Шрифт:
| expr OR expr { code(or); }
| NOT expr { $$ = $2; code(not); }
;
prlist: expr { code(prexpr); }
| STRING { $$ = code2(prstr, (Inst)$1); }
| prlist expr { code(prexpr); }
| prlist STRING { code2(prstr, (Inst)$3); }
;
defn: FUNC procname { $2->type=FUNCTION; indef=1; }
'(' ')' stmt { code(procret); define($2); indef=0; }
| PROC procname { $2->type=PROCEDURE; indef=1; }
'(' ')' stmt { code(procret); define($2); indef=0; }
;
procname: VAR
| FUNCTION
| PROCEDURE
;
arglist: /* nothing */ { $$ = 0; }
| expr { $$ = 1; }
| arglist expr { $$ = $1 + 1; }
;
%%
/* end of grammar */
#include <stdio.h>
#include <ctype.h>
char *progname;
int lineno = 1;
#include <signal.h>
#include <setjmp.h>
jmp_buf begin;
int indef;
char *infile; /* input file name */
FILE *fin; /* input file pointer */
char **gargv; /* global argument list */
int gargc;
int c; /* global for use by warning */
yylex /* hoc6 */
{
while ((c=getc(fin)) == ' ' || c == '\t')
;
if (c == EOF)
return 0;
if (c == '.' || isdigit(c)) { /* number */
double d;
ungetc(c, fin);
fscanf(fin, "%lf", &d);
yylval.sym = install("", NUMBER, d);
return NUMBER;
}
if (isalpha(c)) {
Symbol *s;
char sbuf[100], *p = sbuf;
do {
if (p >= sbuf + sizeof(sbuf) - 1) {
*p = '\0';
execerror("name too long", sbuf);
}
*p++ = c;
} while ((c=getc(fin)) != EOF && isalnum(c));
ungetc(c, fin);
*p = '\0';
if ((s=lookup(sbuf)) == 0)
s = install(sbuf, UNDEF, 0.0);
yylval.sym = s;
return s->type == UNDEF ? VAR : s->type;
}
if (c == '$') { /* argument? */
int n = 0;
while (isdigit(c=getc(fin)))
n=10*n+c- '0';
ungetc(c, fin);
if (n == 0)
execerror("strange $...", (char*)0);
yylval.narg = n;
return ARG;
}
if (c == '"') { /* quoted string */
char sbuf[100], *p, *emalloc;
for (p = sbuf; (c=getc(fin)) != '"'; p++) {
if (с == '\n' || c == EOF)
execerror("missing quote", "");
if (p >= sbuf + sizeof(sbuf) - 1) {
*p = '\0';
execerror("string too long", sbuf);
}
*p = backslash(c);
}
*p = 0;
yylval.sym = (Symbol*)emalloc(strlen(sbuf)+1);
strcpy(yylval.sym, sbuf);