Fix libsass unit order

Author: mgreter

src/ast.hpp

@@ -236,6 +236,7 @@ namespace Sass {
     virtual const T& at(size_t i) const { return elements_.at(i); }
     virtual T& at(size_t i) { return elements_.at(i); }
     const T& get(size_t i) const { return elements_[i]; }
+    // ToDo: might insert am item (update ordered list)
     const T& operator[](size_t i) const { return elements_[i]; }
 
     // Implicitly get the std::vector from our object

src/ordered_map.hpp

@@ -1,6 +1,8 @@
 #ifndef SASS_ORDERED_MAP_H
 #define SASS_ORDERED_MAP_H
 
+#include <unordered_map>
+
 namespace Sass {
 
   // ##########################################################################
@@ -27,6 +29,8 @@ namespace Sass {
 
     // Keep insertion order
     std::vector<Key> _keys;
+    // That does not makes sense
+    // Value might be updated ...
     std::vector<T> _values;
 
     const KeyEqual _keyEqual;
@@ -91,6 +95,16 @@ namespace Sass {
       throw std::runtime_error("Key does not exist");
     }
 
+    T& operator[](const std::string& key) {
+      if (hasKey(key)) {
+        return _map[key];
+      }
+      T& value = _map[key];
+      _keys.push_back(key);
+      _values.push_back(value);
+      return value;
+    }
+
     using iterator = typename std::vector<Key>::iterator;
     using const_iterator = typename std::vector<Key>::const_iterator;
     using reverse_iterator = typename std::vector<Key>::reverse_iterator;

src/units.cpp

@@ -3,6 +3,7 @@
 #include <stdexcept>
 #include <algorithm>
 #include "units.hpp"
+#include "ordered_map.hpp"
 #include "error_handling.hpp"
 
 namespace Sass {
@@ -285,7 +286,7 @@ namespace Sass {
     // it seems that a map table will fit nicely to do this
     // we basically construct exponents for each unit
     // has the advantage that they will be pre-sorted
-    std::map<std::string, int> exponents;
+    ordered_map<std::string, int> exponents;
 
     // initialize by summing up occurences in unit vectors
     // this will already cancel out equivalent units (e.q. px/px)
@@ -311,12 +312,12 @@ namespace Sass {
     denominators.clear();
 
     // recreate sorted units vectors
-    for (auto exp : exponents) {
-      int &exponent = exp.second;
+    for (auto key : exponents) {
+      int &exponent = exponents[key];
       while (exponent > 0 && exponent --)
-        numerators.push_back(exp.first);
+        numerators.push_back(key);
       while (exponent < 0 && exponent ++)
-        denominators.push_back(exp.first);
+        denominators.push_back(key);
     }
 
     // return for conversion