File:  [gforth] / gforth / Attic / kernal.fs
Revision 1.8: download - view: text, annotated - select for diffs
Fri Jun 17 12:35:07 1994 UTC (25 years, 8 months ago) by anton
Branches: MAIN
CVS tags: HEAD
Integrated locals (in particular automatic scoping) into the system.

    1: \ KERNAL.FS    ANS figFORTH kernal                     17dec92py
    2: \ $ID:
    3: \ Idea and implementation: Bernd Paysan (py)
    4: \ Copyright 1992 by the ANSI figForth Development Group
    5: 
    6: \ Log:  ', '- usw. durch [char] ... ersetzt
    7: \       man sollte die unterschiedlichen zahlensysteme
    8: \       mit $ und & zumindest im interpreter weglassen
    9: \       schon erledigt!
   10: \       11may93jaw
   11: \ name>         0= nicht vorhanden              17may93jaw
   12: \               nfa can be lfa or nfa!
   13: \ find          splited into find and (find)
   14: \               (find) for later use            17may93jaw
   15: \ search        replaced by lookup because
   16: \               it is a word of the string wordset
   17: \                                               20may93jaw
   18: \ postpone      added immediate                 21may93jaw
   19: \ to            added immediate                 07jun93jaw
   20: \ cfa, header   put "here lastcfa !" in
   21: \               cfa, this is more logical
   22: \               and noname: works wothout
   23: \               extra "here lastcfa !"          08jun93jaw
   24: \ (parse-white) thrown out
   25: \ refill        added outer trick
   26: \               to show there is something
   27: \               going on                        09jun93jaw
   28: \ leave ?leave  somebody forgot UNLOOP!!!       09jun93jaw
   29: \ leave ?leave  unloop thrown out
   30: \               unloop after loop is used       10jun93jaw
   31: 
   32: HEX
   33: 
   34: \ Bit string manipulation                              06oct92py
   35: 
   36: Create bits  80 c, 40 c, 20 c, 10 c, 8 c, 4 c, 2 c, 1 c,
   37: DOES> ( n -- )  + c@ ;
   38: 
   39: : >bit  ( addr n -- c-addr mask )  8 /mod rot + swap bits ;
   40: : +bit  ( addr n -- )  >bit over c@ or swap c! ;
   41: 
   42: : relinfo ( -- addr )  forthstart dup @ + ;
   43: : >rel  ( addr -- n )  forthstart - ;
   44: : relon ( addr -- )  relinfo swap >rel cell / +bit ;
   45: 
   46: \ here allot , c, A,                                   17dec92py
   47: 
   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: 
   70: 
   71: : A!    ( addr1 addr2 -- )  dup relon ! ;
   72: : A,    ( addr -- )     here cell allot A! ;
   73: 
   74: \ on off                                               23feb93py
   75: 
   76: : on  ( addr -- )  true  swap ! ;
   77: : off ( addr -- )  false swap ! ;
   78: 
   79: \ name> found                                          17dec92py
   80: 
   81: : (name>)  ( nfa -- cfa )    count  $1F and  +  aligned ;
   82: : name>    ( nfa -- cfa )
   83:   dup  (name>) swap  c@ $80 and 0= IF  @ THEN ;
   84: 
   85: : found ( nfa -- cfa n )  cell+
   86:   dup c@ >r  (name>) r@ $80 and  0= IF  @       THEN
   87: \                  -1 r@ $40 and     IF  1-      THEN
   88:                   -1 r> $20 and     IF  negate  THEN  ;
   89: 
   90: \ (find)                                               17dec92py
   91: 
   92: \ : (find) ( addr count nfa1 -- nfa2 / false )
   93: \   BEGIN  dup  WHILE  dup >r
   94: \          cell+ count $1F and dup >r 2over r> =
   95: \          IF  -text  0= IF  2drop r> EXIT  THEN
   96: \          ELSE  2drop drop  THEN  r> @
   97: \   REPEAT nip nip ;
   98: 
   99: \ place bounds                                         13feb93py
  100: 
  101: : place  ( addr len to -- ) over >r  rot over 1+  r> move c! ;
  102: : bounds ( beg count -- end beg )  over + swap ;
  103: 
  104: \ input stream primitives                              23feb93py
  105: 
  106: : tib   >tib @ ;
  107: Defer source
  108: : (source) ( -- addr count ) tib #tib @ ;
  109: ' (source) IS source
  110: 
  111: \ (word)                                               22feb93py
  112: 
  113: : scan   ( addr1 n1 char -- addr2 n2 )  >r
  114:   BEGIN  dup  WHILE  over c@ r@ <>  WHILE  1 /string
  115:   REPEAT  THEN  rdrop ;
  116: : skip   ( addr1 n1 char -- addr2 n2 )  >r
  117:   BEGIN  dup  WHILE  over c@ r@  =  WHILE  1 /string
  118:   REPEAT  THEN  rdrop ;
  119: 
  120: : (word) ( addr1 n1 char -- addr2 n2 )
  121:   dup >r skip 2dup r> scan  nip - ;
  122: 
  123: \ (word) should fold white spaces
  124: \ this is what (parse-white) does
  125: 
  126: \ word parse                                           23feb93py
  127: 
  128: : parse-word  ( char -- addr len )
  129:   source 2dup >r >r >in @ /string
  130:   rot dup bl = IF  drop (parse-white)  ELSE  (word)  THEN
  131:   2dup + r> - 1+ r> min >in ! ;
  132: : word   ( char -- addr )
  133:   parse-word here place  bl here count + c!  here ;
  134: 
  135: : parse    ( char -- addr len )
  136:   >r  source  >in @ /string  over  swap r>  scan >r
  137:   over - dup r> IF 1+ THEN  >in +! ;
  138: 
  139: \ name                                                 13feb93py
  140: 
  141: : capitalize ( addr -- addr )
  142:   dup count chars bounds
  143:   ?DO  I c@ toupper I c! 1 chars +LOOP ;
  144: : (name)  ( -- addr )  bl word ;
  145: : (cname) ( -- addr )  bl word capitalize ;
  146: 
  147: \ Literal                                              17dec92py
  148: 
  149: : Literal  ( n -- )  state @ IF postpone lit  , THEN ;
  150:                                                       immediate
  151: : ALiteral ( n -- )  state @ IF postpone lit A, THEN ;
  152:                                                       immediate
  153: 
  154: : char   ( 'char' -- n )  bl word char+ c@ ;
  155: : [char] ( 'char' -- n )  char postpone Literal ; immediate
  156: ' [char] Alias Ascii immediate
  157: 
  158: : (compile) ( -- )  r> dup cell+ >r @ A, ;
  159: : postpone ( "name" -- )
  160:   name find dup 0= abort" Can't compile "
  161:   0> IF  A,  ELSE  postpone (compile) A,  THEN ;
  162:                                              immediate restrict
  163: 
  164: \ Use (compile) for the old behavior of compile!
  165: 
  166: \ digit?                                               17dec92py
  167: 
  168: : digit?   ( char -- digit true/ false )
  169:   base @ $100 =
  170:   IF
  171:     true EXIT
  172:   THEN
  173:   toupper [char] 0 - dup 9 u> IF
  174:     [ 'A '9 1 + -  ] literal -
  175:     dup 9 u<= IF
  176:       drop false EXIT
  177:     THEN
  178:   THEN
  179:   dup base @ u>= IF
  180:     drop false EXIT
  181:   THEN
  182:   true ;
  183: 
  184: : accumulate ( +d0 addr digit - +d1 addr )
  185:   swap >r swap  base @  um* drop rot  base @  um* d+ r> ;
  186: : >number ( d addr count -- d addr count )
  187:   0 ?DO  count digit? WHILE  accumulate  LOOP 0
  188:   ELSE  1- I' I - UNLOOP  THEN ;
  189: 
  190: \ number? number                                       23feb93py
  191: 
  192: Create bases   10 ,   2 ,   A , 100 ,
  193: \              16     2    10   Zeichen
  194: \ !! this saving and restoring base is an abomination! - anton
  195: : getbase ( addr u -- addr' u' )  over c@ [char] $ - dup 4 u<
  196:   IF  cells bases + @ base ! 1 /string  ELSE  drop  THEN ;
  197: : number?  ( string -- string 0 / n -1 )  base @ >r
  198:   dup count over c@ [char] - = dup >r  IF 1 /string  THEN
  199:   getbase  dpl on  0 0 2swap
  200:   BEGIN  dup >r >number dup  WHILE  dup r> -  WHILE
  201:          dup dpl ! over c@ [char] . =  WHILE
  202:          1 /string
  203:   REPEAT  THEN  2drop 2drop rdrop false r> base ! EXIT  THEN
  204:   2drop rot drop rdrop r> IF dnegate THEN
  205:   dpl @ dup 0< IF  nip  THEN  r> base ! ;
  206: : s>d ( n -- d ) dup 0< ;
  207: : number ( string -- d )
  208:   number? ?dup 0= abort" ?"  0< IF s>d THEN ;
  209: 
  210: \ space spaces ud/mod                                  21mar93py
  211: decimal
  212: Create spaces  bl 80 times \ times from target compiler! 11may93jaw
  213: DOES>   ( u -- )  swap
  214:         0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
  215: hex
  216: : space   1 spaces ;
  217: 
  218: : ud/mod ( ud1 u2 -- urem udquot )  >r 0 r@ um/mod r> swap >r
  219:                                     um/mod r> ;
  220: 
  221: : pad    ( -- addr )
  222:   here [ $20 8 2* cells + 2 + cell+ ] Literal + aligned ;
  223: 
  224: \ hold <# #> sign # #s                                 25jan92py
  225: 
  226: : hold    ( char -- )         pad cell - -1 chars over +! @ c! ;
  227: 
  228: : <#                          pad cell - dup ! ;
  229: 
  230: : #>      ( 64b -- addr +n )  2drop pad cell - dup @ tuck - ;
  231: 
  232: : sign    ( n -- )            0< IF  [char] - hold  THEN ;
  233: 
  234: : #       ( +d1 -- +d2 )    base @ 2 max ud/mod rot 9 over <
  235:   IF [ char A char 9 - 1- ] Literal +  THEN  [char] 0 + hold ;
  236: 
  237: : #s      ( +d -- 0 0 )         BEGIN  # 2dup d0=  UNTIL ;
  238: 
  239: \ print numbers                                        07jun92py
  240: 
  241: : d.r      >r tuck  dabs  <# #s  rot sign #>
  242:            r> over - spaces  type ;
  243: 
  244: : ud.r     >r <# #s #> r> over - spaces type ;
  245: 
  246: : .r       >r s>d r> d.r ;
  247: : u.r      0 swap ud.r ;
  248: 
  249: : d.       0 d.r space ;
  250: : ud.      0 ud.r space ;
  251: 
  252: : .        s>d d. ;
  253: : u.       0 ud. ;
  254: 
  255: \ catch throw                                          23feb93py
  256: \ bounce                                                08jun93jaw
  257: 
  258: \ !! allow the user to add rollback actions    anton
  259: \ !! use a separate exception stack?           anton
  260: 
  261: : lp@ ( -- addr )
  262:  laddr# [ 0 , ] ;
  263: 
  264: : catch ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error )
  265:   >r sp@ r> swap >r       \ don't count xt! jaw
  266:   fp@ >r
  267:   lp@ >r
  268:   handler @ >r
  269:   rp@ handler !
  270:   execute
  271:   r> handler ! rdrop rdrop rdrop 0 ;
  272: 
  273: : throw ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error )
  274:   ?DUP IF
  275:     handler @ rp!
  276:     r> handler !
  277:     r> lp!
  278:     r> fp!
  279:     r> swap >r sp! r>
  280:   THEN ;
  281: 
  282: \ Bouncing is very fine,
  283: \ programming without wasting time...   jaw
  284: : bounce ( y1 .. ym error/0 -- y1 .. ym error / y1 .. ym )
  285: \ a throw without data or fp stack restauration
  286:   ?DUP IF
  287:     handler @ rp!
  288:     r> handler !
  289:     r> lp!
  290:     rdrop
  291:     rdrop
  292:   THEN ;
  293: 
  294: \ ?stack                                               23feb93py
  295: 
  296: : ?stack ( ?? -- ?? )  sp@ s0 @ > IF  -4 throw  THEN ;
  297: \ ?stack should be code -- it touches an empty stack!
  298: 
  299: \ interpret                                            10mar92py
  300: 
  301: Defer parser
  302: Defer name      ' (name) IS name
  303: Defer notfound
  304: 
  305: : no.extensions  ( string -- )  IF  &-13 bounce  THEN ;
  306: 
  307: ' no.extensions IS notfound
  308: 
  309: : interpret
  310:   BEGIN  ?stack name dup c@  WHILE  parser  REPEAT drop ;
  311: 
  312: \ interpreter compiler                                 30apr92py
  313: 
  314: : interpreter  ( name -- ) find ?dup
  315:   IF  1 and  IF execute  EXIT THEN  -&14 throw  THEN
  316:   number? 0= IF  notfound THEN ;
  317: 
  318: ' interpreter  IS  parser
  319: 
  320: : compiler     ( name -- ) find  ?dup
  321:   IF  0> IF  execute EXIT THEN compile, EXIT THEN number? dup
  322:   IF  0> IF  swap postpone Literal  THEN  postpone Literal
  323:   ELSE  drop notfound  THEN ;
  324: 
  325: : [     ['] interpreter  IS parser state off ; immediate
  326: : ]     ['] compiler     IS parser state on  ;
  327: 
  328: \ locals stuff needed for control structures
  329: 
  330: variable locals-size \ this is the current size of the locals stack
  331: 		     \ frame of the current word
  332: 
  333: : compile-lp+! ( n -- )
  334:     dup negate locals-size +!
  335:     0 over = if
  336:     else -4 over = if postpone -4lp+!
  337:     else  8 over = if postpone  8lp+!
  338:     else 16 over = if postpone 16lp+!
  339:     else postpone lp+!# dup ,
  340:     then then then then drop ;
  341: 
  342: : adjust-locals-size ( n -- )
  343:     \ sets locals-size to n and generates an appropriate lp+!
  344:     locals-size @ swap - compile-lp+! ;
  345: 
  346: 
  347: here 0 , \ just a dummy, the real value of locals-list is patched into it in glocals.fs
  348: AConstant locals-list \ acts like a variable that contains
  349: 		     \ a linear list of locals names
  350: 
  351: 
  352: variable dead-code \ true if normal code at "here" would be dead
  353: 
  354: : unreachable ( -- )
  355: \ declares the current point of execution as unreachable
  356:  dead-code on ;
  357: 
  358: \ locals list operations
  359: 
  360: : common-list ( list1 list2 -- list3 )
  361: \ list1 and list2 are lists, where the heads are at higher addresses than
  362: \ the tail. list3 is the largest sublist of both lists.
  363:  begin
  364:    2dup u<>
  365:  while
  366:    2dup u>
  367:    if
  368:      swap
  369:    then
  370:    @
  371:  repeat
  372:  drop ;
  373: 
  374: : sub-list? ( list1 list2 -- f )
  375: \ true iff list1 is a sublist of list2
  376:  begin
  377:    2dup u<
  378:  while
  379:    @
  380:  repeat
  381:  = ;
  382: 
  383: : list-size ( list -- u )
  384: \ size of the locals frame represented by list
  385:  0 ( list n )
  386:  begin
  387:    over 0<>
  388:  while
  389:    over
  390:    cell+ name> >body @ max
  391:    swap @ swap ( get next )
  392:  repeat
  393:  faligned nip ;
  394: 
  395: : set-locals-size-list ( list -- )
  396:  dup locals-list !
  397:  list-size locals-size ! ;
  398: 
  399: : check-begin ( list -- )
  400: \ warn if list is not a sublist of locals-list
  401:  locals-list @ sub-list? 0= if
  402:    \ !! print current position
  403:    ." compiler was overly optimistic about locals at a BEGIN" cr
  404:    \ !! print assumption and reality
  405:  then ;
  406: 
  407: \ Control Flow Stack
  408: \ orig, etc. have the following structure:
  409: \ type ( defstart, live-orig, dead-orig, dest, do-dest, scopestart) ( TOS )
  410: \ address (of the branch or the instruction to be branched to) (second)
  411: \ locals-list (valid at address) (third)
  412: 
  413: \ types
  414: 0 constant defstart
  415: 1 constant live-orig
  416: 2 constant dead-orig
  417: 3 constant dest \ the loopback branch is always assumed live
  418: 4 constant do-dest
  419: 5 constant scopestart
  420: 
  421: : def? ( n -- )
  422:     defstart <> abort" unstructured " ;
  423: 
  424: : orig? ( n -- )
  425:  dup live-orig <> swap dead-orig <> and abort" expected orig " ;
  426: 
  427: : dest? ( n -- )
  428:  dest <> abort" expected dest " ;
  429: 
  430: : do-dest? ( n -- )
  431:  do-dest <> abort" expected do-dest " ;
  432: 
  433: : scope? ( n -- )
  434:  scopestart <> abort" expected scope " ;
  435: 
  436: : non-orig? ( n -- )
  437:  dest scopestart 1+ within 0= abort" expected dest, do-dest or scope" ;
  438: 
  439: : cs-item? ( n -- )
  440:  live-orig scopestart 1+ within 0= abort" expected control flow stack item" ;
  441: 
  442: 3 constant cs-item-size
  443: 
  444: : CS-PICK ( ... u -- ... destu )
  445:  1+ cs-item-size * 1- >r
  446:  r@ pick  r@ pick  r@ pick
  447:  rdrop
  448:  dup non-orig? ;
  449: 
  450: : CS-ROLL ( destu/origu .. dest0/orig0 u -- .. dest0/orig0 destu/origu )
  451:  1+ cs-item-size * 1- >r
  452:  r@ roll r@ roll r@ roll
  453:  rdrop
  454:  dup cs-item? ; 
  455: 
  456: : cs-push-part ( -- list addr )
  457:  locals-list @ here ;
  458: 
  459: : cs-push-orig ( -- orig )
  460:  cs-push-part dead-code @
  461:  if
  462:    dead-orig
  463:  else
  464:    live-orig
  465:  then ;   
  466: 
  467: \ Structural Conditionals                              12dec92py
  468: 
  469: : ?struc      ( flag -- )       abort" unstructured " ;
  470: : sys?        ( sys -- )        dup 0= ?struc ;
  471: : >mark ( -- orig )
  472:  cs-push-orig 0 , ;
  473: : >resolve    ( addr -- )        here over - swap ! ;
  474: : <resolve    ( addr -- )        here - , ;
  475: 
  476: : BUT       1 cs-roll ;                      immediate restrict
  477: : YET       0 cs-pick ;                       immediate restrict
  478: 
  479: \ Structural Conditionals                              12dec92py
  480: 
  481: : AHEAD ( -- orig )
  482:  POSTPONE branch >mark unreachable ; immediate restrict
  483: 
  484: : IF ( -- orig )
  485:  POSTPONE ?branch >mark ; immediate restrict
  486: 
  487: : ?DUP-IF \ general
  488: \ This is the preferred alternative to the idiom "?DUP IF", since it can be
  489: \ better handled by tools like stack checkers
  490:     POSTPONE ?dup POSTPONE if ;       immediate restrict
  491: : ?DUP-NOT-IF \ general
  492:     POSTPONE ?dup POSTPONE 0= POSTPONE if ; immediate restrict
  493: 
  494: : THEN ( orig -- )
  495:     dup orig?
  496:     dead-code @
  497:     if
  498: 	dead-orig =
  499: 	if
  500: 	    >resolve drop
  501: 	else
  502: 	    >resolve set-locals-size-list dead-code off
  503: 	then
  504:     else
  505: 	dead-orig =
  506: 	if
  507: 	    >resolve drop
  508: 	else \ both live
  509: 	    over list-size adjust-locals-size
  510: 	    >resolve
  511: 	    locals-list @ common-list dup list-size adjust-locals-size
  512: 	    locals-list !
  513: 	then
  514:     then ; immediate restrict
  515: 
  516: ' THEN alias ENDIF immediate restrict \ general
  517: \ Same as "THEN". This is what you use if your program will be seen by
  518: \ people who have not been brought up with Forth (or who have been
  519: \ brought up with fig-Forth).
  520: 
  521: : ELSE ( orig1 -- orig2 )
  522:     POSTPONE ahead
  523:     1 cs-roll
  524:     POSTPONE then ; immediate restrict
  525: 
  526: 
  527: : BEGIN ( -- dest )
  528:     dead-code @ if
  529: 	\ set up an assumption of the locals visible here
  530: 	\ currently we just take the top cs-item
  531: 	\ it would be more intelligent to take the top orig
  532: 	\   but that can be arranged by the user
  533: 	dup defstart <> if
  534: 	    dup cs-item?
  535: 	    2 pick
  536: 	else
  537: 	    0
  538: 	then
  539: 	set-locals-size-list
  540:     then
  541:     cs-push-part dest
  542:     dead-code off ; immediate restrict
  543: 
  544: \ AGAIN (the current control flow joins another, earlier one):
  545: \ If the dest-locals-list is not a subset of the current locals-list,
  546: \ issue a warning (see below). The following code is generated:
  547: \ lp+!# (current-local-size - dest-locals-size)
  548: \ branch <begin>
  549: : AGAIN ( dest -- )
  550:     dest?
  551:     over list-size adjust-locals-size
  552:     POSTPONE branch
  553:     <resolve
  554:     check-begin
  555:     unreachable ; immediate restrict
  556: 
  557: \ UNTIL (the current control flow may join an earlier one or continue):
  558: \ Similar to AGAIN. The new locals-list and locals-size are the current
  559: \ ones. The following code is generated:
  560: \ ?branch-lp+!# <begin> (current-local-size - dest-locals-size)
  561: : until-like ( list addr xt1 xt2 -- )
  562:     \ list and addr are a fragment of a cs-item
  563:     \ xt1 is the conditional branch without lp adjustment, xt2 is with
  564:     >r >r
  565:     locals-size @ 2 pick list-size - dup if ( list dest-addr adjustment )
  566: 	r> drop r> compile,
  567: 	swap <resolve ( list adjustment ) ,
  568:     else ( list dest-addr adjustment )
  569: 	drop
  570: 	r> compile, <resolve
  571: 	r> drop
  572:     then ( list )
  573:     check-begin ;
  574: 
  575: : UNTIL ( dest -- )
  576:     dest? ['] ?branch ['] ?branch-lp+!# until-like ; immediate restrict
  577: 
  578: : WHILE ( dest -- orig dest )
  579:     POSTPONE if
  580:     1 cs-roll ; immediate restrict
  581: 
  582: : REPEAT ( orig dest -- )
  583:     POSTPONE again
  584:     POSTPONE then ; immediate restrict
  585: 
  586: 
  587: \ counted loops
  588: 
  589: \ leave poses a little problem here
  590: \ we have to store more than just the address of the branch, so the
  591: \ traditional linked list approach is no longer viable.
  592: \ This is solved by storing the information about the leavings in a
  593: \ special stack. The leavings of different DO-LOOPs are separated
  594: \ by a 0 entry
  595: 
  596: \ !! remove the fixed size limit. 'Tis not hard.
  597: 20 constant leave-stack-size
  598: create leave-stack 60 cells allot
  599: Avariable leave-sp  leave-stack leave-sp !
  600: 
  601: : clear-leave-stack ( -- )
  602:     leave-stack leave-sp ! ;
  603: 
  604: \ : leave-empty? ( -- f )
  605: \  leave-sp @ leave-stack = ;
  606: 
  607: : >leave ( orig -- )
  608:     \ push on leave-stack
  609:     leave-sp @
  610:     dup [ leave-stack 60 cells + ] Aliteral
  611:     >= abort" leave-stack full"
  612:     tuck ! cell+
  613:     tuck ! cell+
  614:     tuck ! cell+
  615:     leave-sp ! ;
  616: 
  617: : leave> ( -- orig )
  618:     \ pop from leave-stack
  619:     leave-sp @
  620:     dup leave-stack <= abort" leave-stack empty"
  621:     cell - dup @ swap
  622:     cell - dup @ swap
  623:     cell - dup @ swap
  624:     leave-sp ! ;
  625: 
  626: : done ( -- )
  627:     \ !! the original done had ( addr -- )
  628:     begin
  629: 	leave>
  630: 	dup
  631:     while
  632: 	POSTPONE then
  633:     repeat
  634:     2drop drop ; immediate
  635: 
  636: : LEAVE ( -- )
  637:     POSTPONE ahead
  638:     >leave ; immediate
  639: 
  640: : ?LEAVE ( -- )
  641:     POSTPONE 0= POSTPONE if
  642:     >leave ; immediate
  643: 
  644: : DO ( -- do-sys )
  645:     POSTPONE (do)
  646:     POSTPONE begin drop do-dest
  647:     0 0 0 >leave ; immediate
  648: 
  649: : ?DO ( -- do-sys )
  650:     0 0 0 >leave
  651:     POSTPONE (?do)
  652:     >mark >leave
  653:     POSTPONE begin drop do-dest ; immediate
  654: 
  655: : FOR ( -- do-sys )
  656:     POSTPONE (for)
  657:     POSTPONE begin drop do-dest
  658:     0 0 0 >leave ; immediate
  659: 
  660: \ LOOP etc. are just like UNTIL
  661: 
  662: : loop-like ( do-sys xt1 xt2 -- )
  663:     rot do-dest?
  664:     until-like  POSTPONE done  POSTPONE unloop ;
  665: 
  666: : LOOP ( do-sys -- )
  667:  ['] (loop) ['] (loop)-lp+!# loop-like ; immediate
  668: 
  669: : +LOOP ( do-sys -- )
  670:  ['] (+loop) ['] (+loop)-lp+!# loop-like ; immediate
  671: 
  672: \ A symmetric version of "+LOOP". I.e., "-high -low ?DO -inc S+LOOP"
  673: \ will iterate as often as "high low ?DO inc S+LOOP". For positive
  674: \ increments it behaves like "+LOOP". Use S+LOOP instead of +LOOP for
  675: \ negative increments.
  676: : S+LOOP ( do-sys -- )
  677:  ['] (s+loop) ['] (s+loop)-lp+!# loop-like ; immediate
  678: 
  679: : NEXT ( do-sys -- )
  680:  ['] (next) ['] (next)-lp+!# loop-like ; immediate
  681: 
  682: \ Structural Conditionals                              12dec92py
  683: 
  684: : EXIT ( -- )
  685:     0 adjust-locals-size
  686:     POSTPONE ;s
  687:     unreachable ; immediate restrict
  688: 
  689: : ?EXIT ( -- )
  690:      POSTPONE if POSTPONE exit POSTPONE then ; immediate restrict
  691: 
  692: \ Strings                                              22feb93py
  693: 
  694: : ," ( "string"<"> -- ) [char] " parse
  695:   here over char+ allot  place align ;
  696: : "lit ( -- addr )
  697:   r> r> dup count + aligned >r swap >r ;               restrict
  698: : (.")     "lit count type ;                           restrict
  699: : (S")     "lit count ;                                restrict
  700: : SLiteral postpone (S") here over char+ allot  place align ;
  701:                                              immediate restrict
  702: : S"       [char] " parse  state @ IF  postpone SLiteral  THEN ;
  703:                                              immediate
  704: : ."       state @  IF    postpone (.") ,"  align
  705:                     ELSE  [char] " parse type  THEN  ;  immediate
  706: : (        [char] ) parse 2drop ;                       immediate
  707: : \        source >in ! drop ;                          immediate
  708: 
  709: \ error handling                                       22feb93py
  710: \ 'abort thrown out!                                   11may93jaw
  711: 
  712: : (abort")      "lit >r IF  r> "error ! -2 throw  THEN
  713:                 rdrop ;
  714: : abort"        postpone (abort") ," ;        immediate restrict
  715: 
  716: \ Header states                                        23feb93py
  717: 
  718: : flag! ( 8b -- )   last @ cell+ tuck c@ xor swap c! ;
  719: : immediate     $20 flag! ;
  720: \ : restrict      $40 flag! ;
  721: ' noop alias restrict
  722: 
  723: \ Header                                               23feb93py
  724: 
  725: \ input-stream, nextname and noname are quite ugly (passing
  726: \ information through global variables), but they are useful for dealing
  727: \ with existing/independent defining words
  728: 
  729: defer header
  730: 
  731: : name,  ( "name" -- )
  732:     name c@ 1+ chars allot align ;
  733: : input-stream-header ( "name" -- )
  734:     \ !! this is f83-implementation-dependent
  735:     align here last !  -1 A,
  736:     name, $80 flag! ;
  737: 
  738: : input-stream ( -- )  \ general
  739: \ switches back to getting the name from the input stream ;
  740:     ['] input-stream-header IS header ;
  741: 
  742: ' input-stream-header IS header
  743: 
  744: \ !! make that a 2variable
  745: create nextname-buffer 32 chars allot
  746: 
  747: : nextname-header ( -- )
  748:     \ !! f83-implementation-dependent
  749:     nextname-buffer count
  750:     align here last ! -1 A,
  751:     dup c,  here swap chars  dup allot  move  align
  752:     $80 flag!
  753:     input-stream ;
  754: 
  755: \ the next name is given in the string
  756: : nextname ( c-addr u -- ) \ general
  757:     dup 31 u> -19 and throw ( is name too long? )
  758:     nextname-buffer c! ( c-addr )
  759:     nextname-buffer count move
  760:     ['] nextname-header IS header ;
  761: 
  762: : noname-header ( -- )
  763:     0 last !
  764:     input-stream ;
  765: 
  766: : noname ( -- ) \ general
  767: \ the next defined word remains anonymous. The xt of that word is given by lastxt
  768:     ['] noname-header IS header ;
  769: 
  770: : lastxt ( -- xt ) \ general
  771: \ 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
  772:     lastcfa @ ;
  773: 
  774: : Alias    ( cfa "name" -- )
  775:   Header reveal , $80 flag! ;
  776: 
  777: : name>string ( nfa -- addr count )
  778:  cell+ count $1F and ;
  779: 
  780: Create ???  ," ???"
  781: : >name ( cfa -- nfa )
  782:  $21 cell do
  783:    dup i - count $9F and + aligned over $80 + = if
  784:      i - cell - unloop exit
  785:    then
  786:  cell +loop
  787:  drop ??? ( wouldn't 0 be better? ) ;
  788: 
  789: \ indirect threading                                   17mar93py
  790: 
  791: : cfa,     ( code-address -- )
  792:     here lastcfa !
  793:     here  0 A, 0 ,  code-address! ;
  794: : compile, ( xt -- )		A, ;
  795: : !does    ( addr -- )		lastcfa @ does-code! ;
  796: : (;code)  ( R: addr -- )	r> /does-handler + !does ;
  797: : dodoes,  ( -- )
  798:   here /does-handler allot does-handler! ;
  799: 
  800: \ direct threading is implementation dependent
  801: 
  802: : Create    Header reveal [ :dovar ] Literal cfa, ;
  803: 
  804: \ DOES>                                                17mar93py
  805: 
  806: : DOES>  ( compilation: -- )
  807:     state @
  808:     IF
  809: 	;-hook postpone (;code) dodoes,
  810:     ELSE
  811: 	dodoes, here !does 0 ]
  812:     THEN 
  813:     :-hook ; immediate
  814: 
  815: \ Create Variable User Constant                        17mar93py
  816: 
  817: : Variable  Create 0 , ;
  818: : AVariable Create 0 A, ;
  819: : 2VARIABLE ( "name" -- ) \ double
  820:     create 0 , 0 , ;
  821:     
  822: : User      Variable ;
  823: : AUser     AVariable ;
  824: 
  825: : (Constant)  Header reveal [ :docon ] Literal cfa, ;
  826: : Constant  (Constant) , ;
  827: : AConstant (Constant) A, ;
  828: 
  829: : 2CONSTANT
  830:     create ( w1 w2 "name" -- )
  831:         2,
  832:     does> ( -- w1 w2 )
  833:         2@ ;
  834:     
  835: \ IS Defer What's Defers TO                            24feb93py
  836: 
  837: : Defer
  838:   Create ( -- ) 
  839:     ['] noop A,
  840:   DOES> ( ??? )
  841:     @ execute ;
  842: 
  843: : IS ( addr "name" -- )
  844:     ' >body
  845:     state @
  846:     IF    postpone ALiteral postpone !  
  847:     ELSE  !
  848:     THEN ;  immediate
  849: ' IS Alias TO immediate
  850: 
  851: : What's ( "name" -- addr )  ' >body
  852:   state @ IF  postpone ALiteral postpone @  ELSE  @  THEN ;
  853:                                              immediate
  854: : Defers ( "name" -- )  ' >body @ compile, ;
  855:                                              immediate restrict
  856: 
  857: \ : ;                                                  24feb93py
  858: 
  859: defer :-hook ( sys1 -- sys2 )
  860: defer ;-hook ( sys2 -- sys1 )
  861: 
  862: : : ( -- colon-sys )  Header [ :docol ] Literal cfa, defstart ] :-hook ;
  863: : ; ( colon-sys -- )  ;-hook ?struc postpone exit reveal postpone [ ;
  864:   immediate restrict
  865: 
  866: : :noname ( -- xt colon-sys )  here [ :docol ] Literal cfa, 0 ] :-hook ;
  867: 
  868: \ Search list handling                                 23feb93py
  869: 
  870: AVariable current
  871: 
  872: : last?   ( -- false / nfa nfa )    last @ ?dup ;
  873: : (reveal) ( -- )
  874:   last?
  875:   IF
  876:       dup @ 0<
  877:       IF
  878: 	current @ @ over ! current @ !
  879:       ELSE
  880: 	drop
  881:       THEN
  882:   THEN ;
  883: 
  884: \ object oriented search list                          17mar93py
  885: 
  886: \ word list structure:
  887: \ struct
  888: \   1 cells: field find-method   \ xt: ( c_addr u wid -- name-id )
  889: \   1 cells: field reveal-method \ xt: ( -- )
  890: \   1 cells: field rehash-method \ xt: ( wid -- )
  891: \   \ !! what else
  892: \ end-struct wordlist-map-struct
  893: 
  894: \ struct
  895: \   1 cells: field wordlist-id \ not the same as wid; representation depends on implementation
  896: \   1 cells: field wordlist-map \ pointer to a wordlist-map-struct
  897: \   1 cells: field wordlist-link \ link field to other wordlists
  898: \   1 cells: field wordlist-extend \ points to wordlist extensions (eg hash)
  899: \ end-struct wordlist-struct
  900: 
  901: : f83find      ( addr len wordlist -- nfa / false )  @ (f83find) ;
  902: : f83casefind  ( addr len wordlist -- nfa / false )  @ (f83casefind) ;
  903: 
  904: \ Search list table: find reveal
  905: Create f83search       ' f83casefind A,  ' (reveal) A,  ' drop A,
  906: 
  907: : caps-name       ['] (cname) IS name  ['] f83find     f83search ! ;
  908: : case-name       ['] (name)  IS name  ['] f83casefind f83search ! ;
  909: : case-sensitive  ['] (name)  IS name  ['] f83find     f83search ! ;
  910: 
  911: Create forth-wordlist  NIL A, G f83search T A, NIL A, NIL A,
  912: AVariable search       G forth-wordlist search T !
  913: G forth-wordlist current T !
  914: 
  915: : (search-wordlist)  ( addr count wid -- nfa / false )
  916:   dup ( @ swap ) cell+ @ @ execute ;
  917: 
  918: : search-wordlist  ( addr count wid -- 0 / xt +-1 )
  919:   (search-wordlist) dup  IF  found  THEN ;
  920: 
  921: Variable warnings  G -1 warnings T !
  922: 
  923: : check-shadow  ( addr count wid -- )
  924: \ prints a warning if the string is already present in the wordlist
  925: \ !! should be refined so the user can suppress the warnings
  926:  >r 2dup 2dup r> (search-wordlist) warnings @ and ?dup if
  927:    ." redefined " name>string 2dup type
  928:    compare 0<> if
  929:      ."  with " type
  930:    else
  931:      2drop
  932:    then
  933:    space space EXIT
  934:  then
  935:  2drop 2drop ;
  936: 
  937: : find   ( addr -- cfa +-1 / string false )  dup
  938:   count search @ search-wordlist  dup IF  rot drop  THEN ;
  939: 
  940: : reveal ( -- )
  941:  last? if
  942:    name>string current @ check-shadow
  943:  then
  944:  current @ cell+ @ cell+ @ execute ;
  945: 
  946: : rehash  ( wid -- )  dup cell+ @ cell+ cell+ @ execute ;
  947: 
  948: : '    ( "name" -- addr )  name find 0= no.extensions ;
  949: : [']  ( "name" -- addr )  ' postpone ALiteral ; immediate
  950: \ Input                                                13feb93py
  951: 
  952: 07 constant #bell
  953: 08 constant #bs
  954: 7F constant #del
  955: 0D constant #cr                \ the newline key code
  956: 0A constant #lf
  957: 
  958: : bell  #bell emit ;
  959: 
  960: : backspaces  0 ?DO  #bs emit  LOOP ;
  961: : >string  ( span addr pos1 -- span addr pos1 addr2 len )
  962:   over 3 pick 2 pick chars /string ;
  963: : type-rest ( span addr pos1 -- span addr pos1 back )
  964:   >string tuck type ;
  965: : (del)  ( max span addr pos1 -- max span addr pos2 )
  966:   1- >string over 1+ -rot move
  967:   rot 1- -rot  #bs emit  type-rest bl emit 1+ backspaces ;
  968: : (ins)  ( max span addr pos1 char -- max span addr pos2 )
  969:   >r >string over 1+ swap move 2dup chars + r> swap c!
  970:   rot 1+ -rot type-rest 1- backspaces 1+ ;
  971: : ?del ( max span addr pos1 -- max span addr pos2 0 )
  972:   dup  IF  (del)  THEN  0 ;
  973: : (ret)  type-rest drop true space ;
  974: : back  dup  IF  1- #bs emit  ELSE  #bell emit  THEN 0 ;
  975: : forw 2 pick over <> IF  2dup + c@ emit 1+  ELSE  #bell emit  THEN 0 ;
  976: 
  977: Create crtlkeys
  978:   ] false false back  false  false false forw  false
  979:     ?del  false (ret) false  false (ret) false false
  980:     false false false false  false false false false
  981:     false false false false  false false false false [
  982: 
  983: : decode ( max span addr pos1 key -- max span addr pos2 flag )
  984:   dup #del = IF  drop #bs  THEN  \ del is rubout
  985:   dup bl <   IF  cells crtlkeys + @ execute  EXIT  THEN
  986:   >r 2over = IF  rdrop bell 0 EXIT  THEN
  987:   r> (ins) 0 ;
  988: 
  989: \ decode should better use a table for control key actions
  990: \ to define keyboard bindings later
  991: 
  992: : accept   ( addr len -- len )
  993:   dup 0< IF    abs over dup 1 chars - c@ tuck type 
  994: \ this allows to edit given strings
  995:          ELSE  0  THEN rot over
  996:   BEGIN  key decode  UNTIL
  997:   2drop nip ;
  998: 
  999: \ Output                                               13feb93py
 1000: 
 1001: DEFER type      \ defer type for a output buffer or fast
 1002:                 \ screen write
 1003: 
 1004: : (type) ( addr len -- )
 1005:   bounds ?DO  I c@ emit  LOOP ;
 1006: 
 1007: ' (TYPE) IS Type
 1008: 
 1009: \ DEFER Emit
 1010: 
 1011: \ ' (Emit) IS Emit
 1012: 
 1013: \ : form  ( -- rows cols )  &24 &80 ;
 1014: \ form should be implemented using TERMCAPS or CURSES
 1015: \ : rows  form drop ;
 1016: \ : cols  form nip  ;
 1017: 
 1018: \ Query                                                07apr93py
 1019: 
 1020: : refill ( -- flag )
 1021:   tib /line
 1022:   loadfile @ ?dup
 1023:   IF    dup file-position throw linestart 2!
 1024:         read-line throw
 1025:   ELSE  linestart @ IF 2drop false EXIT THEN
 1026:         accept true
 1027:   THEN
 1028:   1 loadline +!
 1029:   swap #tib ! >in off ;
 1030: 
 1031: : Query  ( -- )  loadfile off refill drop ;
 1032: 
 1033: \ File specifiers                                       11jun93jaw
 1034: 
 1035: 
 1036: \ 1 c, here char r c, 0 c,                0 c, 0 c, char b c, 0 c,
 1037: \ 2 c, here char r c, char + c, 0 c,
 1038: \ 2 c, here char w c, char + c, 0 c, align
 1039: 4 Constant w/o
 1040: 2 Constant r/w
 1041: 0 Constant r/o
 1042: 
 1043: \ BIN WRITE-LINE                                        11jun93jaw
 1044: 
 1045: \ : bin           dup 1 chars - c@
 1046: \                 r/o 4 chars + over - dup >r swap move r> ;
 1047: 
 1048: : bin  1+ ;
 1049: 
 1050: create nl$ 1 c, A c, 0 c, \ gnu includes usually a cr in dos
 1051:                            \ or not unix environments if
 1052:                            \ bin is not selected
 1053: 
 1054: : write-line    dup >r write-file ?dup IF r> drop EXIT THEN
 1055:                 nl$ count r> write-file ;
 1056: 
 1057: \ include-file                                         07apr93py
 1058: 
 1059: : include-file ( i*x fid -- j*x )
 1060:   linestart @ >r loadline @ >r loadfile @ >r
 1061:   blk @ >r >tib @ >r  #tib @ dup >r  >in @ >r
 1062: 
 1063:   >tib +! loadfile !
 1064:   0 loadline ! blk off
 1065:   BEGIN  refill  WHILE  interpret  REPEAT
 1066:   loadfile @ close-file throw
 1067: 
 1068:   r> >in !  r> #tib !  r> >tib ! r> blk !
 1069:   r> loadfile ! r> loadline ! r> linestart ! ;
 1070: 
 1071: : included ( i*x addr u -- j*x )
 1072:   r/o open-file throw include-file ;
 1073: 
 1074: \ HEX DECIMAL                                           2may93jaw
 1075: 
 1076: : decimal a base ! ;
 1077: : hex     10 base ! ;
 1078: 
 1079: \ DEPTH                                                 9may93jaw
 1080: 
 1081: : depth ( -- +n )  sp@ s0 @ swap - cell / ;
 1082: 
 1083: \ INCLUDE                                               9may93jaw
 1084: 
 1085: : include  ( "file" -- )
 1086:   bl word count included ;
 1087: 
 1088: \ RECURSE                                               17may93jaw
 1089: 
 1090: : recurse  last @ cell+ name> a, ; immediate restrict
 1091: \ !! does not work with anonymous words; use lastxt compile,
 1092: 
 1093: \ */MOD */                                              17may93jaw
 1094: 
 1095: : */mod >r m* r> sm/rem ;
 1096: 
 1097: : */ */mod nip ;
 1098: 
 1099: \ EVALUATE                                              17may93jaw
 1100: 
 1101: : evaluate ( c-addr len -- )
 1102:   linestart @ >r loadline @ >r loadfile @ >r
 1103:   blk @ >r >tib @ >r  #tib @ dup >r  >in @ >r
 1104: 
 1105:   >tib +! dup #tib ! >tib @ swap move
 1106:   >in off blk off loadfile off -1 linestart !
 1107: 
 1108:   BEGIN  interpret  >in @ #tib @ u>= UNTIL
 1109: 
 1110:   r> >in !  r> #tib !  r> >tib ! r> blk !
 1111:   r> loadfile ! r> loadline ! r> linestart ! ;
 1112: 
 1113: 
 1114: : abort -1 throw ;
 1115: 
 1116: \+ environment? true ENV" CORE"
 1117: \ core wordset is now complete!
 1118: 
 1119: \ Quit                                                 13feb93py
 1120: 
 1121: Defer 'quit
 1122: Defer .status
 1123: : prompt        state @ IF ."  compiled" EXIT THEN ."  ok" ;
 1124: : (quit)        BEGIN .status cr query interpret prompt AGAIN ;
 1125: ' (quit) IS 'quit
 1126: 
 1127: \ DOERROR (DOERROR)                                     13jun93jaw
 1128: 
 1129: DEFER DOERROR
 1130: 
 1131: : (DoError) ( throw-code -- )
 1132:          LoadFile @
 1133:          IF
 1134:          	." Error in line: " Loadline @ . cr
 1135:          THEN
 1136:          cr source type cr
 1137:          source drop >in @ -trailing
 1138:          here c@ 1F min dup >r - 1- 0 max nip
 1139:          dup spaces 
 1140: 	 IF
 1141: 		." ^"
 1142: 	 THEN
 1143: 	 r> 0 ?DO
 1144: 		." -" 
 1145: 	 LOOP
 1146: 	 ." ^"
 1147:          dup -2 =
 1148:          IF 
 1149: 		"error @ ?dup
 1150: 		IF
 1151: 			cr count type 
 1152: 		THEN
 1153: 		drop
 1154:          ELSE
 1155: 		.error
 1156: 	 THEN
 1157:          normal-dp dpp ! ;
 1158: 
 1159: ' (DoError) IS DoError
 1160: 
 1161: : quit   r0 @ rp! handler off >tib @ >r
 1162:   BEGIN
 1163:     postpone [
 1164:     ['] 'quit CATCH dup
 1165:   WHILE
 1166:     DoError r@ >tib !
 1167:   REPEAT
 1168:   drop r> >tib ! ;
 1169: 
 1170: \ Cold                                                 13feb93py
 1171: 
 1172: \ : .name ( name -- ) cell+ count $1F and type space ;
 1173: \ : words  listwords @
 1174: \          BEGIN  @ dup  WHILE  dup .name  REPEAT drop ;
 1175: 
 1176: : >len  ( cstring -- addr n )  100 0 scan 0 swap 100 - /string ;
 1177: : arg ( n -- addr count )  cells argv @ + @ >len ;
 1178: : #!       postpone \ ;  immediate
 1179: 
 1180: Variable env
 1181: Variable argv
 1182: Variable argc
 1183: 
 1184: : get-args ( -- )  #tib off
 1185:   argc @ 1 ?DO  I arg 2dup source + swap move
 1186:                 #tib +! drop  bl source + c! 1 #tib +!  LOOP
 1187:   >in off #tib @ 0<> #tib +! ;
 1188: 
 1189: : script? ( -- flag )  0 arg 1 arg dup 3 pick - /string compare 0= ;
 1190: 
 1191: : cold ( -- )  
 1192:   argc @ 1 >
 1193:   IF  script?
 1194:       IF  1 arg ['] included  ELSE   get-args ['] interpret  THEN
 1195:       catch ?dup IF  dup >r DoError cr r> (bye)  THEN THEN
 1196:   ." ANS FORTH-93 (c) 1993 by the ANS FORTH-93 Team" cr quit ;
 1197: 
 1198: : boot ( **env **argv argc -- )
 1199:   argc ! argv ! env !  main-task up!
 1200:   sp@ dup s0 ! $10 + >tib ! rp@ r0 !  fp@ f0 !  cold ;
 1201: 
 1202: : bye  cr 0 (bye) ;
 1203: 
 1204: \ **argv may be scanned by the C starter to get some important
 1205: \ information, as -display and -geometry for an X client FORTH
 1206: \ or space and stackspace overrides
 1207: 
 1208: \ 0 arg contains, however, the name of the program.

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