File:  [gforth] / gforth / Attic / kernal.fs
Revision 1.40: download - view: text, annotated - select for diffs
Wed Sep 6 21:00:21 1995 UTC (24 years, 4 months ago) by pazsan
Branches: MAIN
CVS tags: HEAD
Removed BUGS, tried to clean up.

    1: \ KERNAL.FS    GNU FORTH kernal                        17dec92py
    2: \ $ID:
    3: \ Idea and implementation: Bernd Paysan (py)
    4: \ Copyright 1992 by the ANSI figForth Development Group
    5: 
    6: \ Log:  ', '- usw. durch [char] ... ersetzt
    7: \       man sollte die unterschiedlichen zahlensysteme
    8: \       mit $ und & zumindest im interpreter weglassen
    9: \       schon erledigt!
   10: \       11may93jaw
   11: \ name>         0= nicht vorhanden              17may93jaw
   12: \               nfa can be lfa or nfa!
   13: \ find          splited into find and (find)
   14: \               (find) for later use            17may93jaw
   15: \ search        replaced by lookup because
   16: \               it is a word of the string wordset
   17: \                                               20may93jaw
   18: \ postpone      added immediate                 21may93jaw
   19: \ to            added immediate                 07jun93jaw
   20: \ cfa, header   put "here lastcfa !" in
   21: \               cfa, this is more logical
   22: \               and noname: works wothout
   23: \               extra "here lastcfa !"          08jun93jaw
   24: \ (parse-white) thrown out
   25: \ refill        added outer trick
   26: \               to show there is something
   27: \               going on                        09jun93jaw
   28: \ leave ?leave  somebody forgot UNLOOP!!!       09jun93jaw
   29: \ leave ?leave  unloop thrown out
   30: \               unloop after loop is used       10jun93jaw
   31: 
   32: HEX
   33: 
   34: \ Bit string manipulation                              06oct92py
   35: 
   36: Create bits  80 c, 40 c, 20 c, 10 c, 8 c, 4 c, 2 c, 1 c,
   37: DOES> ( n -- )  + c@ ;
   38: 
   39: : >bit  ( addr n -- c-addr mask )  8 /mod rot + swap bits ;
   40: : +bit  ( addr n -- )  >bit over c@ or swap c! ;
   41: 
   42: : relinfo ( -- addr )  forthstart dup @ + ;
   43: : >rel  ( addr -- n )  forthstart - ;
   44: : relon ( addr -- )  relinfo swap >rel cell / +bit ;
   45: 
   46: \ here allot , c, A,                                   17dec92py
   47: 
   48: : dp	( -- addr )  dpp @ ;
   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: 
   60: : faligned ( addr -- f-addr )
   61:   [ 1 floats 1- ] Literal + [ -1 floats ] Literal and ;
   62: 
   63: : falign ( -- )
   64:   here dup faligned swap
   65:   ?DO
   66:       bl c,
   67:   LOOP ;
   68: 
   69: \ !! 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: 
   78: : chars ; immediate
   79: 
   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: 
   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 ;
   95: 
   96: : found ( nfa -- cfa n )  cell+
   97:   dup c@ >r  (name>) r@ $80 and  0= IF  @       THEN
   98:                   -1 r@ $40 and     IF  1-      THEN
   99:                      r> $20 and     IF  negate  THEN  ;
  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: 
  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 ;
  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 )
  156:   source 2dup >r >r >in @ over min /string
  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 )
  163:   >r  source  >in @ over min /string  over  swap r>  scan >r
  164:   over - dup r> IF 1+ THEN  >in +! ;
  165: 
  166: \ name                                                 13feb93py
  167: 
  168: : capitalize ( addr len -- addr len )
  169:   2dup chars chars bounds
  170:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
  171: : (name) ( -- c-addr count )
  172:     source 2dup >r >r >in @ /string (parse-white)
  173:     2dup + r> - 1+ r> min >in ! ;
  174: \    name count ;
  175: 
  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: 
  182: \ Literal                                              17dec92py
  183: 
  184: : Literal  ( n -- )  state @ IF postpone lit  , THEN ;
  185:                                                       immediate
  186: : ALiteral ( n -- )  state @ IF postpone lit A, THEN ;
  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: 
  193: : (compile) ( -- )  r> dup cell+ >r @ compile, ;
  194: : postpone ( "name" -- )
  195:   name sfind dup 0= abort" Can't compile "
  196:   0> IF  compile,  ELSE  postpone (compile) A,  THEN ;
  197:                                              immediate restrict
  198: 
  199: \ Use (compile) for the old behavior of compile!
  200: 
  201: \ digit?                                               17dec92py
  202: 
  203: : digit?   ( char -- digit true/ false )
  204:   base @ $100 =
  205:   IF
  206:     true EXIT
  207:   THEN
  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 ;
  232: : s>number ( addr len -- d )  base @ >r  dpl on
  233:   over c@ '- =  dup >r  IF  1 /string  THEN
  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
  238:   REPEAT  THEN  2drop rdrop dpl off  ELSE
  239:   2drop rdrop r> IF  dnegate  THEN
  240:   THEN r> base ! ;
  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 ;
  249: : number? ( string -- string 0 / n -1 / d 0> )
  250:     dup >r count snumber? dup if
  251: 	rdrop
  252:     else
  253: 	r> swap
  254:     then ;
  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 ;
  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 ;
  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: 
  313: : lp@ ( -- addr )
  314:  laddr# [ 0 , ] ;
  315: 
  316: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
  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
  323:   r> handler ! rdrop rdrop rdrop 0 ;
  324: 
  325: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
  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 ;
  334: 
  335: \ Bouncing is very fine,
  336: \ programming without wasting time...   jaw
  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 ;
  346: 
  347: \ ?stack                                               23feb93py
  348: 
  349: : ?stack ( ?? -- ?? )
  350:     sp@ s0 @ > IF    -4 throw  THEN
  351:     fp@ f0 @ > IF  -&45 throw  THEN  ;
  352: \ ?stack should be code -- it touches an empty stack!
  353: 
  354: \ interpret                                            10mar92py
  355: 
  356: Defer parser
  357: Defer name      ' (name) IS name
  358: Defer notfound ( c-addr count -- )
  359: 
  360: : no.extensions  ( addr u -- )  2drop -&13 bounce ;
  361: 
  362: ' no.extensions IS notfound
  363: 
  364: : interpret
  365:     BEGIN
  366: 	?stack name dup
  367:     WHILE
  368: 	parser
  369:     REPEAT
  370:     2drop ;
  371: 
  372: \ interpreter compiler                                 30apr92py
  373: 
  374: : interpreter  ( c-addr u -- ) 
  375:     \ interpretation semantics for the name/number c-addr u
  376:     2dup sfind dup
  377:     IF
  378: 	1 and
  379: 	IF \ not restricted to compile state?
  380: 	    nip nip execute EXIT
  381: 	THEN
  382: 	-&14 throw
  383:     THEN
  384:     drop
  385:     2dup 2>r snumber?
  386:     IF
  387: 	2rdrop
  388:     ELSE
  389: 	2r> notfound
  390:     THEN ;
  391: 
  392: ' interpreter  IS  parser
  393: 
  394: : compiler     ( c-addr u -- )
  395:     \ compilation semantics for the name/number c-addr u
  396:     2dup sfind dup
  397:     IF
  398: 	0>
  399: 	IF
  400: 	    nip nip execute EXIT
  401: 	THEN
  402: 	compile, 2drop EXIT
  403:     THEN
  404:     drop
  405:     2dup snumber? dup
  406:     IF
  407: 	0>
  408: 	IF
  409: 	    swap postpone Literal
  410: 	THEN
  411: 	postpone Literal
  412: 	2drop
  413:     ELSE
  414: 	drop notfound
  415:     THEN ;
  416: 
  417: : [     ['] interpreter  IS parser state off ; immediate
  418: : ]     ['] compiler     IS parser state on  ;
  419: 
  420: \ locals stuff needed for control structures
  421: 
  422: : compile-lp+! ( n -- )
  423:     dup negate locals-size +!
  424:     0 over = if
  425:     else -1 cells  over = if postpone lp-
  426:     else  1 floats over = if postpone lp+
  427:     else  2 floats over = if postpone lp+2
  428:     else postpone lp+!# dup ,
  429:     then then then then drop ;
  430: 
  431: : adjust-locals-size ( n -- )
  432:     \ sets locals-size to n and generates an appropriate lp+!
  433:     locals-size @ swap - compile-lp+! ;
  434: 
  435: 
  436: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
  437: AConstant locals-list \ acts like a variable that contains
  438: 		      \ a linear list of locals names
  439: 
  440: 
  441: variable dead-code \ true if normal code at "here" would be dead
  442: variable backedge-locals
  443:     \ contains the locals list that BEGIN will assume to be live on
  444:     \ the back edge if the BEGIN is unreachable from above. Set by
  445:     \ ASSUME-LIVE, reset by UNREACHABLE.
  446: 
  447: : UNREACHABLE ( -- )
  448:     \ declares the current point of execution as unreachable
  449:     dead-code on
  450:     0 backedge-locals ! ; immediate
  451: 
  452: : ASSUME-LIVE ( orig -- orig )
  453:     \ used immediateliy before a BEGIN that is not reachable from
  454:     \ above.  causes the BEGIN to assume that the same locals are live
  455:     \ as at the orig point
  456:     dup orig?
  457:     2 pick backedge-locals ! ; immediate
  458:     
  459: \ locals list operations
  460: 
  461: : common-list ( list1 list2 -- list3 )
  462: \ list1 and list2 are lists, where the heads are at higher addresses than
  463: \ the tail. list3 is the largest sublist of both lists.
  464:  begin
  465:    2dup u<>
  466:  while
  467:    2dup u>
  468:    if
  469:      swap
  470:    then
  471:    @
  472:  repeat
  473:  drop ;
  474: 
  475: : sub-list? ( list1 list2 -- f )
  476: \ true iff list1 is a sublist of list2
  477:  begin
  478:    2dup u<
  479:  while
  480:    @
  481:  repeat
  482:  = ;
  483: 
  484: : list-size ( list -- u )
  485: \ size of the locals frame represented by list
  486:  0 ( list n )
  487:  begin
  488:    over 0<>
  489:  while
  490:    over
  491:    name> >body @ max
  492:    swap @ swap ( get next )
  493:  repeat
  494:  faligned nip ;
  495: 
  496: : set-locals-size-list ( list -- )
  497:  dup locals-list !
  498:  list-size locals-size ! ;
  499: 
  500: : check-begin ( list -- )
  501: \ warn if list is not a sublist of locals-list
  502:  locals-list @ sub-list? 0= if
  503:    \ !! print current position
  504:    ." compiler was overly optimistic about locals at a BEGIN" cr
  505:    \ !! print assumption and reality
  506:  then ;
  507: 
  508: \ Control Flow Stack
  509: \ orig, etc. have the following structure:
  510: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
  511: \ address (of the branch or the instruction to be branched to) (second)
  512: \ locals-list (valid at address) (third)
  513: 
  514: \ types
  515: 0 constant defstart
  516: 1 constant live-orig
  517: 2 constant dead-orig
  518: 3 constant dest \ the loopback branch is always assumed live
  519: 4 constant do-dest
  520: 5 constant scopestart
  521: 
  522: : def? ( n -- )
  523:     defstart <> abort" unstructured " ;
  524: 
  525: : orig? ( n -- )
  526:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
  527: 
  528: : dest? ( n -- )
  529:  dest <> abort" expected dest " ;
  530: 
  531: : do-dest? ( n -- )
  532:  do-dest <> abort" expected do-dest " ;
  533: 
  534: : scope? ( n -- )
  535:  scopestart <> abort" expected scope " ;
  536: 
  537: : non-orig? ( n -- )
  538:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
  539: 
  540: : cs-item? ( n -- )
  541:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
  542: 
  543: 3 constant cs-item-size
  544: 
  545: : CS-PICK ( ... u -- ... destu )
  546:  1+ cs-item-size * 1- >r
  547:  r@ pick  r@ pick  r@ pick
  548:  rdrop
  549:  dup non-orig? ;
  550: 
  551: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
  552:  1+ cs-item-size * 1- >r
  553:  r@ roll r@ roll r@ roll
  554:  rdrop
  555:  dup cs-item? ; 
  556: 
  557: : cs-push-part ( -- list addr )
  558:  locals-list @ here ;
  559: 
  560: : cs-push-orig ( -- orig )
  561:  cs-push-part dead-code @
  562:  if
  563:    dead-orig
  564:  else
  565:    live-orig
  566:  then ;   
  567: 
  568: \ Structural Conditionals                              12dec92py
  569: 
  570: : ?struc      ( flag -- )       abort" unstructured " ;
  571: : sys?        ( sys -- )        dup 0= ?struc ;
  572: : >mark ( -- orig )
  573:  cs-push-orig 0 , ;
  574: : >resolve    ( addr -- )        here over - swap ! ;
  575: : <resolve    ( addr -- )        here - , ;
  576: 
  577: : BUT       1 cs-roll ;                      immediate restrict
  578: : YET       0 cs-pick ;                       immediate restrict
  579: 
  580: \ Structural Conditionals                              12dec92py
  581: 
  582: : AHEAD ( -- orig )
  583:  POSTPONE branch >mark POSTPONE unreachable ; immediate restrict
  584: 
  585: : IF ( -- orig )
  586:  POSTPONE ?branch >mark ; immediate restrict
  587: 
  588: : ?DUP-IF \ general
  589: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
  590: \ better handled by tools like stack checkers
  591:     POSTPONE ?dup POSTPONE if ;       immediate restrict
  592: : ?DUP-0=-IF \ general
  593:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
  594: 
  595: : THEN ( orig -- )
  596:     dup orig?
  597:     dead-orig =
  598:     if
  599:         >resolve drop
  600:     else
  601:         dead-code @
  602:         if
  603: 	    >resolve set-locals-size-list dead-code off
  604: 	else \ both live
  605: 	    over list-size adjust-locals-size
  606: 	    >resolve
  607: 	    locals-list @ common-list dup list-size adjust-locals-size
  608: 	    locals-list !
  609: 	then
  610:     then ; immediate restrict
  611: 
  612: ' THEN alias ENDIF immediate restrict \ general
  613: \ Same as "THEN". This is what you use if your program will be seen by
  614: \ people who have not been brought up with Forth (or who have been
  615: \ brought up with fig-Forth).
  616: 
  617: : ELSE ( orig1 -- orig2 )
  618:     POSTPONE ahead
  619:     1 cs-roll
  620:     POSTPONE then ; immediate restrict
  621: 
  622: 
  623: : BEGIN ( -- dest )
  624:     dead-code @ if
  625: 	\ set up an assumption of the locals visible here.  if the
  626: 	\ users want something to be visible, they have to declare
  627: 	\ that using ASSUME-LIVE
  628: 	backedge-locals @ set-locals-size-list
  629:     then
  630:     cs-push-part dest
  631:     dead-code off ; immediate restrict
  632: 
  633: \ AGAIN (the current control flow joins another, earlier one):
  634: \ If the dest-locals-list is not a subset of the current locals-list,
  635: \ issue a warning (see below). The following code is generated:
  636: \ lp+!# (current-local-size - dest-locals-size)
  637: \ branch <begin>
  638: : AGAIN ( dest -- )
  639:     dest?
  640:     over list-size adjust-locals-size
  641:     POSTPONE branch
  642:     <resolve
  643:     check-begin
  644:     POSTPONE unreachable ; immediate restrict
  645: 
  646: \ UNTIL (the current control flow may join an earlier one or continue):
  647: \ Similar to AGAIN. The new locals-list and locals-size are the current
  648: \ ones. The following code is generated:
  649: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
  650: : until-like ( list addr xt1 xt2 -- )
  651:     \ list and addr are a fragment of a cs-item
  652:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
  653:     >r >r
  654:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
  655: 	r> drop r> compile,
  656: 	swap <resolve ( list adjustment ) ,
  657:     else ( list dest-addr adjustment )
  658: 	drop
  659: 	r> compile, <resolve
  660: 	r> drop
  661:     then ( list )
  662:     check-begin ;
  663: 
  664: : UNTIL ( dest -- )
  665:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
  666: 
  667: : WHILE ( dest -- orig dest )
  668:     POSTPONE if
  669:     1 cs-roll ; immediate restrict
  670: 
  671: : REPEAT ( orig dest -- )
  672:     POSTPONE again
  673:     POSTPONE then ; immediate restrict
  674: 
  675: 
  676: \ counted loops
  677: 
  678: \ leave poses a little problem here
  679: \ we have to store more than just the address of the branch, so the
  680: \ traditional linked list approach is no longer viable.
  681: \ This is solved by storing the information about the leavings in a
  682: \ special stack.
  683: 
  684: \ !! remove the fixed size limit. 'Tis not hard.
  685: 20 constant leave-stack-size
  686: create leave-stack  60 cells allot
  687: Avariable leave-sp  leave-stack 3 cells + leave-sp !
  688: 
  689: : clear-leave-stack ( -- )
  690:     leave-stack leave-sp ! ;
  691: 
  692: \ : leave-empty? ( -- f )
  693: \  leave-sp @ leave-stack = ;
  694: 
  695: : >leave ( orig -- )
  696:     \ push on leave-stack
  697:     leave-sp @
  698:     dup [ leave-stack 60 cells + ] Aliteral
  699:     >= abort" leave-stack full"
  700:     tuck ! cell+
  701:     tuck ! cell+
  702:     tuck ! cell+
  703:     leave-sp ! ;
  704: 
  705: : leave> ( -- orig )
  706:     \ pop from leave-stack
  707:     leave-sp @
  708:     dup leave-stack <= IF
  709:        drop 0 0 0  EXIT  THEN
  710:     cell - dup @ swap
  711:     cell - dup @ swap
  712:     cell - dup @ swap
  713:     leave-sp ! ;
  714: 
  715: : DONE ( orig -- )
  716:     \ !! the original done had ( addr -- )
  717:     drop >r drop
  718:     begin
  719: 	leave>
  720: 	over r@ u>=
  721:     while
  722: 	POSTPONE then
  723:     repeat
  724:     >leave rdrop ; immediate restrict
  725: 
  726: : LEAVE ( -- )
  727:     POSTPONE ahead
  728:     >leave ; immediate restrict
  729: 
  730: : ?LEAVE ( -- )
  731:     POSTPONE 0= POSTPONE if
  732:     >leave ; immediate restrict
  733: 
  734: : DO ( -- do-sys )
  735:     POSTPONE (do)
  736:     POSTPONE begin drop do-dest
  737:     ( 0 0 0 >leave ) ; immediate restrict
  738: 
  739: : ?DO ( -- do-sys )
  740:     ( 0 0 0 >leave )
  741:     POSTPONE (?do)
  742:     >mark >leave
  743:     POSTPONE begin drop do-dest ; immediate restrict
  744: 
  745: : FOR ( -- do-sys )
  746:     POSTPONE (for)
  747:     POSTPONE begin drop do-dest
  748:     ( 0 0 0 >leave ) ; immediate restrict
  749: 
  750: \ LOOP etc. are just like UNTIL
  751: 
  752: : loop-like ( do-sys xt1 xt2 -- )
  753:     >r >r 0 cs-pick swap cell - swap 1 cs-roll r> r> rot do-dest?
  754:     until-like  POSTPONE done  POSTPONE unloop ;
  755: 
  756: : LOOP ( do-sys -- )
  757:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate restrict
  758: 
  759: : +LOOP ( do-sys -- )
  760:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate restrict
  761: 
  762: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
  763: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
  764: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
  765: \ negative increments.
  766: : S+LOOP ( do-sys -- )
  767:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate restrict
  768: 
  769: : NEXT ( do-sys -- )
  770:  ['] (next) ['] (next)-lp+!# loop-like ; immediate restrict
  771: 
  772: \ Structural Conditionals                              12dec92py
  773: 
  774: : EXIT ( -- )
  775:     0 adjust-locals-size
  776:     POSTPONE ;s
  777:     POSTPONE unreachable ; immediate restrict
  778: 
  779: : ?EXIT ( -- )
  780:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
  781: 
  782: \ Strings                                              22feb93py
  783: 
  784: : ," ( "string"<"> -- ) [char] " parse
  785:   here over char+ allot  place align ;
  786: : "lit ( -- addr )
  787:   r> r> dup count + aligned >r swap >r ;               restrict
  788: : (.")     "lit count type ;                           restrict
  789: : (S")     "lit count ;                                restrict
  790: : SLiteral postpone (S") here over char+ allot  place align ;
  791:                                              immediate restrict
  792: create s"-buffer /line chars allot
  793: : S" ( run-time: -- c-addr u )
  794:     [char] " parse
  795:     state @
  796:     IF
  797: 	postpone SLiteral
  798:     ELSE
  799: 	/line min >r s"-buffer r@ cmove
  800: 	s"-buffer r>
  801:     THEN ;
  802:                                              immediate
  803: : ."       state @  IF    postpone (.") ,"  align
  804:                     ELSE  [char] " parse type  THEN  ;  immediate
  805: : (        [char] ) parse 2drop ;                       immediate
  806: : \ ( -- ) \ core-ext backslash
  807:     blk @
  808:     IF
  809: 	>in @ c/l / 1+ c/l * >in !
  810: 	EXIT
  811:     THEN
  812:     source >in ! drop ; immediate
  813: 
  814: : \G ( -- ) \ new backslash
  815:     POSTPONE \ ; immediate
  816: 
  817: \ error handling                                       22feb93py
  818: \ 'abort thrown out!                                   11may93jaw
  819: 
  820: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
  821:                 rdrop ;
  822: : abort"        postpone (abort") ," ;        immediate restrict
  823: 
  824: \ Header states                                        23feb93py
  825: 
  826: : flag! ( 8b -- )
  827:     last @ dup 0= abort" last word was headerless"
  828:     cell+ tuck c@ xor swap c! ;
  829: : immediate     $20 flag! ;
  830: : restrict      $40 flag! ;
  831: \ ' noop alias restrict
  832: 
  833: \ Header                                               23feb93py
  834: 
  835: \ input-stream, nextname and noname are quite ugly (passing
  836: \ information through global variables), but they are useful for dealing
  837: \ with existing/independent defining words
  838: 
  839: defer (header)
  840: defer header     ' (header) IS header
  841: 
  842: : string, ( c-addr u -- )
  843:     \ puts down string as cstring
  844:     dup c, here swap chars dup allot move ;
  845: 
  846: : name,  ( "name" -- )
  847:     name name-too-short? name-too-long?
  848:     string, cfalign ;
  849: : input-stream-header ( "name" -- )
  850:     \ !! this is f83-implementation-dependent
  851:     align here last !  -1 A,
  852:     name, $80 flag! ;
  853: 
  854: : input-stream ( -- )  \ general
  855: \ switches back to getting the name from the input stream ;
  856:     ['] input-stream-header IS (header) ;
  857: 
  858: ' input-stream-header IS (header)
  859: 
  860: \ !! make that a 2variable
  861: create nextname-buffer 32 chars allot
  862: 
  863: : nextname-header ( -- )
  864:     \ !! f83-implementation-dependent
  865:     nextname-buffer count
  866:     align here last ! -1 A,
  867:     string, cfalign
  868:     $80 flag!
  869:     input-stream ;
  870: 
  871: \ the next name is given in the string
  872: : nextname ( c-addr u -- ) \ general
  873:     name-too-long?
  874:     nextname-buffer c! ( c-addr )
  875:     nextname-buffer count move
  876:     ['] nextname-header IS (header) ;
  877: 
  878: : noname-header ( -- )
  879:     0 last ! cfalign
  880:     input-stream ;
  881: 
  882: : noname ( -- ) \ general
  883: \ the next defined word remains anonymous. The xt of that word is given by lastxt
  884:     ['] noname-header IS (header) ;
  885: 
  886: : lastxt ( -- xt ) \ general
  887: \ 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
  888:     lastcfa @ ;
  889: 
  890: : Alias    ( cfa "name" -- )
  891:   Header reveal , $80 flag! ;
  892: 
  893: : name>string ( nfa -- addr count )
  894:  cell+ count $1F and ;
  895: 
  896: Create ???  0 , 3 c, char ? c, char ? c, char ? c,
  897: : >name ( cfa -- nfa )
  898:  $21 cell do
  899:    dup i - count $9F and + cfaligned over $80 + = if
  900:      i - cell - unloop exit
  901:    then
  902:  cell +loop
  903:  drop ??? ( wouldn't 0 be better? ) ;
  904: 
  905: \ indirect threading                                   17mar93py
  906: 
  907: : cfa,     ( code-address -- )
  908:     here lastcfa !
  909:     here  0 A, 0 ,  code-address! ;
  910: : compile, ( xt -- )		A, ;
  911: : !does    ( addr -- )		lastcfa @ does-code! ;
  912: : (;code)  ( R: addr -- )	r> /does-handler + !does ;
  913: : dodoes,  ( -- )
  914:   here /does-handler allot does-handler! ;
  915: 
  916: \ direct threading is implementation dependent
  917: 
  918: : Create    Header reveal [ :dovar ] Literal cfa, ;
  919: 
  920: \ DOES>                                                17mar93py
  921: 
  922: : DOES>  ( compilation: -- )
  923:     state @
  924:     IF
  925: 	;-hook postpone (;code) dodoes,
  926:     ELSE
  927: 	dodoes, here !does 0 ]
  928:     THEN 
  929:     :-hook ; immediate
  930: 
  931: \ Create Variable User Constant                        17mar93py
  932: 
  933: : Variable  Create 0 , ;
  934: : AVariable Create 0 A, ;
  935: : 2VARIABLE ( "name" -- ) \ double
  936:     create 0 , 0 , ;
  937:     
  938: : User      Variable ;
  939: : AUser     AVariable ;
  940: 
  941: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
  942: : Constant  (Constant) , ;
  943: : AConstant (Constant) A, ;
  944: 
  945: : 2Constant
  946:     Create ( w1 w2 "name" -- )
  947:         2,
  948:     DOES> ( -- w1 w2 )
  949:         2@ ;
  950:     
  951: \ IS Defer What's Defers TO                            24feb93py
  952: 
  953: : Defer ( -- )
  954:     \ !! shouldn't it be initialized with abort or something similar?
  955:     Header Reveal [ :dodefer ] Literal cfa,
  956:     ['] noop A, ;
  957: \     Create ( -- ) 
  958: \ 	['] noop A,
  959: \     DOES> ( ??? )
  960: \ 	@ execute ;
  961: 
  962: : IS ( addr "name" -- )
  963:     ' >body
  964:     state @
  965:     IF    postpone ALiteral postpone !  
  966:     ELSE  !
  967:     THEN ;  immediate
  968: ' IS Alias TO immediate
  969: 
  970: : What's ( "name" -- addr )  ' >body
  971:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
  972:                                              immediate
  973: : Defers ( "name" -- )  ' >body @ compile, ;
  974:                                              immediate
  975: 
  976: \ : ;                                                  24feb93py
  977: 
  978: defer :-hook ( sys1 -- sys2 )
  979: defer ;-hook ( sys2 -- sys1 )
  980: 
  981: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
  982: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
  983:   immediate restrict
  984: 
  985: : :noname ( -- xt colon-sys )
  986:     0 last !
  987:     here [ :docol ] Literal cfa, 0 ] :-hook ;
  988: 
  989: \ Search list handling                                 23feb93py
  990: 
  991: AVariable current
  992: 
  993: : last?   ( -- false / nfa nfa )    last @ ?dup ;
  994: : (reveal) ( -- )
  995:     last?
  996:     IF
  997: 	dup @ 0<
  998: 	IF
  999: 	    current @ @ over ! current @ !
 1000: 	ELSE
 1001: 	    drop
 1002: 	THEN
 1003:     THEN ;
 1004: 
 1005: \ object oriented search list                          17mar93py
 1006: 
 1007: \ word list structure:
 1008: 
 1009: struct
 1010:   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
 1011:   1 cells: field reveal-method \ xt: ( -- )
 1012:   1 cells: field rehash-method \ xt: ( wid -- )
 1013: \   \ !! what else
 1014: end-struct wordlist-map-struct
 1015: 
 1016: struct
 1017:   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
 1018:   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
 1019:   1 cells: field wordlist-link \ link field to other wordlists
 1020:   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
 1021: end-struct wordlist-struct
 1022: 
 1023: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
 1024: 
 1025: \ Search list table: find reveal
 1026: Create f83search       ' f83find A,  ' (reveal) A,  ' drop A,
 1027: 
 1028: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
 1029: AVariable lookup       G forth-wordlist lookup T !
 1030: G forth-wordlist current T !
 1031: 
 1032: : (search-wordlist)  ( addr count wid -- nfa / false )
 1033:   dup wordlist-map @ find-method @ execute ;
 1034: 
 1035: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
 1036:     (search-wordlist) dup  IF  found  THEN ;
 1037: 
 1038: Variable warnings  G -1 warnings T !
 1039: 
 1040: : check-shadow  ( addr count wid -- )
 1041: \ prints a warning if the string is already present in the wordlist
 1042: \ !! should be refined so the user can suppress the warnings
 1043:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
 1044:    ." redefined " name>string 2dup type
 1045:    compare 0<> if
 1046:      ."  with " type
 1047:    else
 1048:      2drop
 1049:    then
 1050:    space space EXIT
 1051:  then
 1052:  2drop 2drop ;
 1053: 
 1054: : sfind ( c-addr u -- xt n / 0 )
 1055:     lookup @ search-wordlist ;
 1056: 
 1057: : find   ( addr -- cfa +-1 / string false )
 1058:     \ !! not ANS conformant: returns +-2 for restricted words
 1059:     dup count sfind dup if
 1060: 	rot drop
 1061:     then ;
 1062: 
 1063: : reveal ( -- )
 1064:  last? if
 1065:    name>string current @ check-shadow
 1066:  then
 1067:  current @ wordlist-map @ reveal-method @ execute ;
 1068: 
 1069: : rehash  ( wid -- )  dup wordlist-map @ rehash-method @ execute ;
 1070: 
 1071: : '    ( "name" -- addr )  name sfind 0= if -&13 bounce then ;
 1072: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
 1073: \ Input                                                13feb93py
 1074: 
 1075: 07 constant #bell
 1076: 08 constant #bs
 1077: 09 constant #tab
 1078: 7F constant #del
 1079: 0D constant #cr                \ the newline key code
 1080: 0C constant #ff
 1081: 0A constant #lf
 1082: 
 1083: : bell  #bell emit ;
 1084: 
 1085: \ : backspaces  0 ?DO  #bs emit  LOOP ;
 1086: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
 1087:   over 3 pick 2 pick chars /string ;
 1088: : type-rest ( span addr pos1 -- span addr pos1 back )
 1089:   >string tuck type ;
 1090: : (del)  ( max span addr pos1 -- max span addr pos2 )
 1091:   1- >string over 1+ -rot move
 1092:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
 1093: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
 1094:   >r >string over 1+ swap move 2dup chars + r> swap c!
 1095:   rot 1+ -rot type-rest 1- backspaces 1+ ;
 1096: : ?del ( max span addr pos1 -- max span addr pos2 0 )
 1097:   dup  IF  (del)  THEN  0 ;
 1098: : (ret)  type-rest drop true space ;
 1099: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
 1100: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
 1101: : eof  2 pick 0=  IF  bye  ELSE  (ret)  THEN ;
 1102: 
 1103: Create ctrlkeys
 1104:   ] false false back  false  eof   false forw  false
 1105:     ?del  false (ret) false  false (ret) false false
 1106:     false false false false  false false false false
 1107:     false false false false  false false false false [
 1108: 
 1109: defer everychar
 1110: ' noop IS everychar
 1111: 
 1112: : decode ( max span addr pos1 key -- max span addr pos2 flag )
 1113:   everychar
 1114:   dup #del = IF  drop #bs  THEN  \ del is rubout
 1115:   dup bl <   IF  cells ctrlkeys + @ execute  EXIT  THEN
 1116:   >r 2over = IF  rdrop bell 0 EXIT  THEN
 1117:   r> (ins) 0 ;
 1118: 
 1119: \ decode should better use a table for control key actions
 1120: \ to define keyboard bindings later
 1121: 
 1122: : accept   ( addr len -- len )
 1123:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
 1124: \ this allows to edit given strings
 1125:          ELSE  0  THEN rot over
 1126:   BEGIN  key decode  UNTIL
 1127:   2drop nip ;
 1128: 
 1129: \ Output                                               13feb93py
 1130: 
 1131: Defer type      \ defer type for a output buffer or fast
 1132:                 \ screen write
 1133: 
 1134: \ : (type) ( addr len -- )
 1135: \   bounds ?DO  I c@ emit  LOOP ;
 1136: 
 1137: ' (type) IS Type
 1138: 
 1139: Defer emit
 1140: 
 1141: ' (Emit) IS Emit
 1142: 
 1143: Defer key
 1144: ' (key) IS key
 1145: 
 1146: \ : form  ( -- rows cols )  &24 &80 ;
 1147: \ form should be implemented using TERMCAPS or CURSES
 1148: \ : rows  form drop ;
 1149: \ : cols  form nip  ;
 1150: 
 1151: \ Query                                                07apr93py
 1152: 
 1153: : refill ( -- flag )
 1154:   blk @  IF  1 blk +!  true  0 >in !  EXIT  THEN
 1155:   tib /line
 1156:   loadfile @ ?dup
 1157:   IF    read-line throw
 1158:   ELSE  loadline @ 0< IF 2drop false EXIT THEN
 1159:         accept true
 1160:   THEN
 1161:   1 loadline +!
 1162:   swap #tib ! 0 >in ! ;
 1163: 
 1164: : Query  ( -- )  loadfile off  blk off  refill drop ;
 1165: 
 1166: \ File specifiers                                       11jun93jaw
 1167: 
 1168: 
 1169: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
 1170: \ 2 c, here char r c, char + c, 0 c,
 1171: \ 2 c, here char w c, char + c, 0 c, align
 1172: 4 Constant w/o
 1173: 2 Constant r/w
 1174: 0 Constant r/o
 1175: 
 1176: \ BIN WRITE-LINE                                        11jun93jaw
 1177: 
 1178: \ : bin           dup 1 chars - c@
 1179: \                 r/o 4 chars + over - dup >r swap move r> ;
 1180: 
 1181: : bin  1 or ;
 1182: 
 1183: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
 1184:                            \ or not unix environments if
 1185:                            \ bin is not selected
 1186: 
 1187: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
 1188:                 nl$ count r> write-file ;
 1189: 
 1190: \ include-file                                         07apr93py
 1191: 
 1192: : push-file  ( -- )  r>
 1193:   loadline @ >r loadfile @ >r
 1194:   blk @ >r >tib @ >r  #tib @ dup >r  >tib +!  >in @ >r  >r ;
 1195: 
 1196: : pop-file   ( throw-code -- throw-code )
 1197:   dup IF
 1198:          source >in @ loadline @ loadfilename 2@
 1199: 	 error-stack dup @ dup 1+
 1200: 	 max-errors 1- min error-stack !
 1201: 	 6 * cells + cell+
 1202: 	 5 cells bounds swap DO
 1203: 	                    I !
 1204: 	 -1 cells +LOOP
 1205:   THEN
 1206:   r>
 1207:   r> >in !  r> #tib !  r> >tib !  r> blk !
 1208:   r> loadfile ! r> loadline !  >r ;
 1209: 
 1210: : read-loop ( i*x -- j*x )
 1211:   BEGIN  refill  WHILE  interpret  REPEAT ;
 1212: 
 1213: : include-file ( i*x fid -- j*x )
 1214:   push-file  loadfile !
 1215:   0 loadline ! blk off  ['] read-loop catch
 1216:   loadfile @ close-file swap 2dup or
 1217:   pop-file  drop throw throw ;
 1218: 
 1219: create pathfilenamebuf 256 chars allot \ !! make this grow on demand
 1220: 
 1221: \ : check-file-prefix  ( addr len -- addr' len' flag )
 1222: \   dup 0=                    IF  true EXIT  THEN 
 1223: \   over c@ '/ =              IF  true EXIT  THEN 
 1224: \   over 2 S" ./" compare 0=  IF  true EXIT  THEN 
 1225: \   over 3 S" ../" compare 0= IF  true EXIT  THEN
 1226: \   over 2 S" ~/" compare 0=
 1227: \   IF     1 /string
 1228: \          S" HOME" getenv tuck pathfilenamebuf swap move
 1229: \          2dup + >r pathfilenamebuf + swap move
 1230: \          pathfilenamebuf r> true
 1231: \   ELSE   false
 1232: \   THEN ;
 1233: 
 1234: : open-path-file ( c-addr1 u1 -- file-id c-addr2 u2 )
 1235:     \ opens a file for reading, searching in the path for it (unless
 1236:     \ the filename contains a slash); c-addr2 u2 is the full filename
 1237:     \ (valid until the next call); if the file is not found (or in
 1238:     \ case of other errors for each try), -38 (non-existant file) is
 1239:     \ thrown. Opening for other access modes makes little sense, as
 1240:     \ the path will usually contain dirs that are only readable for
 1241:     \ the user
 1242:     \ !! use file-status to determine access mode?
 1243:     2dup [char] / scan nip ( 0<> )
 1244:     if \ the filename contains a slash
 1245: 	2dup r/o open-file throw ( c-addr1 u1 file-id )
 1246: 	-rot >r pathfilenamebuf r@ cmove ( file-id R: u1 )
 1247: 	pathfilenamebuf r> EXIT
 1248:     then
 1249:     pathdirs 2@ 0
 1250: \    check-file-prefix 0= 
 1251: \    IF  pathdirs 2@ 0
 1252:     ?DO ( c-addr1 u1 dirnamep )
 1253: 	dup >r 2@ dup >r pathfilenamebuf swap cmove ( addr u )
 1254: 	2dup pathfilenamebuf r@ chars + swap cmove ( addr u )
 1255: 	pathfilenamebuf over r> + dup >r r/o open-file 0=
 1256: 	IF ( addr u file-id )
 1257: 	    nip nip r> rdrop 0 LEAVE
 1258: 	THEN
 1259: 	rdrop drop r> cell+ cell+
 1260:     LOOP
 1261: \    ELSE   2dup open-file throw -rot  THEN 
 1262:     0<> -&38 and throw ( file-id u2 )
 1263:     pathfilenamebuf swap ;
 1264: 
 1265: create included-files 0 , 0 , ( pointer to and count of included files )
 1266: 
 1267: : included? ( c-addr u -- f )
 1268:     \ true, iff filename c-addr u is in included-files
 1269:     included-files 2@ 0
 1270:     ?do ( c-addr u addr )
 1271: 	dup >r 2@ 2over compare 0=
 1272: 	if
 1273: 	    2drop rdrop unloop
 1274: 	    true EXIT
 1275: 	then
 1276: 	r> cell+ cell+
 1277:     loop
 1278:     2drop drop false ;
 1279: 
 1280: : add-included-file ( c-addr u -- )
 1281:     \ add name c-addr u to included-files
 1282:     included-files 2@ tuck 1+ 2* cells resize throw
 1283:     swap 2dup 1+ included-files 2!
 1284:     2* cells + 2! ;
 1285: 
 1286: : save-string		( addr1 u -- addr2 u )
 1287:     swap >r
 1288:     dup allocate throw
 1289:     swap 2dup r> -rot move ;
 1290: 
 1291: : included1 ( i*x file-id c-addr u -- j*x )
 1292:     \ include the file file-id with the name given by c-addr u
 1293:     loadfilename 2@ >r >r
 1294:     save-string 2dup loadfilename 2! add-included-file ( file-id )
 1295:     ['] include-file catch
 1296:     r> r> loadfilename 2!  throw ;
 1297:     
 1298: : included ( i*x addr u -- j*x )
 1299:     open-path-file included1 ;
 1300: 
 1301: : required ( i*x addr u -- j*x )
 1302:     \ include the file with the name given by addr u, if it is not
 1303:     \ included already. Currently this works by comparing the name of
 1304:     \ the file (with path) against the names of earlier included
 1305:     \ files; however, it would probably be better to fstat the file,
 1306:     \ and compare the device and inode. The advantages would be: no
 1307:     \ problems with several paths to the same file (e.g., due to
 1308:     \ links) and we would catch files included with include-file and
 1309:     \ write a require-file.
 1310:     open-path-file 2dup included?
 1311:     if
 1312: 	2drop close-file throw
 1313:     else
 1314: 	included1
 1315:     then ;
 1316: 
 1317: \ HEX DECIMAL                                           2may93jaw
 1318: 
 1319: : decimal a base ! ;
 1320: : hex     10 base ! ;
 1321: 
 1322: \ DEPTH                                                 9may93jaw
 1323: 
 1324: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
 1325: : clearstack ( ... -- )  s0 @ sp! ;
 1326: 
 1327: \ INCLUDE                                               9may93jaw
 1328: 
 1329: : include  ( "file" -- )
 1330:   name included ;
 1331: 
 1332: : require  ( "file" -- )
 1333:   name required ;
 1334: 
 1335: \ RECURSE                                               17may93jaw
 1336: 
 1337: : recurse ( -- )
 1338:     lastxt compile, ; immediate restrict
 1339: : recursive ( -- )
 1340:     reveal last off ; immediate
 1341: 
 1342: \ */MOD */                                              17may93jaw
 1343: 
 1344: \ !! I think */mod should have the same rounding behaviour as / - anton
 1345: : */mod >r m* r> sm/rem ;
 1346: 
 1347: : */ */mod nip ;
 1348: 
 1349: \ EVALUATE                                              17may93jaw
 1350: 
 1351: : evaluate ( c-addr len -- )
 1352:   push-file  dup #tib ! >tib @ swap move
 1353:   >in off blk off loadfile off -1 loadline !
 1354: 
 1355: \  BEGIN  interpret  >in @ #tib @ u>= UNTIL
 1356:   ['] interpret catch
 1357:   pop-file throw ;
 1358: 
 1359: 
 1360: : abort -1 throw ;
 1361: 
 1362: \+ environment? true ENV" CORE"
 1363: \ core wordset is now complete!
 1364: 
 1365: \ Quit                                                 13feb93py
 1366: 
 1367: Defer 'quit
 1368: Defer .status
 1369: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
 1370: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
 1371: ' (quit) IS 'quit
 1372: 
 1373: \ DOERROR (DOERROR)                                     13jun93jaw
 1374: 
 1375: 8 Constant max-errors
 1376: Variable error-stack  0 error-stack !
 1377: max-errors 6 * cells allot
 1378: \ format of one cell:
 1379: \ source ( addr u )
 1380: \ >in
 1381: \ line-number
 1382: \ Loadfilename ( addr u )
 1383: 
 1384: : dec. ( n -- )
 1385:     \ print value in decimal representation
 1386:     base @ decimal swap . base ! ;
 1387: 
 1388: : typewhite ( addr u -- )
 1389:     \ like type, but white space is printed instead of the characters
 1390:     bounds ?do
 1391: 	i c@ 9 = if \ check for tab
 1392: 	    9
 1393: 	else
 1394: 	    bl
 1395: 	then
 1396: 	emit
 1397:     loop
 1398: ;
 1399: 
 1400: DEFER DOERROR
 1401: 
 1402: : .error-frame ( addr1 u1 n1 n2 addr2 u2 -- )
 1403:   cr error-stack @
 1404:   IF
 1405:      ." in file included from "
 1406:      type ." :" dec.  drop 2drop
 1407:   ELSE
 1408:      type ." :" dec.
 1409:      cr dup 2over type cr drop
 1410:      nip -trailing 1- ( line-start index2 )
 1411:      0 >r  BEGIN
 1412:                   2dup + c@ bl >  WHILE
 1413: 		  r> 1+ >r  1- dup 0<  UNTIL  THEN  1+
 1414:      ( line-start index1 )
 1415:      typewhite
 1416:      r> 1 max 0 ?do \ we want at least one "^", even if the length is 0
 1417:                   [char] ^ emit
 1418:      loop
 1419:   THEN
 1420: ;
 1421: 
 1422: : (DoError) ( throw-code -- )
 1423:   loadline @ IF
 1424:                source >in @ loadline @ 0 0 .error-frame
 1425:   THEN
 1426:   error-stack @ 0 ?DO
 1427:     -1 error-stack +!
 1428:     error-stack dup @ 6 * cells + cell+
 1429:     6 cells bounds DO
 1430:       I @
 1431:     cell +LOOP
 1432:     .error-frame
 1433:   LOOP
 1434:   dup -2 =
 1435:   IF 
 1436:      "error @ ?dup
 1437:      IF
 1438:         cr count type 
 1439:      THEN
 1440:      drop
 1441:   ELSE
 1442:      .error
 1443:   THEN
 1444:   normal-dp dpp ! ;
 1445: 
 1446: ' (DoError) IS DoError
 1447: 
 1448: : quit   r0 @ rp! handler off >tib @ >r
 1449:   BEGIN
 1450:     postpone [
 1451:     ['] 'quit CATCH dup
 1452:   WHILE
 1453:     DoError r@ >tib !
 1454:   REPEAT
 1455:   drop r> >tib ! ;
 1456: 
 1457: \ Cold                                                 13feb93py
 1458: 
 1459: \ : .name ( name -- ) cell+ count $1F and type space ;
 1460: \ : words  listwords @
 1461: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
 1462: 
 1463: : cstring>sstring  ( cstring -- addr n )  -1 0 scan 0 swap 1+ /string ;
 1464: : arg ( n -- addr count )  cells argv @ + @ cstring>sstring ;
 1465: : #!       postpone \ ;  immediate
 1466: 
 1467: Create pathstring 2 cells allot \ string
 1468: Create pathdirs   2 cells allot \ dir string array, pointer and count
 1469: Variable argv
 1470: Variable argc
 1471: 
 1472: 0 Value script? ( -- flag )
 1473: 
 1474: : process-path ( addr1 u1 -- addr2 u2 )
 1475:     \ addr1 u1 is a path string, addr2 u2 is an array of dir strings
 1476:     here >r
 1477:     BEGIN
 1478: 	over >r [char] : scan
 1479: 	over r> tuck - ( rest-str this-str )
 1480: 	dup
 1481: 	IF
 1482: 	    2dup 1- chars + c@ [char] / <>
 1483: 	    IF
 1484: 		2dup chars + [char] / swap c!
 1485: 		1+
 1486: 	    THEN
 1487: 	    2,
 1488: 	ELSE
 1489: 	    2drop
 1490: 	THEN
 1491: 	dup
 1492:     WHILE
 1493: 	1 /string
 1494:     REPEAT
 1495:     2drop
 1496:     here r> tuck - 2 cells / ;
 1497: 
 1498: : do-option ( addr1 len1 addr2 len2 -- n )
 1499:     2swap
 1500:     2dup s" -e"         compare  0= >r
 1501:     2dup s" --evaluate" compare  0= r> or
 1502:     IF  2drop dup >r ['] evaluate catch
 1503: 	?dup IF  dup >r DoError r> negate (bye)  THEN
 1504: 	r> >tib +!  2 EXIT  THEN
 1505:     ." Unknown option: " type cr 2drop 1 ;
 1506: 
 1507: : process-args ( -- )
 1508:     >tib @ >r
 1509:     argc @ 1
 1510:     ?DO
 1511: 	I arg over c@ [char] - <>
 1512: 	IF
 1513: 	    required 1
 1514: 	ELSE
 1515: 	    I 1+ argc @ =  IF  s" "  ELSE  I 1+ arg  THEN
 1516: 	    do-option
 1517: 	THEN
 1518:     +LOOP
 1519:     r> >tib ! ;
 1520: 
 1521: Defer 'cold ' noop IS 'cold
 1522: 
 1523: : cold ( -- )
 1524:     pathstring 2@ process-path pathdirs 2!
 1525:     0 0 included-files 2!
 1526:     'cold
 1527:     argc @ 1 >
 1528:     IF
 1529: 	true to script?
 1530: 	['] process-args catch ?dup
 1531: 	IF
 1532: 	    dup >r DoError cr r> negate (bye)
 1533: 	THEN
 1534: 	cr
 1535:     THEN
 1536:     false to script?
 1537:     ." GNU Forth " version-string type ." , Copyright (C) 1994 Free Software Foundation, Inc." cr
 1538:     ." GNU Forth comes with ABSOLUTELY NO WARRANTY; for details type `license'" cr
 1539:     ." Type `bye' to exit"
 1540:     loadline off quit ;
 1541: 
 1542: : license ( -- ) cr
 1543:  ." This program is free software; you can redistribute it and/or modify" cr
 1544:  ." it under the terms of the GNU General Public License as published by" cr
 1545:  ." the Free Software Foundation; either version 2 of the License, or" cr
 1546:  ." (at your option) any later version." cr cr
 1547: 
 1548:  ." This program is distributed in the hope that it will be useful," cr
 1549:  ." but WITHOUT ANY WARRANTY; without even the implied warranty of" cr
 1550:  ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" cr
 1551:  ." GNU General Public License for more details." cr cr
 1552: 
 1553:  ." You should have received a copy of the GNU General Public License" cr
 1554:  ." along with this program; if not, write to the Free Software" cr
 1555:  ." Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA." cr ;
 1556: 
 1557: : boot ( path **argv argc -- )
 1558:   argc ! argv ! cstring>sstring pathstring 2!  main-task up!
 1559:   sp@ dup s0 ! $10 + >tib ! #tib off >in off
 1560:   rp@ r0 !  fp@ f0 !  cold ;
 1561: 
 1562: : bye  script? 0= IF  cr  THEN  0 (bye) ;
 1563: 
 1564: \ **argv may be scanned by the C starter to get some important
 1565: \ information, as -display and -geometry for an X client FORTH
 1566: \ or space and stackspace overrides
 1567: 
 1568: \ 0 arg contains, however, the name of the program.

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