Annotation of gforth/kernal.fs, revision 1.39

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: 
1.28      anton      69: \ !! this is machine-dependent, but works on all but the strangest machines
                     70: ' faligned Alias maxaligned
                     71: ' falign Alias maxalign
                     72: 
                     73: \ the code field is aligned if its body is maxaligned
                     74: \ !! machine-dependent and won't work if "0 >body" <> "0 >body maxaligned"
                     75: ' maxaligned Alias cfaligned
                     76: ' maxalign Alias cfalign
                     77: 
1.22      anton      78: : chars ; immediate
1.8       anton      79: 
1.1       anton      80: : A!    ( addr1 addr2 -- )  dup relon ! ;
                     81: : A,    ( addr -- )     here cell allot A! ;
                     82: 
                     83: \ on off                                               23feb93py
                     84: 
                     85: : on  ( addr -- )  true  swap ! ;
                     86: : off ( addr -- )  false swap ! ;
                     87: 
                     88: \ name> found                                          17dec92py
                     89: 
1.28      anton      90: : (name>)  ( nfa -- cfa )
                     91:     count  $1F and  +  cfaligned ;
                     92: : name>    ( nfa -- cfa )
                     93:     cell+
                     94:     dup  (name>) swap  c@ $80 and 0= IF  @ THEN ;
1.1       anton      95: 
                     96: : found ( nfa -- cfa n )  cell+
                     97:   dup c@ >r  (name>) r@ $80 and  0= IF  @       THEN
1.9       pazsan     98:                   -1 r@ $40 and     IF  1-      THEN
                     99:                      r> $20 and     IF  negate  THEN  ;
1.1       anton     100: 
                    101: \ (find)                                               17dec92py
                    102: 
                    103: \ : (find) ( addr count nfa1 -- nfa2 / false )
                    104: \   BEGIN  dup  WHILE  dup >r
                    105: \          cell+ count $1F and dup >r 2over r> =
                    106: \          IF  -text  0= IF  2drop r> EXIT  THEN
                    107: \          ELSE  2drop drop  THEN  r> @
                    108: \   REPEAT nip nip ;
                    109: 
                    110: \ place bounds                                         13feb93py
                    111: 
                    112: : place  ( addr len to -- ) over >r  rot over 1+  r> move c! ;
                    113: : bounds ( beg count -- end beg )  over + swap ;
                    114: 
                    115: \ input stream primitives                              23feb93py
                    116: 
                    117: : tib   >tib @ ;
                    118: Defer source
                    119: : (source) ( -- addr count ) tib #tib @ ;
                    120: ' (source) IS source
                    121: 
                    122: \ (word)                                               22feb93py
                    123: 
1.19      anton     124: : scan   ( addr1 n1 char -- addr2 n2 )
                    125:     \ skip all characters not 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 ;
                    135: : skip   ( addr1 n1 char -- addr2 n2 )
                    136:     \ skip all characters equal to char
                    137:     >r
                    138:     BEGIN
                    139:        dup
                    140:     WHILE
                    141:        over c@ r@  =
                    142:     WHILE
                    143:        1 /string
                    144:     REPEAT  THEN
                    145:     rdrop ;
1.1       anton     146: 
                    147: : (word) ( addr1 n1 char -- addr2 n2 )
                    148:   dup >r skip 2dup r> scan  nip - ;
                    149: 
                    150: \ (word) should fold white spaces
                    151: \ this is what (parse-white) does
                    152: 
                    153: \ word parse                                           23feb93py
                    154: 
                    155: : parse-word  ( char -- addr len )
1.35      anton     156:   source 2dup >r >r >in @ over min /string
1.1       anton     157:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
                    158:   2dup + r> - 1+ r> min >in ! ;
                    159: : word   ( char -- addr )
                    160:   parse-word here place  bl here count + c!  here ;
                    161: 
                    162: : parse    ( char -- addr len )
1.35      anton     163:   >r  source  >in @ over min /string  over  swap r>  scan >r
1.1       anton     164:   over - dup r> IF 1+ THEN  >in +! ;
                    165: 
                    166: \ name                                                 13feb93py
                    167: 
1.20      pazsan    168: : capitalize ( addr len -- addr len )
                    169:   2dup chars chars bounds
1.1       anton     170:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
1.20      pazsan    171: : (name) ( -- c-addr count )
1.15      anton     172:     source 2dup >r >r >in @ /string (parse-white)
                    173:     2dup + r> - 1+ r> min >in ! ;
                    174: \    name count ;
1.1       anton     175: 
1.35      anton     176: : name-too-short? ( c-addr u -- c-addr u )
                    177:     dup 0= -&16 and throw ;
                    178: 
                    179: : name-too-long? ( c-addr u -- c-addr u )
                    180:     dup $1F u> -&19 and throw ;
                    181: 
1.1       anton     182: \ Literal                                              17dec92py
                    183: 
1.8       anton     184: : Literal  ( n -- )  state @ IF postpone lit  , THEN ;
1.1       anton     185:                                                       immediate
1.8       anton     186: : ALiteral ( n -- )  state @ IF postpone lit A, THEN ;
1.1       anton     187:                                                       immediate
                    188: 
                    189: : char   ( 'char' -- n )  bl word char+ c@ ;
                    190: : [char] ( 'char' -- n )  char postpone Literal ; immediate
                    191: ' [char] Alias Ascii immediate
                    192: 
1.22      anton     193: : (compile) ( -- )  r> dup cell+ >r @ compile, ;
1.1       anton     194: : postpone ( "name" -- )
1.20      pazsan    195:   name sfind dup 0= abort" Can't compile "
1.22      anton     196:   0> IF  compile,  ELSE  postpone (compile) A,  THEN ;
1.1       anton     197:                                              immediate restrict
                    198: 
                    199: \ Use (compile) for the old behavior of compile!
                    200: 
                    201: \ digit?                                               17dec92py
                    202: 
                    203: : digit?   ( char -- digit true/ false )
1.8       anton     204:   base @ $100 =
                    205:   IF
                    206:     true EXIT
                    207:   THEN
1.1       anton     208:   toupper [char] 0 - dup 9 u> IF
                    209:     [ 'A '9 1 + -  ] literal -
                    210:     dup 9 u<= IF
                    211:       drop false EXIT
                    212:     THEN
                    213:   THEN
                    214:   dup base @ u>= IF
                    215:     drop false EXIT
                    216:   THEN
                    217:   true ;
                    218: 
                    219: : accumulate ( +d0 addr digit - +d1 addr )
                    220:   swap >r swap  base @  um* drop rot  base @  um* d+ r> ;
                    221: : >number ( d addr count -- d addr count )
                    222:   0 ?DO  count digit? WHILE  accumulate  LOOP 0
                    223:   ELSE  1- I' I - UNLOOP  THEN ;
                    224: 
                    225: \ number? number                                       23feb93py
                    226: 
                    227: Create bases   10 ,   2 ,   A , 100 ,
                    228: \              16     2    10   Zeichen
                    229: \ !! this saving and restoring base is an abomination! - anton
                    230: : getbase ( addr u -- addr' u' )  over c@ [char] $ - dup 4 u<
                    231:   IF  cells bases + @ base ! 1 /string  ELSE  drop  THEN ;
1.12      pazsan    232: : s>number ( addr len -- d )  base @ >r  dpl on
                    233:   over c@ '- =  dup >r  IF  1 /string  THEN
1.1       anton     234:   getbase  dpl on  0 0 2swap
                    235:   BEGIN  dup >r >number dup  WHILE  dup r> -  WHILE
                    236:          dup dpl ! over c@ [char] . =  WHILE
                    237:          1 /string
1.12      pazsan    238:   REPEAT  THEN  2drop rdrop dpl off  ELSE
                    239:   2drop rdrop r> IF  dnegate  THEN
                    240:   THEN r> base ! ;
1.15      anton     241: : snumber? ( c-addr u -- 0 / n -1 / d 0> )
                    242:     s>number dpl @ 0=
                    243:     IF
                    244:        2drop false  EXIT
                    245:     THEN
                    246:     dpl @ dup 0> 0= IF
                    247:        nip
                    248:     THEN ;
1.12      pazsan    249: : number? ( string -- string 0 / n -1 / d 0> )
1.15      anton     250:     dup >r count snumber? dup if
                    251:        rdrop
                    252:     else
                    253:        r> swap
                    254:     then ;
1.1       anton     255: : s>d ( n -- d ) dup 0< ;
                    256: : number ( string -- d )
                    257:   number? ?dup 0= abort" ?"  0< IF s>d THEN ;
                    258: 
                    259: \ space spaces ud/mod                                  21mar93py
                    260: decimal
                    261: Create spaces  bl 80 times \ times from target compiler! 11may93jaw
                    262: DOES>   ( u -- )  swap
                    263:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.23      pazsan    264: Create backspaces  08 80 times \ times from target compiler! 11may93jaw
                    265: DOES>   ( u -- )  swap
                    266:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.1       anton     267: hex
                    268: : space   1 spaces ;
                    269: 
                    270: : ud/mod ( ud1 u2 -- urem udquot )  >r 0 r@ um/mod r> swap >r
                    271:                                     um/mod r> ;
                    272: 
                    273: : pad    ( -- addr )
                    274:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
                    275: 
                    276: \ hold <# #> sign # #s                                 25jan92py
                    277: 
                    278: : hold    ( char -- )         pad cell - -1 chars over +! @ c! ;
                    279: 
                    280: : <#                          pad cell - dup ! ;
                    281: 
                    282: : #>      ( 64b -- addr +n )  2drop pad cell - dup @ tuck - ;
                    283: 
                    284: : sign    ( n -- )            0< IF  [char] - hold  THEN ;
                    285: 
                    286: : #       ( +d1 -- +d2 )    base @ 2 max ud/mod rot 9 over <
                    287:   IF [ char A char 9 - 1- ] Literal +  THEN  [char] 0 + hold ;
                    288: 
                    289: : #s      ( +d -- 0 0 )         BEGIN  # 2dup d0=  UNTIL ;
                    290: 
                    291: \ print numbers                                        07jun92py
                    292: 
                    293: : d.r      >r tuck  dabs  <# #s  rot sign #>
                    294:            r> over - spaces  type ;
                    295: 
                    296: : ud.r     >r <# #s #> r> over - spaces type ;
                    297: 
                    298: : .r       >r s>d r> d.r ;
                    299: : u.r      0 swap ud.r ;
                    300: 
                    301: : d.       0 d.r space ;
                    302: : ud.      0 ud.r space ;
                    303: 
                    304: : .        s>d d. ;
                    305: : u.       0 ud. ;
                    306: 
                    307: \ catch throw                                          23feb93py
                    308: \ bounce                                                08jun93jaw
                    309: 
                    310: \ !! allow the user to add rollback actions    anton
                    311: \ !! use a separate exception stack?           anton
                    312: 
1.5       anton     313: : lp@ ( -- addr )
                    314:  laddr# [ 0 , ] ;
                    315: 
1.1       anton     316: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
1.5       anton     317:   >r sp@ r> swap >r       \ don't count xt! jaw
                    318:   fp@ >r
                    319:   lp@ >r
                    320:   handler @ >r
                    321:   rp@ handler !
                    322:   execute
1.6       pazsan    323:   r> handler ! rdrop rdrop rdrop 0 ;
                    324: 
1.5       anton     325: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
1.10      anton     326:     ?DUP IF
                    327:        [ here 4 cells ! ]
                    328:        handler @ rp!
                    329:        r> handler !
                    330:        r> lp!
                    331:        r> fp!
                    332:        r> swap >r sp! r>
                    333:     THEN ;
1.6       pazsan    334: 
1.1       anton     335: \ Bouncing is very fine,
                    336: \ programming without wasting time...   jaw
1.5       anton     337: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym )
                    338: \ a throw without data or fp stack restauration
                    339:   ?DUP IF
                    340:     handler @ rp!
                    341:     r> handler !
                    342:     r> lp!
                    343:     rdrop
                    344:     rdrop
                    345:   THEN ;
1.1       anton     346: 
                    347: \ ?stack                                               23feb93py
                    348: 
                    349: : ?stack ( ?? -- ?? )  sp@ s0 @ > IF  -4 throw  THEN ;
                    350: \ ?stack should be code -- it touches an empty stack!
                    351: 
                    352: \ interpret                                            10mar92py
                    353: 
                    354: Defer parser
                    355: Defer name      ' (name) IS name
1.15      anton     356: Defer notfound ( c-addr count -- )
1.1       anton     357: 
1.15      anton     358: : no.extensions  ( addr u -- )  2drop -&13 bounce ;
1.1       anton     359: 
                    360: ' no.extensions IS notfound
                    361: 
                    362: : interpret
1.15      anton     363:     BEGIN
1.20      pazsan    364:        ?stack name dup
1.15      anton     365:     WHILE
                    366:        parser
                    367:     REPEAT
                    368:     2drop ;
                    369: 
1.20      pazsan    370: \ interpreter compiler                                 30apr92py
1.15      anton     371: 
1.20      pazsan    372: : interpreter  ( c-addr u -- ) 
1.15      anton     373:     \ interpretation semantics for the name/number c-addr u
                    374:     2dup sfind dup
                    375:     IF
                    376:        1 and
                    377:        IF \ not restricted to compile state?
1.28      anton     378:            nip nip execute EXIT
1.15      anton     379:        THEN
                    380:        -&14 throw
                    381:     THEN
                    382:     drop
                    383:     2dup 2>r snumber?
                    384:     IF
                    385:        2rdrop
                    386:     ELSE
                    387:        2r> notfound
                    388:     THEN ;
1.1       anton     389: 
1.20      pazsan    390: ' interpreter  IS  parser
1.1       anton     391: 
1.20      pazsan    392: : compiler     ( c-addr u -- )
1.15      anton     393:     \ compilation semantics for the name/number c-addr u
                    394:     2dup sfind dup
                    395:     IF
                    396:        0>
                    397:        IF
                    398:            nip nip execute EXIT
                    399:        THEN
                    400:        compile, 2drop EXIT
                    401:     THEN
                    402:     drop
                    403:     2dup snumber? dup
                    404:     IF
                    405:        0>
                    406:        IF
                    407:            swap postpone Literal
                    408:        THEN
                    409:        postpone Literal
                    410:        2drop
                    411:     ELSE
                    412:        drop notfound
                    413:     THEN ;
1.1       anton     414: 
1.20      pazsan    415: : [     ['] interpreter  IS parser state off ; immediate
                    416: : ]     ['] compiler     IS parser state on  ;
1.1       anton     417: 
1.8       anton     418: \ locals stuff needed for control structures
                    419: 
                    420: : compile-lp+! ( n -- )
                    421:     dup negate locals-size +!
                    422:     0 over = if
1.20      pazsan    423:     else -1 cells  over = if postpone lp-
                    424:     else  1 floats over = if postpone lp+
                    425:     else  2 floats over = if postpone lp+2
1.8       anton     426:     else postpone lp+!# dup ,
                    427:     then then then then drop ;
                    428: 
                    429: : adjust-locals-size ( n -- )
                    430:     \ sets locals-size to n and generates an appropriate lp+!
                    431:     locals-size @ swap - compile-lp+! ;
                    432: 
                    433: 
                    434: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
                    435: AConstant locals-list \ acts like a variable that contains
1.10      anton     436:                      \ a linear list of locals names
1.8       anton     437: 
                    438: 
                    439: variable dead-code \ true if normal code at "here" would be dead
1.22      anton     440: variable backedge-locals
                    441:     \ contains the locals list that BEGIN will assume to be live on
                    442:     \ the back edge if the BEGIN is unreachable from above. Set by
                    443:     \ ASSUME-LIVE, reset by UNREACHABLE.
                    444: 
                    445: : UNREACHABLE ( -- )
                    446:     \ declares the current point of execution as unreachable
                    447:     dead-code on
                    448:     0 backedge-locals ! ; immediate
                    449: 
                    450: : ASSUME-LIVE ( orig -- orig )
                    451:     \ used immediateliy before a BEGIN that is not reachable from
                    452:     \ above.  causes the BEGIN to assume that the same locals are live
                    453:     \ as at the orig point
                    454:     dup orig?
                    455:     2 pick backedge-locals ! ; immediate
                    456:     
1.8       anton     457: \ locals list operations
                    458: 
                    459: : common-list ( list1 list2 -- list3 )
                    460: \ list1 and list2 are lists, where the heads are at higher addresses than
                    461: \ the tail. list3 is the largest sublist of both lists.
                    462:  begin
                    463:    2dup u<>
                    464:  while
                    465:    2dup u>
                    466:    if
                    467:      swap
                    468:    then
                    469:    @
                    470:  repeat
                    471:  drop ;
                    472: 
                    473: : sub-list? ( list1 list2 -- f )
                    474: \ true iff list1 is a sublist of list2
                    475:  begin
                    476:    2dup u<
                    477:  while
                    478:    @
                    479:  repeat
                    480:  = ;
                    481: 
                    482: : list-size ( list -- u )
                    483: \ size of the locals frame represented by list
                    484:  0 ( list n )
                    485:  begin
                    486:    over 0<>
                    487:  while
                    488:    over
1.11      pazsan    489:    name> >body @ max
1.8       anton     490:    swap @ swap ( get next )
                    491:  repeat
                    492:  faligned nip ;
                    493: 
                    494: : set-locals-size-list ( list -- )
                    495:  dup locals-list !
                    496:  list-size locals-size ! ;
                    497: 
                    498: : check-begin ( list -- )
                    499: \ warn if list is not a sublist of locals-list
                    500:  locals-list @ sub-list? 0= if
                    501:    \ !! print current position
                    502:    ." compiler was overly optimistic about locals at a BEGIN" cr
                    503:    \ !! print assumption and reality
                    504:  then ;
                    505: 
                    506: \ Control Flow Stack
                    507: \ orig, etc. have the following structure:
                    508: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
                    509: \ address (of the branch or the instruction to be branched to) (second)
                    510: \ locals-list (valid at address) (third)
                    511: 
                    512: \ types
                    513: 0 constant defstart
                    514: 1 constant live-orig
                    515: 2 constant dead-orig
                    516: 3 constant dest \ the loopback branch is always assumed live
                    517: 4 constant do-dest
                    518: 5 constant scopestart
                    519: 
                    520: : def? ( n -- )
                    521:     defstart <> abort" unstructured " ;
                    522: 
                    523: : orig? ( n -- )
                    524:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
                    525: 
                    526: : dest? ( n -- )
                    527:  dest <> abort" expected dest " ;
                    528: 
                    529: : do-dest? ( n -- )
                    530:  do-dest <> abort" expected do-dest " ;
                    531: 
                    532: : scope? ( n -- )
                    533:  scopestart <> abort" expected scope " ;
                    534: 
                    535: : non-orig? ( n -- )
                    536:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
                    537: 
                    538: : cs-item? ( n -- )
                    539:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
                    540: 
                    541: 3 constant cs-item-size
                    542: 
                    543: : CS-PICK ( ... u -- ... destu )
                    544:  1+ cs-item-size * 1- >r
                    545:  r@ pick  r@ pick  r@ pick
                    546:  rdrop
                    547:  dup non-orig? ;
                    548: 
                    549: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
                    550:  1+ cs-item-size * 1- >r
                    551:  r@ roll r@ roll r@ roll
                    552:  rdrop
                    553:  dup cs-item? ; 
                    554: 
                    555: : cs-push-part ( -- list addr )
                    556:  locals-list @ here ;
                    557: 
                    558: : cs-push-orig ( -- orig )
                    559:  cs-push-part dead-code @
                    560:  if
                    561:    dead-orig
                    562:  else
                    563:    live-orig
                    564:  then ;   
                    565: 
1.1       anton     566: \ Structural Conditionals                              12dec92py
                    567: 
                    568: : ?struc      ( flag -- )       abort" unstructured " ;
                    569: : sys?        ( sys -- )        dup 0= ?struc ;
1.8       anton     570: : >mark ( -- orig )
                    571:  cs-push-orig 0 , ;
                    572: : >resolve    ( addr -- )        here over - swap ! ;
                    573: : <resolve    ( addr -- )        here - , ;
1.1       anton     574: 
1.8       anton     575: : BUT       1 cs-roll ;                      immediate restrict
                    576: : YET       0 cs-pick ;                       immediate restrict
1.1       anton     577: 
                    578: \ Structural Conditionals                              12dec92py
                    579: 
1.8       anton     580: : AHEAD ( -- orig )
1.22      anton     581:  POSTPONE branch >mark POSTPONE unreachable ; immediate restrict
1.8       anton     582: 
                    583: : IF ( -- orig )
                    584:  POSTPONE ?branch >mark ; immediate restrict
                    585: 
1.1       anton     586: : ?DUP-IF \ general
                    587: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
                    588: \ better handled by tools like stack checkers
1.8       anton     589:     POSTPONE ?dup POSTPONE if ;       immediate restrict
1.14      anton     590: : ?DUP-0=-IF \ general
1.8       anton     591:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
                    592: 
                    593: : THEN ( orig -- )
                    594:     dup orig?
1.20      pazsan    595:     dead-orig =
1.8       anton     596:     if
1.20      pazsan    597:         >resolve drop
                    598:     else
                    599:         dead-code @
                    600:         if
1.8       anton     601:            >resolve set-locals-size-list dead-code off
                    602:        else \ both live
                    603:            over list-size adjust-locals-size
                    604:            >resolve
                    605:            locals-list @ common-list dup list-size adjust-locals-size
                    606:            locals-list !
                    607:        then
                    608:     then ; immediate restrict
                    609: 
1.1       anton     610: ' THEN alias ENDIF immediate restrict \ general
                    611: \ Same as "THEN". This is what you use if your program will be seen by
                    612: \ people who have not been brought up with Forth (or who have been
                    613: \ brought up with fig-Forth).
                    614: 
1.8       anton     615: : ELSE ( orig1 -- orig2 )
                    616:     POSTPONE ahead
                    617:     1 cs-roll
                    618:     POSTPONE then ; immediate restrict
                    619: 
                    620: 
                    621: : BEGIN ( -- dest )
                    622:     dead-code @ if
1.22      anton     623:        \ set up an assumption of the locals visible here.  if the
                    624:        \ users want something to be visible, they have to declare
                    625:        \ that using ASSUME-LIVE
                    626:        backedge-locals @ set-locals-size-list
1.8       anton     627:     then
                    628:     cs-push-part dest
                    629:     dead-code off ; immediate restrict
                    630: 
                    631: \ AGAIN (the current control flow joins another, earlier one):
                    632: \ If the dest-locals-list is not a subset of the current locals-list,
                    633: \ issue a warning (see below). The following code is generated:
                    634: \ lp+!# (current-local-size - dest-locals-size)
                    635: \ branch <begin>
                    636: : AGAIN ( dest -- )
                    637:     dest?
                    638:     over list-size adjust-locals-size
                    639:     POSTPONE branch
                    640:     <resolve
                    641:     check-begin
1.22      anton     642:     POSTPONE unreachable ; immediate restrict
1.8       anton     643: 
                    644: \ UNTIL (the current control flow may join an earlier one or continue):
                    645: \ Similar to AGAIN. The new locals-list and locals-size are the current
                    646: \ ones. The following code is generated:
                    647: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
                    648: : until-like ( list addr xt1 xt2 -- )
                    649:     \ list and addr are a fragment of a cs-item
                    650:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
                    651:     >r >r
                    652:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
                    653:        r> drop r> compile,
                    654:        swap <resolve ( list adjustment ) ,
                    655:     else ( list dest-addr adjustment )
                    656:        drop
                    657:        r> compile, <resolve
                    658:        r> drop
                    659:     then ( list )
                    660:     check-begin ;
                    661: 
                    662: : UNTIL ( dest -- )
                    663:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
                    664: 
                    665: : WHILE ( dest -- orig dest )
                    666:     POSTPONE if
                    667:     1 cs-roll ; immediate restrict
                    668: 
                    669: : REPEAT ( orig dest -- )
                    670:     POSTPONE again
                    671:     POSTPONE then ; immediate restrict
                    672: 
                    673: 
                    674: \ counted loops
                    675: 
                    676: \ leave poses a little problem here
                    677: \ we have to store more than just the address of the branch, so the
                    678: \ traditional linked list approach is no longer viable.
                    679: \ This is solved by storing the information about the leavings in a
1.9       pazsan    680: \ special stack.
1.8       anton     681: 
                    682: \ !! remove the fixed size limit. 'Tis not hard.
                    683: 20 constant leave-stack-size
1.9       pazsan    684: create leave-stack  60 cells allot
                    685: Avariable leave-sp  leave-stack 3 cells + leave-sp !
1.8       anton     686: 
                    687: : clear-leave-stack ( -- )
                    688:     leave-stack leave-sp ! ;
                    689: 
                    690: \ : leave-empty? ( -- f )
                    691: \  leave-sp @ leave-stack = ;
                    692: 
                    693: : >leave ( orig -- )
                    694:     \ push on leave-stack
                    695:     leave-sp @
                    696:     dup [ leave-stack 60 cells + ] Aliteral
                    697:     >= abort" leave-stack full"
                    698:     tuck ! cell+
                    699:     tuck ! cell+
                    700:     tuck ! cell+
                    701:     leave-sp ! ;
                    702: 
                    703: : leave> ( -- orig )
                    704:     \ pop from leave-stack
                    705:     leave-sp @
1.9       pazsan    706:     dup leave-stack <= IF
                    707:        drop 0 0 0  EXIT  THEN
1.8       anton     708:     cell - dup @ swap
                    709:     cell - dup @ swap
                    710:     cell - dup @ swap
                    711:     leave-sp ! ;
                    712: 
1.29      anton     713: : DONE ( orig -- )
1.8       anton     714:     \ !! the original done had ( addr -- )
1.29      anton     715:     drop >r drop
1.8       anton     716:     begin
                    717:        leave>
1.9       pazsan    718:        over r@ u>=
1.8       anton     719:     while
                    720:        POSTPONE then
                    721:     repeat
1.9       pazsan    722:     >leave rdrop ; immediate restrict
1.8       anton     723: 
                    724: : LEAVE ( -- )
                    725:     POSTPONE ahead
1.9       pazsan    726:     >leave ; immediate restrict
1.8       anton     727: 
                    728: : ?LEAVE ( -- )
                    729:     POSTPONE 0= POSTPONE if
1.9       pazsan    730:     >leave ; immediate restrict
1.8       anton     731: 
                    732: : DO ( -- do-sys )
                    733:     POSTPONE (do)
                    734:     POSTPONE begin drop do-dest
1.9       pazsan    735:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     736: 
                    737: : ?DO ( -- do-sys )
1.9       pazsan    738:     ( 0 0 0 >leave )
1.8       anton     739:     POSTPONE (?do)
                    740:     >mark >leave
1.9       pazsan    741:     POSTPONE begin drop do-dest ; immediate restrict
1.8       anton     742: 
                    743: : FOR ( -- do-sys )
                    744:     POSTPONE (for)
                    745:     POSTPONE begin drop do-dest
1.9       pazsan    746:     ( 0 0 0 >leave ) ; immediate restrict
1.8       anton     747: 
                    748: \ LOOP etc. are just like UNTIL
                    749: 
                    750: : loop-like ( do-sys xt1 xt2 -- )
1.9       pazsan    751:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
1.8       anton     752:     until-like  POSTPONE done  POSTPONE unloop ;
                    753: 
                    754: : LOOP ( do-sys -- )
1.9       pazsan    755:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
1.8       anton     756: 
                    757: : +LOOP ( do-sys -- )
1.9       pazsan    758:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
1.8       anton     759: 
                    760: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
                    761: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
                    762: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
                    763: \ negative increments.
                    764: : S+LOOP ( do-sys -- )
1.9       pazsan    765:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
1.5       anton     766: 
1.8       anton     767: : NEXT ( do-sys -- )
1.9       pazsan    768:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
1.1       anton     769: 
                    770: \ Structural Conditionals                              12dec92py
                    771: 
1.8       anton     772: : EXIT ( -- )
                    773:     0 adjust-locals-size
                    774:     POSTPONE ;s
1.22      anton     775:     POSTPONE unreachable ; immediate restrict
1.1       anton     776: 
1.8       anton     777: : ?EXIT ( -- )
                    778:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
1.1       anton     779: 
                    780: \ Strings                                              22feb93py
                    781: 
                    782: : ," ( "string"<"> -- ) [char] " parse
                    783:   here over char+ allot  place align ;
                    784: : "lit ( -- addr )
                    785:   r> r> dup count + aligned >r swap >r ;               restrict
                    786: : (.")     "lit count type ;                           restrict
                    787: : (S")     "lit count ;                                restrict
                    788: : SLiteral postpone (S") here over char+ allot  place align ;
                    789:                                              immediate restrict
1.35      anton     790: create s"-buffer /line chars allot
                    791: : S" ( run-time: -- c-addr u )
                    792:     [char] " parse
                    793:     state @
                    794:     IF
                    795:        postpone SLiteral
                    796:     ELSE
                    797:        /line min >r s"-buffer r@ cmove
                    798:        s"-buffer r>
                    799:     THEN ;
1.1       anton     800:                                              immediate
                    801: : ."       state @  IF    postpone (.") ,"  align
                    802:                     ELSE  [char] " parse type  THEN  ;  immediate
                    803: : (        [char] ) parse 2drop ;                       immediate
1.32      anton     804: : \ ( -- ) \ core-ext backslash
                    805:     blk @
                    806:     IF
                    807:        >in @ c/l / 1+ c/l * >in !
                    808:        EXIT
                    809:     THEN
                    810:     source >in ! drop ; immediate
                    811: 
1.33      anton     812: : \G ( -- ) \ new backslash
1.32      anton     813:     POSTPONE \ ; immediate
1.1       anton     814: 
                    815: \ error handling                                       22feb93py
                    816: \ 'abort thrown out!                                   11may93jaw
                    817: 
                    818: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
                    819:                 rdrop ;
                    820: : abort"        postpone (abort") ," ;        immediate restrict
                    821: 
                    822: \ Header states                                        23feb93py
                    823: 
1.10      anton     824: : flag! ( 8b -- )
                    825:     last @ dup 0= abort" last word was headerless"
                    826:     cell+ tuck c@ xor swap c! ;
1.1       anton     827: : immediate     $20 flag! ;
1.9       pazsan    828: : restrict      $40 flag! ;
                    829: \ ' noop alias restrict
1.1       anton     830: 
                    831: \ Header                                               23feb93py
                    832: 
                    833: \ input-stream, nextname and noname are quite ugly (passing
                    834: \ information through global variables), but they are useful for dealing
                    835: \ with existing/independent defining words
                    836: 
1.20      pazsan    837: defer (header)
                    838: defer header     ' (header) IS header
1.1       anton     839: 
1.28      anton     840: : string, ( c-addr u -- )
                    841:     \ puts down string as cstring
                    842:     dup c, here swap chars dup allot move ;
                    843: 
1.1       anton     844: : name,  ( "name" -- )
1.35      anton     845:     name name-too-short? name-too-long?
1.28      anton     846:     string, cfalign ;
1.1       anton     847: : input-stream-header ( "name" -- )
                    848:     \ !! this is f83-implementation-dependent
                    849:     align here last !  -1 A,
                    850:     name, $80 flag! ;
                    851: 
                    852: : input-stream ( -- )  \ general
                    853: \ switches back to getting the name from the input stream ;
1.20      pazsan    854:     ['] input-stream-header IS (header) ;
1.1       anton     855: 
1.20      pazsan    856: ' input-stream-header IS (header)
1.1       anton     857: 
                    858: \ !! make that a 2variable
1.5       anton     859: create nextname-buffer 32 chars allot
1.1       anton     860: 
                    861: : nextname-header ( -- )
                    862:     \ !! f83-implementation-dependent
1.5       anton     863:     nextname-buffer count
1.1       anton     864:     align here last ! -1 A,
1.28      anton     865:     string, cfalign
1.1       anton     866:     $80 flag!
                    867:     input-stream ;
                    868: 
                    869: \ the next name is given in the string
                    870: : nextname ( c-addr u -- ) \ general
1.35      anton     871:     name-too-long?
1.5       anton     872:     nextname-buffer c! ( c-addr )
                    873:     nextname-buffer count move
1.20      pazsan    874:     ['] nextname-header IS (header) ;
1.1       anton     875: 
                    876: : noname-header ( -- )
1.28      anton     877:     0 last ! cfalign
1.1       anton     878:     input-stream ;
                    879: 
                    880: : noname ( -- ) \ general
                    881: \ the next defined word remains anonymous. The xt of that word is given by lastxt
1.20      pazsan    882:     ['] noname-header IS (header) ;
1.1       anton     883: 
                    884: : lastxt ( -- xt ) \ general
                    885: \ 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
                    886:     lastcfa @ ;
                    887: 
                    888: : Alias    ( cfa "name" -- )
                    889:   Header reveal , $80 flag! ;
                    890: 
                    891: : name>string ( nfa -- addr count )
                    892:  cell+ count $1F and ;
                    893: 
1.9       pazsan    894: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
1.1       anton     895: : >name ( cfa -- nfa )
                    896:  $21 cell do
1.28      anton     897:    dup i - count $9F and + cfaligned over $80 + = if
1.1       anton     898:      i - cell - unloop exit
                    899:    then
                    900:  cell +loop
                    901:  drop ??? ( wouldn't 0 be better? ) ;
                    902: 
                    903: \ indirect threading                                   17mar93py
                    904: 
                    905: : cfa,     ( code-address -- )
                    906:     here lastcfa !
                    907:     here  0 A, 0 ,  code-address! ;
                    908: : compile, ( xt -- )           A, ;
                    909: : !does    ( addr -- )         lastcfa @ does-code! ;
                    910: : (;code)  ( R: addr -- )      r> /does-handler + !does ;
                    911: : dodoes,  ( -- )
                    912:   here /does-handler allot does-handler! ;
                    913: 
                    914: \ direct threading is implementation dependent
                    915: 
1.4       pazsan    916: : Create    Header reveal [ :dovar ] Literal cfa, ;
1.1       anton     917: 
                    918: \ DOES>                                                17mar93py
                    919: 
1.5       anton     920: : DOES>  ( compilation: -- )
                    921:     state @
                    922:     IF
                    923:        ;-hook postpone (;code) dodoes,
                    924:     ELSE
                    925:        dodoes, here !does 0 ]
                    926:     THEN 
                    927:     :-hook ; immediate
1.1       anton     928: 
                    929: \ Create Variable User Constant                        17mar93py
                    930: 
                    931: : Variable  Create 0 , ;
                    932: : AVariable Create 0 A, ;
                    933: : 2VARIABLE ( "name" -- ) \ double
                    934:     create 0 , 0 , ;
                    935:     
                    936: : User      Variable ;
                    937: : AUser     AVariable ;
                    938: 
1.4       pazsan    939: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
1.1       anton     940: : Constant  (Constant) , ;
                    941: : AConstant (Constant) A, ;
1.5       anton     942: 
1.31      pazsan    943: : 2Constant
                    944:     Create ( w1 w2 "name" -- )
1.5       anton     945:         2,
1.31      pazsan    946:     DOES> ( -- w1 w2 )
1.5       anton     947:         2@ ;
1.1       anton     948:     
                    949: \ IS Defer What's Defers TO                            24feb93py
                    950: 
1.15      anton     951: : Defer ( -- )
                    952:     \ !! shouldn't it be initialized with abort or something similar?
                    953:     Header Reveal [ :dodefer ] Literal cfa,
                    954:     ['] noop A, ;
                    955: \     Create ( -- ) 
                    956: \      ['] noop A,
                    957: \     DOES> ( ??? )
                    958: \      @ execute ;
1.1       anton     959: 
                    960: : IS ( addr "name" -- )
                    961:     ' >body
                    962:     state @
                    963:     IF    postpone ALiteral postpone !  
                    964:     ELSE  !
                    965:     THEN ;  immediate
                    966: ' IS Alias TO immediate
                    967: 
                    968: : What's ( "name" -- addr )  ' >body
                    969:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
                    970:                                              immediate
                    971: : Defers ( "name" -- )  ' >body @ compile, ;
1.12      pazsan    972:                                              immediate
1.1       anton     973: 
                    974: \ : ;                                                  24feb93py
                    975: 
1.5       anton     976: defer :-hook ( sys1 -- sys2 )
                    977: defer ;-hook ( sys2 -- sys1 )
                    978: 
1.8       anton     979: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
1.5       anton     980: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
1.1       anton     981:   immediate restrict
1.5       anton     982: 
1.10      anton     983: : :noname ( -- xt colon-sys )
                    984:     0 last !
                    985:     here [ :docol ] Literal cfa, 0 ] :-hook ;
1.1       anton     986: 
                    987: \ Search list handling                                 23feb93py
                    988: 
                    989: AVariable current
                    990: 
                    991: : last?   ( -- false / nfa nfa )    last @ ?dup ;
1.5       anton     992: : (reveal) ( -- )
                    993:   last?
                    994:   IF
                    995:       dup @ 0<
                    996:       IF
                    997:        current @ @ over ! current @ !
                    998:       ELSE
                    999:        drop
                   1000:       THEN
                   1001:   THEN ;
1.1       anton    1002: 
                   1003: \ object oriented search list                          17mar93py
                   1004: 
1.5       anton    1005: \ word list structure:
1.31      pazsan   1006: 
                   1007: struct
                   1008:   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
                   1009:   1 cells: field reveal-method \ xt: ( -- )
                   1010:   1 cells: field rehash-method \ xt: ( wid -- )
1.5       anton    1011: \   \ !! what else
1.31      pazsan   1012: end-struct wordlist-map-struct
1.5       anton    1013: 
1.31      pazsan   1014: struct
                   1015:   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
                   1016:   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
                   1017:   1 cells: field wordlist-link \ link field to other wordlists
                   1018:   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
                   1019: end-struct wordlist-struct
1.5       anton    1020: 
1.7       pazsan   1021: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
1.5       anton    1022: 
1.1       anton    1023: \ Search list table: find reveal
1.12      pazsan   1024: Create f83search       ' f83find A,  ' (reveal) A,  ' drop A,
1.7       pazsan   1025: 
1.1       anton    1026: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
1.18      pazsan   1027: AVariable lookup       G forth-wordlist lookup T !
1.1       anton    1028: G forth-wordlist current T !
                   1029: 
                   1030: : (search-wordlist)  ( addr count wid -- nfa / false )
1.31      pazsan   1031:   dup wordlist-map @ find-method @ execute ;
1.1       anton    1032: 
                   1033: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
1.28      anton    1034:     (search-wordlist) dup  IF  found  THEN ;
1.1       anton    1035: 
                   1036: Variable warnings  G -1 warnings T !
                   1037: 
                   1038: : check-shadow  ( addr count wid -- )
                   1039: \ prints a warning if the string is already present in the wordlist
                   1040: \ !! should be refined so the user can suppress the warnings
                   1041:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
                   1042:    ." redefined " name>string 2dup type
                   1043:    compare 0<> if
                   1044:      ."  with " type
                   1045:    else
                   1046:      2drop
                   1047:    then
                   1048:    space space EXIT
                   1049:  then
                   1050:  2drop 2drop ;
                   1051: 
1.15      anton    1052: : sfind ( c-addr u -- xt n / 0 )
1.18      pazsan   1053:     lookup @ search-wordlist ;
1.15      anton    1054: 
                   1055: : find   ( addr -- cfa +-1 / string false )
                   1056:     \ !! not ANS conformant: returns +-2 for restricted words
                   1057:     dup count sfind dup if
                   1058:        rot drop
                   1059:     then ;
1.1       anton    1060: 
                   1061: : reveal ( -- )
                   1062:  last? if
                   1063:    name>string current @ check-shadow
                   1064:  then
1.31      pazsan   1065:  current @ wordlist-map @ reveal-method @ execute ;
1.7       pazsan   1066: 
1.31      pazsan   1067: : rehash  ( wid -- )  dup wordlist-map @ rehash-method @ execute ;
1.1       anton    1068: 
1.20      pazsan   1069: : '    ( "name" -- addr )  name sfind 0= if -&13 bounce then ;
1.1       anton    1070: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
                   1071: \ Input                                                13feb93py
                   1072: 
                   1073: 07 constant #bell
                   1074: 08 constant #bs
1.16      anton    1075: 09 constant #tab
1.1       anton    1076: 7F constant #del
1.18      pazsan   1077: 0D constant #cr                \ the newline key code
1.17      pazsan   1078: 0C constant #ff
1.1       anton    1079: 0A constant #lf
                   1080: 
                   1081: : bell  #bell emit ;
                   1082: 
1.23      pazsan   1083: \ : backspaces  0 ?DO  #bs emit  LOOP ;
1.1       anton    1084: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
                   1085:   over 3 pick 2 pick chars /string ;
                   1086: : type-rest ( span addr pos1 -- span addr pos1 back )
                   1087:   >string tuck type ;
                   1088: : (del)  ( max span addr pos1 -- max span addr pos2 )
                   1089:   1- >string over 1+ -rot move
                   1090:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
                   1091: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
                   1092:   >r >string over 1+ swap move 2dup chars + r> swap c!
                   1093:   rot 1+ -rot type-rest 1- backspaces 1+ ;
                   1094: : ?del ( max span addr pos1 -- max span addr pos2 0 )
                   1095:   dup  IF  (del)  THEN  0 ;
                   1096: : (ret)  type-rest drop true space ;
                   1097: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
                   1098: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
                   1099: 
1.21      pazsan   1100: Create ctrlkeys
1.1       anton    1101:   ] false false back  false  false false forw  false
                   1102:     ?del  false (ret) false  false (ret) false false
                   1103:     false false false false  false false false false
                   1104:     false false false false  false false false false [
                   1105: 
1.21      pazsan   1106: defer everychar
                   1107: ' noop IS everychar
                   1108: 
1.1       anton    1109: : decode ( max span addr pos1 key -- max span addr pos2 flag )
1.21      pazsan   1110:   everychar
1.1       anton    1111:   dup #del = IF  drop #bs  THEN  \ del is rubout
1.21      pazsan   1112:   dup bl <   IF  cells ctrlkeys + @ execute  EXIT  THEN
1.1       anton    1113:   >r 2over = IF  rdrop bell 0 EXIT  THEN
                   1114:   r> (ins) 0 ;
                   1115: 
                   1116: \ decode should better use a table for control key actions
                   1117: \ to define keyboard bindings later
                   1118: 
                   1119: : accept   ( addr len -- len )
                   1120:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
                   1121: \ this allows to edit given strings
                   1122:          ELSE  0  THEN rot over
                   1123:   BEGIN  key decode  UNTIL
                   1124:   2drop nip ;
                   1125: 
                   1126: \ Output                                               13feb93py
                   1127: 
1.17      pazsan   1128: Defer type      \ defer type for a output buffer or fast
1.1       anton    1129:                 \ screen write
                   1130: 
1.9       pazsan   1131: \ : (type) ( addr len -- )
                   1132: \   bounds ?DO  I c@ emit  LOOP ;
1.1       anton    1133: 
1.17      pazsan   1134: ' (type) IS Type
1.1       anton    1135: 
1.17      pazsan   1136: Defer emit
1.1       anton    1137: 
1.9       pazsan   1138: ' (Emit) IS Emit
1.1       anton    1139: 
1.17      pazsan   1140: Defer key
                   1141: ' (key) IS key
                   1142: 
1.1       anton    1143: \ : form  ( -- rows cols )  &24 &80 ;
                   1144: \ form should be implemented using TERMCAPS or CURSES
                   1145: \ : rows  form drop ;
                   1146: \ : cols  form nip  ;
                   1147: 
                   1148: \ Query                                                07apr93py
                   1149: 
                   1150: : refill ( -- flag )
1.39    ! pazsan   1151:   blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
1.1       anton    1152:   tib /line
                   1153:   loadfile @ ?dup
1.17      pazsan   1154:   IF    read-line throw
1.12      pazsan   1155:   ELSE  loadline @ 0< IF 2drop false EXIT THEN
1.1       anton    1156:         accept true
                   1157:   THEN
                   1158:   1 loadline +!
1.10      anton    1159:   swap #tib ! 0 >in ! ;
1.1       anton    1160: 
1.17      pazsan   1161: : Query  ( -- )  loadfile off  blk off  refill drop ;
1.1       anton    1162: 
                   1163: \ File specifiers                                       11jun93jaw
                   1164: 
                   1165: 
                   1166: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
                   1167: \ 2 c, here char r c, char + c, 0 c,
                   1168: \ 2 c, here char w c, char + c, 0 c, align
                   1169: 4 Constant w/o
                   1170: 2 Constant r/w
                   1171: 0 Constant r/o
                   1172: 
                   1173: \ BIN WRITE-LINE                                        11jun93jaw
                   1174: 
                   1175: \ : bin           dup 1 chars - c@
                   1176: \                 r/o 4 chars + over - dup >r swap move r> ;
                   1177: 
1.35      anton    1178: : bin  1 or ;
1.1       anton    1179: 
                   1180: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
                   1181:                            \ or not unix environments if
                   1182:                            \ bin is not selected
                   1183: 
                   1184: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
                   1185:                 nl$ count r> write-file ;
                   1186: 
                   1187: \ include-file                                         07apr93py
                   1188: 
1.12      pazsan   1189: : push-file  ( -- )  r>
1.17      pazsan   1190:   loadline @ >r loadfile @ >r
1.12      pazsan   1191:   blk @ >r >tib @ >r  #tib @ dup >r  >tib +!  >in @ >r  >r ;
                   1192: 
1.18      pazsan   1193: : pop-file   ( throw-code -- throw-code )
                   1194:   dup IF
                   1195:          source >in @ loadline @ loadfilename 2@
                   1196:         error-stack dup @ dup 1+
                   1197:         max-errors 1- min error-stack !
                   1198:         6 * cells + cell+
                   1199:         5 cells bounds swap DO
                   1200:                            I !
                   1201:         -1 cells +LOOP
                   1202:   THEN
                   1203:   r>
1.17      pazsan   1204:   r> >in !  r> #tib !  r> >tib !  r> blk !
                   1205:   r> loadfile ! r> loadline !  >r ;
                   1206: 
                   1207: : read-loop ( i*x -- j*x )
                   1208:   BEGIN  refill  WHILE  interpret  REPEAT ;
1.12      pazsan   1209: 
1.1       anton    1210: : include-file ( i*x fid -- j*x )
1.12      pazsan   1211:   push-file  loadfile !
1.17      pazsan   1212:   0 loadline ! blk off  ['] read-loop catch
1.20      pazsan   1213:   loadfile @ close-file swap 2dup or
                   1214:   pop-file  drop throw throw ;
1.1       anton    1215: 
1.19      anton    1216: create pathfilenamebuf 256 chars allot \ !! make this grow on demand
                   1217: 
1.37      anton    1218: \ : check-file-prefix  ( addr len -- addr' len' flag )
                   1219: \   dup 0=                    IF  true EXIT  THEN 
                   1220: \   over c@ '/ =              IF  true EXIT  THEN 
                   1221: \   over 2 S" ./" compare 0=  IF  true EXIT  THEN 
                   1222: \   over 3 S" ../" compare 0= IF  true EXIT  THEN
                   1223: \   over 2 S" ~/" compare 0=
                   1224: \   IF     1 /string
                   1225: \          S" HOME" getenv tuck pathfilenamebuf swap move
                   1226: \          2dup + >r pathfilenamebuf + swap move
                   1227: \          pathfilenamebuf r> true
                   1228: \   ELSE   false
                   1229: \   THEN ;
1.36      pazsan   1230: 
1.19      anton    1231: : open-path-file ( c-addr1 u1 -- file-id c-addr2 u2 )
1.37      anton    1232:     \ opens a file for reading, searching in the path for it (unless
                   1233:     \ the filename contains a slash); c-addr2 u2 is the full filename
                   1234:     \ (valid until the next call); if the file is not found (or in
                   1235:     \ case of other errors for each try), -38 (non-existant file) is
                   1236:     \ thrown. Opening for other access modes makes little sense, as
                   1237:     \ the path will usually contain dirs that are only readable for
                   1238:     \ the user
                   1239:     \ !! use file-status to determine access mode?
                   1240:     2dup [char] / scan nip ( 0<> )
                   1241:     if \ the filename contains a slash
                   1242:        2dup r/o open-file throw ( c-addr1 u1 file-id )
                   1243:        -rot >r pathfilenamebuf r@ cmove ( file-id R: u1 )
                   1244:        pathfilenamebuf r> EXIT
                   1245:     then
                   1246:     pathdirs 2@ 0
                   1247: \    check-file-prefix 0= 
                   1248: \    IF  pathdirs 2@ 0
1.19      anton    1249:     ?DO ( c-addr1 u1 dirnamep )
                   1250:        dup >r 2@ dup >r pathfilenamebuf swap cmove ( addr u )
                   1251:        2dup pathfilenamebuf r@ chars + swap cmove ( addr u )
                   1252:        pathfilenamebuf over r> + dup >r r/o open-file 0=
1.36      pazsan   1253:        IF ( addr u file-id )
1.37      anton    1254:            nip nip r> rdrop 0 LEAVE
1.36      pazsan   1255:        THEN
1.19      anton    1256:        rdrop drop r> cell+ cell+
                   1257:     LOOP
1.37      anton    1258: \    ELSE   2dup open-file throw -rot  THEN 
1.19      anton    1259:     0<> -&38 and throw ( file-id u2 )
                   1260:     pathfilenamebuf swap ;
                   1261: 
1.27      anton    1262: create included-files 0 , 0 , ( pointer to and count of included files )
                   1263: 
                   1264: : included? ( c-addr u -- f )
                   1265:     \ true, iff filename c-addr u is in included-files
                   1266:     included-files 2@ 0
                   1267:     ?do ( c-addr u addr )
                   1268:        dup >r 2@ 2over compare 0=
                   1269:        if
                   1270:            2drop rdrop unloop
                   1271:            true EXIT
                   1272:        then
                   1273:        r> cell+ cell+
                   1274:     loop
                   1275:     2drop drop false ;
                   1276: 
                   1277: : add-included-file ( c-addr u -- )
                   1278:     \ add name c-addr u to included-files
                   1279:     included-files 2@ tuck 1+ 2* cells resize throw
                   1280:     swap 2dup 1+ included-files 2!
                   1281:     2* cells + 2! ;
                   1282: 
                   1283: : save-string          ( addr1 u -- addr2 u )
                   1284:     swap >r
                   1285:     dup allocate throw
                   1286:     swap 2dup r> -rot move ;
                   1287: 
                   1288: : included1 ( i*x file-id c-addr u -- j*x )
                   1289:     \ include the file file-id with the name given by c-addr u
1.10      anton    1290:     loadfilename 2@ >r >r
1.27      anton    1291:     save-string 2dup loadfilename 2! add-included-file ( file-id )
1.20      pazsan   1292:     ['] include-file catch
                   1293:     r> r> loadfilename 2!  throw ;
1.27      anton    1294:     
                   1295: : included ( i*x addr u -- j*x )
                   1296:     open-path-file included1 ;
                   1297: 
                   1298: : required ( i*x addr u -- j*x )
                   1299:     \ include the file with the name given by addr u, if it is not
                   1300:     \ included already. Currently this works by comparing the name of
                   1301:     \ the file (with path) against the names of earlier included
                   1302:     \ files; however, it would probably be better to fstat the file,
                   1303:     \ and compare the device and inode. The advantages would be: no
                   1304:     \ problems with several paths to the same file (e.g., due to
                   1305:     \ links) and we would catch files included with include-file and
                   1306:     \ write a require-file.
                   1307:     open-path-file 2dup included?
                   1308:     if
                   1309:        2drop close-file throw
                   1310:     else
                   1311:        included1
                   1312:     then ;
1.1       anton    1313: 
                   1314: \ HEX DECIMAL                                           2may93jaw
                   1315: 
                   1316: : decimal a base ! ;
                   1317: : hex     10 base ! ;
                   1318: 
                   1319: \ DEPTH                                                 9may93jaw
                   1320: 
                   1321: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
1.21      pazsan   1322: : clearstack ( ... -- )  s0 @ sp! ;
1.1       anton    1323: 
                   1324: \ INCLUDE                                               9may93jaw
                   1325: 
1.6       pazsan   1326: : include  ( "file" -- )
1.20      pazsan   1327:   name included ;
1.27      anton    1328: 
                   1329: : require  ( "file" -- )
                   1330:   name required ;
1.1       anton    1331: 
                   1332: \ RECURSE                                               17may93jaw
                   1333: 
1.10      anton    1334: : recurse ( -- )
                   1335:     lastxt compile, ; immediate restrict
                   1336: : recursive ( -- )
                   1337:     reveal ; immediate
1.1       anton    1338: 
                   1339: \ */MOD */                                              17may93jaw
                   1340: 
1.13      anton    1341: \ !! I think */mod should have the same rounding behaviour as / - anton
1.1       anton    1342: : */mod >r m* r> sm/rem ;
                   1343: 
                   1344: : */ */mod nip ;
                   1345: 
                   1346: \ EVALUATE                                              17may93jaw
                   1347: 
                   1348: : evaluate ( c-addr len -- )
1.12      pazsan   1349:   push-file  dup #tib ! >tib @ swap move
                   1350:   >in off blk off loadfile off -1 loadline !
1.1       anton    1351: 
1.17      pazsan   1352: \  BEGIN  interpret  >in @ #tib @ u>= UNTIL
                   1353:   ['] interpret catch
                   1354:   pop-file throw ;
1.1       anton    1355: 
                   1356: 
                   1357: : abort -1 throw ;
                   1358: 
                   1359: \+ environment? true ENV" CORE"
                   1360: \ core wordset is now complete!
                   1361: 
                   1362: \ Quit                                                 13feb93py
                   1363: 
                   1364: Defer 'quit
                   1365: Defer .status
                   1366: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
                   1367: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
                   1368: ' (quit) IS 'quit
                   1369: 
                   1370: \ DOERROR (DOERROR)                                     13jun93jaw
                   1371: 
1.18      pazsan   1372: 8 Constant max-errors
                   1373: Variable error-stack  0 error-stack !
                   1374: max-errors 6 * cells allot
                   1375: \ format of one cell:
                   1376: \ source ( addr u )
                   1377: \ >in
                   1378: \ line-number
                   1379: \ Loadfilename ( addr u )
                   1380: 
1.10      anton    1381: : dec. ( n -- )
                   1382:     \ print value in decimal representation
                   1383:     base @ decimal swap . base ! ;
                   1384: 
                   1385: : typewhite ( addr u -- )
                   1386:     \ like type, but white space is printed instead of the characters
1.18      pazsan   1387:     bounds ?do
                   1388:        i c@ 9 = if \ check for tab
1.10      anton    1389:            9
                   1390:        else
                   1391:            bl
                   1392:        then
                   1393:        emit
                   1394:     loop
1.18      pazsan   1395: ;
1.10      anton    1396: 
1.1       anton    1397: DEFER DOERROR
                   1398: 
1.18      pazsan   1399: : .error-frame ( addr1 u1 n1 n2 addr2 u2 -- )
                   1400:   cr error-stack @
                   1401:   IF
                   1402:      ." in file included from "
                   1403:      type ." :" dec.  drop 2drop
                   1404:   ELSE
                   1405:      type ." :" dec.
                   1406:      cr dup 2over type cr drop
1.20      pazsan   1407:      nip -trailing 1- ( line-start index2 )
1.18      pazsan   1408:      0 >r  BEGIN
1.20      pazsan   1409:                   2dup + c@ bl >  WHILE
                   1410:                  r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
1.18      pazsan   1411:      ( line-start index1 )
                   1412:      typewhite
                   1413:      r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
                   1414:                   [char] ^ emit
                   1415:      loop
                   1416:   THEN
                   1417: ;
                   1418: 
1.1       anton    1419: : (DoError) ( throw-code -- )
1.18      pazsan   1420:   loadline @ IF
                   1421:                source >in @ loadline @ 0 0 .error-frame
                   1422:   THEN
                   1423:   error-stack @ 0 ?DO
                   1424:     -1 error-stack +!
                   1425:     error-stack dup @ 6 * cells + cell+
                   1426:     6 cells bounds DO
                   1427:       I @
                   1428:     cell +LOOP
                   1429:     .error-frame
                   1430:   LOOP
                   1431:   dup -2 =
                   1432:   IF 
                   1433:      "error @ ?dup
                   1434:      IF
                   1435:         cr count type 
                   1436:      THEN
                   1437:      drop
                   1438:   ELSE
                   1439:      .error
                   1440:   THEN
                   1441:   normal-dp dpp ! ;
1.1       anton    1442: 
                   1443: ' (DoError) IS DoError
                   1444: 
                   1445: : quit   r0 @ rp! handler off >tib @ >r
1.5       anton    1446:   BEGIN
                   1447:     postpone [
                   1448:     ['] 'quit CATCH dup
                   1449:   WHILE
                   1450:     DoError r@ >tib !
                   1451:   REPEAT
                   1452:   drop r> >tib ! ;
1.1       anton    1453: 
                   1454: \ Cold                                                 13feb93py
                   1455: 
                   1456: \ : .name ( name -- ) cell+ count $1F and type space ;
                   1457: \ : words  listwords @
                   1458: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
                   1459: 
1.19      anton    1460: : cstring>sstring  ( cstring -- addr n )  -1 0 scan 0 swap 1+ /string ;
                   1461: : arg ( n -- addr count )  cells argv @ + @ cstring>sstring ;
1.1       anton    1462: : #!       postpone \ ;  immediate
                   1463: 
1.19      anton    1464: Create pathstring 2 cells allot \ string
                   1465: Create pathdirs   2 cells allot \ dir string array, pointer and count
1.1       anton    1466: Variable argv
                   1467: Variable argc
                   1468: 
1.12      pazsan   1469: 0 Value script? ( -- flag )
                   1470: 
1.19      anton    1471: : process-path ( addr1 u1 -- addr2 u2 )
                   1472:     \ addr1 u1 is a path string, addr2 u2 is an array of dir strings
                   1473:     here >r
                   1474:     BEGIN
                   1475:        over >r [char] : scan
                   1476:        over r> tuck - ( rest-str this-str )
                   1477:        dup
                   1478:        IF
                   1479:            2dup 1- chars + c@ [char] / <>
                   1480:            IF
                   1481:                2dup chars + [char] / swap c!
                   1482:                1+
                   1483:            THEN
                   1484:            2,
                   1485:        ELSE
                   1486:            2drop
                   1487:        THEN
                   1488:        dup
                   1489:     WHILE
                   1490:        1 /string
                   1491:     REPEAT
                   1492:     2drop
                   1493:     here r> tuck - 2 cells / ;
                   1494: 
1.32      anton    1495: : do-option ( addr1 len1 addr2 len2 -- n )
                   1496:     2swap
                   1497:     2dup s" -e"         compare  0= >r
                   1498:     2dup s" --evaluate" compare  0= r> or
                   1499:     IF  2drop dup >r ['] evaluate catch
                   1500:        ?dup IF  dup >r DoError r> negate (bye)  THEN
                   1501:        r> >tib +!  2 EXIT  THEN
                   1502:     ." Unknown option: " type cr 2drop 1 ;
1.12      pazsan   1503: 
1.34      anton    1504: : process-args ( -- )
                   1505:     >tib @ >r
                   1506:     true to script?
1.19      anton    1507:     argc @ 1
                   1508:     ?DO
                   1509:        I arg over c@ [char] - <>
                   1510:        IF
1.35      anton    1511:            required 1
1.19      anton    1512:        ELSE
                   1513:            I 1+ arg  do-option
                   1514:        THEN
1.25      pazsan   1515:     +LOOP
1.34      anton    1516:     false to script?
1.25      pazsan   1517:     r> >tib ! ;
1.1       anton    1518: 
1.24      pazsan   1519: Defer 'cold ' noop IS 'cold
                   1520: 
1.19      anton    1521: : cold ( -- )
1.25      pazsan   1522:     pathstring 2@ process-path pathdirs 2!
1.30      pazsan   1523:     0 0 included-files 2!
1.24      pazsan   1524:     'cold
1.10      anton    1525:     argc @ 1 >
1.12      pazsan   1526:     IF
                   1527:        ['] process-args catch ?dup
1.10      anton    1528:        IF
1.12      pazsan   1529:            dup >r DoError cr r> negate (bye)
1.10      anton    1530:        THEN
                   1531:     THEN
1.13      anton    1532:     cr
1.38      anton    1533:     ." GNU Forth " version-string type ." , Copyright (C) 1994 Free Software Foundation, Inc." cr
1.13      anton    1534:     ." GNU Forth comes with ABSOLUTELY NO WARRANTY; for details type `license'" cr
                   1535:     ." Type `bye' to exit"
1.26      pazsan   1536:     loadline off quit ;
1.1       anton    1537: 
1.12      pazsan   1538: : license ( -- ) cr
                   1539:  ." This program is free software; you can redistribute it and/or modify" cr
                   1540:  ." it under the terms of the GNU General Public License as published by" cr
1.13      anton    1541:  ." the Free Software Foundation; either version 2 of the License, or" cr
                   1542:  ." (at your option) any later version." cr cr
1.12      pazsan   1543: 
                   1544:  ." This program is distributed in the hope that it will be useful," cr
                   1545:  ." but WITHOUT ANY WARRANTY; without even the implied warranty of" cr
                   1546:  ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" cr
                   1547:  ." GNU General Public License for more details." cr cr
                   1548: 
                   1549:  ." You should have received a copy of the GNU General Public License" cr
                   1550:  ." along with this program; if not, write to the Free Software" cr
                   1551:  ." Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA." cr ;
                   1552: 
1.19      anton    1553: : boot ( path **argv argc -- )
                   1554:   argc ! argv ! cstring>sstring pathstring 2!  main-task up!
1.25      pazsan   1555:   sp@ dup s0 ! $10 + >tib ! #tib off >in off
                   1556:   rp@ r0 !  fp@ f0 !  cold ;
1.1       anton    1557: 
1.12      pazsan   1558: : bye  script? 0= IF  cr  THEN  0 (bye) ;
1.1       anton    1559: 
                   1560: \ **argv may be scanned by the C starter to get some important
                   1561: \ information, as -display and -geometry for an X client FORTH
                   1562: \ or space and stackspace overrides
                   1563: 
                   1564: \ 0 arg contains, however, the name of the program.

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