File:  [gforth] / gforth / hash.fs
Revision 1.9: download - view: text, annotated - select for diffs
Mon Mar 13 09:17:28 1995 UTC (26 years, 9 months ago) by anton
Branches: MAIN
CVS tags: HEAD
Added stuff for documenting Forth source and integrating it into the texi file
changed checks for DOMAINOS to checks for apollo (which is defined on apollos)
changed "-evaluate" (which did not work anyway) to "--evaluate"
added debugging.fs and assert.fs to startup.fs

    1: \ Hashed dictionaries                                  15jul94py
    2: 
    3: 11 value hashbits
    4: 1 hashbits lshift Value Hashlen
    5: 
    6: Variable insRule        insRule on
    7: Variable revealed
    8: 
    9: \ Memory handling                                      10oct94py
   10: 
   11: Variable HashPointer
   12: Variable HashTable
   13: Variable HashIndex
   14: 
   15: \ DelFix and NewFix are from bigFORTH                  15jul94py
   16: 
   17: : DelFix ( addr root -- ) dup @ 2 pick ! ! ;
   18: : NewFix  ( root len # -- addr )
   19:   BEGIN  2 pick @ ?dup  0= WHILE  2dup * allocate throw
   20:          over 0 ?DO  dup 4 pick DelFix 2 pick +  LOOP  drop
   21:   REPEAT  >r drop r@ @ rot ! r@ swap erase r> ;
   22: 
   23: \ compute hash key                                     15jul94py
   24: 
   25: : hash ( addr len -- key )
   26:     hashbits (hashkey1) ;
   27: \   (hashkey)
   28: \   Hashlen 1- and ;
   29: 
   30: 
   31: : hash-find ( addr len wordlist -- nfa / false )
   32:     [ 3 cells ] Literal + @ >r
   33:     2dup hash r> xor cells HashTable @ + @ (hashfind) ;
   34: 
   35: \ hash vocabularies                                    16jul94py
   36: 
   37: : lastlink! ( addr link -- )
   38:   BEGIN  dup @ dup  WHILE  nip  REPEAT  drop ! ;
   39: 
   40: : (reveal ( addr voc -- )  [ 3 cells ] Literal + dup @ 0< IF  2drop EXIT  THEN
   41:   @ over cell+ count $1F and Hash xor cells >r
   42:   HashPointer 2 Cells $400 NewFix
   43:   tuck cell+ ! r> HashTable @ + insRule @
   44:   IF  dup @ 2 pick ! !  ELSE  lastlink!  THEN  revealed on ;
   45: 
   46: : hash-reveal ( -- )  (reveal) last?  IF
   47:   current @ (reveal  THEN ;
   48: 
   49: : addall  ( -- )
   50:     voclink
   51:     BEGIN  @ dup @  WHILE  dup 'initvoc  REPEAT  drop ;
   52: 
   53: : clearhash  ( -- )
   54:     HashTable @ Hashlen cells bounds
   55:     DO  I @
   56:         BEGIN  dup  WHILE
   57:                dup @ swap HashPointer DelFix
   58:         REPEAT  I !
   59:     cell +LOOP  HashIndex off ;
   60: 
   61: : re-hash  clearhash addall ;
   62: : (rehash) ( addr -- )
   63:   drop revealed @ IF  re-hash revealed off  THEN ;
   64: 
   65: Create hashsearch  ' hash-find A, ' hash-reveal A, ' (rehash) A,
   66: 
   67: \ hash allocate and vocabulary initialization          10oct94py
   68: 
   69: : hash-alloc ( addr -- addr )  HashTable @ 0= IF
   70:   Hashlen cells allocate throw HashTable !
   71:   HashTable @ Hashlen cells erase THEN
   72:   HashIndex @ over !  1 HashIndex +!
   73:   HashIndex @ Hashlen >=
   74:   IF  clearhash
   75:       1 hashbits 1+ dup  to hashbits  lshift  to hashlen
   76:       HashTable @ free
   77:       addall
   78:   THEN ;
   79: 
   80: : (initvoc) ( addr -- )
   81:     cell+ dup @ 0< IF  drop EXIT  THEN
   82:     insRule @ >r  insRule off  hash-alloc
   83:     3 cells - hashsearch over cell+ ! dup
   84:     BEGIN  @ dup  WHILE  2dup swap (reveal  REPEAT
   85:     2drop  r> insRule ! ;
   86: 
   87: ' (initvoc) IS 'initvoc
   88: 
   89: \ Hash-Find                                            01jan93py
   90: 
   91: addall          \ Baum aufbauen
   92: \ Baumsuche ist installiert.
   93: 
   94: : hash-cold  ( -- ) Defers 'cold
   95:   HashPointer off  HashTable off  HashIndex off
   96:   voclink
   97:   BEGIN  @ dup @  WHILE
   98:          dup cell - @ >r
   99:          dup 'initvoc
  100:          r> over cell - !
  101:   REPEAT  drop ;
  102: ' hash-cold IS 'cold
  103: 
  104: : .words  ( -- )
  105:   base @ >r hex HashTable @  Hashlen 0
  106:   DO  cr  i 2 .r ." : " dup i cells +
  107:       BEGIN  @ dup  WHILE
  108:              dup cell+ @ .name  REPEAT  drop
  109:   LOOP  drop r> base ! ;
  110: 
  111: \ \ this stuff is for evaluating the hash function
  112: \ : square dup * ;
  113: 
  114: \ : countwl  ( -- sum sumsq )
  115: \     \ gives the number of words in the current wordlist
  116: \     \ and the sum of squares for the sublist lengths
  117: \     0 0
  118: \     hashtable @ Hashlen cells bounds DO
  119: \        0 i BEGIN
  120: \            @ dup WHILE
  121: \            swap 1+ swap
  122: \        REPEAT
  123: \        drop
  124: \        swap over square +
  125: \        >r + r>
  126: \        1 cells
  127: \    +LOOP ;
  128: 
  129: \ : chisq ( -- n )
  130: \     \ n should have about the same size as Hashlen
  131: \     countwl Hashlen 2 pick */ swap - ;

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