string case conversion functions

Author: wonja

context.cpp

@@ -365,6 +365,8 @@ namespace Sass {
     register_function(ctx, str_insert_sig, str_insert, env);
     register_function(ctx, str_index_sig, str_index, env);
     register_function(ctx, str_slice_sig, str_slice, env);
+    register_function(ctx, to_upper_case_sig, to_upper_case, env);
+    register_function(ctx, to_lower_case_sig, to_lower_case, env);
     // Number Functions
     register_function(ctx, percentage_sig, percentage, env);
     register_function(ctx, round_sig, round, env);

functions.cpp

@@ -800,6 +800,32 @@ namespace Sass {
 
     }
 
+    Signature to_upper_case_sig = "to-upper-case($string)";
+    BUILT_IN(to_upper_case)
+    {
+      String_Constant* s = ARG("$string", String_Constant);
+      string str = s->value();
+
+      for (size_t i = 0, L = str.length(); i < L; ++i) {
+        str[i] = std::toupper(str[i]);
+      }
+
+      return new (ctx.mem) String_Constant(path, position, str);
+    }
+
+    Signature to_lower_case_sig = "to-lower-case($string)";
+    BUILT_IN(to_lower_case)
+    {
+      String_Constant* s = ARG("$string", String_Constant);
+      string str = s->value();
+
+      for (size_t i = 0, L = str.length(); i < L; ++i) {
+        str[i] = std::tolower(str[i]);
+      }
+
+      return new (ctx.mem) String_Constant(path, position, str);
+    }
+
     ///////////////////
     // NUMBER FUNCTIONS
     ///////////////////

functions.hpp

@@ -68,6 +68,8 @@ namespace Sass {
     extern Signature str_insert_sig;
     extern Signature str_index_sig;
     extern Signature str_slice_sig;
+    extern Signature to_upper_case_sig;
+    extern Signature to_lower_case_sig;
     extern Signature percentage_sig;
     extern Signature round_sig;
     extern Signature ceil_sig;
@@ -123,6 +125,8 @@ namespace Sass {
     BUILT_IN(str_insert);
     BUILT_IN(str_index);
     BUILT_IN(str_slice);
+    BUILT_IN(to_upper_case);
+    BUILT_IN(to_lower_case);
     BUILT_IN(percentage);
     BUILT_IN(round);
     BUILT_IN(ceil);