Merge 6694854 into b47b33b

traits/api.py

@@ -41,8 +41,9 @@
         Method, Module, Python, ReadOnly, Disallow, Constant,
         Delegate, DelegatesTo, PrototypedFrom, Expression, PythonValue, File,
         Directory, Range, Enum, Tuple, List, CList, Set, CSet, Dict, Instance,
-        AdaptedTo, AdaptsTo, Event, Button, ToolbarButton, Either, Type,
-        Symbol, WeakRef, Date, Time, false, true, undefined, Supports)
+        IdentifierStr, AdaptedTo, AdaptsTo, Event, Button, ToolbarButton,
+        Either, Type, Symbol, WeakRef, Date, Time, false, true, undefined,
+        Supports)
 
 from .trait_types import (ListInt, ListFloat, ListStr, ListUnicode,
         ListComplex, ListBool, ListFunction, ListMethod,

traits/tests/test_traits.py

@@ -20,9 +20,10 @@
 from traits.testing.unittest_tools import unittest
 
 from ..api import (Any, CFloat, CInt, CLong, Delegate, Float, HasTraits,
-                   Instance, Int, List, Long, Str, Trait, TraitError,
-                   TraitList, TraitPrefixList, TraitPrefixMap, TraitRange,
-                   Tuple, pop_exception_handler, push_exception_handler)
+                   IdentifierStr, Instance, Int, List, Long, Str, Trait,
+                   TraitError, TraitList, TraitPrefixList, TraitPrefixMap,
+                   TraitRange, Tuple, Undefined, pop_exception_handler,
+                   push_exception_handler)
 
 #  Base unit test classes:
 
@@ -307,6 +308,21 @@ def coerce(self, value):
         return str(value)
 
 
+class IdentifierStrTrait(HasTraits):
+    value = IdentifierStr
+
+
+class IdentifierStrTest(AnyTraitTest):
+    obj = IdentifierStrTrait()
+
+    _default_value = Undefined
+    _good_values = ['i', '_i', 'foo_bar']
+    _bad_values = [None, '1', 1, u'unicode', 'for', "0chupacabra", '']
+
+    def coerce(self, value):
+        return str(value)
+
+
 class UnicodeTrait(HasTraits):
     value = Trait(u'unicode')
 

traits/trait_types.py

@@ -26,6 +26,7 @@
 
 import datetime
 import operator
+import keyword
 import re
 import sys
 from os.path import isfile, isdir
@@ -365,6 +366,30 @@ class Str ( BaseStr ):
     fast_validate = ( 11, basestring )
 
 
+class IdentifierStr(BaseStr):
+    #: A description of the type of value this trait accepts:
+    info_text = 'an ASCII identifier string'
+
+    #: The default value when first created
+    default_value = Undefined
+
+    # Regexp for identifier recognition
+    _identifier_regex = re.compile("[_A-Za-z][_a-zA-Z0-9]*$")
+
+    def validate ( self, object, name, value ):
+        """ Validates that a specified value is valid for this trait.
+        """
+
+        if (isinstance( value, str ) and
+                len(value) > 0 and
+                not keyword.iskeyword(value) and
+                self._identifier_regex.match(value)):
+
+            return value
+
+        self.error( object, name, value )
+
+
 class Title ( Str ):
     """ Defines a string type which by default uses the traits ui TitleEditor
         when used in a View.
@@ -826,6 +851,8 @@ def __setstate__ ( self, state ):
         self.__dict__.update( state )
         self._init()
 
+
+
 #-------------------------------------------------------------------------------
 #  'Regex' trait:
 #-------------------------------------------------------------------------------