Annotation of gforth/kernal.fs, revision 1.27

1.24      pazsan      1: \ KERNAL.FS    GNU FORTH kernal                        17dec92py
1.1       anton       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: 
1.22      anton      69: : chars ; immediate
1.8       anton      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: 
1.19      anton     113: : scan   ( addr1 n1 char -- addr2 n2 )
                    114:     \ skip all characters not equal to char
                    115:     >r
                    116:     BEGIN
                    117:        dup
                    118:     WHILE
                    119:        over c@ r@ <>
                    120:     WHILE
                    121:        1 /string
                    122:     REPEAT  THEN
                    123:     rdrop ;
                    124: : skip   ( addr1 n1 char -- addr2 n2 )
                    125:     \ skip all characters equal to char
                    126:     >r
                    127:     BEGIN
                    128:        dup
                    129:     WHILE
                    130:        over c@ r@  =
                    131:     WHILE
                    132:        1 /string
                    133:     REPEAT  THEN
                    134:     rdrop ;
1.1       anton     135: 
                    136: : (word) ( addr1 n1 char -- addr2 n2 )
                    137:   dup >r skip 2dup r> scan  nip - ;
                    138: 
                    139: \ (word) should fold white spaces
                    140: \ this is what (parse-white) does
                    141: 
                    142: \ word parse                                           23feb93py
                    143: 
                    144: : parse-word  ( char -- addr len )
                    145:   source 2dup >r >r >in @ /string
                    146:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
                    147:   2dup + r> - 1+ r> min >in ! ;
                    148: : word   ( char -- addr )
                    149:   parse-word here place  bl here count + c!  here ;
                    150: 
                    151: : parse    ( char -- addr len )
                    152:   >r  source  >in @ /string  over  swap r>  scan >r
                    153:   over - dup r> IF 1+ THEN  >in +! ;
                    154: 
                    155: \ name                                                 13feb93py
                    156: 
1.20      pazsan    157: : capitalize ( addr len -- addr len )
                    158:   2dup chars chars bounds
1.1       anton     159:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
1.20      pazsan    160: : (name) ( -- c-addr count )
1.15      anton     161:     source 2dup >r >r >in @ /string (parse-white)
                    162:     2dup + r> - 1+ r> min >in ! ;
                    163: \    name count ;
1.1       anton     164: 
                    165: \ Literal                                              17dec92py
                    166: 
1.8       anton     167: : Literal  ( n -- )  state @ IF postpone lit  , THEN ;
1.1       anton     168:                                                       immediate
1.8       anton     169: : ALiteral ( n -- )  state @ IF postpone lit A, THEN ;
1.1       anton     170:                                                       immediate
                    171: 
                    172: : char   ( 'char' -- n )  bl word char+ c@ ;
                    173: : [char] ( 'char' -- n )  char postpone Literal ; immediate
                    174: ' [char] Alias Ascii immediate
                    175: 
1.22      anton     176: : (compile) ( -- )  r> dup cell+ >r @ compile, ;
1.1       anton     177: : postpone ( "name" -- )
1.20      pazsan    178:   name sfind dup 0= abort" Can't compile "
1.22      anton     179:   0> IF  compile,  ELSE  postpone (compile) A,  THEN ;
1.1       anton     180:                                              immediate restrict
                    181: 
                    182: \ Use (compile) for the old behavior of compile!
                    183: 
                    184: \ digit?                                               17dec92py
                    185: 
                    186: : digit?   ( char -- digit true/ false )
1.8       anton     187:   base @ $100 =
                    188:   IF
                    189:     true EXIT
                    190:   THEN
1.1       anton     191:   toupper [char] 0 - dup 9 u> IF
                    192:     [ 'A '9 1 + -  ] literal -
                    193:     dup 9 u<= IF
                    194:       drop false EXIT
                    195:     THEN
                    196:   THEN
                    197:   dup base @ u>= IF
                    198:     drop false EXIT
                    199:   THEN
                    200:   true ;
                    201: 
                    202: : accumulate ( +d0 addr digit - +d1 addr )
                    203:   swap >r swap  base @  um* drop rot  base @  um* d+ r> ;
                    204: : >number ( d addr count -- d addr count )
                    205:   0 ?DO  count digit? WHILE  accumulate  LOOP 0
                    206:   ELSE  1- I' I - UNLOOP  THEN ;
                    207: 
                    208: \ number? number                                       23feb93py
                    209: 
                    210: Create bases   10 ,   2 ,   A , 100 ,
                    211: \              16     2    10   Zeichen
                    212: \ !! this saving and restoring base is an abomination! - anton
                    213: : getbase ( addr u -- addr' u' )  over c@ [char] $ - dup 4 u<
                    214:   IF  cells bases + @ base ! 1 /string  ELSE  drop  THEN ;
1.12      pazsan    215: : s>number ( addr len -- d )  base @ >r  dpl on
                    216:   over c@ '- =  dup >r  IF  1 /string  THEN
1.1       anton     217:   getbase  dpl on  0 0 2swap
                    218:   BEGIN  dup >r >number dup  WHILE  dup r> -  WHILE
                    219:          dup dpl ! over c@ [char] . =  WHILE
                    220:          1 /string
1.12      pazsan    221:   REPEAT  THEN  2drop rdrop dpl off  ELSE
                    222:   2drop rdrop r> IF  dnegate  THEN
                    223:   THEN r> base ! ;
1.15      anton     224: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
                    225:     s>number dpl @ 0=
                    226:     IF
                    227:        2drop false  EXIT
                    228:     THEN
                    229:     dpl @ dup 0> 0= IF
                    230:        nip
                    231:     THEN ;
1.12      pazsan    232: : number? ( string -- string 0 / n -1 / d 0> )
1.15      anton     233:     dup >r count snumber? dup if
                    234:        rdrop
                    235:     else
                    236:        r> swap
                    237:     then ;
1.1       anton     238: : s>d ( n -- d ) dup 0< ;
                    239: : number ( string -- d )
                    240:   number? ?dup 0= abort" ?"  0< IF s>d THEN ;
                    241: 
                    242: \ space spaces ud/mod                                  21mar93py
                    243: decimal
                    244: Create spaces  bl 80 times \ times from target compiler! 11may93jaw
                    245: DOES>   ( u -- )  swap
                    246:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.23      pazsan    247: Create backspaces  08 80 times \ times from target compiler! 11may93jaw
                    248: DOES>   ( u -- )  swap
                    249:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.1       anton     250: hex
                    251: : space   1 spaces ;
                    252: 
                    253: : ud/mod ( ud1 u2 -- urem udquot )  >r 0 r@ um/mod r> swap >r
                    254:                                     um/mod r> ;
                    255: 
                    256: : pad    ( -- addr )
                    257:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
                    258: 
                    259: \ hold <# #> sign # #s                                 25jan92py
                    260: 
                    261: : hold    ( char -- )         pad cell - -1 chars over +! @ c! ;
                    262: 
                    263: : <#                          pad cell - dup ! ;
                    264: 
                    265: : #>      ( 64b -- addr +n )  2drop pad cell - dup @ tuck - ;
                    266: 
                    267: : sign    ( n -- )            0< IF  [char] - hold  THEN ;
                    268: 
                    269: : #       ( +d1 -- +d2 )    base @ 2 max ud/mod rot 9 over <
                    270:   IF [ char A char 9 - 1- ] Literal +  THEN  [char] 0 + hold ;
                    271: 
                    272: : #s      ( +d -- 0 0 )         BEGIN  # 2dup d0=  UNTIL ;
                    273: 
                    274: \ print numbers                                        07jun92py
                    275: 
                    276: : d.r      >r tuck  dabs  <# #s  rot sign #>
                    277:            r> over - spaces  type ;
                    278: 
                    279: : ud.r     >r <# #s #> r> over - spaces type ;
                    280: 
                    281: : .r       >r s>d r> d.r ;
                    282: : u.r      0 swap ud.r ;
                    283: 
                    284: : d.       0 d.r space ;
                    285: : ud.      0 ud.r space ;
                    286: 
                    287: : .        s>d d. ;
                    288: : u.       0 ud. ;
                    289: 
                    290: \ catch throw                                          23feb93py
                    291: \ bounce                                                08jun93jaw
                    292: 
                    293: \ !! allow the user to add rollback actions    anton
                    294: \ !! use a separate exception stack?           anton
                    295: 
1.5       anton     296: : lp@ ( -- addr )
                    297:  laddr# [ 0 , ] ;
                    298: 
1.1       anton     299: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
1.5       anton     300:   >r sp@ r> swap >r       \ don't count xt! jaw
                    301:   fp@ >r
                    302:   lp@ >r
                    303:   handler @ >r
                    304:   rp@ handler !
                    305:   execute
1.6       pazsan    306:   r> handler ! rdrop rdrop rdrop 0 ;
                    307: 
1.5       anton     308: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
1.10      anton     309:     ?DUP IF
                    310:        [ here 4 cells ! ]
                    311:        handler @ rp!
                    312:        r> handler !
                    313:        r> lp!
                    314:        r> fp!
                    315:        r> swap >r sp! r>
                    316:     THEN ;
1.6       pazsan    317: 
1.1       anton     318: \ Bouncing is very fine,
                    319: \ programming without wasting time...   jaw
1.5       anton     320: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym )
                    321: \ a throw without data or fp stack restauration
                    322:   ?DUP IF
                    323:     handler @ rp!
                    324:     r> handler !
                    325:     r> lp!
                    326:     rdrop
                    327:     rdrop
                    328:   THEN ;
1.1       anton     329: 
                    330: \ ?stack                                               23feb93py
                    331: 
                    332: : ?stack ( ?? -- ?? )  sp@ s0 @ > IF  -4 throw  THEN ;
                    333: \ ?stack should be code -- it touches an empty stack!
                    334: 
                    335: \ interpret                                            10mar92py
                    336: 
                    337: Defer parser
                    338: Defer name      ' (name) IS name
1.15      anton     339: Defer notfound ( c-addr count -- )
1.1       anton     340: 
1.15      anton     341: : no.extensions  ( addr u -- )  2drop -&13 bounce ;
1.1       anton     342: 
                    343: ' no.extensions IS notfound
                    344: 
                    345: : interpret
1.15      anton     346:     BEGIN
1.20      pazsan    347:        ?stack name dup
1.15      anton     348:     WHILE
                    349:        parser
                    350:     REPEAT
                    351:     2drop ;
                    352: 
1.20      pazsan    353: \ interpreter compiler                                 30apr92py
1.15      anton     354: 
1.20      pazsan    355: : interpreter  ( c-addr u -- ) 
1.15      anton     356:     \ interpretation semantics for the name/number c-addr u
                    357:     2dup sfind dup
                    358:     IF
                    359:        1 and
                    360:        IF \ not restricted to compile state?
                    361:            nip nip execute  EXIT
                    362:        THEN
                    363:        -&14 throw
                    364:     THEN
                    365:     drop
                    366:     2dup 2>r snumber?
                    367:     IF
                    368:        2rdrop
                    369:     ELSE
                    370:        2r> notfound
                    371:     THEN ;
1.1       anton     372: 
1.20      pazsan    373: ' interpreter  IS  parser
1.1       anton     374: 
1.20      pazsan    375: : compiler     ( c-addr u -- )
1.15      anton     376:     \ compilation semantics for the name/number c-addr u
                    377:     2dup sfind dup
                    378:     IF
                    379:        0>
                    380:        IF
                    381:            nip nip execute EXIT
                    382:        THEN
                    383:        compile, 2drop EXIT
                    384:     THEN
                    385:     drop
                    386:     2dup snumber? dup
                    387:     IF
                    388:        0>
                    389:        IF
                    390:            swap postpone Literal
                    391:        THEN
                    392:        postpone Literal
                    393:        2drop
                    394:     ELSE
                    395:        drop notfound
                    396:     THEN ;
1.1       anton     397: 
1.20      pazsan    398: : [     ['] interpreter  IS parser state off ; immediate
                    399: : ]     ['] compiler     IS parser state on  ;
1.1       anton     400: 
1.8       anton     401: \ locals stuff needed for control structures
                    402: 
                    403: : compile-lp+! ( n -- )
                    404:     dup negate locals-size +!
                    405:     0 over = if
1.20      pazsan    406:     else -1 cells  over = if postpone lp-
                    407:     else  1 floats over = if postpone lp+
                    408:     else  2 floats over = if postpone lp+2
1.8       anton     409:     else postpone lp+!# dup ,
                    410:     then then then then drop ;
                    411: 
                    412: : adjust-locals-size ( n -- )
                    413:     \ sets locals-size to n and generates an appropriate lp+!
                    414:     locals-size @ swap - compile-lp+! ;
                    415: 
                    416: 
                    417: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
                    418: AConstant locals-list \ acts like a variable that contains
1.10      anton     419:                      \ a linear list of locals names
1.8       anton     420: 
                    421: 
                    422: variable dead-code \ true if normal code at "here" would be dead
1.22      anton     423: variable backedge-locals
                    424:     \ contains the locals list that BEGIN will assume to be live on
                    425:     \ the back edge if the BEGIN is unreachable from above. Set by
                    426:     \ ASSUME-LIVE, reset by UNREACHABLE.
                    427: 
                    428: : UNREACHABLE ( -- )
                    429:     \ declares the current point of execution as unreachable
                    430:     dead-code on
                    431:     0 backedge-locals ! ; immediate
                    432: 
                    433: : ASSUME-LIVE ( orig -- orig )
                    434:     \ used immediateliy before a BEGIN that is not reachable from
                    435:     \ above.  causes the BEGIN to assume that the same locals are live
                    436:     \ as at the orig point
                    437:     dup orig?
                    438:     2 pick backedge-locals ! ; immediate
                    439:     
1.8       anton     440: \ locals list operations
                    441: 
                    442: : common-list ( list1 list2 -- list3 )
                    443: \ list1 and list2 are lists, where the heads are at higher addresses than
                    444: \ the tail. list3 is the largest sublist of both lists.
                    445:  begin
                    446:    2dup u<>
                    447:  while
                    448:    2dup u>
                    449:    if
                    450:      swap
                    451:    then
                    452:    @
                    453:  repeat
                    454:  drop ;
                    455: 
                    456: : sub-list? ( list1 list2 -- f )
                    457: \ true iff list1 is a sublist of list2
                    458:  begin
                    459:    2dup u<
                    460:  while
                    461:    @
                    462:  repeat
                    463:  = ;
                    464: 
                    465: : list-size ( list -- u )
                    466: \ size of the locals frame represented by list
                    467:  0 ( list n )
                    468:  begin
                    469:    over 0<>
                    470:  while
                    471:    over
1.11      pazsan    472:    name> >body @ max
1.8       anton     473:    swap @ swap ( get next )
                    474:  repeat
                    475:  faligned nip ;
                    476: 
                    477: : set-locals-size-list ( list -- )
                    478:  dup locals-list !
                    479:  list-size locals-size ! ;
                    480: 
                    481: : check-begin ( list -- )
                    482: \ warn if list is not a sublist of locals-list
                    483:  locals-list @ sub-list? 0= if
                    484:    \ !! print current position
                    485:    ." compiler was overly optimistic about locals at a BEGIN" cr
                    486:    \ !! print assumption and reality
                    487:  then ;
                    488: 
                    489: \ Control Flow Stack
                    490: \ orig, etc. have the following structure:
                    491: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
                    492: \ address (of the branch or the instruction to be branched to) (second)
                    493: \ locals-list (valid at address) (third)
                    494: 
                    495: \ types
                    496: 0 constant defstart
                    497: 1 constant live-orig
                    498: 2 constant dead-orig
                    499: 3 constant dest \ the loopback branch is always assumed live
                    500: 4 constant do-dest
                    501: 5 constant scopestart
                    502: 
                    503: : def? ( n -- )
                    504:     defstart <> abort" unstructured " ;
                    505: 
                    506: : orig? ( n -- )
                    507:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
                    508: 
                    509: : dest? ( n -- )
                    510:  dest <> abort" expected dest " ;
                    511: 
                    512: : do-dest? ( n -- )
                    513:  do-dest <> abort" expected do-dest " ;
                    514: 
                    515: : scope? ( n -- )
                    516:  scopestart <> abort" expected scope " ;
                    517: 
                    518: : non-orig? ( n -- )
                    519:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
                    520: 
                    521: : cs-item? ( n -- )
                    522:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
                    523: 
                    524: 3 constant cs-item-size
                    525: 
                    526: : CS-PICK ( ... u -- ... destu )
                    527:  1+ cs-item-size * 1- >r
                    528:  r@ pick  r@ pick  r@ pick
                    529:  rdrop
                    530:  dup non-orig? ;
                    531: 
                    532: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
                    533:  1+ cs-item-size * 1- >r
                    534:  r@ roll r@ roll r@ roll
                    535:  rdrop
                    536:  dup cs-item? ; 
                    537: 
                    538: : cs-push-part ( -- list addr )
                    539:  locals-list @ here ;
                    540: 
                    541: : cs-push-orig ( -- orig )
                    542:  cs-push-part dead-code @
                    543:  if
                    544:    dead-orig
                    545:  else
                    546:    live-orig
                    547:  then ;   
                    548: 
1.1       anton     549: \ Structural Conditionals                              12dec92py
                    550: 
                    551: : ?struc      ( flag -- )       abort" unstructured " ;
                    552: : sys?        ( sys -- )        dup 0= ?struc ;
1.8       anton     553: : >mark ( -- orig )
                    554:  cs-push-orig 0 , ;
                    555: : >resolve    ( addr -- )        here over - swap ! ;
                    556: : <resolve    ( addr -- )        here - , ;
1.1       anton     557: 
1.8       anton     558: : BUT       1 cs-roll ;                      immediate restrict
                    559: : YET       0 cs-pick ;                       immediate restrict
1.1       anton     560: 
                    561: \ Structural Conditionals                              12dec92py
                    562: 
1.8       anton     563: : AHEAD ( -- orig )
1.22      anton     564:  POSTPONE branch >mark POSTPONE unreachable ; immediate restrict
1.8       anton     565: 
                    566: : IF ( -- orig )
                    567:  POSTPONE ?branch >mark ; immediate restrict
                    568: 
1.1       anton     569: : ?DUP-IF \ general
                    570: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
                    571: \ better handled by tools like stack checkers
1.8       anton     572:     POSTPONE ?dup POSTPONE if ;       immediate restrict
1.14      anton     573: : ?DUP-0=-IF \ general
1.8       anton     574:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
                    575: 
                    576: : THEN ( orig -- )
                    577:     dup orig?
1.20      pazsan    578:     dead-orig =
1.8       anton     579:     if
1.20      pazsan    580:         >resolve drop
                    581:     else
                    582:         dead-code @
                    583:         if
1.8       anton     584:            >resolve set-locals-size-list dead-code off
                    585:        else \ both live
                    586:            over list-size adjust-locals-size
                    587:            >resolve
                    588:            locals-list @ common-list dup list-size adjust-locals-size
                    589:            locals-list !
                    590:        then
                    591:     then ; immediate restrict
                    592: 
1.1       anton     593: ' THEN alias ENDIF immediate restrict \ general
                    594: \ Same as "THEN". This is what you use if your program will be seen by
                    595: \ people who have not been brought up with Forth (or who have been
                    596: \ brought up with fig-Forth).
                    597: 
1.8       anton     598: : ELSE ( orig1 -- orig2 )
                    599:     POSTPONE ahead
                    600:     1 cs-roll
                    601:     POSTPONE then ; immediate restrict
                    602: 
                    603: 
                    604: : BEGIN ( -- dest )
                    605:     dead-code @ if
1.22      anton     606:        \ set up an assumption of the locals visible here.  if the
                    607:        \ users want something to be visible, they have to declare
                    608:        \ that using ASSUME-LIVE
                    609:        backedge-locals @ set-locals-size-list
1.8       anton     610:     then
                    611:     cs-push-part dest
                    612:     dead-code off ; immediate restrict
                    613: 
                    614: \ AGAIN (the current control flow joins another, earlier one):
                    615: \ If the dest-locals-list is not a subset of the current locals-list,
                    616: \ issue a warning (see below). The following code is generated:
                    617: \ lp+!# (current-local-size - dest-locals-size)
                    618: \ branch <begin>
                    619: : AGAIN ( dest -- )
                    620:     dest?
                    621:     over list-size adjust-locals-size
                    622:     POSTPONE branch
                    623:     <resolve
                    624:     check-begin
1.22      anton     625:     POSTPONE unreachable ; immediate restrict
1.8       anton     626: 
                    627: \ UNTIL (the current control flow may join an earlier one or continue):
                    628: \ Similar to AGAIN. The new locals-list and locals-size are the current
                    629: \ ones. The following code is generated:
                    630: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
                    631: : until-like ( list addr xt1 xt2 -- )
                    632:     \ list and addr are a fragment of a cs-item
                    633:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
                    634:     >r >r
                    635:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
                    636:        r> drop r> compile,
                    637:        swap <resolve ( list adjustment ) ,
                    638:     else ( list dest-addr adjustment )
                    639:        drop
                    640:        r> compile, <resolve
                    641:        r> drop
                    642:     then ( list )
                    643:     check-begin ;
                    644: 
                    645: : UNTIL ( dest -- )
                    646:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
                    647: 
                    648: : WHILE ( dest -- orig dest )
                    649:     POSTPONE if
                    650:     1 cs-roll ; immediate restrict
                    651: 
                    652: : REPEAT ( orig dest -- )
                    653:     POSTPONE again
                    654:     POSTPONE then ; immediate restrict
                    655: 
                    656: 
                    657: \ counted loops
                    658: 
                    659: \ leave poses a little problem here
                    660: \ we have to store more than just the address of the branch, so the
                    661: \ traditional linked list approach is no longer viable.
                    662: \ This is solved by storing the information about the leavings in a
1.9       pazsan    663: \ special stack.
1.8       anton     664: 
                    665: \ !! remove the fixed size limit. 'Tis not hard.
                    666: 20 constant leave-stack-size
1.9       pazsan    667: create leave-stack  60 cells allot
                    668: Avariable leave-sp  leave-stack 3 cells + leave-sp !
1.8       anton     669: 
                    670: : clear-leave-stack ( -- )
                    671:     leave-stack leave-sp ! ;
                    672: 
                    673: \ : leave-empty? ( -- f )
                    674: \  leave-sp @ leave-stack = ;
                    675: 
                    676: : >leave ( orig -- )
                    677:     \ push on leave-stack
                    678:     leave-sp @
                    679:     dup [ leave-stack 60 cells + ] Aliteral
                    680:     >= abort" leave-stack full"
                    681:     tuck ! cell+
                    682:     tuck ! cell+
                    683:     tuck ! cell+
                    684:     leave-sp ! ;
                    685: 
                    686: : leave> ( -- orig )
                    687:     \ pop from leave-stack
                    688:     leave-sp @
1.9       pazsan    689:     dup leave-stack <= IF
                    690:        drop 0 0 0  EXIT  THEN
1.8       anton     691:     cell - dup @ swap
                    692:     cell - dup @ swap
                    693:     cell - dup @ swap
                    694:     leave-sp ! ;
                    695: 
1.9       pazsan    696: : DONE ( orig -- )  drop >r drop
1.8       anton     697:     \ !! the original done had ( addr -- )
                    698:     begin
                    699:        leave>
1.9       pazsan    700:        over r@ u>=
1.8       anton     701:     while
                    702:        POSTPONE then
                    703:     repeat
1.9       pazsan    704:     >leave rdrop ; immediate restrict
1.8       anton     705: 
                    706: : LEAVE ( -- )
                    707:     POSTPONE ahead
1.9       pazsan    708:     >leave ; immediate restrict
1.8       anton     709: 
                    710: : ?LEAVE ( -- )
                    711:     POSTPONE 0= POSTPONE if
1.9       pazsan    712:     >leave ; immediate restrict
1.8       anton     713: 
                    714: : DO ( -- do-sys )
                    715:     POSTPONE (do)
                    716:     POSTPONE begin drop do-dest
1.9       pazsan    717:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     718: 
                    719: : ?DO ( -- do-sys )
1.9       pazsan    720:     ( 0 0 0 >leave )
1.8       anton     721:     POSTPONE (?do)
                    722:     >mark >leave
1.9       pazsan    723:     POSTPONE begin drop do-dest ; immediate restrict
1.8       anton     724: 
                    725: : FOR ( -- do-sys )
                    726:     POSTPONE (for)
                    727:     POSTPONE begin drop do-dest
1.9       pazsan    728:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     729: 
                    730: \ LOOP etc. are just like UNTIL
                    731: 
                    732: : loop-like ( do-sys xt1 xt2 -- )
1.9       pazsan    733:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
1.8       anton     734:     until-like  POSTPONE done  POSTPONE unloop ;
                    735: 
                    736: : LOOP ( do-sys -- )
1.9       pazsan    737:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
1.8       anton     738: 
                    739: : +LOOP ( do-sys -- )
1.9       pazsan    740:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
1.8       anton     741: 
                    742: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
                    743: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
                    744: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
                    745: \ negative increments.
                    746: : S+LOOP ( do-sys -- )
1.9       pazsan    747:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
1.5       anton     748: 
1.8       anton     749: : NEXT ( do-sys -- )
1.9       pazsan    750:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
1.1       anton     751: 
                    752: \ Structural Conditionals                              12dec92py
                    753: 
1.8       anton     754: : EXIT ( -- )
                    755:     0 adjust-locals-size
                    756:     POSTPONE ;s
1.22      anton     757:     POSTPONE unreachable ; immediate restrict
1.1       anton     758: 
1.8       anton     759: : ?EXIT ( -- )
                    760:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
1.1       anton     761: 
                    762: \ Strings                                              22feb93py
                    763: 
                    764: : ," ( "string"<"> -- ) [char] " parse
                    765:   here over char+ allot  place align ;
                    766: : "lit ( -- addr )
                    767:   r> r> dup count + aligned >r swap >r ;               restrict
                    768: : (.")     "lit count type ;                           restrict
                    769: : (S")     "lit count ;                                restrict
                    770: : SLiteral postpone (S") here over char+ allot  place align ;
                    771:                                              immediate restrict
                    772: : S"       [char] " parse  state @ IF  postpone SLiteral  THEN ;
                    773:                                              immediate
                    774: : ."       state @  IF    postpone (.") ,"  align
                    775:                     ELSE  [char] " parse type  THEN  ;  immediate
                    776: : (        [char] ) parse 2drop ;                       immediate
1.17      pazsan    777: : \        blk @ IF  >in @ c/l / 1+ c/l * >in !  EXIT  THEN
                    778:            source >in ! drop ;                          immediate
1.1       anton     779: 
                    780: \ error handling                                       22feb93py
                    781: \ 'abort thrown out!                                   11may93jaw
                    782: 
                    783: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
                    784:                 rdrop ;
                    785: : abort"        postpone (abort") ," ;        immediate restrict
                    786: 
                    787: \ Header states                                        23feb93py
                    788: 
1.10      anton     789: : flag! ( 8b -- )
                    790:     last @ dup 0= abort" last word was headerless"
                    791:     cell+ tuck c@ xor swap c! ;
1.1       anton     792: : immediate     $20 flag! ;
1.9       pazsan    793: : restrict      $40 flag! ;
                    794: \ ' noop alias restrict
1.1       anton     795: 
                    796: \ Header                                               23feb93py
                    797: 
                    798: \ input-stream, nextname and noname are quite ugly (passing
                    799: \ information through global variables), but they are useful for dealing
                    800: \ with existing/independent defining words
                    801: 
1.20      pazsan    802: defer (header)
                    803: defer header     ' (header) IS header
1.1       anton     804: 
                    805: : name,  ( "name" -- )
1.20      pazsan    806:     name
1.12      pazsan    807:     dup $1F u> -&19 and throw ( is name too long? )
1.20      pazsan    808:     dup c,  here swap chars  dup allot  move  align ;
1.1       anton     809: : input-stream-header ( "name" -- )
                    810:     \ !! this is f83-implementation-dependent
                    811:     align here last !  -1 A,
                    812:     name, $80 flag! ;
                    813: 
                    814: : input-stream ( -- )  \ general
                    815: \ switches back to getting the name from the input stream ;
1.20      pazsan    816:     ['] input-stream-header IS (header) ;
1.1       anton     817: 
1.20      pazsan    818: ' input-stream-header IS (header)
1.1       anton     819: 
                    820: \ !! make that a 2variable
1.5       anton     821: create nextname-buffer 32 chars allot
1.1       anton     822: 
                    823: : nextname-header ( -- )
                    824:     \ !! f83-implementation-dependent
1.5       anton     825:     nextname-buffer count
1.1       anton     826:     align here last ! -1 A,
                    827:     dup c,  here swap chars  dup allot  move  align
                    828:     $80 flag!
                    829:     input-stream ;
                    830: 
                    831: \ the next name is given in the string
                    832: : nextname ( c-addr u -- ) \ general
1.12      pazsan    833:     dup $1F u> -&19 and throw ( is name too long? )
1.5       anton     834:     nextname-buffer c! ( c-addr )
                    835:     nextname-buffer count move
1.20      pazsan    836:     ['] nextname-header IS (header) ;
1.1       anton     837: 
                    838: : noname-header ( -- )
                    839:     0 last !
                    840:     input-stream ;
                    841: 
                    842: : noname ( -- ) \ general
                    843: \ the next defined word remains anonymous. The xt of that word is given by lastxt
1.20      pazsan    844:     ['] noname-header IS (header) ;
1.1       anton     845: 
                    846: : lastxt ( -- xt ) \ general
                    847: \ 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
                    848:     lastcfa @ ;
                    849: 
                    850: : Alias    ( cfa "name" -- )
                    851:   Header reveal , $80 flag! ;
                    852: 
                    853: : name>string ( nfa -- addr count )
                    854:  cell+ count $1F and ;
                    855: 
1.9       pazsan    856: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
1.1       anton     857: : >name ( cfa -- nfa )
                    858:  $21 cell do
                    859:    dup i - count $9F and + aligned over $80 + = if
                    860:      i - cell - unloop exit
                    861:    then
                    862:  cell +loop
                    863:  drop ??? ( wouldn't 0 be better? ) ;
                    864: 
                    865: \ indirect threading                                   17mar93py
                    866: 
                    867: : cfa,     ( code-address -- )
                    868:     here lastcfa !
                    869:     here  0 A, 0 ,  code-address! ;
                    870: : compile, ( xt -- )           A, ;
                    871: : !does    ( addr -- )         lastcfa @ does-code! ;
                    872: : (;code)  ( R: addr -- )      r> /does-handler + !does ;
                    873: : dodoes,  ( -- )
                    874:   here /does-handler allot does-handler! ;
                    875: 
                    876: \ direct threading is implementation dependent
                    877: 
1.4       pazsan    878: : Create    Header reveal [ :dovar ] Literal cfa, ;
1.1       anton     879: 
                    880: \ DOES>                                                17mar93py
                    881: 
1.5       anton     882: : DOES>  ( compilation: -- )
                    883:     state @
                    884:     IF
                    885:        ;-hook postpone (;code) dodoes,
                    886:     ELSE
                    887:        dodoes, here !does 0 ]
                    888:     THEN 
                    889:     :-hook ; immediate
1.1       anton     890: 
                    891: \ Create Variable User Constant                        17mar93py
                    892: 
                    893: : Variable  Create 0 , ;
                    894: : AVariable Create 0 A, ;
                    895: : 2VARIABLE ( "name" -- ) \ double
                    896:     create 0 , 0 , ;
                    897:     
                    898: : User      Variable ;
                    899: : AUser     AVariable ;
                    900: 
1.4       pazsan    901: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
1.1       anton     902: : Constant  (Constant) , ;
                    903: : AConstant (Constant) A, ;
1.5       anton     904: 
                    905: : 2CONSTANT
                    906:     create ( w1 w2 "name" -- )
                    907:         2,
                    908:     does> ( -- w1 w2 )
                    909:         2@ ;
1.1       anton     910:     
                    911: \ IS Defer What's Defers TO                            24feb93py
                    912: 
1.15      anton     913: : Defer ( -- )
                    914:     \ !! shouldn't it be initialized with abort or something similar?
                    915:     Header Reveal [ :dodefer ] Literal cfa,
                    916:     ['] noop A, ;
                    917: \     Create ( -- ) 
                    918: \      ['] noop A,
                    919: \     DOES> ( ??? )
                    920: \      @ execute ;
1.1       anton     921: 
                    922: : IS ( addr "name" -- )
                    923:     ' >body
                    924:     state @
                    925:     IF    postpone ALiteral postpone !  
                    926:     ELSE  !
                    927:     THEN ;  immediate
                    928: ' IS Alias TO immediate
                    929: 
                    930: : What's ( "name" -- addr )  ' >body
                    931:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
                    932:                                              immediate
                    933: : Defers ( "name" -- )  ' >body @ compile, ;
1.12      pazsan    934:                                              immediate
1.1       anton     935: 
                    936: \ : ;                                                  24feb93py
                    937: 
1.5       anton     938: defer :-hook ( sys1 -- sys2 )
                    939: defer ;-hook ( sys2 -- sys1 )
                    940: 
1.8       anton     941: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
1.5       anton     942: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
1.1       anton     943:   immediate restrict
1.5       anton     944: 
1.10      anton     945: : :noname ( -- xt colon-sys )
                    946:     0 last !
                    947:     here [ :docol ] Literal cfa, 0 ] :-hook ;
1.1       anton     948: 
                    949: \ Search list handling                                 23feb93py
                    950: 
                    951: AVariable current
                    952: 
                    953: : last?   ( -- false / nfa nfa )    last @ ?dup ;
1.5       anton     954: : (reveal) ( -- )
                    955:   last?
                    956:   IF
                    957:       dup @ 0<
                    958:       IF
                    959:        current @ @ over ! current @ !
                    960:       ELSE
                    961:        drop
                    962:       THEN
                    963:   THEN ;
1.1       anton     964: 
                    965: \ object oriented search list                          17mar93py
                    966: 
1.5       anton     967: \ word list structure:
                    968: \ struct
1.7       pazsan    969: \   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
1.5       anton     970: \   1 cells: field reveal-method \ xt: ( -- )
1.7       pazsan    971: \   1 cells: field rehash-method \ xt: ( wid -- )
1.5       anton     972: \   \ !! what else
                    973: \ end-struct wordlist-map-struct
                    974: 
                    975: \ struct
                    976: \   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
                    977: \   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
1.7       pazsan    978: \   1 cells: field wordlist-link \ link field to other wordlists
                    979: \   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
1.5       anton     980: \ end-struct wordlist-struct
                    981: 
1.7       pazsan    982: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
1.5       anton     983: 
1.1       anton     984: \ Search list table: find reveal
1.12      pazsan    985: Create f83search       ' f83find A,  ' (reveal) A,  ' drop A,
1.7       pazsan    986: 
1.1       anton     987: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
1.18      pazsan    988: AVariable lookup       G forth-wordlist lookup T !
1.1       anton     989: G forth-wordlist current T !
                    990: 
                    991: : (search-wordlist)  ( addr count wid -- nfa / false )
1.18      pazsan    992:   dup cell+ @ @ execute ;
1.1       anton     993: 
                    994: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
                    995:   (search-wordlist) dup  IF  found  THEN ;
                    996: 
                    997: Variable warnings  G -1 warnings T !
                    998: 
                    999: : check-shadow  ( addr count wid -- )
                   1000: \ prints a warning if the string is already present in the wordlist
                   1001: \ !! should be refined so the user can suppress the warnings
                   1002:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
                   1003:    ." redefined " name>string 2dup type
                   1004:    compare 0<> if
                   1005:      ."  with " type
                   1006:    else
                   1007:      2drop
                   1008:    then
                   1009:    space space EXIT
                   1010:  then
                   1011:  2drop 2drop ;
                   1012: 
1.15      anton    1013: : sfind ( c-addr u -- xt n / 0 )
1.18      pazsan   1014:     lookup @ search-wordlist ;
1.15      anton    1015: 
                   1016: : find   ( addr -- cfa +-1 / string false )
                   1017:     \ !! not ANS conformant: returns +-2 for restricted words
                   1018:     dup count sfind dup if
                   1019:        rot drop
                   1020:     then ;
1.1       anton    1021: 
                   1022: : reveal ( -- )
                   1023:  last? if
                   1024:    name>string current @ check-shadow
                   1025:  then
                   1026:  current @ cell+ @ cell+ @ execute ;
1.7       pazsan   1027: 
                   1028: : rehash  ( wid -- )  dup cell+ @ cell+ cell+ @ execute ;
1.1       anton    1029: 
1.20      pazsan   1030: : '    ( "name" -- addr )  name sfind 0= if -&13 bounce then ;
1.1       anton    1031: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
                   1032: \ Input                                                13feb93py
                   1033: 
                   1034: 07 constant #bell
                   1035: 08 constant #bs
1.16      anton    1036: 09 constant #tab
1.1       anton    1037: 7F constant #del
1.18      pazsan   1038: 0D constant #cr                \ the newline key code
1.17      pazsan   1039: 0C constant #ff
1.1       anton    1040: 0A constant #lf
                   1041: 
                   1042: : bell  #bell emit ;
                   1043: 
1.23      pazsan   1044: \ : backspaces  0 ?DO  #bs emit  LOOP ;
1.1       anton    1045: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
                   1046:   over 3 pick 2 pick chars /string ;
                   1047: : type-rest ( span addr pos1 -- span addr pos1 back )
                   1048:   >string tuck type ;
                   1049: : (del)  ( max span addr pos1 -- max span addr pos2 )
                   1050:   1- >string over 1+ -rot move
                   1051:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
                   1052: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
                   1053:   >r >string over 1+ swap move 2dup chars + r> swap c!
                   1054:   rot 1+ -rot type-rest 1- backspaces 1+ ;
                   1055: : ?del ( max span addr pos1 -- max span addr pos2 0 )
                   1056:   dup  IF  (del)  THEN  0 ;
                   1057: : (ret)  type-rest drop true space ;
                   1058: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
                   1059: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
                   1060: 
1.21      pazsan   1061: Create ctrlkeys
1.1       anton    1062:   ] false false back  false  false false forw  false
                   1063:     ?del  false (ret) false  false (ret) false false
                   1064:     false false false false  false false false false
                   1065:     false false false false  false false false false [
                   1066: 
1.21      pazsan   1067: defer everychar
                   1068: ' noop IS everychar
                   1069: 
1.1       anton    1070: : decode ( max span addr pos1 key -- max span addr pos2 flag )
1.21      pazsan   1071:   everychar
1.1       anton    1072:   dup #del = IF  drop #bs  THEN  \ del is rubout
1.21      pazsan   1073:   dup bl <   IF  cells ctrlkeys + @ execute  EXIT  THEN
1.1       anton    1074:   >r 2over = IF  rdrop bell 0 EXIT  THEN
                   1075:   r> (ins) 0 ;
                   1076: 
                   1077: \ decode should better use a table for control key actions
                   1078: \ to define keyboard bindings later
                   1079: 
                   1080: : accept   ( addr len -- len )
                   1081:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
                   1082: \ this allows to edit given strings
                   1083:          ELSE  0  THEN rot over
                   1084:   BEGIN  key decode  UNTIL
                   1085:   2drop nip ;
                   1086: 
                   1087: \ Output                                               13feb93py
                   1088: 
1.17      pazsan   1089: Defer type      \ defer type for a output buffer or fast
1.1       anton    1090:                 \ screen write
                   1091: 
1.9       pazsan   1092: \ : (type) ( addr len -- )
                   1093: \   bounds ?DO  I c@ emit  LOOP ;
1.1       anton    1094: 
1.17      pazsan   1095: ' (type) IS Type
1.1       anton    1096: 
1.17      pazsan   1097: Defer emit
1.1       anton    1098: 
1.9       pazsan   1099: ' (Emit) IS Emit
1.1       anton    1100: 
1.17      pazsan   1101: Defer key
                   1102: ' (key) IS key
                   1103: 
1.1       anton    1104: \ : form  ( -- rows cols )  &24 &80 ;
                   1105: \ form should be implemented using TERMCAPS or CURSES
                   1106: \ : rows  form drop ;
                   1107: \ : cols  form nip  ;
                   1108: 
                   1109: \ Query                                                07apr93py
                   1110: 
                   1111: : refill ( -- flag )
1.17      pazsan   1112:   blk @  IF  1 blk +!  true  EXIT  THEN
1.1       anton    1113:   tib /line
                   1114:   loadfile @ ?dup
1.17      pazsan   1115:   IF    read-line throw
1.12      pazsan   1116:   ELSE  loadline @ 0< IF 2drop false EXIT THEN
1.1       anton    1117:         accept true
                   1118:   THEN
                   1119:   1 loadline +!
1.10      anton    1120:   swap #tib ! 0 >in ! ;
1.1       anton    1121: 
1.17      pazsan   1122: : Query  ( -- )  loadfile off  blk off  refill drop ;
1.1       anton    1123: 
                   1124: \ File specifiers                                       11jun93jaw
                   1125: 
                   1126: 
                   1127: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
                   1128: \ 2 c, here char r c, char + c, 0 c,
                   1129: \ 2 c, here char w c, char + c, 0 c, align
                   1130: 4 Constant w/o
                   1131: 2 Constant r/w
                   1132: 0 Constant r/o
                   1133: 
                   1134: \ BIN WRITE-LINE                                        11jun93jaw
                   1135: 
                   1136: \ : bin           dup 1 chars - c@
                   1137: \                 r/o 4 chars + over - dup >r swap move r> ;
                   1138: 
                   1139: : bin  1+ ;
                   1140: 
                   1141: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
                   1142:                            \ or not unix environments if
                   1143:                            \ bin is not selected
                   1144: 
                   1145: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
                   1146:                 nl$ count r> write-file ;
                   1147: 
                   1148: \ include-file                                         07apr93py
                   1149: 
1.12      pazsan   1150: : push-file  ( -- )  r>
1.17      pazsan   1151:   loadline @ >r loadfile @ >r
1.12      pazsan   1152:   blk @ >r >tib @ >r  #tib @ dup >r  >tib +!  >in @ >r  >r ;
                   1153: 
1.18      pazsan   1154: : pop-file   ( throw-code -- throw-code )
                   1155:   dup IF
                   1156:          source >in @ loadline @ loadfilename 2@
                   1157:         error-stack dup @ dup 1+
                   1158:         max-errors 1- min error-stack !
                   1159:         6 * cells + cell+
                   1160:         5 cells bounds swap DO
                   1161:                            I !
                   1162:         -1 cells +LOOP
                   1163:   THEN
                   1164:   r>
1.17      pazsan   1165:   r> >in !  r> #tib !  r> >tib !  r> blk !
                   1166:   r> loadfile ! r> loadline !  >r ;
                   1167: 
                   1168: : read-loop ( i*x -- j*x )
                   1169:   BEGIN  refill  WHILE  interpret  REPEAT ;
1.12      pazsan   1170: 
1.1       anton    1171: : include-file ( i*x fid -- j*x )
1.12      pazsan   1172:   push-file  loadfile !
1.17      pazsan   1173:   0 loadline ! blk off  ['] read-loop catch
1.20      pazsan   1174:   loadfile @ close-file swap 2dup or
                   1175:   pop-file  drop throw throw ;
1.1       anton    1176: 
1.19      anton    1177: create pathfilenamebuf 256 chars allot \ !! make this grow on demand
                   1178: 
                   1179: : open-path-file ( c-addr1 u1 -- file-id c-addr2 u2 )
                   1180:     \ opens a file for reading, searching in the path for it; c-addr2
                   1181:     \ u2 is the full filename (valid until the next call); if the file
                   1182:     \ is not found (or in case of other errors for each try), -38
                   1183:     \ (non-existant file) is thrown. Opening for other access modes
                   1184:     \ makes little sense, as the path will usually contain dirs that
                   1185:     \ are only readable for the user
                   1186:     \ !! check for "/", "./", "../" in original filename; check for "~/"?
                   1187:     pathdirs 2@ 0
                   1188:     ?DO ( c-addr1 u1 dirnamep )
                   1189:        dup >r 2@ dup >r pathfilenamebuf swap cmove ( addr u )
                   1190:        2dup pathfilenamebuf r@ chars + swap cmove ( addr u )
                   1191:        pathfilenamebuf over r> + dup >r r/o open-file 0=
                   1192:        if ( addr u file-id )
                   1193:            nip nip r> rdrop 0 leave
                   1194:        then
                   1195:        rdrop drop r> cell+ cell+
                   1196:     LOOP
                   1197:     0<> -&38 and throw ( file-id u2 )
                   1198:     pathfilenamebuf swap ;
                   1199: 
1.27    ! anton    1200: create included-files 0 , 0 , ( pointer to and count of included files )
        !          1201: 
        !          1202: : included? ( c-addr u -- f )
        !          1203:     \ true, iff filename c-addr u is in included-files
        !          1204:     included-files 2@ 0
        !          1205:     ?do ( c-addr u addr )
        !          1206:        dup >r 2@ 2over compare 0=
        !          1207:        if
        !          1208:            2drop rdrop unloop
        !          1209:            true EXIT
        !          1210:        then
        !          1211:        r> cell+ cell+
        !          1212:     loop
        !          1213:     2drop drop false ;
        !          1214: 
        !          1215: : add-included-file ( c-addr u -- )
        !          1216:     \ add name c-addr u to included-files
        !          1217:     included-files 2@ tuck 1+ 2* cells resize throw
        !          1218:     swap 2dup 1+ included-files 2!
        !          1219:     2* cells + 2! ;
        !          1220: 
        !          1221: : save-string          ( addr1 u -- addr2 u )
        !          1222:     swap >r
        !          1223:     dup allocate throw
        !          1224:     swap 2dup r> -rot move ;
        !          1225: 
        !          1226: : included1 ( i*x file-id c-addr u -- j*x )
        !          1227:     \ include the file file-id with the name given by c-addr u
1.10      anton    1228:     loadfilename 2@ >r >r
1.27    ! anton    1229:     save-string 2dup loadfilename 2! add-included-file ( file-id )
1.20      pazsan   1230:     ['] include-file catch
                   1231:     r> r> loadfilename 2!  throw ;
1.27    ! anton    1232:     
        !          1233: : included ( i*x addr u -- j*x )
        !          1234:     open-path-file included1 ;
        !          1235: 
        !          1236: : required ( i*x addr u -- j*x )
        !          1237:     \ include the file with the name given by addr u, if it is not
        !          1238:     \ included already. Currently this works by comparing the name of
        !          1239:     \ the file (with path) against the names of earlier included
        !          1240:     \ files; however, it would probably be better to fstat the file,
        !          1241:     \ and compare the device and inode. The advantages would be: no
        !          1242:     \ problems with several paths to the same file (e.g., due to
        !          1243:     \ links) and we would catch files included with include-file and
        !          1244:     \ write a require-file.
        !          1245:     open-path-file 2dup included?
        !          1246:     if
        !          1247:        2drop close-file throw
        !          1248:     else
        !          1249:        included1
        !          1250:     then ;
1.1       anton    1251: 
                   1252: \ HEX DECIMAL                                           2may93jaw
                   1253: 
                   1254: : decimal a base ! ;
                   1255: : hex     10 base ! ;
                   1256: 
                   1257: \ DEPTH                                                 9may93jaw
                   1258: 
                   1259: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
1.21      pazsan   1260: : clearstack ( ... -- )  s0 @ sp! ;
1.1       anton    1261: 
                   1262: \ INCLUDE                                               9may93jaw
                   1263: 
1.6       pazsan   1264: : include  ( "file" -- )
1.20      pazsan   1265:   name included ;
1.27    ! anton    1266: 
        !          1267: : require  ( "file" -- )
        !          1268:   name required ;
1.1       anton    1269: 
                   1270: \ RECURSE                                               17may93jaw
                   1271: 
1.10      anton    1272: : recurse ( -- )
                   1273:     lastxt compile, ; immediate restrict
                   1274: : recursive ( -- )
                   1275:     reveal ; immediate
1.1       anton    1276: 
                   1277: \ */MOD */                                              17may93jaw
                   1278: 
1.13      anton    1279: \ !! I think */mod should have the same rounding behaviour as / - anton
1.1       anton    1280: : */mod >r m* r> sm/rem ;
                   1281: 
                   1282: : */ */mod nip ;
                   1283: 
                   1284: \ EVALUATE                                              17may93jaw
                   1285: 
                   1286: : evaluate ( c-addr len -- )
1.12      pazsan   1287:   push-file  dup #tib ! >tib @ swap move
                   1288:   >in off blk off loadfile off -1 loadline !
1.1       anton    1289: 
1.17      pazsan   1290: \  BEGIN  interpret  >in @ #tib @ u>= UNTIL
                   1291:   ['] interpret catch
                   1292:   pop-file throw ;
1.1       anton    1293: 
                   1294: 
                   1295: : abort -1 throw ;
                   1296: 
                   1297: \+ environment? true ENV" CORE"
                   1298: \ core wordset is now complete!
                   1299: 
                   1300: \ Quit                                                 13feb93py
                   1301: 
                   1302: Defer 'quit
                   1303: Defer .status
                   1304: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
                   1305: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
                   1306: ' (quit) IS 'quit
                   1307: 
                   1308: \ DOERROR (DOERROR)                                     13jun93jaw
                   1309: 
1.18      pazsan   1310: 8 Constant max-errors
                   1311: Variable error-stack  0 error-stack !
                   1312: max-errors 6 * cells allot
                   1313: \ format of one cell:
                   1314: \ source ( addr u )
                   1315: \ >in
                   1316: \ line-number
                   1317: \ Loadfilename ( addr u )
                   1318: 
1.10      anton    1319: : dec. ( n -- )
                   1320:     \ print value in decimal representation
                   1321:     base @ decimal swap . base ! ;
                   1322: 
                   1323: : typewhite ( addr u -- )
                   1324:     \ like type, but white space is printed instead of the characters
1.18      pazsan   1325:     bounds ?do
                   1326:        i c@ 9 = if \ check for tab
1.10      anton    1327:            9
                   1328:        else
                   1329:            bl
                   1330:        then
                   1331:        emit
                   1332:     loop
1.18      pazsan   1333: ;
1.10      anton    1334: 
1.1       anton    1335: DEFER DOERROR
                   1336: 
1.18      pazsan   1337: : .error-frame ( addr1 u1 n1 n2 addr2 u2 -- )
                   1338:   cr error-stack @
                   1339:   IF
                   1340:      ." in file included from "
                   1341:      type ." :" dec.  drop 2drop
                   1342:   ELSE
                   1343:      type ." :" dec.
                   1344:      cr dup 2over type cr drop
1.20      pazsan   1345:      nip -trailing 1- ( line-start index2 )
1.18      pazsan   1346:      0 >r  BEGIN
1.20      pazsan   1347:                   2dup + c@ bl >  WHILE
                   1348:                  r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
1.18      pazsan   1349:      ( line-start index1 )
                   1350:      typewhite
                   1351:      r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
                   1352:                   [char] ^ emit
                   1353:      loop
                   1354:   THEN
                   1355: ;
                   1356: 
1.1       anton    1357: : (DoError) ( throw-code -- )
1.18      pazsan   1358:   loadline @ IF
                   1359:                source >in @ loadline @ 0 0 .error-frame
                   1360:   THEN
                   1361:   error-stack @ 0 ?DO
                   1362:     -1 error-stack +!
                   1363:     error-stack dup @ 6 * cells + cell+
                   1364:     6 cells bounds DO
                   1365:       I @
                   1366:     cell +LOOP
                   1367:     .error-frame
                   1368:   LOOP
                   1369:   dup -2 =
                   1370:   IF 
                   1371:      "error @ ?dup
                   1372:      IF
                   1373:         cr count type 
                   1374:      THEN
                   1375:      drop
                   1376:   ELSE
                   1377:      .error
                   1378:   THEN
                   1379:   normal-dp dpp ! ;
1.1       anton    1380: 
                   1381: ' (DoError) IS DoError
                   1382: 
                   1383: : quit   r0 @ rp! handler off >tib @ >r
1.5       anton    1384:   BEGIN
                   1385:     postpone [
                   1386:     ['] 'quit CATCH dup
                   1387:   WHILE
                   1388:     DoError r@ >tib !
                   1389:   REPEAT
                   1390:   drop r> >tib ! ;
1.1       anton    1391: 
                   1392: \ Cold                                                 13feb93py
                   1393: 
                   1394: \ : .name ( name -- ) cell+ count $1F and type space ;
                   1395: \ : words  listwords @
                   1396: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
                   1397: 
1.19      anton    1398: : cstring>sstring  ( cstring -- addr n )  -1 0 scan 0 swap 1+ /string ;
                   1399: : arg ( n -- addr count )  cells argv @ + @ cstring>sstring ;
1.1       anton    1400: : #!       postpone \ ;  immediate
                   1401: 
1.19      anton    1402: Create pathstring 2 cells allot \ string
                   1403: Create pathdirs   2 cells allot \ dir string array, pointer and count
1.1       anton    1404: Variable argv
                   1405: Variable argc
                   1406: 
1.12      pazsan   1407: 0 Value script? ( -- flag )
                   1408: 
1.19      anton    1409: : process-path ( addr1 u1 -- addr2 u2 )
                   1410:     \ addr1 u1 is a path string, addr2 u2 is an array of dir strings
                   1411:     here >r
                   1412:     BEGIN
                   1413:        over >r [char] : scan
                   1414:        over r> tuck - ( rest-str this-str )
                   1415:        dup
                   1416:        IF
                   1417:            2dup 1- chars + c@ [char] / <>
                   1418:            IF
                   1419:                2dup chars + [char] / swap c!
                   1420:                1+
                   1421:            THEN
                   1422:            2,
                   1423:        ELSE
                   1424:            2drop
                   1425:        THEN
                   1426:        dup
                   1427:     WHILE
                   1428:        1 /string
                   1429:     REPEAT
                   1430:     2drop
                   1431:     here r> tuck - 2 cells / ;
                   1432: 
1.12      pazsan   1433: : do-option ( addr1 len1 addr2 len2 -- n )  2swap
                   1434:   2dup s" -e"        compare  0= >r
                   1435:   2dup s" -evaluate" compare  0= r> or
1.25      pazsan   1436:   IF  2drop dup >r ['] evaluate catch
                   1437:       ?dup IF  dup >r DoError r> negate (bye)  THEN
                   1438:       r> >tib +!  2 EXIT  THEN
1.12      pazsan   1439:   ." Unknown option: " type cr 2drop 1 ;
                   1440: 
1.25      pazsan   1441: : process-args ( -- )  >tib @ >r
1.19      anton    1442:     argc @ 1
                   1443:     ?DO
                   1444:        I arg over c@ [char] - <>
                   1445:        IF
                   1446:            true to script? included  false to script? 1
                   1447:        ELSE
                   1448:            I 1+ arg  do-option
                   1449:        THEN
1.25      pazsan   1450:     +LOOP
                   1451:     r> >tib ! ;
1.1       anton    1452: 
1.24      pazsan   1453: Defer 'cold ' noop IS 'cold
                   1454: 
1.19      anton    1455: : cold ( -- )
1.25      pazsan   1456:     pathstring 2@ process-path pathdirs 2!
1.24      pazsan   1457:     'cold
1.10      anton    1458:     argc @ 1 >
1.12      pazsan   1459:     IF
                   1460:        ['] process-args catch ?dup
1.10      anton    1461:        IF
1.12      pazsan   1462:            dup >r DoError cr r> negate (bye)
1.10      anton    1463:        THEN
                   1464:     THEN
1.13      anton    1465:     cr
                   1466:     ." GNU Forth 0.0alpha, Copyright (C) 1994 Free Software Foundation, Inc." cr
                   1467:     ." GNU Forth comes with ABSOLUTELY NO WARRANTY; for details type `license'" cr
                   1468:     ." Type `bye' to exit"
1.26      pazsan   1469:     loadline off quit ;
1.1       anton    1470: 
1.12      pazsan   1471: : license ( -- ) cr
                   1472:  ." This program is free software; you can redistribute it and/or modify" cr
                   1473:  ." it under the terms of the GNU General Public License as published by" cr
1.13      anton    1474:  ." the Free Software Foundation; either version 2 of the License, or" cr
                   1475:  ." (at your option) any later version." cr cr
1.12      pazsan   1476: 
                   1477:  ." This program is distributed in the hope that it will be useful," cr
                   1478:  ." but WITHOUT ANY WARRANTY; without even the implied warranty of" cr
                   1479:  ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" cr
                   1480:  ." GNU General Public License for more details." cr cr
                   1481: 
                   1482:  ." You should have received a copy of the GNU General Public License" cr
                   1483:  ." along with this program; if not, write to the Free Software" cr
                   1484:  ." Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA." cr ;
                   1485: 
1.19      anton    1486: : boot ( path **argv argc -- )
                   1487:   argc ! argv ! cstring>sstring pathstring 2!  main-task up!
1.25      pazsan   1488:   sp@ dup s0 ! $10 + >tib ! #tib off >in off
                   1489:   rp@ r0 !  fp@ f0 !  cold ;
1.1       anton    1490: 
1.12      pazsan   1491: : bye  script? 0= IF  cr  THEN  0 (bye) ;
1.1       anton    1492: 
                   1493: \ **argv may be scanned by the C starter to get some important
                   1494: \ information, as -display and -geometry for an X client FORTH
                   1495: \ or space and stackspace overrides
                   1496: 
                   1497: \ 0 arg contains, however, the name of the program.

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