ref: a8873f75169ddcb7d280f23e834926ef577b2530
dir: misc/calc.c
#line 2 "/usr/qwx/p/misc/calc.y"
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>
int yylex(void);
int yyparse(void);
void yyerror(char*);
Biobuf *bf;
#line 14 "/usr/qwx/p/misc/calc.y"
typedef union {
int i;
} YYSTYPE;
extern int yyerrflag;
#ifndef YYMAXDEPTH
#define YYMAXDEPTH 150
#endif
YYSTYPE yylval;
YYSTYPE yyval;
#define NUM 57346
#define YYEOFCODE 1
#define YYERRCODE 2
#line 36 "/usr/qwx/p/misc/calc.y"
void
yyerror(char *s)
{
fprint(2, "%s\n", s);
}
int
getnum(int c)
{
char s[64], *p;
for(p=s, *p++=c; isdigit(c=Bgetc(bf));)
if(p < s+sizeof(s)-1)
*p++ = c;
*p = 0;
Bungetc(bf);
return strtol(s, nil, 10);
}
int
yylex(void)
{
int n, c;
do
c = Bgetc(bf);
while(c != '\n' && isspace(c));
if(isdigit(c)){
yylval.i = getnum(c);
return NUM;
}else if(c == 'd'){
n = getnum(Bgetc(bf));
yylval.i = nrand(n != 0 ? n : 1);
return NUM;
}else
return c;
}
void
main(int argc, char **argv)
{
ARGBEGIN{
}ARGEND
if((bf = Bfdopen(0, OREAD)) == nil)
sysfatal("Bfdopen: %r");
yyparse();
}
short yyexca[] =
{-1, 1,
1, -1,
-2, 0,
};
#define YYNPROD 10
#define YYPRIVATE 57344
#define YYLAST 31
short yyact[] =
{
6, 7, 8, 9, 10, 2, 1, 17, 0, 0,
11, 0, 12, 13, 14, 15, 16, 6, 7, 8,
9, 10, 5, 3, 8, 9, 10, 0, 0, 0,
4
};
short yypact[] =
{
-1000, 19, 12,-1000, 19,-1000, 19, 19, 19, 19,
19, -5, 17, 17,-1000,-1000,-1000,-1000
};
short yypgo[] =
{
0, 5, 6
};
short yyr1[] =
{
0, 2, 2, 1, 1, 1, 1, 1, 1, 1
};
short yyr2[] =
{
0, 0, 3, 1, 3, 3, 3, 3, 3, 3
};
short yychk[] =
{
-1000, -2, -1, 4, 11, 10, 5, 6, 7, 8,
9, -1, -1, -1, -1, -1, -1, 12
};
short yydef[] =
{
1, -2, 0, 3, 0, 2, 0, 0, 0, 0,
0, 0, 5, 6, 7, 8, 9, 4
};
short yytok1[] =
{
1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
10, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 9, 0, 0,
11, 12, 7, 5, 0, 6, 0, 8
};
short yytok2[] =
{
2, 3, 4
};
long yytok3[] =
{
0
};
#line 1 "/sys/lib/yaccpar"
#define YYFLAG -1000
#define yyclearin yychar = -1
#define yyerrok yyerrflag = 0
#ifdef yydebug
#include "y.debug"
#else
#define yydebug 0
char* yytoknames[1]; /* for debugging */
char* yystates[1]; /* for debugging */
#endif
/* parser for yacc output */
int yynerrs = 0; /* number of errors */
int yyerrflag = 0; /* error recovery flag */
extern int fprint(int, char*, ...);
extern int sprint(char*, char*, ...);
char*
yytokname(int yyc)
{
static char x[16];
if(yyc > 0 && yyc <= sizeof(yytoknames)/sizeof(yytoknames[0]))
if(yytoknames[yyc-1])
return yytoknames[yyc-1];
sprint(x, "<%d>", yyc);
return x;
}
char*
yystatname(int yys)
{
static char x[16];
if(yys >= 0 && yys < sizeof(yystates)/sizeof(yystates[0]))
if(yystates[yys])
return yystates[yys];
sprint(x, "<%d>\n", yys);
return x;
}
long
yylex1(void)
{
long yychar;
long *t3p;
int c;
yychar = yylex();
if(yychar <= 0) {
c = yytok1[0];
goto out;
}
if(yychar < sizeof(yytok1)/sizeof(yytok1[0])) {
c = yytok1[yychar];
goto out;
}
if(yychar >= YYPRIVATE)
if(yychar < YYPRIVATE+sizeof(yytok2)/sizeof(yytok2[0])) {
c = yytok2[yychar-YYPRIVATE];
goto out;
}
for(t3p=yytok3;; t3p+=2) {
c = t3p[0];
if(c == yychar) {
c = t3p[1];
goto out;
}
if(c == 0)
break;
}
c = 0;
out:
if(c == 0)
c = yytok2[1]; /* unknown char */
if(yydebug >= 3)
fprint(2, "lex %.4lux %s\n", yychar, yytokname(c));
return c;
}
int
yyparse(void)
{
struct
{
YYSTYPE yyv;
int yys;
} yys[YYMAXDEPTH], *yyp, *yypt;
short *yyxi;
int yyj, yym, yystate, yyn, yyg;
long yychar;
YYSTYPE save1, save2;
int save3, save4;
save1 = yylval;
save2 = yyval;
save3 = yynerrs;
save4 = yyerrflag;
yystate = 0;
yychar = -1;
yynerrs = 0;
yyerrflag = 0;
yyp = &yys[-1];
goto yystack;
ret0:
yyn = 0;
goto ret;
ret1:
yyn = 1;
goto ret;
ret:
yylval = save1;
yyval = save2;
yynerrs = save3;
yyerrflag = save4;
return yyn;
yystack:
/* put a state and value onto the stack */
if(yydebug >= 4)
fprint(2, "char %s in %s", yytokname(yychar), yystatname(yystate));
yyp++;
if(yyp >= &yys[YYMAXDEPTH]) {
yyerror("yacc stack overflow");
goto ret1;
}
yyp->yys = yystate;
yyp->yyv = yyval;
yynewstate:
yyn = yypact[yystate];
if(yyn <= YYFLAG)
goto yydefault; /* simple state */
if(yychar < 0)
yychar = yylex1();
yyn += yychar;
if(yyn < 0 || yyn >= YYLAST)
goto yydefault;
yyn = yyact[yyn];
if(yychk[yyn] == yychar) { /* valid shift */
yychar = -1;
yyval = yylval;
yystate = yyn;
if(yyerrflag > 0)
yyerrflag--;
goto yystack;
}
yydefault:
/* default state action */
yyn = yydef[yystate];
if(yyn == -2) {
if(yychar < 0)
yychar = yylex1();
/* look through exception table */
for(yyxi=yyexca;; yyxi+=2)
if(yyxi[0] == -1 && yyxi[1] == yystate)
break;
for(yyxi += 2;; yyxi += 2) {
yyn = yyxi[0];
if(yyn < 0 || yyn == yychar)
break;
}
yyn = yyxi[1];
if(yyn < 0)
goto ret0;
}
if(yyn == 0) {
/* error ... attempt to resume parsing */
switch(yyerrflag) {
case 0: /* brand new error */
yyerror("syntax error");
yynerrs++;
if(yydebug >= 1) {
fprint(2, "%s", yystatname(yystate));
fprint(2, "saw %s\n", yytokname(yychar));
}
case 1:
case 2: /* incompletely recovered error ... try again */
yyerrflag = 3;
/* find a state where "error" is a legal shift action */
while(yyp >= yys) {
yyn = yypact[yyp->yys] + YYERRCODE;
if(yyn >= 0 && yyn < YYLAST) {
yystate = yyact[yyn]; /* simulate a shift of "error" */
if(yychk[yystate] == YYERRCODE)
goto yystack;
}
/* the current yyp has no shift onn "error", pop stack */
if(yydebug >= 2)
fprint(2, "error recovery pops state %d, uncovers %d\n",
yyp->yys, (yyp-1)->yys );
yyp--;
}
/* there is no state on the stack with an error shift ... abort */
goto ret1;
case 3: /* no shift yet; clobber input char */
if(yydebug >= 2)
fprint(2, "error recovery discards %s\n", yytokname(yychar));
if(yychar == YYEOFCODE)
goto ret1;
yychar = -1;
goto yynewstate; /* try again in the same state */
}
}
/* reduction by production yyn */
if(yydebug >= 2)
fprint(2, "reduce %d in:\n\t%s", yyn, yystatname(yystate));
yypt = yyp;
yyp -= yyr2[yyn];
yyval = (yyp+1)->yyv;
yym = yyn;
/* consult goto table to find next state */
yyn = yyr1[yyn];
yyg = yypgo[yyn];
yyj = yyg + yyp->yys + 1;
if(yyj >= YYLAST || yychk[yystate=yyact[yyj]] != -yyn)
yystate = yyact[yyg];
switch(yym) {
case 2:
#line 26 "/usr/qwx/p/misc/calc.y"
{ print("%d\n", yypt[-1].yyv.i); } break;
case 3:
#line 28 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-0].yyv.i; } break;
case 4:
#line 29 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-1].yyv.i; } break;
case 5:
#line 30 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-2].yyv.i + yypt[-0].yyv.i; } break;
case 6:
#line 31 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-2].yyv.i - yypt[-0].yyv.i; } break;
case 7:
#line 32 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-2].yyv.i * yypt[-0].yyv.i; } break;
case 8:
#line 33 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-2].yyv.i / yypt[-0].yyv.i; } break;
case 9:
#line 34 "/usr/qwx/p/misc/calc.y"
{ yyval.i = yypt[-2].yyv.i % yypt[-0].yyv.i; } break;
}
goto yystack; /* stack new state and value */
}