[unix-history] / usr / src / old / eqn / common_source / lex.c

/*	lex.c	4.1	83/02/11	*/

#include "e.h"
#include "e.def"

#define	SSIZE	400
char	token[SSIZE];
int	sp;
#define	putbak(c)	*ip++ = c;
#define	PUSHBACK	300	/* maximum pushback characters */
char	ibuf[PUSHBACK+SSIZE];	/* pushback buffer for definitions, etc. */
char	*ip	= ibuf;

gtc() {
  loop:
	if (ip > ibuf)
		return(*--ip);	/* already present */
	lastchar = getc(curfile);
	if (lastchar=='\n')
		linect++;
	if (lastchar != EOF)
		return(lastchar);
	if (++ifile > svargc) {
		return(EOF);
	}
	fclose(curfile);
	linect = 1;
	if ((curfile=fopen(svargv[ifile], "r")) != NULL)
		goto loop;
	error(FATAL, "can't open file %s", svargv[ifile]);
	return(EOF);
}

pbstr(str)
register char *str;
{
	register char *p;

	p = str;
	while (*p++);
	--p;
	if (ip >= &ibuf[PUSHBACK])
		error( FATAL, "pushback overflow");
	while (p > str)
		putbak(*--p);
}

yylex() {
	register int c;
	tbl *tp, *lookup();
	extern tbl **keytbl, **deftbl;

  beg:
	while ((c=gtc())==' ' || c=='\n')
		;
	yylval=c;
	switch(c) {

	case EOF:
		return(EOF);
	case '~':
		return(SPACE);
	case '^':
		return(THIN);
	case '\t':
		return(TAB);
	case '{':
		return('{');
	case '}':
		return('}');
	case '"':
		for (sp=0; (c=gtc())!='"' && c != '\n'; ) {
			if (c == '\\')
				if ((c = gtc()) != '"')
					token[sp++] = '\\';
			token[sp++] = c;
			if (sp>=SSIZE)
				error(FATAL, "quoted string %.20s... too long", token);
		}
		token[sp]='\0';
		yylval = (int) &token[0];
		if (c == '\n')
			error(!FATAL, "missing \" in %.20s", token);
		return(QTEXT);
	}
	if (c==righteq)
		return(EOF);

	putbak(c);
	getstr(token, SSIZE);
	if (dbg)printf(".\tlex token = |%s|\n", token);
	if ((tp = lookup(&deftbl, token, NULL)) != NULL) {
		putbak(' ');
		pbstr(tp->defn);
		putbak(' ');
		if (dbg)
			printf(".\tfound %s|=%s|\n", token, tp->defn);
	}
	else if ((tp = lookup(&keytbl, token, NULL)) == NULL) {
		if(dbg)printf(".\t%s is not a keyword\n", token);
		return(CONTIG);
	}
	else if (tp->defn == (char *) DEFINE || tp->defn == (char *) NDEFINE || tp->defn == (char *) TDEFINE)
		define(tp->defn);
	else if (tp->defn == (char *) DELIM)
		delim();
	else if (tp->defn == (char *) GSIZE)
		globsize();
	else if (tp->defn == (char *) GFONT)
		globfont();
	else if (tp->defn == (char *) INCLUDE)
		include();
	else {
		return((int) tp->defn);
	}
	goto beg;
}

getstr(s, n) char *s; register int n; {
	register int c;
	register char *p;

	p = s;
	while ((c = gtc()) == ' ' || c == '\n')
		;
	if (c == EOF) {
		*s = 0;
		return;
	}
	while (c != ' ' && c != '\t' && c != '\n' && c != '{' && c != '}'
	  && c != '"' && c != '~' && c != '^' && c != righteq) {
		if (c == '\\')
			if ((c = gtc()) != '"')
				*p++ = '\\';
		*p++ = c;
		if (--n <= 0)
			error(FATAL, "token %.20s... too long", s);
		c = gtc();
	}
	if (c=='{' || c=='}' || c=='"' || c=='~' || c=='^' || c=='\t' || c==righteq)
		putbak(c);
	*p = '\0';
	yylval = (int) s;
}

cstr(s, quote, maxs) char *s; int quote; {
	int del, c, i;

	while((del=gtc()) == ' ' || del == '\t' || del == '\n');
	if (quote)
		for (i=0; (c=gtc()) != del && c != EOF;) {
			s[i++] = c;
			if (i >= maxs)
				return(1);	/* disaster */
		}
	else {
		s[0] = del;
		for (i=1; (c=gtc())!=' ' && c!= '\t' && c!='\n' && c!=EOF;) {
			s[i++]=c;
			if (i >= maxs)
				return(1);	/* disaster */
		}
	}
	s[i] = '\0';
	if (c == EOF)
		error(FATAL, "Unexpected end of input at %.20s", s);
	return(0);
}

define(type) int type; {
	char *strsave(), *p1, *p2;
	tbl *lookup();
	extern tbl **deftbl;

	getstr(token, SSIZE);	/* get name */
	if (type != DEFINE) {
		cstr(token, 1, SSIZE);	/* skip the definition too */
		return;
	}
	p1 = strsave(token);
	if (cstr(token, 1, SSIZE))
		error(FATAL, "Unterminated definition at %.20s", token);
	p2 = strsave(token);
	lookup(&deftbl, p1, p2);
	if (dbg)printf(".\tname %s defined as %s\n", p1, p2);
}

char *strsave(s)
char *s;
{
	char *malloc();
	register char *q;

	q = malloc(strlen(s)+1);
	if (q == NULL)
		error(FATAL, "out of space in strsave on %s", s);
	strcpy(q, s);
	return(q);
}

include() {
	error(!FATAL, "Include not yet implemented");
}

delim() {
	yyval = eqnreg = 0;
	if (cstr(token, 0, SSIZE))
		error(FATAL, "Bizarre delimiters at %.20s", token);
	lefteq = token[0];
	righteq = token[1];
	if (lefteq == 'o' && righteq == 'f')
		lefteq = righteq = '\0';
}
Commit	Line	Data
a32b3978 BS	1	/* lex.c 4.1 83/02/11 */
	2
	3	#include "e.h"
	4	#include "e.def"
	5
	6	#define SSIZE 400
	7	char token[SSIZE];
	8	int sp;
	9	#define putbak(c) *ip++ = c;
	10	#define PUSHBACK 300 /* maximum pushback characters */
	11	char ibuf[PUSHBACK+SSIZE]; /* pushback buffer for definitions, etc. */
	12	char *ip = ibuf;
	13
	14	gtc() {
	15	loop:
	16	if (ip > ibuf)
	17	return(--ip); / already present */
	18	lastchar = getc(curfile);
	19	if (lastchar=='\n')
	20	linect++;
	21	if (lastchar != EOF)
	22	return(lastchar);
	23	if (++ifile > svargc) {
	24	return(EOF);
	25	}
	26	fclose(curfile);
	27	linect = 1;
	28	if ((curfile=fopen(svargv[ifile], "r")) != NULL)
	29	goto loop;
	30	error(FATAL, "can't open file %s", svargv[ifile]);
	31	return(EOF);
	32	}
	33
	34	pbstr(str)
	35	register char *str;
	36	{
	37	register char *p;
	38
	39	p = str;
	40	while (*p++);
	41	--p;
	42	if (ip >= &ibuf[PUSHBACK])
	43	error( FATAL, "pushback overflow");
	44	while (p > str)
	45	putbak(*--p);
	46	}
	47
	48	yylex() {
	49	register int c;
	50	tbl tp, lookup();
	51	extern tbl keytbl, deftbl;
	52
	53	beg:
	54	while ((c=gtc())==' ' \|\| c=='\n')
	55	;
	56	yylval=c;
	57	switch(c) {
	58
	59	case EOF:
	60	return(EOF);
	61	case '~':
	62	return(SPACE);
	63	case '^':
	64	return(THIN);
65	case '\t':
66	return(TAB);
67	case '{':
68	return('{');
69	case '}':
70	return('}');
71	case '"':
72	for (sp=0; (c=gtc())!='"' && c != '\n'; ) {
73	if (c == '\\')
74	if ((c = gtc()) != '"')
75	token[sp++] = '\\';
76	token[sp++] = c;
77	if (sp>=SSIZE)
78	error(FATAL, "quoted string %.20s... too long", token);
79	}
80	token[sp]='\0';
81	yylval = (int) &token[0];
82	if (c == '\n')
83	error(!FATAL, "missing \" in %.20s", token);
84	return(QTEXT);
85	}
86	if (c==righteq)
87	return(EOF);
88
89	putbak(c);
90	getstr(token, SSIZE);
91	if (dbg)printf(".\tlex token = \|%s\|\n", token);
92	if ((tp = lookup(&deftbl, token, NULL)) != NULL) {
93	putbak(' ');
94	pbstr(tp->defn);
95	putbak(' ');
96	if (dbg)
97	printf(".\tfound %s\|=%s\|\n", token, tp->defn);
98	}
99	else if ((tp = lookup(&keytbl, token, NULL)) == NULL) {
100	if(dbg)printf(".\t%s is not a keyword\n", token);
101	return(CONTIG);
102	}
103	else if (tp->defn == (char ) DEFINE \|\| tp->defn == (char ) NDEFINE \|\| tp->defn == (char *) TDEFINE)
104	define(tp->defn);
105	else if (tp->defn == (char *) DELIM)
106	delim();
107	else if (tp->defn == (char *) GSIZE)
108	globsize();
109	else if (tp->defn == (char *) GFONT)
110	globfont();
111	else if (tp->defn == (char *) INCLUDE)
112	include();
113	else {
114	return((int) tp->defn);
115	}
116	goto beg;
117	}
118
119	getstr(s, n) char *s; register int n; {
120	register int c;
121	register char *p;
122
123	p = s;
124	while ((c = gtc()) == ' ' \|\| c == '\n')
125	;
126	if (c == EOF) {
127	*s = 0;
128	return;
129	}
130	while (c != ' ' && c != '\t' && c != '\n' && c != '{' && c != '}'
131	&& c != '"' && c != '~' && c != '^' && c != righteq) {
132	if (c == '\\')
133	if ((c = gtc()) != '"')
134	*p++ = '\\';
135	*p++ = c;
136	if (--n <= 0)
137	error(FATAL, "token %.20s... too long", s);
138	c = gtc();
139	}
140	if (c=='{' \|\| c=='}' \|\| c=='"' \|\| c=='~' \|\| c=='^' \|\| c=='\t' \|\| c==righteq)
141	putbak(c);
142	*p = '\0';
143	yylval = (int) s;
144	}
145
146	cstr(s, quote, maxs) char *s; int quote; {
147	int del, c, i;
148
149	while((del=gtc()) == ' ' \|\| del == '\t' \|\| del == '\n');
150	if (quote)
151	for (i=0; (c=gtc()) != del && c != EOF;) {
152	s[i++] = c;
153	if (i >= maxs)
154	return(1); /* disaster */
155	}
156	else {
157	s[0] = del;
158	for (i=1; (c=gtc())!=' ' && c!= '\t' && c!='\n' && c!=EOF;) {
159	s[i++]=c;
160	if (i >= maxs)
161	return(1); /* disaster */
162	}
163	}
164	s[i] = '\0';
165	if (c == EOF)
166	error(FATAL, "Unexpected end of input at %.20s", s);
167	return(0);
168	}
169
170	define(type) int type; {
171	char strsave(), p1, *p2;
172	tbl *lookup();
173	extern tbl **deftbl;
174
175	getstr(token, SSIZE); /* get name */
176	if (type != DEFINE) {
177	cstr(token, 1, SSIZE); /* skip the definition too */
178	return;
179	}
180	p1 = strsave(token);
181	if (cstr(token, 1, SSIZE))
182	error(FATAL, "Unterminated definition at %.20s", token);
183	p2 = strsave(token);
184	lookup(&deftbl, p1, p2);
185	if (dbg)printf(".\tname %s defined as %s\n", p1, p2);
186	}
187
188	char *strsave(s)
189	char *s;
190	{
191	char *malloc();
192	register char *q;
193
194	q = malloc(strlen(s)+1);
195	if (q == NULL)
196	error(FATAL, "out of space in strsave on %s", s);
197	strcpy(q, s);
198	return(q);
199	}
200
201	include() {
202	error(!FATAL, "Include not yet implemented");
203	}
204
205	delim() {
206	yyval = eqnreg = 0;
207	if (cstr(token, 0, SSIZE))
208	error(FATAL, "Bizarre delimiters at %.20s", token);
209	lefteq = token[0];
210	righteq = token[1];
211	if (lefteq == 'o' && righteq == 'f')
212	lefteq = righteq = '\0';
213	}