Add default values for the parameters in the functions

interface.yaml

@@ -51,3 +51,10 @@
   params:
     - { name: ip_address,  type: text}
 
+- name: cdb_geocode_street_point
+  return_type: Geometry
+  params:
+    - { name: searchtext,  type: text}
+    - { name: city,  type: text, default: 'NULL'}
+    - { name: state_province,  type: text, default: 'NULL'}
+    - { name: country,  type: text, default: 'NULL'}

sql-template-renderer

@@ -40,7 +40,14 @@ class SqlTemplateRenderer
   end
 
   def params_with_type
-    @function_signature['params'].map { |p| "#{p['name']} #{p['type']}"}.join(', ')
+    parameters = @function_signature['params'].map do |p|
+      if not p['default'].nil?
+        "#{p['name']} #{p['type']} DEFAULT #{p['default']}"
+      else
+        "#{p['name']} #{p['type']}"
+      end
+    end
+    return parameters.join(', ')
   end
 
 end