Implement exponents for numbers

Author: mgreter

src/lexer.cpp

@@ -49,6 +49,12 @@ namespace Sass {
       return unsigned(chr - '0') <= '9' - '0';
     }
 
+    bool is_number(const char& chr)
+    {
+      // adapted the technique from is_alpha
+      return is_digit(chr) || chr == '-' || chr == '+';
+    }
+
     bool is_xdigit(const char& chr)
     {
       // adapted the technique from is_alpha

src/lexer.hpp

@@ -29,6 +29,7 @@ namespace Sass {
     bool is_alpha(const char& src);
     bool is_punct(const char& src);
     bool is_digit(const char& src);
+    bool is_number(const char& src);
     bool is_alnum(const char& src);
     bool is_xdigit(const char& src);
     bool is_unicode(const char& src);

src/parser.cpp

@@ -1472,7 +1472,7 @@ namespace Sass {
   {
     Number_Ptr nr = SASS_MEMORY_NEW(Number,
                                     pstate,
-                                    sass_atof(parsed.c_str()),
+                                    sass_strtod(parsed.c_str()),
                                     "",
                                     number_has_zero(parsed));
     nr->is_interpolant(false);
@@ -1484,7 +1484,7 @@ namespace Sass {
   {
     Number_Ptr nr = SASS_MEMORY_NEW(Number,
                                     pstate,
-                                    sass_atof(parsed.c_str()),
+                                    sass_strtod(parsed.c_str()),
                                     "%",
                                     true);
     nr->is_interpolant(false);
@@ -1498,11 +1498,14 @@ namespace Sass {
     size_t num_pos = parsed.find_first_not_of(" \n\r\t");
     if (num_pos == std::string::npos) num_pos = L;
     size_t unit_pos = parsed.find_first_not_of("-+0123456789.", num_pos);
+    if (parsed[unit_pos] == 'e' && is_number(parsed[unit_pos+1]) ) {
+      unit_pos = parsed.find_first_not_of("-+0123456789.", ++ unit_pos);
+    }
     if (unit_pos == std::string::npos) unit_pos = L;
     const std::string& num = parsed.substr(num_pos, unit_pos - num_pos);
     Number_Ptr nr = SASS_MEMORY_NEW(Number,
                                     pstate,
-                                    sass_atof(num.c_str()),
+                                    sass_strtod(num.c_str()),
                                     Token(number(parsed.c_str())),
                                     number_has_zero(parsed));
     nr->is_interpolant(false);

src/prelexer.cpp

@@ -998,7 +998,17 @@ namespace Sass {
                           digits>(src);
     }
     const char* number(const char* src) {
-      return sequence< optional<sign>, unsigned_number>(src);
+      return sequence<
+          optional<sign>,
+          unsigned_number,
+          optional<
+            sequence<
+              exactly<'e'>,
+              optional<sign>,
+              unsigned_number
+            >
+          >
+        >(src);
     }
     const char* coefficient(const char* src) {
       return alternatives< sequence< optional<sign>, digits >,

src/util.cpp

@@ -35,7 +35,7 @@ namespace Sass {
   }
 
   /* Locale unspecific atof function. */
-  double sass_atof(const char *str)
+  double sass_strtod(const char *str)
   {
     char separator = *(localeconv()->decimal_point);
     if(separator != '.'){
@@ -48,13 +48,13 @@ namespace Sass {
         // of the string. This is slower but it is thread safe.
         char *copy = sass_copy_c_string(str);
         *(copy + (found - str)) = separator;
-        double res = atof(copy);
+        double res = strtod(copy, NULL);
         free(copy);
         return res;
       }
     }
 
-    return atof(str);
+    return strtod(str, NULL);
   }
 
   // helper for safe access to c_ctx

src/util.hpp

@@ -18,7 +18,7 @@ namespace Sass {
     } while (0)
 
   double round(double val, size_t precision = 0);
-  double sass_atof(const char* str);
+  double sass_strtod(const char* str);
   const char* safe_str(const char *, const char* = "");
   void free_string_array(char **);
   char **copy_strings(const std::vector<std::string>&, char ***, int = 0);