Merge pull request #516 from justinethier/issue-513-parsing-of-rationals

Issue 513 parsing of rationals
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Justin Ethier 2023-11-27 22:45:15 -05:00 committed by GitHub
commit 6c04ce4ca4
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3 changed files with 73 additions and 4 deletions

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@ -2,6 +2,10 @@
## 0.36.0 - TBD
Features
- Enhanced the reader to parse rationals and store them as inexact numbers.
Bug Fixes
- Fix `exact` to properly handle complex numbers, including raising an error when passed `nan` or `inf` double values.

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@ -2557,7 +2557,8 @@ typedef enum {
STR2INT_SUCCESS,
STR2INT_OVERFLOW,
STR2INT_UNDERFLOW,
STR2INT_INCONVERTIBLE
STR2INT_INCONVERTIBLE,
STR2INT_RATIONAL
} str2int_errno;
/*
@ -2588,12 +2589,18 @@ static str2int_errno str2int(int *out, char *s, int base)
errno = 0;
long l = strtol(s, &end, base);
/* Both checks are needed because INT_MAX == LONG_MAX is possible. */
if (l > CYC_FIXNUM_MAX /*INT_MAX*/ || (errno == ERANGE && l == LONG_MAX))
if (l > CYC_FIXNUM_MAX /*INT_MAX*/ || (errno == ERANGE && l == LONG_MAX)) {
return STR2INT_OVERFLOW;
if (l < CYC_FIXNUM_MIN /*INT_MIN*/ || (errno == ERANGE && l == LONG_MIN))
}
if (l < CYC_FIXNUM_MIN /*INT_MIN*/ || (errno == ERANGE && l == LONG_MIN)) {
return STR2INT_UNDERFLOW;
if (*end != '\0')
}
if (*end == '/') {
return STR2INT_RATIONAL;
}
if (*end != '\0') {
return STR2INT_INCONVERTIBLE;
}
*out = l;
return STR2INT_SUCCESS;
}
@ -2610,6 +2617,51 @@ int str_is_bignum(str2int_errno errnum, char *c)
return 1;
}
/**
* @brief Read a rational number from given string.
* @param data Thread data object for the caller.
* @param char* String to read
* @return double Return number as double, since cyclone does
* not support a rational number type at this time
*/
double string2rational(void *data, char *s)
{
// Duplicate string so we can safely create separate strings
// for numerator and denominator
char *nom = _strdup(s);
if (nom == NULL) {
return 0.0;
}
char *denom = strchr(nom, '/');
if (denom == NULL) {
// Should never happen since we check for '/' elsewhere
return 0.0;
}
denom[0] = '\0';
denom++;
// Parse both rational components as bignums since
// that code handles any integer
alloc_bignum(data, bn_nom);
if (MP_OKAY != mp_read_radix(&(bignum_value(bn_nom)), nom, 10)) {
Cyc_rt_raise2(data, "Error converting string to bignum", nom);
}
alloc_bignum(data, bn_denom);
if (MP_OKAY != mp_read_radix(&(bignum_value(bn_denom)), denom, 10)) {
Cyc_rt_raise2(data, "Error converting string to bignum", denom);
}
// Prevent memory leak
free(nom);
// Compute final result as double
double x = mp_get_double(&bignum_value(bn_nom));
double y = mp_get_double(&bignum_value(bn_denom));
return x / y;
}
object Cyc_string2number_(void *data, object cont, object str)
{
int result, rv;
@ -2622,6 +2674,14 @@ object Cyc_string2number_(void *data, object cont, object str)
rv = str2int(&result, s, 10);
if (rv == STR2INT_SUCCESS) {
_return_closcall1(data, cont, obj_int2obj(result));
} else if (rv == STR2INT_RATIONAL ||
// Could still be a rational if numerator is
// bignum, so in that case do one more scan
((rv == STR2INT_OVERFLOW || rv == STR2INT_UNDERFLOW) &&
strchr(s, '/') != NULL)) {
double d = string2rational(data, s);
make_double(result, d);
_return_closcall1(data, cont, &result);
} else if (str_is_bignum(rv, s)) {
alloc_bignum(data, bn);
if (MP_OKAY != mp_read_radix(&(bignum_value(bn)), s, 10)) {

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@ -48,6 +48,11 @@
"rationals"
(test 3.0 (numerator (/ 6 4)))
(test 2.0 (denominator (/ 6 4)))
(test 3.0 (expt 81 1/4))
(test #t
(< 1.0e+40
(/ 33333333333333333333333333333333333333333 3.0)
1.2e+40))
)
(test-group