Feature/validated tuple

[itziakos]

This PR adds a new Tuple trait that supports custom validation for the field values in addition to the individual field validation.

>>> from traits.api import Int, HasStrictTraits, ValidatedTuple
>>> 
>>> class MyClass(HasStrictTraits):
...     value_range = ValidatedTuple(Int(0), Int(1), validation=lambda x: x[0] < x[1])
... 
>>>
>>> a = MyClass()
>>> a.value_range
(0, 1)
>>> a.value_range = (2, 1)
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
  File "c:\users\itziakos\projects\meta-geophysics\geocanopy\geophysics\util\validated_tuple.py", line 43, in validate
    self.error(object, name, value)
  File "C:\Users\itziakos\Projects\traits\traits\trait_handlers.py", line 172, in error
    value )
TraitError: The 'value_range' trait of a MyClass instance must be a tuple of the form: (an integer (int or long), an integer (int or long)) that passes custom validation, but a value of (2, 1) <type 'tuple'> was specified.
>>> a.value_range = (1, 2)
>>> a.value_range
(1, 2)
>>> 

[itziakos]

Thanks @rkern, This PR is ready for review

[itziakos]

I could probably provide add an optional string in the trait metadata to be used for the TraitError. For example if would be nice is we could get this error

TraitError: The 'value_range' trait of a MyClass instance must be a tuple of the form: (an integer (int or long), an integer (int or long)) that passes custom validation: value_range[0] < value_rane[1], but a value of (2, 1) <type 'tuple'> was specified.

[coveralls]

Coverage increased (+0.16%) when pulling 2dc9ad6 on feature/validated-tuple into 1ce982e on master.

[mdickinson]

Can we change the name of this keyword argument? validator would be more accurate than validation. Alternatively, how about just valid (to be thought of as "is_valid").

[rkern]

The convention in Traits seems to be validate for this kind of argument.

[mdickinson]

Works for me.

[itziakos]

there is a method called validate in TraitType. I have renamed the keyword to fvalidatewhich is the same used for Property traits.

[mdickinson]

We need docs for the new Trait type.

[mdickinson]

Too much whitespace! Please remove the last blank line inside the docstring, to be consistent with the surrounding style.

[itziakos]

removed

[coveralls]

Coverage increased (+0.09%) when pulling 81fe37f on feature/validated-tuple into 1ce982e on master.

[itziakos]

@mdickinson, the PR is now updated. I tried to follow the local style, please let me know if I missed anything.

[coveralls]

Coverage increased (+0.11%) when pulling 81b3cc5 on feature/validated-tuple into 1ce982e on master.

[coveralls]

Coverage increased (+0.11%) when pulling 81b3cc5 on feature/validated-tuple into 1ce982e on master.

[coveralls]

Coverage increased (+0.11%) when pulling 8d3138a on feature/validated-tuple into 1ce982e on master.

[itziakos]

please delay review. I should add a change log comment

[itziakos]

@mdickinson, the PR is ready for another review round

[coveralls]

Coverage increased (+0.24%) when pulling f2ca313 on feature/validated-tuple into 87e0bab on master.

[mdickinson]

@itziakos: I've tweaked a bit. Please let me know if you're happy with the changes in the last 4 commits.

[coveralls]

Coverage increased (+0.24%) when pulling ecef9ec on feature/validated-tuple into 87e0bab on master.

[itziakos]

@mdickinson, changes look ok.

[mdickinson]

@itziakos: Thanks. Merging.