BSD 4_1c_2 release

[unix-history] / usr / src / usr.bin / troff / n8.c

#ifndef lint
static char sccsid[] = "@(#)n8.c        4.1 6/7/82";
#endif lint

#include "tdef.h"

/*
troff8.c

hyphenation
*/

char hbuf[NHEX];
char *nexth = hbuf;
int *hyend;
extern int *wdstart, *wdend;
extern int *hyptr[];
extern int **hyp;
extern int hyoff;
extern int noscale;
extern int xxx;
#define THRESH 160 /*digram goodness threshold*/
int thresh = THRESH;

hyphen(wp)
int *wp;
{
       register *i, j;

       i = wp;
       while(punct(*i++))
               ;
       if (!alph(*--i))
               return;
       wdstart = i++;
       while(alph(*i++))
               ;
       hyend = wdend = --i-1;
       while(punct(*i++))
               ;
       if (*--i)
               return;
       if ((wdend-wdstart-4) < 0)
               return;
       hyp = hyptr;
       *hyp = 0;
       hyoff = 2;
       if (!exword() && !suffix())
               digram();
       *hyp++ = 0;
       if (*hyptr) for(j = 1; j;) {
               j = 0;
               for(hyp = hyptr+1; *hyp != 0; hyp++) {
                       if (*(hyp-1) > *hyp) {
                               j++;
                               i = *hyp;
                               *hyp = *(hyp-1);
                               *(hyp-1) = i;
                       }
               }
       }
}

punct(i)
int i;
{
       if (!i || alph(i))
               return(0);
       else
               return(1);
}

alph(i)
int i;
{
       register j;

       j = i & CMASK;
       if (((j >= 'A') && (j <= 'Z')) || ((j >= 'a') && (j <= 'z')))
               return(1);
       else
               return(0);
}

caseht()
{
       thresh = THRESH;
       if (skip())
               return;
       noscale++;
       thresh = atoi();
       noscale = 0;
}

casehw()
{
       register i, k;
       register char *j;

       k = 0;
       while(!skip()) {
               if ((j = nexth) >= (hbuf + NHEX - 2))
                       goto full;
               for (;;) {
                       if ((i = getch()) & MOT)
                               continue;
                       if (((i &= CMASK) == ' ') || (i == '\n')) {
                               *j++ = 0;
                               nexth = j;
                               *j = 0;
                               if (i == ' ')
                                       break;
                               else
                                       return;
                       }
                       if (i == '-') {
                               k = 0200;
                               continue;
                       }
                       *j++ = maplow(i) | k;
                       k = 0;
                       if (j >= (hbuf + NHEX - 2))
                               goto full;
               }
       }
       return;
full:
       prstr("Exception word list full.\n");
       *nexth = 0;
}

exword()
{
       register int *w;
       register char *e;
       char *save;

       e = hbuf;
       while(1) {
               save = e;
               if (*e == 0)return(0);
               w = wdstart;
               while((*e && (w <= hyend)) &&
                     ((*e & 0177) == maplow(*w & CMASK))) {e++; w++;};
               if (!*e) {
                       if (((w-1) == hyend) ||
                          ((w == wdend) && (maplow(*w & CMASK) == 's'))) {
                               w = wdstart;
                               for(e = save; *e; e++) {
                                       if (*e & 0200)*hyp++ = w;
                                       if (hyp > (hyptr+NHYP-1))
                                               hyp = hyptr+NHYP-1;
                                       w++;
                               }
                               return(1);
                       }else{e++; continue;}
               }else while(*e++);
       }
}

suffix()
{
       register int *w;
       register char *s, *s0;
       int i;
       extern char *suftab[];
       extern int *chkvow();

again:
       if (!alph(i = *hyend & CMASK))
               return(0);
       if (i < 'a')
               i -= 'A'-'a';
       if ((s0 = suftab[i-'a']) == 0)
               return(0);
       for (;;) {
               if ((i = *s0 & 017) == 0)
                       return(0);
               s = s0 + i - 1;
               w = hyend - 1;
               while(((s > s0) && (w >= wdstart)) &&
                  ((*s & 0177) == maplow(*w))) {
                       s--;
                       w--;
               }
               if (s == s0)
                       break;
               s0 += i;
       }
       s = s0 + i - 1;
       w = hyend;
       if (*s0 & 0200) goto mark;
       while(s > s0) {
               w--;
               if (*s-- & 0200) {
       mark:
                       hyend = w - 1;
                       if (*s0 & 0100)
                               continue;
                       if (!chkvow(w))
                               return(0);
                       *hyp++ = w;
               }
       }
       if (*s0 & 040)
               return(0);
       if (exword())
               return(1);
       goto again;
}

maplow(i)
int i;
{
       if ((i &= CMASK) < 'a')i += 'a' - 'A';
       return(i);
}

vowel(i)
int i;
{
       switch(maplow(i)) {
               case 'a':
               case 'e':
               case 'i':
               case 'o':
               case 'u':
               case 'y':
                       return(1);
               default:
                       return(0);
       }
}

int *chkvow(w)
int *w;
{
       while(--w >= wdstart)if(vowel(*w & CMASK))return(w);
       return(0);
}

digram() {
       register *w, val;
       int *nhyend, *maxw, maxval;
       extern char bxh[26][13], bxxh[26][13], xxh[26][13], xhx[26][13], hxx[26][13];

again:
       if (!(w=chkvow(hyend+1)))return;
       hyend = w;
       if (!(w=chkvow(hyend)))return;
       nhyend = w;
       maxval = 0;
       w--;
       while((++w < hyend) && (w < (wdend-1))) {
               val = 1;
               if (w == wdstart)val *= dilook('a',*w,bxh);
               else if(w == wdstart+1)val *= dilook(*(w-1),*w,bxxh);
               else val *= dilook(*(w-1),*w,xxh);
               val *= dilook(*w, *(w+1), xhx);
               val *= dilook(*(w+1), *(w+2), hxx);
               if (val > maxval) {
                       maxval = val;
                       maxw = w + 1;
               }
       }
       hyend = nhyend;
       if (maxval > thresh)*hyp++ = maxw;
       goto again;
}

dilook(a,b,t)
int a, b;
char t[26][13];
{
       register i, j;

       i = t[maplow(a)-'a'][(j = maplow(b)-'a')/2];
       if (!(j & 01))i >>= 4;
       return(i & 017);
}