pcollins.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include <bio.h>
#include "dict.h"

/*
 * Routines for handling dictionaries in the "Paperback Collins"
 * format (with tags surrounded by >....<)
 */
enum {
	Buflen=1000,
};

/* More special runes */
enum {
	B = MULTIE+1,	/* bold */
	H,		/* headword start */
	I,		/* italics */
	Ps,		/* pronunciation start */
	Pe,		/* pronunciation end */
	R,		/* roman */
	X,		/* headword end */
};

/* Assoc tables must be sorted on first field */

static Assoc tagtab[] = {
	{"AA",		L'Å'},
	{"AC",		LACU},
	{"B",		B},
	{"CE",		LCED},
	{"CI",		LFRN},
	{"Di",		L'ı'},
	{"EL",		L'-'},
	{"GR",		LGRV},
	{"H",		H},
	{"I",		I},
	{"OE",		L'Œ'},
	{"R",		R},
	{"TI",		LTIL},
	{"UM",		LUML},
	{"X",		X},
	{"[",		Ps},
	{"]",		Pe},
	{"ac",		LACU},
	{"ce",		LCED},
	{"ci",		LFRN},
	{"gr",		LGRV},
	{"oe",		L'œ'},
	{"supe",	L'e'},		/* should be raised */
	{"supo",	L'o'},		/* should be raised */
	{"ti",		LTIL},
	{"um",		LUML},
	{"{",		Ps},
	{"~",		L'~'},
	{"~~",		MTT},
};

static Rune normtab[128] = {
	/*0*/	/*1*/	/*2*/	/*3*/	/*4*/	/*5*/	/*6*/	/*7*/
/*00*/	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,
	NONE,	NONE,	L' ',	NONE,	NONE,	NONE,	NONE,	NONE,
/*10*/	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,
	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,	NONE,
/*20*/	L' ',	L'!',	L'"',	L'#',	L'$',	L'%',	L'&',	L'\'',
	L'(',	L')',	L'*',	L'+',	L',',	L'-',	L'.',	L'/',
/*30*/  L'0',	L'1',	L'2',	L'3',	L'4',	L'5',	L'6',	L'7',
	L'8',	L'9',	L':',	L';',	TAGE,	L'=',	TAGS,	L'?',
/*40*/  L'@',	L'A',	L'B',	L'C',	L'D',	L'E',	L'F',	L'G',
	L'H',	L'I',	L'J',	L'K',	L'L',	L'M',	L'N',	L'O',
/*50*/	L'P',	L'Q',	L'R',	L'S',	L'T',	L'U',	L'V',	L'W',
	L'X',	L'Y',	L'Z',	L'[',	L'\\',	L']',	L'^',	L'_',
/*60*/	L'`',	L'a',	L'b',	L'c',	L'd',	L'e',	L'f',	L'g',
	L'h',	L'i',	L'j',	L'k',	L'l',	L'm',	L'n',	L'o',
/*70*/	L'p',	L'q',	L'r',	L's',	L't',	L'u',	L'v',	L'w',
	L'x',	L'y',	L'z',	L'{',	L'|',	L'}',	L'~',	NONE,
};

static char *gettag(char *, char *);

static Entry	curentry;
static char	tag[Buflen];
#define cursize (curentry.end-curentry.start)

void
pcollprintentry(Entry e, int cmd)
{
	char *p, *pe;
	long r, rprev, t, rlig;
	int saveoi;
	Rune *transtab;

	p = e.start;
	pe = e.end;
	transtab = normtab;
	rprev = NONE;
	changett(0, 0, 0);
	curentry = e;
	saveoi = 0;
	if(cmd == 'h')
		outinhibit = 1;
	while(p < pe) {
		if(cmd == 'r') {
			outchar(*p++);
			continue;
		}
		r = transtab[(*p++)&0x7F];
		if(r < NONE) {
			/* Emit the rune, but buffer in case of ligature */
			if(rprev != NONE)
				outrune(rprev);
			rprev = r;
		} else if(r == TAGS) {
			p = gettag(p, pe);
			t = lookassoc(tagtab, asize(tagtab), tag);
			if(t == -1) {
				if(debug && !outinhibit)
					err("tag %ld %d %s",
						e.doff, cursize, tag);
				continue;
			}
			if(t < NONE) {
				if(rprev != NONE)
					outrune(rprev);
				rprev = t;
			} else if(t >= LIGS && t < LIGE) {
				/* handle possible ligature */
				rlig = liglookup(t, rprev);
				if(rlig != NONE)
					rprev = rlig;	/* overwrite rprev */
				else {
					/* could print accent, but let's not */
					if(rprev != NONE) outrune(rprev);
					rprev = NONE;
				}
			} else if(t >= MULTI && t < MULTIE) {
				if(rprev != NONE) {
					outrune(rprev);
					rprev = NONE;
				}
				outrunes(multitab[t-MULTI]);
			} else {
				if(rprev != NONE) {
					outrune(rprev);
					rprev = NONE;
				}
				switch(t){
				case H:
					if(cmd == 'h')
						outinhibit = 0;
					else
						outnl(0);
					break;
				case X:
					if(cmd == 'h')
						outinhibit = 1;
					else
						outchars(".  ");
					break;
				case Ps:
					/* don't know enough of pron. key yet */
					saveoi = outinhibit;
					outinhibit = 1;
					break;
				case Pe:
					outinhibit = saveoi;
					break;
				}
			}
		}
	}
	if(cmd == 'h')
		outinhibit = 0;
	outnl(0);
}

long
pcollnextoff(long fromoff)
{
	long a;
	char *p;

	a = Bseek(bdict, fromoff, 0);
	if(a < 0)
		return -1;
	for(;;) {
		p = Brdline(bdict, '\n');
		if(!p)
			break;
		if(p[0] == '>' && p[1] == 'H' && p[2] == '<')
			return (Boffset(bdict)-Blinelen(bdict));
	}
	return -1;
}

void
pcollprintkey(void)
{
	Bprint(bout, "No pronunciation key yet\n");
}

/*
 * f points just after '>'; fe points at end of entry.
 * Expect next characters from bin to match:
 *  [^ <]+<
 *     tag
 * Accumulate the tag in tag[].
 * Return pointer to after final '<'.
 */
static char *
gettag(char *f, char *fe)
{
	char *t;
	int c, i;

	t = tag;
	i = Buflen;
	while(--i > 0) {
		c = *f++;
		if(c == '<' || f == fe)
			break;
		*t++ = c;
	}
	*t = 0;
	return f;
}