Merge pull request #639 from kachick/implement-string,hash-try_convert

Implement String.try_convert, Hash.try_convert

spec/tags/core/hash/try_convert_tags.txt

@@ -1,8 +1 @@
-fails:Hash.try_convert returns the argument if it's a Hash
-fails:Hash.try_convert returns the argument if it's a kind of Hash
-fails:Hash.try_convert returns nil when the argument does not respond to #to_hash
-fails:Hash.try_convert sends #to_hash to the argument and returns the result if it's nil
-fails:Hash.try_convert sends #to_hash to the argument and returns the result if it's a Hash
-fails:Hash.try_convert sends #to_hash to the argument and returns the result if it's a kind of Hash
-fails:Hash.try_convert sends #to_hash to the argument and raises TypeError if it's not a kind of Hash
 fails:Hash.try_convert does not rescue exceptions raised by #to_hash

spec/tags/core/string/try_convert_tags.txt

@@ -1,8 +1 @@
-fails:String.try_convert returns the argument if it's a String
-fails:String.try_convert returns the argument if it's a kind of String
-fails:String.try_convert returns nil when the argument does not respond to #to_str
-fails:String.try_convert sends #to_str to the argument and returns the result if it's nil
-fails:String.try_convert sends #to_str to the argument and returns the result if it's a String
-fails:String.try_convert sends #to_str to the argument and returns the result if it's a kind of String
-fails:String.try_convert sends #to_str to the argument and raises TypeError if it's not a kind of String
 fails:String.try_convert does not rescue exceptions raised by #to_str

topaz/objects/hashobject.py

@@ -30,6 +30,12 @@ def singleton_method_subscript(self, space, w_obj=None):
         result.contents.update(w_res.contents)
         return result
 
+    @classdef.singleton_method("try_convert")
+    def method_try_convert(self, space, w_obj):
+        if not space.is_kind_of(w_obj, space.w_hash):
+            w_obj = space.convert_type(w_obj, space.w_hash, "to_hash", raise_error=False)
+        return w_obj
+
     @classdef.method("initialize")
     def method_initialize(self, space, w_default=None, block=None):
         if w_default is not None:

topaz/objects/stringobject.py

@@ -401,6 +401,12 @@ def singleton_method_allocate(self, space, w_s=None):
         storage = strategy.erase("")
         return W_StringObject(space, storage, strategy, self)
 
+    @classdef.singleton_method("try_convert")
+    def method_try_convert(self, space, w_obj):
+        if not space.is_kind_of(w_obj, space.w_string):
+            w_obj = space.convert_type(w_obj, space.w_string, "to_str", raise_error=False)
+        return w_obj
+
     @classdef.method("initialize")
     def method_initialize(self, space, w_s=None):
         if w_s is not None: