begin work on a common string-to-floating-point implementation

1 files changed, 33 insertions, 2 deletions

diff --git a/src/stdlib/strtold.c b/src/stdlib/strtold.c
index eeb0b8b0..eb19fcc0 100644
--- a/src/stdlib/strtold.c
+++ b/src/stdlib/strtold.c
@@ -1,11 +1,42 @@
 #include <stdlib.h>
+#include "float.h"
+#include "ctype.h"
+#include "errno.h"
+#include "math.h"
+
+/** convert string to floating-point **/
 
 long double strtold(const char * restrict nptr, char ** restrict endptr)
 {
-	(void)nptr; (void)endptr;
-	return 0;
+	long double ret = 0.0;
+	long double max = LDBL_MAX;
+	long double min = LDBL_MIN;
+	long double huge = HUGE_VALL;
+	long double inf = INFINITY;
+	long double nan = NAN;
+
+	#include "_strtod.h"
+
+	return ret;
 }
 
+/***
+converts the string at ARGUMENT(nptr) to a TYPE(double).
+Leading whitespace is ignored. The first character that is not a valid character
+for a floating-point constant and any characters after it are also ignored. A
+pointer to the first invalid character is stored in ARGUMENT(endptr), unless
+ARGUMENT(endptr) is CONSTANT(NULL).
+
+The converted portion of the string may start with an optional plus or minus
+sign, followed by a nonempty series of digits, optionally containing a
+decimal-point character. This may optionally be followed by an exponent.
+***/
+
 /*
+LC_CTYPE
+RETURN(ZERO, underflow or no conversion could be performed)
+RETURN(CONSTANT(HUGE_VALL), converted value too large)
+RETURN(CONSTANT(-HUGE_VALL), converted value too small)
+RETURN(VAR(a TYPE(long double)), the converted value)
 STDC(199901)
 */