From 655b56e39033df5ec41b1f1fd0065b445e8acae3 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Tue, 5 Jul 2016 23:09:12 -0400
Subject: [PATCH] Do not automatically convert floats to ints

---
 runtime.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 65 insertions(+), 6 deletions(-)

diff --git a/runtime.c b/runtime.c
index 6c07901c..327bd60d 100644
--- a/runtime.c
+++ b/runtime.c
@@ -13,6 +13,8 @@
 #include "cyclone/types.h"
 #include "cyclone/runtime.h"
 #include "cyclone/ck_ht_hash.h"
+#include <errno.h>
+#include <limits.h>
 //#include <signal.h> // TODO: only used for debugging!
 
 //int JAE_DEBUG = 0;
@@ -1349,21 +1351,78 @@ object Cyc_string2number2_(void *data, object cont, int argc, object str, ...)
   Cyc_string2number_(data, cont, str);
 }
 
+typedef enum {
+    STR2INT_SUCCESS,
+    STR2INT_OVERFLOW,
+    STR2INT_UNDERFLOW,
+    STR2INT_INCONVERTIBLE
+} str2int_errno;
+
+/*
+Convert string s to int out.
+
+@param[out] out The converted int. Cannot be NULL.
+
+@param[in] s Input string to be converted.
+
+    The format is the same as strtol,
+    except that the following are inconvertible:
+
+    - empty string
+    - leading whitespace
+    - any trailing characters that are not part of the number
+
+    Cannot be NULL.
+
+@param[in] base Base to interpret string in. Same range as strtol (2 to 36).
+
+@return Indicates if the operation succeeded, or why it failed.
+*/
+str2int_errno str2int(int *out, char *s, int base) 
+{
+    char *end;
+    if (s[0] == '\0' || isspace((unsigned char) s[0]))
+        return STR2INT_INCONVERTIBLE;
+    errno = 0;
+    long l = strtol(s, &end, base);
+    /* Both checks are needed because INT_MAX == LONG_MAX is possible. */
+    if (l > INT_MAX || (errno == ERANGE && l == LONG_MAX))
+        return STR2INT_OVERFLOW;
+    if (l < INT_MIN || (errno == ERANGE && l == LONG_MIN))
+        return STR2INT_UNDERFLOW;
+    if (*end != '\0')
+        return STR2INT_INCONVERTIBLE;
+    *out = l;
+    return STR2INT_SUCCESS;
+}
+
+int str2double(double *out, char *s) 
+{
+  *out = strtold(s, NULL);
+  // TODO: error checking, EG: HUGE_VALL
+  return 0;
+}
+
 object Cyc_string2number_(void *data, object cont, object str)
 {
-  int result;
+  int result, rv;
+  long l;
   double n;
+  char *s, *end;
   Cyc_check_obj(data, string_tag, str);
   Cyc_check_str(data, str);
   if (type_of(str) == string_tag && ((string_type *) str)->str) {
-    n = atof(((string_type *) str)->str);
+    s = ((string_type *) str)->str;
 
-    if (ceilf(n) == n) {
-      result = (int)n;
+    rv = str2int(&result, s, 10);
+    if (rv == STR2INT_SUCCESS) {
       return_closcall1(data, cont, obj_int2obj(result));
     } else {
-      make_double(result, n);
-      return_closcall1(data, cont, &result);
+      str2double(&n, s);
+      {
+        make_double(result, n);
+        return_closcall1(data, cont, &result);
+      }
     }
   } else {
     // TODO: not good enough because we do pointer comparisons to #f