refactor bc_str2num

Author: SakiTakamachi

ext/bcmath/libbcmath/src/str2num.c

@@ -38,10 +38,9 @@
 bool bc_str2num(bc_num *num, char *str, size_t scale)
 {
 	size_t digits = 0;
-	size_t strscale = 0;
+	size_t str_scale = 0;
 	char *ptr, *nptr, *integer_ptr, *integer_end, *fractional_ptr = NULL, *fractional_end = NULL, *decimal_point;
 	bool zero_int = false;
-	size_t len = strlen(str);
 	sign num_sign = PLUS;
 
 	/* Prepare num. */
@@ -82,45 +81,43 @@ bool bc_str2num(bc_num *num, char *str, size_t scale)
 	if (decimal_point) {
 		/* search */
 		fractional_ptr = decimal_point + 1;
-		fractional_end = str + len - 1;
-		bool has_trailing_zero = false;
-		while (*fractional_end == '0' && fractional_end >= fractional_ptr) {
+		fractional_end = fractional_ptr + strlen(fractional_ptr) - 1;
+		while (*fractional_end == '0' && fractional_end >= decimal_point) {
 			fractional_end--;
-			has_trailing_zero = true;
-		}
-		if (has_trailing_zero) {
-			fractional_end++;
 		}
+		fractional_end++;
+		str_scale = fractional_end - fractional_ptr;
 
 		/* validate */
-		strscale = fractional_end - fractional_ptr;
-		if (strspn(fractional_ptr, "0123456789") < strscale) {
+		if (strspn(fractional_ptr, "0123456789") < str_scale) {
 			/* invalid num */
-			*num = bc_copy_num(BCG(_zero_));
-			return false;
+			goto fail;
+		}
+
+		while (str_scale > scale) {
+			fractional_end--;
+			str_scale--;
 		}
 	}
 
-	if (digits + strscale == 0) {
-		*num = bc_copy_num(BCG(_zero_));
-		return true;
+	if (digits + str_scale == 0) {
+		goto zero;
 	}
 
 	/* Adjust numbers and allocate storage and initialize fields. */
-	strscale = MIN(strscale, scale);
 	if (digits == 0) {
 		zero_int = true;
 		digits = 1;
 	}
 
-	*num = bc_new_num(digits, strscale);
+	*num = bc_new_num(digits, str_scale);
 	(*num)->n_sign = num_sign;
 	nptr = (*num)->n_value;
 
 	if (zero_int) {
 		nptr++;
-		if (decimal_point) {
-			while (fractional_ptr <= fractional_end) {
+		if (str_scale > 0) {
+			while (fractional_ptr < fractional_end) {
 				*nptr = CH_VAL(*fractional_ptr);
 				nptr++;
 				fractional_ptr++;
@@ -133,8 +130,8 @@ bool bc_str2num(bc_num *num, char *str, size_t scale)
 			nptr++;
 			integer_ptr++;
 		}
-		if (decimal_point) {
-			while (fractional_ptr <= fractional_end) {
+		if (str_scale > 0) {
+			while (fractional_ptr < fractional_end) {
 				*nptr = CH_VAL(*fractional_ptr);
 				nptr++;
 				fractional_ptr++;
@@ -144,6 +141,10 @@ bool bc_str2num(bc_num *num, char *str, size_t scale)
 
 	return true;
 
+zero:
+	*num = bc_copy_num(BCG(_zero_));
+	return true;
+
 fail:
 	*num = bc_copy_num(BCG(_zero_));
 	return false;