projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 94bed826 | 1 | /*- |
| b8e6ef5e KB |
2 | * Copyright (c) 1991, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. | |
| 94bed826 KB |
4 | * |
| 5 | * %sccs.include.proprietary.c% | |
| 6 | * | |
| b8e6ef5e | 7 | * @(#)spell.h 8.1 (Berkeley) %G% |
| 94bed826 | 8 | */ |
| ac1b4ce6 SL |
9 | |
| 10 | #include <stdio.h> | |
| 11 | #include <ctype.h> | |
| 12 | ||
| 13 | #ifndef unix | |
| 14 | #define SHIFT 5 | |
| 15 | #define TABSIZE (int)(400000/(1<<SHIFT)) | |
| 16 | int *tab; /*honeywell loader deficiency*/ | |
| 17 | #else | |
| 18 | #define Tolower(c) (isupper(c)?tolower(c):c) /* ugh!!! */ | |
| 19 | #define SHIFT 4 | |
| 20 | #define TABSIZE 25000 /*(int)(400000/(1<<shift))--pdp11 compiler deficiency*/ | |
| 21 | short tab[TABSIZE]; | |
| 22 | #endif | |
| 23 | long p[] = { | |
| 24 | 399871, | |
| 25 | 399887, | |
| 26 | 399899, | |
| 27 | 399911, | |
| 28 | 399913, | |
| 29 | 399937, | |
| 30 | 399941, | |
| 31 | 399953, | |
| 32 | 399979, | |
| 33 | 399983, | |
| 34 | 399989, | |
| 35 | }; | |
| 36 | #define NP (sizeof(p)/sizeof(p[0])) | |
| 37 | #define NW 30 | |
| 38 | ||
| 39 | /* | |
| 40 | * Hash table for spelling checker has n bits. | |
| 41 | * Each word w is hashed by k different (modular) hash functions, hi. | |
| 42 | * The bits hi(w), i=1..k, are set for words in the dictionary. | |
| 43 | * Assuming independence, the probability that no word of a d-word | |
| 44 | * dictionary sets a particular bit is given by the Poisson formula | |
| 45 | * P = exp(-y)*y**0/0!, where y=d*k/n. | |
| 46 | * The probability that a random string is recognized as a word is then | |
| 47 | * (1-P)**k. For given n and d this is minimum when y=log(2), P=1/2, | |
| 48 | * whence one finds, for example, that a 25000-word dictionary in a | |
| 49 | * 400000-bit table works best with k=11. | |
| 50 | */ | |
| 51 | ||
| 52 | long pow2[NP][NW]; | |
| 53 | ||
| 88618b9c CT |
54 | prime(argc, argv) |
| 55 | int argc; | |
| 56 | register char **argv; | |
| ac1b4ce6 SL |
57 | { |
| 58 | int i, j; | |
| 59 | long h; | |
| 60 | register long *lp; | |
| 61 | ||
| 62 | #ifndef unix | |
| 63 | if ((tab = (int *)calloc(sizeof(*tab), TABSIZE)) == NULL) | |
| 64 | return(0); | |
| 65 | #endif | |
| 66 | if (argc > 1) { | |
| 67 | FILE *f; | |
| 68 | if ((f = fopen(argv[1], "ri")) == NULL) | |
| 69 | return(0); | |
| 70 | if (fread((char *)tab, sizeof(*tab), TABSIZE, f) != TABSIZE) | |
| 71 | return(0); | |
| 72 | fclose(f); | |
| 73 | } | |
| 74 | for (i=0; i<NP; i++) { | |
| 75 | h = *(lp = pow2[i]) = 1<<14; | |
| 76 | for (j=1; j<NW; j++) | |
| 77 | h = *++lp = (h<<7) % p[i]; | |
| 78 | } | |
| 79 | return(1); | |
| 80 | } | |
| 81 | ||
| 82 | #define get(h) (tab[h>>SHIFT]&(1<<((int)h&((1<<SHIFT)-1)))) | |
| 83 | #define set(h) tab[h>>SHIFT] |= 1<<((int)h&((1<<SHIFT)-1)) |