[unix-history] / usr / src / bin / expr / expr.y

/* Yacc productions for "expr" command: */

%token OR AND ADD SUBT MULT DIV REM EQ GT GEQ LT LEQ NEQ
%token A_STRING SUBSTR LENGTH INDEX NOARG MATCH

/* operators listed below in increasing precedence: */
%left OR
%left AND
%left EQ LT GT GEQ LEQ NEQ
%left ADD SUBT
%left MULT DIV REM
%left MCH
%left MATCH
%left SUBSTR
%left LENGTH INDEX
%%

/* a single `expression' is evaluated and printed: */

expression:	expr NOARG = {
			printf("%s\n", $1);
			exit((!strcmp($1,"0")||!strcmp($1,"\0"))? 1: 0);
			}
	;


expr:	'(' expr ')' = { $$ = $2; }
	| expr OR expr   = { $$ = conj(OR, $1, $3); }
	| expr AND expr   = { $$ = conj(AND, $1, $3); }
	| expr EQ expr   = { $$ = rel(EQ, $1, $3); }
	| expr GT expr   = { $$ = rel(GT, $1, $3); }
	| expr GEQ expr   = { $$ = rel(GEQ, $1, $3); }
	| expr LT expr   = { $$ = rel(LT, $1, $3); }
	| expr LEQ expr   = { $$ = rel(LEQ, $1, $3); }
	| expr NEQ expr   = { $$ = rel(NEQ, $1, $3); }
	| expr ADD expr   = { $$ = arith(ADD, $1, $3); }
	| expr SUBT expr   = { $$ = arith(SUBT, $1, $3); }
	| expr MULT expr   = { $$ = arith(MULT, $1, $3); }
	| expr DIV expr   = { $$ = arith(DIV, $1, $3); }
	| expr REM expr   = { $$ = arith(REM, $1, $3); }
	| expr MCH expr	 = { $$ = match($1, $3); }
	| MATCH expr expr = { $$ = match($2, $3); }
	| SUBSTR expr expr expr = { $$ = substr($2, $3, $4); }
	| LENGTH expr       = { $$ = length($2); }
	| INDEX expr expr = { $$ = index($2, $3); }
	| A_STRING
	;
%%
/*	expression command */
#include <stdio.h>
#define ESIZE	256
#define error(c)	errxx(c)
#define EQL(x,y) !strcmp(x,y)
long atol();
char	**Av;
int	Ac;
int	Argi;

char Mstring[1][128];
char *malloc();
extern int nbra;

main(argc, argv) char **argv; {
	Ac = argc;
	Argi = 1;
	Av = argv;
	yyparse();
}

char *operators[] = { "|", "&", "+", "-", "*", "/", "%", ":",
	"=", "==", "<", "<=", ">", ">=", "!=",
	"match", "substr", "length", "index", "\0" };
int op[] = { OR, AND, ADD,  SUBT, MULT, DIV, REM, MCH,
	EQ, EQ, LT, LEQ, GT, GEQ, NEQ,
	MATCH, SUBSTR, LENGTH, INDEX };
yylex() {
	register char *p;
	register i;

	if(Argi >= Ac) return NOARG;

	p = Av[Argi++];

	if(*p == '(' || *p == ')')
		return (int)*p;
	for(i = 0; *operators[i]; ++i)
		if(EQL(operators[i], p))
			return op[i];

	yylval = p;
	return A_STRING;
}

char *rel(op, r1, r2) register char *r1, *r2; {
	register long i;

	if(ematch(r1, "-*[0-9]*$") && ematch(r2, "[0-9]*$"))
		i = atol(r1) - atol(r2);
	else
		i = strcmp(r1, r2);
	switch(op) {
	case EQ: i = i==0; break;
	case GT: i = i>0; break;
	case GEQ: i = i>=0; break;
	case LT: i = i<0; break;
	case LEQ: i = i<=0; break;
	case NEQ: i = i!=0; break;
	}
	return i? "1": "0";
}

char *arith(op, r1, r2) char *r1, *r2; {
	long i1, i2;
	register char *rv;

	if(!((ematch(r1, "[0-9]*$") || ematch(r1, "-[0-9]*$")) &&
	     (ematch(r2, "[0-9]*$") || ematch(r2, "-[0-9]*$"))))
		yyerror("non-numeric argument");
	i1 = atol(r1);
	i2 = atol(r2);

	switch(op) {
	case ADD: i1 = i1 + i2; break;
	case SUBT: i1 = i1 - i2; break;
	case MULT: i1 = i1 * i2; break;
	case DIV: i1 = i1 / i2; break;
	case REM: i1 = i1 % i2; break;
	}
	rv = malloc(16);
	(void)sprintf(rv, "%ld", i1);
	return rv;
}
char *conj(op, r1, r2) char *r1, *r2; {
	register char *rv;

	switch(op) {

	case OR:
		if(EQL(r1, "0")
		|| EQL(r1, ""))
			if(EQL(r2, "0")
			|| EQL(r2, ""))
				rv = "0";
			else
				rv = r2;
		else
			rv = r1;
		break;
	case AND:
		if(EQL(r1, "0")
		|| EQL(r1, ""))
			rv = "0";
		else if(EQL(r2, "0")
		|| EQL(r2, ""))
			rv = "0";
		else
			rv = r1;
		break;
	}
	return rv;
}

char *substr(v, s, w) char *v, *s, *w; {
register si, wi;
register char *res;

	si = atol(s);
	wi = atol(w);
	while(--si) if(*v) ++v;

	res = v;

	while(wi--) if(*v) ++v;

	*v = '\0';
	return res;
}

char *length(s) register char *s; {
	register i = 0;
	register char *rv;

	while(*s++) ++i;

	rv = malloc(8);
	(void)sprintf(rv, "%d", i);
	return rv;
}

char *index(s, t) char *s, *t; {
	register i, j;
	register char *rv;

	for(i = 0; s[i] ; ++i)
		for(j = 0; t[j] ; ++j)
			if(s[i]==t[j]) {
				(void)sprintf(rv = malloc(8), "%d", ++i);
				return rv;
			}
	return "0";
}

char *match(s, p)
{
	register char *rv;

	(void)sprintf(rv = malloc(8), "%d", ematch(s, p));
	if(nbra) {
		rv = malloc(strlen(Mstring[0])+1);
		strcpy(rv, Mstring[0]);
	}
	return rv;
}

#define INIT	register char *sp = instring;
#define GETC()		(*sp++)
#define PEEKC()		(*sp)
#define UNGETC(c)	(--sp)
#define RETURN(c)	return
#define ERROR(c)	errxx(c)


ematch(s, p)
char *s;
register char *p;
{
	static char expbuf[ESIZE];
	char *compile();
	register num;
	extern char *braslist[], *braelist[], *loc2;

	compile(p, expbuf, &expbuf[ESIZE], 0);
	if(nbra > 1)
		yyerror("Too many '\\('s");
	if(advance(s, expbuf)) {
		if(nbra == 1) {
			p = braslist[0];
			num = braelist[0] - p;
			strncpy(Mstring[0], p, num);
			Mstring[0][num] = '\0';
		}
		return(loc2-s);
	}
	return(0);
}

errxx(c)
{
	yyerror("RE error");
}

#define	CBRA	2
#define	CCHR	4
#define	CDOT	8
#define	CCL	12
#define	CDOL	20
#define	CEOF	22
#define	CKET	24
#define	CBACK	36

#define	STAR	01
#define RNGE	03

#define	NBRA	9

#define PLACE(c)	ep[c >> 3] |= bittab[c & 07]
#define ISTHERE(c)	(ep[c >> 3] & bittab[c & 07])

char	*braslist[NBRA];
char	*braelist[NBRA];
int	nbra;
char *loc1, *loc2, *locs;
int	sed;

int	circf;
int	low;
int	size;

char	bittab[] = {
	1,
	2,
	4,
	8,
	16,
	32,
	64,
	128
};

char *
compile(instring, ep, endbuf, seof)
register char *ep;
char *instring, *endbuf;
{
	INIT	/* Dependent declarations and initializations */
	register c;
	register eof = seof;
	char *lastep = instring;
	int cclcnt;
	char bracket[NBRA], *bracketp;
	int closed;
	char neg;
	int lc;
	int i, cflg;

	lastep = 0;
	if((c = GETC()) == eof) {
		if(*ep == 0 && !sed)
			ERROR(41);
		RETURN(ep);
	}
	bracketp = bracket;
	circf = closed = nbra = 0;
	if (c == '^')
		circf++;
	else
		UNGETC(c);
	for (;;) {
		if (ep >= endbuf)
			ERROR(50);
		if((c = GETC()) != '*' && ((c != '\\') || (PEEKC() != '{')))
			lastep = ep;
		if (c == eof) {
			*ep++ = CEOF;
			RETURN(ep);
		}
		switch (c) {

		case '.':
			*ep++ = CDOT;
			continue;

		case '\n':
			ERROR(36);
		case '*':
			if (lastep==0 || *lastep==CBRA || *lastep==CKET)
				goto defchar;
			*lastep |= STAR;
			continue;

		case '$':
			if(PEEKC() != eof)
				goto defchar;
			*ep++ = CDOL;
			continue;

		case '[':
			if(&ep[17] >= endbuf)
				ERROR(50);

			*ep++ = CCL;
			lc = 0;
			for(i = 0; i < 16; i++)
				ep[i] = 0;

			neg = 0;
			if((c = GETC()) == '^') {
				neg = 1;
				c = GETC();
			}

			do {
				if(c == '\0' || c == '\n')
					ERROR(49);
				if(c == '-' && lc != 0) {
					if ((c = GETC()) == ']') {
						PLACE('-');
						break;
					}
					while(lc < c) {
						PLACE(lc);
						lc++;
					}
				}
				lc = c;
				PLACE(c);
			} while((c = GETC()) != ']');
			if(neg) {
				for(cclcnt = 0; cclcnt < 16; cclcnt++)
					ep[cclcnt] ^= -1;
				ep[0] &= 0376;
			}

			ep += 16;

			continue;

		case '\\':
			switch(c = GETC()) {

			case '(':
				if(nbra >= NBRA)
					ERROR(43);
				*bracketp++ = nbra;
				*ep++ = CBRA;
				*ep++ = nbra++;
				continue;

			case ')':
				if(bracketp <= bracket)
					ERROR(42);
				*ep++ = CKET;
				*ep++ = *--bracketp;
				closed++;
				continue;

			case '{':
				if(lastep == (char *) (0))
					goto defchar;
				*lastep |= RNGE;
				cflg = 0;
			nlim:
				c = GETC();
				i = 0;
				do {
					if ('0' <= c && c <= '9')
						i = 10 * i + c - '0';
					else
						ERROR(16);
				} while(((c = GETC()) != '\\') && (c != ','));
				if (i > 255)
					ERROR(11);
				*ep++ = i;
				if (c == ',') {
					if(cflg++)
						ERROR(44);
					if((c = GETC()) == '\\')
						*ep++ = 255;
					else {
						UNGETC(c);
						goto nlim; /* get 2'nd number */
					}
				}
				if(GETC() != '}')
					ERROR(45);
				if(!cflg)	/* one number */
					*ep++ = i;
				else if((ep[-1] & 0377) < (ep[-2] & 0377))
					ERROR(46);
				continue;

			case '\n':
				ERROR(36);

			case 'n':
				c = '\n';
				goto defchar;

			default:
				if(c >= '1' && c <= '9') {
					if((c -= '1') >= closed)
						ERROR(25);
					*ep++ = CBACK;
					*ep++ = c;
					continue;
				}
			}
			/* Drop through to default to use \ to turn off special chars */

		defchar:
		default:
			lastep = ep;
			*ep++ = CCHR;
			*ep++ = c;
		}
	}
}

step(p1, p2)
register char *p1, *p2;
{
	register c;

	if (circf) {
		loc1 = p1;
		return(advance(p1, p2));
	}
	/* fast check for first character */
	if (*p2==CCHR) {
		c = p2[1];
		do {
			if (*p1 != c)
				continue;
			if (advance(p1, p2)) {
				loc1 = p1;
				return(1);
			}
		} while (*p1++);
		return(0);
	}
		/* regular algorithm */
	do {
		if (advance(p1, p2)) {
			loc1 = p1;
			return(1);
		}
	} while (*p1++);
	return(0);
}

advance(lp, ep)
register char *lp, *ep;
{
	register char *curlp;
	char c;
	char *bbeg;
	int ct;

	for (;;) switch (*ep++) {

	case CCHR:
		if (*ep++ == *lp++)
			continue;
		return(0);

	case CDOT:
		if (*lp++)
			continue;
		return(0);

	case CDOL:
		if (*lp==0)
			continue;
		return(0);

	case CEOF:
		loc2 = lp;
		return(1);

	case CCL:
		c = *lp++ & 0177;
		if(ISTHERE(c)) {
			ep += 16;
			continue;
		}
		return(0);
	case CBRA:
		braslist[*ep++] = lp;
		continue;

	case CKET:
		braelist[*ep++] = lp;
		continue;

	case CCHR|RNGE:
		c = *ep++;
		getrnge(ep);
		while(low--)
			if(*lp++ != c)
				return(0);
		curlp = lp;
		while(size--) 
			if(*lp++ != c)
				break;
		if(size < 0)
			lp++;
		ep += 2;
		goto star;

	case CDOT|RNGE:
		getrnge(ep);
		while(low--)
			if(*lp++ == '\0')
				return(0);
		curlp = lp;
		while(size--)
			if(*lp++ == '\0')
				break;
		if(size < 0)
			lp++;
		ep += 2;
		goto star;

	case CCL|RNGE:
		getrnge(ep + 16);
		while(low--) {
			c = *lp++ & 0177;
			if(!ISTHERE(c))
				return(0);
		}
		curlp = lp;
		while(size--) {
			c = *lp++ & 0177;
			if(!ISTHERE(c))
				break;
		}
		if(size < 0)
			lp++;
		ep += 18;		/* 16 + 2 */
		goto star;

	case CBACK:
		bbeg = braslist[*ep];
		ct = braelist[*ep++] - bbeg;

		if(ecmp(bbeg, lp, ct)) {
			lp += ct;
			continue;
		}
		return(0);

	case CBACK|STAR:
		bbeg = braslist[*ep];
		ct = braelist[*ep++] - bbeg;
		curlp = lp;
		while(ecmp(bbeg, lp, ct))
			lp += ct;

		while(lp >= curlp) {
			if(advance(lp, ep))	return(1);
			lp -= ct;
		}
		return(0);


	case CDOT|STAR:
		curlp = lp;
		while (*lp++);
		goto star;

	case CCHR|STAR:
		curlp = lp;
		while (*lp++ == *ep);
		ep++;
		goto star;

	case CCL|STAR:
		curlp = lp;
		do {
			c = *lp++ & 0177;
		} while(ISTHERE(c));
		ep += 16;
		goto star;

	star:
		do {
			if(--lp == locs)
				break;
			if (advance(lp, ep))
				return(1);
		} while (lp > curlp);
		return(0);

	}
}

getrnge(str)
register char *str;
{
	low = *str++ & 0377;
	size = (*str & 0377) == 255 ? 20000 : (*str & 0377) - low;
}

ecmp(a, b, count)
register char	*a, *b;
register	count;
{
	if(a == b) /* should have been caught in compile() */
		error(51);
	while(count--)
		if(*a++ != *b++)	return(0);
	return(1);
}

static char *sccsid = "@(#)expr.y	4.7 (Berkeley) %G%";
yyerror(s)

{
	fprintf(stderr, "%s\n", s);
	exit(2);
}
Commit	Line	Data
e95afa8a BJ	1	/* Yacc productions for "expr" command: */
	2
	3	%token OR AND ADD SUBT MULT DIV REM EQ GT GEQ LT LEQ NEQ
	4	%token A_STRING SUBSTR LENGTH INDEX NOARG MATCH
	5
	6	/* operators listed below in increasing precedence: */
	7	%left OR
	8	%left AND
	9	%left EQ LT GT GEQ LEQ NEQ
	10	%left ADD SUBT
	11	%left MULT DIV REM
	12	%left MCH
	13	%left MATCH
	14	%left SUBSTR
	15	%left LENGTH INDEX
	16	%%
	17
	18	/* a single `expression' is evaluated and printed: */
	19
	20	expression: expr NOARG = {
	21	printf("%s\n", $1);
	22	exit((!strcmp($1,"0")\|\|!strcmp($1,"\0"))? 1: 0);
	23	}
	24	;
	25
	26
	27	expr: '(' expr ')' = { $$ = $2; }
	28	\| expr OR expr = { $$ = conj(OR, $1, $3); }
	29	\| expr AND expr = { $$ = conj(AND, $1, $3); }
	30	\| expr EQ expr = { $$ = rel(EQ, $1, $3); }
	31	\| expr GT expr = { $$ = rel(GT, $1, $3); }
	32	\| expr GEQ expr = { $$ = rel(GEQ, $1, $3); }
	33	\| expr LT expr = { $$ = rel(LT, $1, $3); }
	34	\| expr LEQ expr = { $$ = rel(LEQ, $1, $3); }
	35	\| expr NEQ expr = { $$ = rel(NEQ, $1, $3); }
	36	\| expr ADD expr = { $$ = arith(ADD, $1, $3); }
	37	\| expr SUBT expr = { $$ = arith(SUBT, $1, $3); }
	38	\| expr MULT expr = { $$ = arith(MULT, $1, $3); }
	39	\| expr DIV expr = { $$ = arith(DIV, $1, $3); }
	40	\| expr REM expr = { $$ = arith(REM, $1, $3); }
	41	\| expr MCH expr = { $$ = match($1, $3); }
	42	\| MATCH expr expr = { $$ = match($2, $3); }
	43	\| SUBSTR expr expr expr = { $$ = substr($2, $3, $4); }
	44	\| LENGTH expr = { $$ = length($2); }
	45	\| INDEX expr expr = { $$ = index($2, $3); }
	46	\| A_STRING
	47	;
	48	%%
	49	/* expression command */
	50	#include <stdio.h>
	51	#define ESIZE 256
	52	#define error(c) errxx(c)
	53	#define EQL(x,y) !strcmp(x,y)
	54	long atol();
	55	char **Av;
	56	int Ac;
	57	int Argi;
	58
	59	char Mstring[1][128];
	60	char *malloc();
	61	extern int nbra;
	62
	63	main(argc, argv) char **argv; {
	64	Ac = argc;
65	Argi = 1;
66	Av = argv;
67	yyparse();
68	}
69
70	char operators[] = { "\|", "&", "+", "-", "", "/", "%", ":",
71	"=", "==", "<", "<=", ">", ">=", "!=",
72	"match", "substr", "length", "index", "\0" };
73	int op[] = { OR, AND, ADD, SUBT, MULT, DIV, REM, MCH,
74	EQ, EQ, LT, LEQ, GT, GEQ, NEQ,
75	MATCH, SUBSTR, LENGTH, INDEX };
76	yylex() {
77	register char *p;
78	register i;
79
80	if(Argi >= Ac) return NOARG;
81
82	p = Av[Argi++];
83
84	if(p == '(' \|\| p == ')')
85	return (int)*p;
86	for(i = 0; *operators[i]; ++i)
87	if(EQL(operators[i], p))
88	return op[i];
89
90	yylval = p;
91	return A_STRING;
92	}
93
94	char rel(op, r1, r2) register char r1, *r2; {
b940afc0	95	register long i;
e95afa8a BJ	96
	97	if(ematch(r1, "-[0-9]$") && ematch(r2, "[0-9]*$"))
	98	i = atol(r1) - atol(r2);
	99	else
	100	i = strcmp(r1, r2);
	101	switch(op) {
	102	case EQ: i = i==0; break;
	103	case GT: i = i>0; break;
	104	case GEQ: i = i>=0; break;
	105	case LT: i = i<0; break;
df3e00cc	106	case LEQ: i = i<=0; break;
e95afa8a BJ	107	case NEQ: i = i!=0; break;
	108	}
	109	return i? "1": "0";
	110	}
	111
	112	char arith(op, r1, r2) char r1, *r2; {
	113	long i1, i2;
	114	register char *rv;
	115
e1d6f378 KB	116	if(!((ematch(r1, "[0-9]$") \|\| ematch(r1, "-[0-9]$")) &&
e1d6f378 KB	117	(ematch(r2, "[0-9]$") \|\| ematch(r2, "-[0-9]$"))))
e95afa8a BJ	118	yyerror("non-numeric argument");
	119	i1 = atol(r1);
	120	i2 = atol(r2);
	121
	122	switch(op) {
	123	case ADD: i1 = i1 + i2; break;
	124	case SUBT: i1 = i1 - i2; break;
	125	case MULT: i1 = i1 * i2; break;
	126	case DIV: i1 = i1 / i2; break;
	127	case REM: i1 = i1 % i2; break;
	128	}
	129	rv = malloc(16);
6521d648	130	(void)sprintf(rv, "%ld", i1);
e95afa8a BJ	131	return rv;
	132	}
	133	char conj(op, r1, r2) char r1, *r2; {
	134	register char *rv;
	135
	136	switch(op) {
	137
	138	case OR:
	139	if(EQL(r1, "0")
	140	\|\| EQL(r1, ""))
	141	if(EQL(r2, "0")
	142	\|\| EQL(r2, ""))
	143	rv = "0";
	144	else
	145	rv = r2;
	146	else
	147	rv = r1;
	148	break;
	149	case AND:
	150	if(EQL(r1, "0")
	151	\|\| EQL(r1, ""))
	152	rv = "0";
	153	else if(EQL(r2, "0")
	154	\|\| EQL(r2, ""))
	155	rv = "0";
	156	else
	157	rv = r1;
	158	break;
	159	}
	160	return rv;
	161	}
	162
	163	char substr(v, s, w) char v, s, w; {
	164	register si, wi;
	165	register char *res;
	166
	167	si = atol(s);
	168	wi = atol(w);
	169	while(--si) if(*v) ++v;
	170
	171	res = v;
	172
	173	while(wi--) if(*v) ++v;
	174
	175	*v = '\0';
	176	return res;
	177	}
	178
	179	char length(s) register char s; {
	180	register i = 0;
	181	register char *rv;
	182
	183	while(*s++) ++i;
	184
	185	rv = malloc(8);
6521d648	186	(void)sprintf(rv, "%d", i);
e95afa8a BJ	187	return rv;
	188	}
	189
	190	char index(s, t) char s, *t; {
	191	register i, j;
	192	register char *rv;
	193
	194	for(i = 0; s[i] ; ++i)
	195	for(j = 0; t[j] ; ++j)
	196	if(s[i]==t[j]) {
6521d648	197	(void)sprintf(rv = malloc(8), "%d", ++i);
e95afa8a BJ	198	return rv;
	199	}
	200	return "0";
	201	}
	202
	203	char *match(s, p)
	204	{
	205	register char *rv;
	206
6521d648	207	(void)sprintf(rv = malloc(8), "%d", ematch(s, p));
e95afa8a BJ	208	if(nbra) {
	209	rv = malloc(strlen(Mstring[0])+1);
	210	strcpy(rv, Mstring[0]);
	211	}
	212	return rv;
	213	}
	214
	215	#define INIT register char *sp = instring;
	216	#define GETC() (*sp++)
	217	#define PEEKC() (*sp)
	218	#define UNGETC(c) (--sp)
	219	#define RETURN(c) return
	220	#define ERROR(c) errxx(c)
	221
	222
	223	ematch(s, p)
	224	char *s;
	225	register char *p;
	226	{
	227	static char expbuf[ESIZE];
	228	char *compile();
	229	register num;
	230	extern char braslist[], braelist[], *loc2;
	231
6ee2a9ff	232	compile(p, expbuf, &expbuf[ESIZE], 0);
e95afa8a BJ	233	if(nbra > 1)
	234	yyerror("Too many '\\('s");
	235	if(advance(s, expbuf)) {
	236	if(nbra == 1) {
	237	p = braslist[0];
	238	num = braelist[0] - p;
	239	strncpy(Mstring[0], p, num);
	240	Mstring[0][num] = '\0';
	241	}
	242	return(loc2-s);
	243	}
	244	return(0);
	245	}
	246
	247	errxx(c)
	248	{
	249	yyerror("RE error");
	250	}
	251
	252	#define CBRA 2
	253	#define CCHR 4
	254	#define CDOT 8
	255	#define CCL 12
	256	#define CDOL 20
	257	#define CEOF 22
	258	#define CKET 24
	259	#define CBACK 36
	260
	261	#define STAR 01
	262	#define RNGE 03
	263
	264	#define NBRA 9
	265
	266	#define PLACE(c) ep[c >> 3] \|= bittab[c & 07]
	267	#define ISTHERE(c) (ep[c >> 3] & bittab[c & 07])
	268
	269	char *braslist[NBRA];
	270	char *braelist[NBRA];
	271	int nbra;
	272	char loc1, loc2, *locs;
	273	int sed;
	274
	275	int circf;
	276	int low;
	277	int size;
	278
	279	char bittab[] = {
	280	1,
	281	2,
	282	4,
	283	8,
	284	16,
	285	32,
	286	64,
	287	128
	288	};
	289
	290	char *
	291	compile(instring, ep, endbuf, seof)
	292	register char *ep;
	293	char instring, endbuf;
	294	{
	295	INIT /* Dependent declarations and initializations */
	296	register c;
297	register eof = seof;
298	char *lastep = instring;
299	int cclcnt;
300	char bracket[NBRA], *bracketp;
301	int closed;
302	char neg;
303	int lc;
304	int i, cflg;
305
306	lastep = 0;
307	if((c = GETC()) == eof) {
308	if(*ep == 0 && !sed)
309	ERROR(41);
310	RETURN(ep);
311	}
312	bracketp = bracket;
313	circf = closed = nbra = 0;
314	if (c == '^')
315	circf++;
316	else
317	UNGETC(c);
318	for (;;) {
319	if (ep >= endbuf)
320	ERROR(50);
321	if((c = GETC()) != '*' && ((c != '\\') \|\| (PEEKC() != '{')))
322	lastep = ep;
323	if (c == eof) {
324	*ep++ = CEOF;
325	RETURN(ep);
326	}
327	switch (c) {
328
329	case '.':
330	*ep++ = CDOT;
331	continue;
332
333	case '\n':
334	ERROR(36);
335	case '*':
336	if (lastep==0 \|\| lastep==CBRA \|\| lastep==CKET)
337	goto defchar;
338	*lastep \|= STAR;
339	continue;
340
341	case '$':
342	if(PEEKC() != eof)
343	goto defchar;
344	*ep++ = CDOL;
345	continue;
346
347	case '[':
348	if(&ep[17] >= endbuf)
349	ERROR(50);
350
351	*ep++ = CCL;
352	lc = 0;
353	for(i = 0; i < 16; i++)
354	ep[i] = 0;
355
356	neg = 0;
357	if((c = GETC()) == '^') {
358	neg = 1;
359	c = GETC();
360	}
361
362	do {
363	if(c == '\0' \|\| c == '\n')
364	ERROR(49);
365	if(c == '-' && lc != 0) {
366	if ((c = GETC()) == ']') {
367	PLACE('-');
368	break;
369	}
370	while(lc < c) {
371	PLACE(lc);
372	lc++;
373	}
374	}
375	lc = c;
376	PLACE(c);
377	} while((c = GETC()) != ']');
378	if(neg) {
379	for(cclcnt = 0; cclcnt < 16; cclcnt++)
380	ep[cclcnt] ^= -1;
381	ep[0] &= 0376;
382	}
383
384	ep += 16;
385
386	continue;
387
388	case '\\':
389	switch(c = GETC()) {
390
391	case '(':
392	if(nbra >= NBRA)
393	ERROR(43);
394	*bracketp++ = nbra;
395	*ep++ = CBRA;
396	*ep++ = nbra++;
397	continue;
398
399	case ')':
400	if(bracketp <= bracket)
401	ERROR(42);
402	*ep++ = CKET;
403	ep++ = --bracketp;
404	closed++;
405	continue;
406
407	case '{':
408	if(lastep == (char *) (0))
409	goto defchar;
410	*lastep \|= RNGE;
411	cflg = 0;
412	nlim:
413	c = GETC();
414	i = 0;
415	do {
416	if ('0' <= c && c <= '9')
417	i = 10 * i + c - '0';
418	else
419	ERROR(16);
420	} while(((c = GETC()) != '\\') && (c != ','));
421	if (i > 255)
422	ERROR(11);
423	*ep++ = i;
424	if (c == ',') {
425	if(cflg++)
426	ERROR(44);
427	if((c = GETC()) == '\\')
428	*ep++ = 255;
429	else {
430	UNGETC(c);
431	goto nlim; /* get 2'nd number */
432	}
433	}
434	if(GETC() != '}')
435	ERROR(45);
436	if(!cflg) /* one number */
437	*ep++ = i;
438	else if((ep[-1] & 0377) < (ep[-2] & 0377))
439	ERROR(46);
440	continue;
441
442	case '\n':
443	ERROR(36);
444
445	case 'n':
446	c = '\n';
447	goto defchar;
448
449	default:
450	if(c >= '1' && c <= '9') {
451	if((c -= '1') >= closed)
452	ERROR(25);
453	*ep++ = CBACK;
454	*ep++ = c;
455	continue;
456	}
457	}
458	/* Drop through to default to use \ to turn off special chars */
459
460	defchar:
461	default:
462	lastep = ep;
463	*ep++ = CCHR;
464	*ep++ = c;
465	}
466	}
467	}
468
469	step(p1, p2)
470	register char p1, p2;
471	{
472	register c;
473
474	if (circf) {
475	loc1 = p1;
476	return(advance(p1, p2));
477	}
478	/* fast check for first character */
479	if (*p2==CCHR) {
480	c = p2[1];
481	do {
482	if (*p1 != c)
483	continue;
484	if (advance(p1, p2)) {
485	loc1 = p1;
486	return(1);
487	}
488	} while (*p1++);
489	return(0);
490	}
491	/* regular algorithm */
492	do {
493	if (advance(p1, p2)) {
494	loc1 = p1;
495	return(1);
496	}
497	} while (*p1++);
498	return(0);
499	}
500
501	advance(lp, ep)
502	register char lp, ep;
503	{
504	register char *curlp;
505	char c;
506	char *bbeg;
507	int ct;
508
509	for (;;) switch (*ep++) {
510
511	case CCHR:
512	if (ep++ == lp++)
513	continue;
514	return(0);
515
516	case CDOT:
517	if (*lp++)
518	continue;
519	return(0);
520
521	case CDOL:
522	if (*lp==0)
523	continue;
524	return(0);
525
526	case CEOF:
527	loc2 = lp;
528	return(1);
529
530	case CCL:
531	c = *lp++ & 0177;
532	if(ISTHERE(c)) {
533	ep += 16;
534	continue;
535	}
536	return(0);
537	case CBRA:
538	braslist[*ep++] = lp;
539	continue;
540
541	case CKET:
542	braelist[*ep++] = lp;
543	continue;
544
545	case CCHR\|RNGE:
546	c = *ep++;
547	getrnge(ep);
548	while(low--)
549	if(*lp++ != c)
550	return(0);
551	curlp = lp;
552	while(size--)
553	if(*lp++ != c)
554	break;
555	if(size < 0)
556	lp++;
557	ep += 2;
558	goto star;
559
560	case CDOT\|RNGE:
561	getrnge(ep);
562	while(low--)
563	if(*lp++ == '\0')
564	return(0);
565	curlp = lp;
566	while(size--)
567	if(*lp++ == '\0')
568	break;
569	if(size < 0)
570	lp++;
571	ep += 2;
572	goto star;
573
574	case CCL\|RNGE:
575	getrnge(ep + 16);
576	while(low--) {
577	c = *lp++ & 0177;
578	if(!ISTHERE(c))
579	return(0);
580	}
581	curlp = lp;
582	while(size--) {
583	c = *lp++ & 0177;
584	if(!ISTHERE(c))
585	break;
586	}
587	if(size < 0)
588	lp++;
589	ep += 18; /* 16 + 2 */
590	goto star;
591
592	case CBACK:
593	bbeg = braslist[*ep];
594	ct = braelist[*ep++] - bbeg;
595
596	if(ecmp(bbeg, lp, ct)) {
597	lp += ct;
598	continue;
599	}
600	return(0);
601
602	case CBACK\|STAR:
603	bbeg = braslist[*ep];
604	ct = braelist[*ep++] - bbeg;
605	curlp = lp;
606	while(ecmp(bbeg, lp, ct))
607	lp += ct;
608
609	while(lp >= curlp) {
610	if(advance(lp, ep)) return(1);
611	lp -= ct;
612	}
613	return(0);
614
615
616	case CDOT\|STAR:
617	curlp = lp;
618	while (*lp++);
619	goto star;
620
621	case CCHR\|STAR:
622	curlp = lp;
623	while (lp++ == ep);
624	ep++;
625	goto star;
626
627	case CCL\|STAR:
628	curlp = lp;
629	do {
630	c = *lp++ & 0177;
631	} while(ISTHERE(c));
632	ep += 16;
633	goto star;
634
635	star:
636	do {
637	if(--lp == locs)
638	break;
639	if (advance(lp, ep))
640	return(1);
641	} while (lp > curlp);
642	return(0);
643
644	}
645	}
646
647	getrnge(str)
648	register char *str;
649	{
650	low = *str++ & 0377;
15bd6011	651	size = (str & 0377) == 255 ? 20000 : (str & 0377) - low;
e95afa8a BJ	652	}
	653
	654	ecmp(a, b, count)
	655	register char a, b;
	656	register count;
	657	{
	658	if(a == b) /* should have been caught in compile() */
	659	error(51);
	660	while(count--)
	661	if(a++ != b++) return(0);
	662	return(1);
	663	}
	664
15bd6011	665	static char *sccsid = "@(#)expr.y 4.7 (Berkeley) %G%";
e95afa8a BJ	666	yyerror(s)
	667
	668	{
	669	fprintf(stderr, "%s\n", s);
	670	exit(2);
	671	}