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

#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
f42b14c5 BK	1	#include "e.h"
	2	#include "e.def"
	3
	4	#define SSIZE 400
	5	char token[SSIZE];
	6	int sp;
	7	#define putbak(c) *ip++ = c;
	8	#define PUSHBACK 300 /* maximum pushback characters */
	9	char ibuf[PUSHBACK+SSIZE]; /* pushback buffer for definitions, etc. */
	10	char *ip = ibuf;
	11
	12	gtc() {
	13	loop:
	14	if (ip > ibuf)
	15	return(--ip); / already present */
	16	lastchar = getc(curfile);
	17	if (lastchar=='\n')
	18	linect++;
	19	if (lastchar != EOF)
	20	return(lastchar);
	21	if (++ifile > svargc) {
	22	return(EOF);
	23	}
	24	fclose(curfile);
	25	linect = 1;
	26	if ((curfile=fopen(svargv[ifile], "r")) != NULL)
	27	goto loop;
	28	error(FATAL, "can't open file %s", svargv[ifile]);
	29	return(EOF);
	30	}
	31
	32	pbstr(str)
	33	register char *str;
	34	{
	35	register char *p;
	36
	37	p = str;
	38	while (*p++);
	39	--p;
	40	if (ip >= &ibuf[PUSHBACK])
	41	error( FATAL, "pushback overflow");
	42	while (p > str)
	43	putbak(*--p);
	44	}
	45
	46	yylex() {
	47	register int c;
	48	tbl tp, lookup();
	49	extern tbl keytbl, deftbl;
	50
	51	beg:
	52	while ((c=gtc())==' ' \|\| c=='\n')
	53	;
	54	yylval=c;
	55	switch(c) {
	56
	57	case EOF:
	58	return(EOF);
	59	case '~':
	60	return(SPACE);
	61	case '^':
	62	return(THIN);
	63	case '\t':
	64	return(TAB);
65	case '{':
66	return('{');
67	case '}':
68	return('}');
69	case '"':
70	for (sp=0; (c=gtc())!='"' && c != '\n'; ) {
71	if (c == '\\')
72	if ((c = gtc()) != '"')
73	token[sp++] = '\\';
74	token[sp++] = c;
75	if (sp>=SSIZE)
76	error(FATAL, "quoted string %.20s... too long", token);
77	}
78	token[sp]='\0';
79	yylval = (int) &token[0];
80	if (c == '\n')
81	error(!FATAL, "missing \" in %.20s", token);
82	return(QTEXT);
83	}
84	if (c==righteq)
85	return(EOF);
86
87	putbak(c);
88	getstr(token, SSIZE);
89	if (dbg)printf(".\tlex token = \|%s\|\n", token);
90	if ((tp = lookup(&deftbl, token, NULL)) != NULL) {
91	putbak(' ');
92	pbstr(tp->defn);
93	putbak(' ');
94	if (dbg)
95	printf(".\tfound %s\|=%s\|\n", token, tp->defn);
96	}
97	else if ((tp = lookup(&keytbl, token, NULL)) == NULL) {
98	if(dbg)printf(".\t%s is not a keyword\n", token);
99	return(CONTIG);
100	}
101	else if (tp->defn == (char ) DEFINE \|\| tp->defn == (char ) NDEFINE \|\| tp->defn == (char *) TDEFINE)
102	define(tp->defn);
103	else if (tp->defn == (char *) DELIM)
104	delim();
105	else if (tp->defn == (char *) GSIZE)
106	globsize();
107	else if (tp->defn == (char *) GFONT)
108	globfont();
109	else if (tp->defn == (char *) INCLUDE)
110	include();
111	else {
112	return((int) tp->defn);
113	}
114	goto beg;
115	}
116
117	getstr(s, n) char *s; register int n; {
118	register int c;
119	register char *p;
120
121	p = s;
122	while ((c = gtc()) == ' ' \|\| c == '\n')
123	;
124	if (c == EOF) {
125	*s = 0;
126	return;
127	}
128	while (c != ' ' && c != '\t' && c != '\n' && c != '{' && c != '}'
129	&& c != '"' && c != '~' && c != '^' && c != righteq) {
130	if (c == '\\')
131	if ((c = gtc()) != '"')
132	*p++ = '\\';
133	*p++ = c;
134	if (--n <= 0)
135	error(FATAL, "token %.20s... too long", s);
136	c = gtc();
137	}
138	if (c=='{' \|\| c=='}' \|\| c=='"' \|\| c=='~' \|\| c=='^' \|\| c=='\t' \|\| c==righteq)
139	putbak(c);
140	*p = '\0';
141	yylval = (int) s;
142	}
143
144	cstr(s, quote, maxs) char *s; int quote; {
145	int del, c, i;
146
147	while((del=gtc()) == ' ' \|\| del == '\t' \|\| del == '\n');
148	if (quote)
149	for (i=0; (c=gtc()) != del && c != EOF;) {
150	s[i++] = c;
151	if (i >= maxs)
152	return(1); /* disaster */
153	}
154	else {
155	s[0] = del;
156	for (i=1; (c=gtc())!=' ' && c!= '\t' && c!='\n' && c!=EOF;) {
157	s[i++]=c;
158	if (i >= maxs)
159	return(1); /* disaster */
160	}
161	}
162	s[i] = '\0';
163	if (c == EOF)
164	error(FATAL, "Unexpected end of input at %.20s", s);
165	return(0);
166	}
167
168	define(type) int type; {
169	char strsave(), p1, *p2;
170	tbl *lookup();
171	extern tbl **deftbl;
172
173	getstr(token, SSIZE); /* get name */
174	if (type != DEFINE) {
175	cstr(token, 1, SSIZE); /* skip the definition too */
176	return;
177	}
178	p1 = strsave(token);
179	if (cstr(token, 1, SSIZE))
180	error(FATAL, "Unterminated definition at %.20s", token);
181	p2 = strsave(token);
182	lookup(&deftbl, p1, p2);
183	if (dbg)printf(".\tname %s defined as %s\n", p1, p2);
184	}
185
186	char *strsave(s)
187	char *s;
188	{
189	char *malloc();
190	register char *q;
191
192	q = malloc(strlen(s)+1);
193	if (q == NULL)
194	error(FATAL, "out of space in strsave on %s", s);
195	strcpy(q, s);
196	return(q);
197	}
198
199	include() {
200	error(!FATAL, "Include not yet implemented");
201	}
202
203	delim() {
204	yyval = eqnreg = 0;
205	if (cstr(token, 0, SSIZE))
206	error(FATAL, "Bizarre delimiters at %.20s", token);
207	lefteq = token[0];
208	righteq = token[1];
209	if (lefteq == 'o' && righteq == 'f')
210	lefteq = righteq = '\0';
211	}