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Refactor expr.c

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Finish up what has been begun.
This commit is contained in:
FRIGN 2014-11-17 15:39:57 +01:00 committed by sin
parent 166bc3052e
commit 85df198b59
1 changed files with 82 additions and 63 deletions
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133
expr.c
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@ -18,9 +18,10 @@ typedef struct {
intmax_t n; intmax_t n;
} Val; } Val;
static void enan(Val);
static void ezero(intmax_t);
static void doop(int*, int**, Val*, Val**); static void doop(int*, int**, Val*, Val**);
static Val match(Val, Val); static Val match(Val, Val);
static void num(Val);
static int valcmp(Val, Val); static int valcmp(Val, Val);
static char *valstr(Val, char *, size_t); static char *valstr(Val, char *, size_t);
static int lex(char *); static int lex(char *);
@ -29,6 +30,13 @@ static int parse(char **, int);
static size_t intlen; static size_t intlen;
static Val lastval; static Val lastval;
static void
enan(Val v)
{
if (v.s)
enprintf(2, "syntax error: expected integer got `%s'\n", v.s);
}
static void static void
ezero(intmax_t n) ezero(intmax_t n)
{ {
@ -36,43 +44,42 @@ ezero(intmax_t n)
enprintf(2, "division by zero\n"); enprintf(2, "division by zero\n");
} }
/* otop points to one past last op
* vtop points to one past last val
* guaranteed otop != ops
* pop two vals, pop op, apply op, push val
*/
static void static void
doop(int *ops, int **otop, Val *vals, Val **vtop) doop(int *op, int **opp, Val *val, Val **valp)
{ {
Val ret, a, b; Val ret, a, b;
int op; int o;
if ((*otop)[-1] == '(') /* For an operation, we need a valid operator
* and two values on the stack */
if ((*opp)[-1] == '(')
enprintf(2, "syntax error: extra (\n"); enprintf(2, "syntax error: extra (\n");
if (*vtop - vals < 2) if (*valp - val < 2)
enprintf(2, "syntax error: missing expression or extra operator\n"); enprintf(2, "syntax error: missing expression or extra operator\n");
a = (*vtop)[-2]; a = (*valp)[-2];
b = (*vtop)[-1]; b = (*valp)[-1];
op = (*otop)[-1]; o = (*opp)[-1];
switch (op) { switch (o) {
case '|': case '|':
if (a.s && *a.s) if (a.s && *a.s) {
ret = (Val){ a.s, 0 }; ret = (Val){ a.s, 0 };
else if (!a.s && a.n) } else if (!a.s && a.n) {
ret = (Val){ NULL, a.n }; ret = (Val){ NULL, a.n };
else if (b.s && *b.s) } else if (b.s && *b.s) {
ret = (Val){ b.s, 0 }; ret = (Val){ b.s, 0 };
else } else {
ret = (Val){ NULL, b.n }; ret = (Val){ NULL, b.n };
}
break; break;
case '&': case '&':
if (((a.s && *a.s) || a.n) && if (((a.s && *a.s) || a.n) &&
((b.s && *b.s) || b.n)) ((b.s && *b.s) || b.n)) {
ret = a; ret = a;
else } else {
ret = (Val){ NULL, 0 }; ret = (Val){ NULL, 0 };
}
break; break;
case '=': ret = (Val){ NULL, valcmp(a, b) == 0 }; break; case '=': ret = (Val){ NULL, valcmp(a, b) == 0 }; break;
case '>': ret = (Val){ NULL, valcmp(a, b) > 0 }; break; case '>': ret = (Val){ NULL, valcmp(a, b) > 0 }; break;
@ -81,80 +88,84 @@ doop(int *ops, int **otop, Val *vals, Val **vtop)
case LE : ret = (Val){ NULL, valcmp(a, b) <= 0 }; break; case LE : ret = (Val){ NULL, valcmp(a, b) <= 0 }; break;
case NE : ret = (Val){ NULL, valcmp(a, b) != 0 }; break; case NE : ret = (Val){ NULL, valcmp(a, b) != 0 }; break;
case '+': num(a); num(b); ret = (Val){ NULL, a.n + b.n }; break; case '+': enan(a); enan(b); ret = (Val){ NULL, a.n + b.n }; break;
case '-': num(a); num(b); ret = (Val){ NULL, a.n - b.n }; break; case '-': enan(a); enan(b); ret = (Val){ NULL, a.n - b.n }; break;
case '*': num(a); num(b); ret = (Val){ NULL, a.n * b.n }; break; case '*': enan(a); enan(b); ret = (Val){ NULL, a.n * b.n }; break;
case '/': num(a); num(b); ezero(b.n); ret = (Val){ NULL, a.n / b.n }; break; case '/': enan(a); enan(b); ezero(b.n); ret = (Val){ NULL, a.n / b.n }; break;
case '%': num(a); num(b); ezero(b.n); ret = (Val){ NULL, a.n % b.n }; break; case '%': enan(a); enan(b); ezero(b.n); ret = (Val){ NULL, a.n % b.n }; break;
case ':': ret = match(a, b); break; case ':': ret = match(a, b); break;
} }
(*vtop)[-2] = ret; (*valp)[-2] = ret;
(*otop)--; (*opp)--;
(*vtop)--; (*valp)--;
} }
static Val static Val
match(Val vstr, Val vregx) match(Val vstr, Val vregx)
{ {
intmax_t d; intmax_t d;
char *ret, *p; char *anchreg, *ret, *p;
char buf1[intlen], buf2[intlen], *str, *regx;
regoff_t len; regoff_t len;
char b1[intlen], *str = valstr(vstr, b1, sizeof(b1));
char b2[intlen], *regx = valstr(vregx, b2, sizeof(b2));
regex_t re; regex_t re;
regmatch_t matches[2]; regmatch_t matches[2];
char anchreg[strlen(regx) + 2];
snprintf(anchreg, sizeof(anchreg), "^%s", regx); str = valstr(vstr, buf1, sizeof(buf1));
regx = valstr(vregx, buf2, sizeof(buf2));
anchreg = malloc(strlen(regx) + 2);
if (!anchreg)
enprintf(3, "malloc:");
snprintf(anchreg, strlen(regx) + 2, "^%s", regx);
enregcomp(3, &re, anchreg, 0); enregcomp(3, &re, anchreg, 0);
free(anchreg);
if (regexec(&re, str, 2, matches, 0)) if (regexec(&re, str, 2, matches, 0)) {
regfree(&re);
return (Val){ (re.re_nsub ? "" : NULL), 0 }; return (Val){ (re.re_nsub ? "" : NULL), 0 };
}
if (re.re_nsub) { if (re.re_nsub) {
regfree(&re);
len = matches[1].rm_eo - matches[1].rm_so + 1; len = matches[1].rm_eo - matches[1].rm_so + 1;
ret = malloc(len); /* TODO: free ret */ ret = malloc(len);
if (!ret) if (!ret)
enprintf(3, "malloc:"); enprintf(3, "malloc:");
strlcpy(ret, str + matches[1].rm_so, len); strlcpy(ret, str + matches[1].rm_so, len);
d = strtoimax(ret, &p, 10); d = strtoimax(ret, &p, 10);
if (*ret && !*p) if (*ret && !*p) {
free(ret);
return (Val){ NULL, d }; return (Val){ NULL, d };
}
return (Val){ ret, 0 }; return (Val){ ret, 0 };
} }
regfree(&re);
return (Val){ NULL, matches[0].rm_eo - matches[0].rm_so }; return (Val){ NULL, matches[0].rm_eo - matches[0].rm_so };
} }
static void
num(Val v)
{
if (v.s)
enprintf(2, "syntax error: expected integer got `%s'\n", v.s);
}
static int static int
valcmp(Val a, Val b) valcmp(Val a, Val b)
{ {
char b1[intlen], *p = valstr(a, b1, sizeof(b1)); char buf1[intlen], buf2[intlen], *astr, *bstr;
char b2[intlen], *q = valstr(b, b2, sizeof(b2));
if (!a.s && !b.s) astr = valstr(a, buf1, sizeof(buf1));
return (a.n > b.n) - (a.n < b.n); bstr = valstr(b, buf2, sizeof(buf2));
return strcmp(p, q);
return strcmp(astr, bstr);
} }
static char * static char *
valstr(Val val, char *buf, size_t bufsiz) valstr(Val val, char *buf, size_t bufsiz)
{ {
char *p = val.s; if (val.s)
if (!p) { return val.s;
snprintf(buf, bufsiz, "%"PRIdMAX, val.n); snprintf(buf, bufsiz, "%"PRIdMAX, val.n);
p = buf; return buf;
}
return p;
} }
static int static int
@ -163,22 +174,30 @@ lex(char *p)
intmax_t d; intmax_t d;
char *q, *ops = "|&=><+-*/%():"; char *q, *ops = "|&=><+-*/%():";
/* clean integer */
d = strtoimax(p, &q, 10); d = strtoimax(p, &q, 10);
if (*p && !*q) { if (*p && !*q) {
lastval = (Val){ NULL, d }; lastval = (Val){ NULL, d };
return VAL; return VAL;
} }
if (*p && !p[1] && strchr(ops, *p)) /* one-char operand */
if (*p && !*(p+1) && strchr(ops, *p))
return *p; return *p;
if (strcmp(p, ">=") == 0) /* two-char operand */
if (*p && *(p+1) == '=' && !*(p+2)) {
switch (*p) {
case '>':
return GE; return GE;
if (strcmp(p, "<=") == 0) case '<':
return LE; return LE;
if (strcmp(p, "!=") == 0) case '!':
return NE; return NE;
}
}
/* nothing matched, treat as string */
lastval = (Val){ p, 0 }; lastval = (Val){ p, 0 };
return VAL; return VAL;
} }