Add helper method Target#c99ext_identifier

lib/cocoapods/target.rb

@@ -177,5 +177,21 @@ module Pod
     end
 
     #-------------------------------------------------------------------------#
+
+    protected
+
+    # Transforms the given string into a valid +identifier+ after C99ext
+    # standard, so that it can be used in source code where escaping of
+    # ambiguous characters is not applicable.
+    #
+    # @param  [String] name
+    #         any name, which may contain leading numbers, spaces or invalid
+    #         characters.
+    #
+    # @return [String]
+    #
+    def c99ext_identifier(name)
+      name.gsub(/^([0-9])/, '_\1').gsub(/[^a-zA-Z0-9_]/, '_')
+    end
   end
 end

spec/unit/target_spec.rb

@@ -3,5 +3,20 @@ require File.expand_path('../../spec_helper', __FILE__)
 module Pod
   describe Target do
 
+    describe '#c99ext_identifier' do
+      before do
+        @target = Target.new
+      end
+
+      it 'should mask, but keep leading numbers' do
+        @target.send(:c99ext_identifier, '123BananaLib').should == '_123BananaLib'
+      end
+
+      it 'should mask invalid chars' do
+        @target.send(:c99ext_identifier, 'iOS-App BânánàLïb').should == 'iOS_App_B_n_n_L_b'
+      end
+
+    end
+
   end
 end