                    559: \ Similar to AGAIN. The new locals-list and locals-size are the current
                    560: \ ones. The following code is generated:
                    561: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
                    562: : until-like ( list addr xt1 xt2 -- )
                    563:     \ list and addr are a fragment of a cs-item
                    564:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
                    565:     >r >r
                    566:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
                    567:        r> drop r> compile,
                    568:        swap <resolve ( list adjustment ) ,
                    569:     else ( list dest-addr adjustment )
                    570:        drop
                    571:        r> compile, <resolve
                    572:        r> drop
                    573:     then ( list )
                    574:     check-begin ;
                    575: 
                    576: : UNTIL ( dest -- )
                    577:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
                    578: 
                    579: : WHILE ( dest -- orig dest )
                    580:     POSTPONE if
                    581:     1 cs-roll ; immediate restrict
                    582: 
                    583: : REPEAT ( orig dest -- )
                    584:     POSTPONE again
                    585:     POSTPONE then ; immediate restrict
                    586: 
                    587: 
                    588: \ counted loops
                    589: 
                    590: \ leave poses a little problem here
                    591: \ we have to store more than just the address of the branch, so the
                    592: \ traditional linked list approach is no longer viable.
                    593: \ This is solved by storing the information about the leavings in a
1.9       pazsan    594: \ special stack.
1.8       anton     595: 
                    596: \ !! remove the fixed size limit. 'Tis not hard.
                    597: 20 constant leave-stack-size
1.9       pazsan    598: create leave-stack  60 cells allot
                    599: Avariable leave-sp  leave-stack 3 cells + leave-sp !
1.8       anton     600: 
                    601: : clear-leave-stack ( -- )
                    602:     leave-stack leave-sp ! ;
                    603: 
                    604: \ : leave-empty? ( -- f )
                    605: \  leave-sp @ leave-stack = ;
                    606: 
                    607: : >leave ( orig -- )
                    608:     \ push on leave-stack
                    609:     leave-sp @
                    610:     dup [ leave-stack 60 cells + ] Aliteral
                    611:     >= abort" leave-stack full"
                    612:     tuck ! cell+
                    613:     tuck ! cell+
                    614:     tuck ! cell+
                    615:     leave-sp ! ;
                    616: 
                    617: : leave> ( -- orig )
                    618:     \ pop from leave-stack
                    619:     leave-sp @
1.9       pazsan    620:     dup leave-stack <= IF
                    621:        drop 0 0 0  EXIT  THEN
1.8       anton     622:     cell - dup @ swap
                    623:     cell - dup @ swap
                    624:     cell - dup @ swap
                    625:     leave-sp ! ;
                    626: 
1.9       pazsan    627: : DONE ( orig -- )  drop >r drop
1.8       anton     628:     \ !! the original done had ( addr -- )
                    629:     begin
                    630:        leave>
1.9       pazsan    631:        over r@ u>=
1.8       anton     632:     while
                    633:        POSTPONE then
                    634:     repeat
1.9       pazsan    635:     >leave rdrop ; immediate restrict
1.8       anton     636: 
                    637: : LEAVE ( -- )
                    638:     POSTPONE ahead
1.9       pazsan    639:     >leave ; immediate restrict
1.8       anton     640: 
                    641: : ?LEAVE ( -- )
                    642:     POSTPONE 0= POSTPONE if
1.9       pazsan    643:     >leave ; immediate restrict
1.8       anton     644: 
                    645: : DO ( -- do-sys )
                    646:     POSTPONE (do)
                    647:     POSTPONE begin drop do-dest
1.9       pazsan    648:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     649: 
                    650: : ?DO ( -- do-sys )
1.9       pazsan    651:     ( 0 0 0 >leave )
1.8       anton     652:     POSTPONE (?do)
                    653:     >mark >leave
1.9       pazsan    654:     POSTPONE begin drop do-dest ; immediate restrict
1.8       anton     655: 
                    656: : FOR ( -- do-sys )
                    657:     POSTPONE (for)
                    658:     POSTPONE begin drop do-dest
1.9       pazsan    659:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     660: 
                    661: \ LOOP etc. are just like UNTIL
                    662: 
                    663: : loop-like ( do-sys xt1 xt2 -- )
1.9       pazsan    664:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
1.8       anton     665:     until-like  POSTPONE done  POSTPONE unloop ;
                    666: 
                    667: : LOOP ( do-sys -- )
1.9       pazsan    668:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
1.8       anton     669: 
                    670: : +LOOP ( do-sys -- )
1.9       pazsan    671:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
1.8       anton     672: 
                    673: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
                    674: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
                    675: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
                    676: \ negative increments.
                    677: : S+LOOP ( do-sys -- )
1.9       pazsan    678:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
1.5       anton     679: 
1.8       anton     680: : NEXT ( do-sys -- )
1.9       pazsan    681:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
1.1       anton     682: 
                    683: \ Structural Conditionals                              12dec92py
                    684: 
1.8       anton     685: : EXIT ( -- )
                    686:     0 adjust-locals-size
                    687:     POSTPONE ;s
                    688:     unreachable ; immediate restrict
1.1       anton     689: 
1.8       anton     690: : ?EXIT ( -- )
                    691:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
1.1       anton     692: 
                    693: \ Strings                                              22feb93py
                    694: 
                    695: : ," ( "string"<"> -- ) [char] " parse
                    696:   here over char+ allot  place align ;
                    697: : "lit ( -- addr )
                    698:   r> r> dup count + aligned >r swap >r ;               restrict
                    699: : (.")     "lit count type ;                           restrict
                    700: : (S")     "lit count ;                                restrict
                    701: : SLiteral postpone (S") here over char+ allot  place align ;
                    702:                                              immediate restrict
                    703: : S"       [char] " parse  state @ IF  postpone SLiteral  THEN ;
                    704:                                              immediate
                    705: : ."       state @  IF    postpone (.") ,"  align
                    706:                     ELSE  [char] " parse type  THEN  ;  immediate
                    707: : (        [char] ) parse 2drop ;                       immediate
                    708: : \        source >in ! drop ;                          immediate
                    709: 
                    710: \ error handling                                       22feb93py
                    711: \ 'abort thrown out!                                   11may93jaw
                    712: 
                    713: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
                    714:                 rdrop ;
                    715: : abort"        postpone (abort") ," ;        immediate restrict
                    716: 
                    717: \ Header states                                        23feb93py
                    718: 
1.10      anton     719: : flag! ( 8b -- )
                    720:     last @ dup 0= abort" last word was headerless"
                    721:     cell+ tuck c@ xor swap c! ;
1.1       anton     722: : immediate     $20 flag! ;
1.9       pazsan    723: : restrict      $40 flag! ;
                    724: \ ' noop alias restrict
1.1       anton     725: 
                    726: \ Header                                               23feb93py
                    727: 
                    728: \ input-stream, nextname and noname are quite ugly (passing
                    729: \ information through global variables), but they are useful for dealing
                    730: \ with existing/independent defining words
                    731: 
                    732: defer header
                    733: 
                    734: : name,  ( "name" -- )
1.10      anton     735:     name c@
1.12      pazsan    736:     dup $1F u> -&19 and throw ( is name too long? )
1.10      anton     737:     1+ chars allot align ;
1.1       anton     738: : input-stream-header ( "name" -- )
                    739:     \ !! this is f83-implementation-dependent
                    740:     align here last !  -1 A,
                    741:     name, $80 flag! ;
                    742: 
                    743: : input-stream ( -- )  \ general
                    744: \ switches back to getting the name from the input stream ;
                    745:     ['] input-stream-header IS header ;
                    746: 
                    747: ' input-stream-header IS header
                    748: 
                    749: \ !! make that a 2variable
1.5       anton     750: create nextname-buffer 32 chars allot
1.1       anton     751: 
                    752: : nextname-header ( -- )
                    753:     \ !! f83-implementation-dependent
1.5       anton     754:     nextname-buffer count
1.1       anton     755:     align here last ! -1 A,
                    756:     dup c,  here swap chars  dup allot  move  align
                    757:     $80 flag!
                    758:     input-stream ;
                    759: 
                    760: \ the next name is given in the string
                    761: : nextname ( c-addr u -- ) \ general
1.12      pazsan    762:     dup $1F u> -&19 and throw ( is name too long? )
1.5       anton     763:     nextname-buffer c! ( c-addr )
                    764:     nextname-buffer count move
1.1       anton     765:     ['] nextname-header IS header ;
                    766: 
                    767: : noname-header ( -- )
                    768:     0 last !
                    769:     input-stream ;
                    770: 
                    771: : noname ( -- ) \ general
                    772: \ the next defined word remains anonymous. The xt of that word is given by lastxt
                    773:     ['] noname-header IS header ;
                    774: 
                    775: : lastxt ( -- xt ) \ general
                    776: \ 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
                    777:     lastcfa @ ;
                    778: 
                    779: : Alias    ( cfa "name" -- )
                    780:   Header reveal , $80 flag! ;
                    781: 
                    782: : name>string ( nfa -- addr count )
                    783:  cell+ count $1F and ;
                    784: 
1.9       pazsan    785: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
1.1       anton     786: : >name ( cfa -- nfa )
                    787:  $21 cell do
                    788:    dup i - count $9F and + aligned over $80 + = if
                    789:      i - cell - unloop exit
                    790:    then
                    791:  cell +loop
                    792:  drop ??? ( wouldn't 0 be better? ) ;
                    793: 
                    794: \ indirect threading                                   17mar93py
                    795: 
                    796: : cfa,     ( code-address -- )
                    797:     here lastcfa !
                    798:     here  0 A, 0 ,  code-address! ;
                    799: : compile, ( xt -- )           A, ;
                    800: : !does    ( addr -- )         lastcfa @ does-code! ;
                    801: : (;code)  ( R: addr -- )      r> /does-handler + !does ;
                    802: : dodoes,  ( -- )
                    803:   here /does-handler allot does-handler! ;
                    804: 
                    805: \ direct threading is implementation dependent
                    806: 
1.4       pazsan    807: : Create    Header reveal [ :dovar ] Literal cfa, ;
1.1       anton     808: 
                    809: \ DOES>                                                17mar93py
                    810: 
1.5       anton     811: : DOES>  ( compilation: -- )
                    812:     state @
                    813:     IF
                    814:        ;-hook postpone (;code) dodoes,
                    815:     ELSE
                    816:        dodoes, here !does 0 ]
                    817:     THEN 
                    818:     :-hook ; immediate
1.1       anton     819: 
                    820: \ Create Variable User Constant                        17mar93py
                    821: 
                    822: : Variable  Create 0 , ;
                    823: : AVariable Create 0 A, ;
                    824: : 2VARIABLE ( "name" -- ) \ double
                    825:     create 0 , 0 , ;
                    826:     
                    827: : User      Variable ;
                    828: : AUser     AVariable ;
                    829: 
1.4       pazsan    830: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
1.1       anton     831: : Constant  (Constant) , ;
                    832: : AConstant (Constant) A, ;
1.5       anton     833: 
                    834: : 2CONSTANT
                    835:     create ( w1 w2 "name" -- )
                    836:         2,
                    837:     does> ( -- w1 w2 )
                    838:         2@ ;
1.1       anton     839:     
                    840: \ IS Defer What's Defers TO                            24feb93py
                    841: 
1.5       anton     842: : Defer
                    843:   Create ( -- ) 
                    844:     ['] noop A,
                    845:   DOES> ( ??? )
                    846:     @ execute ;
1.1       anton     847: 
                    848: : IS ( addr "name" -- )
                    849:     ' >body
                    850:     state @
                    851:     IF    postpone ALiteral postpone !  
                    852:     ELSE  !
                    853:     THEN ;  immediate
                    854: ' IS Alias TO immediate
                    855: 
                    856: : What's ( "name" -- addr )  ' >body
                    857:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
                    858:                                              immediate
                    859: : Defers ( "name" -- )  ' >body @ compile, ;
1.12      pazsan    860:                                              immediate
1.1       anton     861: 
                    862: \ : ;                                                  24feb93py
                    863: 
1.5       anton     864: defer :-hook ( sys1 -- sys2 )
                    865: defer ;-hook ( sys2 -- sys1 )
                    866: 
1.8       anton     867: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
1.5       anton     868: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
1.1       anton     869:   immediate restrict
1.5       anton     870: 
1.10      anton     871: : :noname ( -- xt colon-sys )
                    872:     0 last !
                    873:     here [ :docol ] Literal cfa, 0 ] :-hook ;
1.1       anton     874: 
                    875: \ Search list handling                                 23feb93py
                    876: 
                    877: AVariable current
                    878: 
                    879: : last?   ( -- false / nfa nfa )    last @ ?dup ;
1.5       anton     880: : (reveal) ( -- )
                    881:   last?
                    882:   IF
                    883:       dup @ 0<
                    884:       IF
                    885:        current @ @ over ! current @ !
                    886:       ELSE
                    887:        drop
                    888:       THEN
                    889:   THEN ;
1.1       anton     890: 
                    891: \ object oriented search list                          17mar93py
                    892: 
1.5       anton     893: \ word list structure:
                    894: \ struct
1.7       pazsan    895: \   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
1.5       anton     896: \   1 cells: field reveal-method \ xt: ( -- )
1.7       pazsan    897: \   1 cells: field rehash-method \ xt: ( wid -- )
1.5       anton     898: \   \ !! what else
                    899: \ end-struct wordlist-map-struct
                    900: 
                    901: \ struct
                    902: \   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
                    903: \   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
1.7       pazsan    904: \   1 cells: field wordlist-link \ link field to other wordlists
                    905: \   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
1.5       anton     906: \ end-struct wordlist-struct
                    907: 
1.7       pazsan    908: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
1.5       anton     909: 
1.1       anton     910: \ Search list table: find reveal
1.12      pazsan    911: Create f83search       ' f83find A,  ' (reveal) A,  ' drop A,
1.7       pazsan    912: 
1.1       anton     913: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
                    914: AVariable search       G forth-wordlist search T !
                    915: G forth-wordlist current T !
                    916: 
                    917: : (search-wordlist)  ( addr count wid -- nfa / false )
1.7       pazsan    918:   dup ( @ swap ) cell+ @ @ execute ;
1.1       anton     919: 
                    920: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
                    921:   (search-wordlist) dup  IF  found  THEN ;
                    922: 
                    923: Variable warnings  G -1 warnings T !
                    924: 
                    925: : check-shadow  ( addr count wid -- )
                    926: \ prints a warning if the string is already present in the wordlist
                    927: \ !! should be refined so the user can suppress the warnings
                    928:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
                    929:    ." redefined " name>string 2dup type
                    930:    compare 0<> if
                    931:      ."  with " type
                    932:    else
                    933:      2drop
                    934:    then
                    935:    space space EXIT
                    936:  then
                    937:  2drop 2drop ;
                    938: 
                    939: : find   ( addr -- cfa +-1 / string false )  dup
                    940:   count search @ search-wordlist  dup IF  rot drop  THEN ;
                    941: 
                    942: : reveal ( -- )
                    943:  last? if
                    944:    name>string current @ check-shadow
                    945:  then
                    946:  current @ cell+ @ cell+ @ execute ;
1.7       pazsan    947: 
                    948: : rehash  ( wid -- )  dup cell+ @ cell+ cell+ @ execute ;
1.1       anton     949: 
                    950: : '    ( "name" -- addr )  name find 0= no.extensions ;
                    951: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
                    952: \ Input                                                13feb93py
                    953: 
                    954: 07 constant #bell
                    955: 08 constant #bs
                    956: 7F constant #del
                    957: 0D constant #cr                \ the newline key code
                    958: 0A constant #lf
                    959: 
                    960: : bell  #bell emit ;
                    961: 
                    962: : backspaces  0 ?DO  #bs emit  LOOP ;
                    963: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
                    964:   over 3 pick 2 pick chars /string ;
                    965: : type-rest ( span addr pos1 -- span addr pos1 back )
                    966:   >string tuck type ;
                    967: : (del)  ( max span addr pos1 -- max span addr pos2 )
                    968:   1- >string over 1+ -rot move
                    969:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
                    970: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
                    971:   >r >string over 1+ swap move 2dup chars + r> swap c!
                    972:   rot 1+ -rot type-rest 1- backspaces 1+ ;
                    973: : ?del ( max span addr pos1 -- max span addr pos2 0 )
                    974:   dup  IF  (del)  THEN  0 ;
                    975: : (ret)  type-rest drop true space ;
                    976: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
                    977: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
                    978: 
                    979: Create crtlkeys
                    980:   ] false false back  false  false false forw  false
                    981:     ?del  false (ret) false  false (ret) false false
                    982:     false false false false  false false false false
                    983:     false false false false  false false false false [
                    984: 
                    985: : decode ( max span addr pos1 key -- max span addr pos2 flag )
                    986:   dup #del = IF  drop #bs  THEN  \ del is rubout
                    987:   dup bl <   IF  cells crtlkeys + @ execute  EXIT  THEN
                    988:   >r 2over = IF  rdrop bell 0 EXIT  THEN
                    989:   r> (ins) 0 ;
                    990: 
                    991: \ decode should better use a table for control key actions
                    992: \ to define keyboard bindings later
                    993: 
                    994: : accept   ( addr len -- len )
                    995:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
                    996: \ this allows to edit given strings
                    997:          ELSE  0  THEN rot over
                    998:   BEGIN  key decode  UNTIL
                    999:   2drop nip ;
                   1000: 
                   1001: \ Output                                               13feb93py
                   1002: 
                   1003: DEFER type      \ defer type for a output buffer or fast
                   1004:                 \ screen write
                   1005: 
1.9       pazsan   1006: \ : (type) ( addr len -- )
                   1007: \   bounds ?DO  I c@ emit  LOOP ;
1.1       anton    1008: 
                   1009: ' (TYPE) IS Type
                   1010: 
1.9       pazsan   1011: DEFER Emit
1.1       anton    1012: 
1.9       pazsan   1013: ' (Emit) IS Emit
1.1       anton    1014: 
                   1015: \ : form  ( -- rows cols )  &24 &80 ;
                   1016: \ form should be implemented using TERMCAPS or CURSES
                   1017: \ : rows  form drop ;
                   1018: \ : cols  form nip  ;
                   1019: 
                   1020: \ Query                                                07apr93py
                   1021: 
                   1022: : refill ( -- flag )
                   1023:   tib /line
                   1024:   loadfile @ ?dup
1.12      pazsan   1025:   IF    \ dup file-position throw linestart 2!
1.1       anton    1026:         read-line throw
1.12      pazsan   1027:   ELSE  loadline @ 0< IF 2drop false EXIT THEN
1.1       anton    1028:         accept true
                   1029:   THEN
                   1030:   1 loadline +!
1.10      anton    1031:   swap #tib ! 0 >in ! ;
1.1       anton    1032: 
1.10      anton    1033: : Query  ( -- )  0 loadfile ! refill drop ;
1.1       anton    1034: 
                   1035: \ File specifiers                                       11jun93jaw
                   1036: 
                   1037: 
                   1038: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
                   1039: \ 2 c, here char r c, char + c, 0 c,
                   1040: \ 2 c, here char w c, char + c, 0 c, align
                   1041: 4 Constant w/o
                   1042: 2 Constant r/w
                   1043: 0 Constant r/o
                   1044: 
                   1045: \ BIN WRITE-LINE                                        11jun93jaw
                   1046: 
                   1047: \ : bin           dup 1 chars - c@
                   1048: \                 r/o 4 chars + over - dup >r swap move r> ;
                   1049: 
                   1050: : bin  1+ ;
                   1051: 
                   1052: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
                   1053:                            \ or not unix environments if
                   1054:                            \ bin is not selected
                   1055: 
                   1056: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
                   1057:                 nl$ count r> write-file ;
                   1058: 
                   1059: \ include-file                                         07apr93py
                   1060: 
1.12      pazsan   1061: : push-file  ( -- )  r>
                   1062:   ( linestart 2@ >r >r ) loadline @ >r loadfile @ >r
                   1063:   blk @ >r >tib @ >r  #tib @ dup >r  >tib +!  >in @ >r  >r ;
                   1064: 
                   1065: : pop-file   ( -- )  r>
                   1066:   r> >in !  r> #tib !  r> >tib ! r> blk !
                   1067:   r> loadfile ! r> loadline ! ( r> r> linestart 2! ) >r ;
                   1068: 
1.1       anton    1069: : include-file ( i*x fid -- j*x )
1.12      pazsan   1070:   push-file  loadfile !
1.1       anton    1071:   0 loadline ! blk off
                   1072:   BEGIN  refill  WHILE  interpret  REPEAT
                   1073:   loadfile @ close-file throw
1.12      pazsan   1074:   pop-file ;
1.1       anton    1075: 
                   1076: : included ( i*x addr u -- j*x )
1.10      anton    1077:     loadfilename 2@ >r >r
                   1078:     dup allocate throw over loadfilename 2!
                   1079:     over loadfilename 2@ move
                   1080:     r/o open-file throw include-file
                   1081:     \ don't free filenames; they don't take much space
                   1082:     \ and are used for debugging
                   1083:     r> r> loadfilename 2! ;
1.1       anton    1084: 
                   1085: \ HEX DECIMAL                                           2may93jaw
                   1086: 
                   1087: : decimal a base ! ;
                   1088: : hex     10 base ! ;
                   1089: 
                   1090: \ DEPTH                                                 9may93jaw
                   1091: 
                   1092: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
                   1093: 
                   1094: \ INCLUDE                                               9may93jaw
                   1095: 
1.6       pazsan   1096: : include  ( "file" -- )
                   1097:   bl word count included ;
1.1       anton    1098: 
                   1099: \ RECURSE                                               17may93jaw
                   1100: 
1.10      anton    1101: : recurse ( -- )
                   1102:     lastxt compile, ; immediate restrict
                   1103: : recursive ( -- )
                   1104:     reveal ; immediate
1.1       anton    1105: 
                   1106: \ */MOD */                                              17may93jaw
                   1107: 
1.13      anton    1108: \ !! I think */mod should have the same rounding behaviour as / - anton
1.1       anton    1109: : */mod >r m* r> sm/rem ;
                   1110: 
                   1111: : */ */mod nip ;
                   1112: 
                   1113: \ EVALUATE                                              17may93jaw
                   1114: 
                   1115: : evaluate ( c-addr len -- )
1.12      pazsan   1116:   push-file  dup #tib ! >tib @ swap move
                   1117:   >in off blk off loadfile off -1 loadline !
1.1       anton    1118: 
                   1119:   BEGIN  interpret  >in @ #tib @ u>= UNTIL
                   1120: 
1.12      pazsan   1121:   pop-file ;
1.1       anton    1122: 
                   1123: 
                   1124: : abort -1 throw ;
                   1125: 
                   1126: \+ environment? true ENV" CORE"
                   1127: \ core wordset is now complete!
                   1128: 
                   1129: \ Quit                                                 13feb93py
                   1130: 
                   1131: Defer 'quit
                   1132: Defer .status
                   1133: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
                   1134: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
                   1135: ' (quit) IS 'quit
                   1136: 
                   1137: \ DOERROR (DOERROR)                                     13jun93jaw
                   1138: 
1.10      anton    1139: : dec. ( n -- )
                   1140:     \ print value in decimal representation
                   1141:     base @ decimal swap . base ! ;
                   1142: 
                   1143: : typewhite ( addr u -- )
                   1144:     \ like type, but white space is printed instead of the characters
                   1145:     0 ?do
                   1146:        dup i + c@ 9 = if \ check for tab
                   1147:            9
                   1148:        else
                   1149:            bl
                   1150:        then
                   1151:        emit
                   1152:     loop
                   1153:     drop ;
                   1154: 
1.1       anton    1155: DEFER DOERROR
                   1156: 
                   1157: : (DoError) ( throw-code -- )
1.10      anton    1158:     LoadFile @
                   1159:     IF
                   1160:        cr loadfilename 2@ type ." :" Loadline @ dec.
                   1161:     THEN
                   1162:     cr source type cr
                   1163:     source drop >in @ -trailing ( throw-code line-start index2 )
                   1164:     here c@ 1F min dup >r - 0 max ( throw-code line-start index1 )
                   1165:     typewhite
                   1166:     r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
                   1167:        ." ^"
                   1168:     loop
                   1169:     dup -2 =
                   1170:     IF 
                   1171:        "error @ ?dup
                   1172:        IF
                   1173:            cr count type 
                   1174:        THEN
                   1175:        drop
                   1176:     ELSE
                   1177:        .error
                   1178:     THEN
                   1179:     normal-dp dpp ! ;
1.1       anton    1180: 
                   1181: ' (DoError) IS DoError
                   1182: 
                   1183: : quit   r0 @ rp! handler off >tib @ >r
1.5       anton    1184:   BEGIN
                   1185:     postpone [
                   1186:     ['] 'quit CATCH dup
                   1187:   WHILE
                   1188:     DoError r@ >tib !
                   1189:   REPEAT
                   1190:   drop r> >tib ! ;
1.1       anton    1191: 
                   1192: \ Cold                                                 13feb93py
                   1193: 
                   1194: \ : .name ( name -- ) cell+ count $1F and type space ;
                   1195: \ : words  listwords @
                   1196: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
                   1197: 
                   1198: : >len  ( cstring -- addr n )  100 0 scan 0 swap 100 - /string ;
                   1199: : arg ( n -- addr count )  cells argv @ + @ >len ;
                   1200: : #!       postpone \ ;  immediate
                   1201: 
                   1202: Variable env
                   1203: Variable argv
                   1204: Variable argc
                   1205: 
1.12      pazsan   1206: 0 Value script? ( -- flag )
                   1207: 
                   1208: : ">tib  ( addr len -- )  dup #tib ! >in off tib swap move ;
1.1       anton    1209: 
1.12      pazsan   1210: : do-option ( addr1 len1 addr2 len2 -- n )  2swap
                   1211:   2dup s" -e"        compare  0= >r
                   1212:   2dup s" -evaluate" compare  0= r> or
                   1213:   IF  2drop ">tib interpret  2 EXIT  THEN
                   1214:   ." Unknown option: " type cr 2drop 1 ;
                   1215: 
                   1216: : process-args ( -- )  argc @ 1
                   1217:   ?DO  I arg over c@ [char] - <>
                   1218:        IF    true to script? included  false to script? 1
                   1219:        ELSE  I 1+ arg  do-option
                   1220:        THEN
                   1221:   +LOOP ;
1.1       anton    1222: 
1.5       anton    1223: : cold ( -- )  
1.10      anton    1224:     argc @ 1 >
1.12      pazsan   1225:     IF
                   1226:        ['] process-args catch ?dup
1.10      anton    1227:        IF
1.12      pazsan   1228:            dup >r DoError cr r> negate (bye)
1.10      anton    1229:        THEN
                   1230:     THEN
1.13      anton    1231:     cr
                   1232:     ." GNU Forth 0.0alpha, Copyright (C) 1994 Free Software Foundation, Inc." cr
                   1233:     ." GNU Forth comes with ABSOLUTELY NO WARRANTY; for details type `license'" cr
                   1234:     ." Type `bye' to exit"
                   1235:     quit ;
1.1       anton    1236: 
1.12      pazsan   1237: : license ( -- ) cr
                   1238:  ." This program is free software; you can redistribute it and/or modify" cr
                   1239:  ." it under the terms of the GNU General Public License as published by" cr
1.13      anton    1240:  ." the Free Software Foundation; either version 2 of the License, or" cr
                   1241:  ." (at your option) any later version." cr cr
1.12      pazsan   1242: 
                   1243:  ." This program is distributed in the hope that it will be useful," cr
                   1244:  ." but WITHOUT ANY WARRANTY; without even the implied warranty of" cr
                   1245:  ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" cr
                   1246:  ." GNU General Public License for more details." cr cr
                   1247: 
                   1248:  ." You should have received a copy of the GNU General Public License" cr
                   1249:  ." along with this program; if not, write to the Free Software" cr
                   1250:  ." Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA." cr ;
                   1251: 
1.1       anton    1252: : boot ( **env **argv argc -- )
1.4       pazsan   1253:   argc ! argv ! env !  main-task up!
1.1       anton    1254:   sp@ dup s0 ! $10 + >tib ! rp@ r0 !  fp@ f0 !  cold ;
                   1255: 
1.12      pazsan   1256: : bye  script? 0= IF  cr  THEN  0 (bye) ;
1.1       anton    1257: 
                   1258: \ **argv may be scanned by the C starter to get some important
                   1259: \ information, as -display and -geometry for an X client FORTH
                   1260: \ or space and stackspace overrides
                   1261: 
                   1262: \ 0 arg contains, however, the name of the program.

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