When to Use the Fiat Prefix "be_" in Methods?

Hello Forum!

I've been trying to pin down a pattern for using the prefixes "be_" and
"is_" in methods.

I've named a variable as <isConstrained>.  Is it acceptable to name
accessor methods in this case as #beConstrained and #beUnconstrained?  I
don't know that I like "self isConstrained: false/true".

In general, what are the guidelines for using "be_"?


Cheers,

Eric

Eric Taylor escribió:
We tend to use the is* testing methods for testing the state of
receiver, but instance variable is named without the is prefix.

I.e. if you want to determine the visibility of an object, you name the
instVar 'visible', and then you have two testing methods and two
"toggling" methods.

Object subclass: #FooClass
        instanceVariableNames: 'visible'
        classVariableNames: ''
        poolDictionaries: ''
        classInstanceVariableNames: ''

Then you have two "testing" methods: #isVisible and #isHidden
And two "toggling" methods: #beVisible (or #show), and #beHidden (or #hide).

Plus you preserve the direct accessor to the "visible" property, which
is useful in cases like:

anObject visible: self selectionIsValid.

Another good example is with 'enabled' instead of 'visible'.

Personally I don't like the #isVisible: kind of selectors, to me the
#is* are just for testing, not to use as setters.

However it's just my point of view (and of some colleagues).


Regards,

--
Esteban

Esteban,

I would agree with you and your colleagues.  We do the same thing in
Eiffel, except that "be_" there typically takes the form of "make_":
visible, make_visible, and make_hidden.  I must say, though, I think
"be_" is rather ingenious.

Cheers,

Eric

and
> > "is_" in methods.
> >
> > I've named a variable as <isConstrained>.  Is it acceptable to name
> > accessor methods in this case as #beConstrained and
#beUnconstrained?  I
> > don't know that I like "self isConstrained: false/true".
> >
> > In general, what are the guidelines for using "be_"?
>
> We tend to use the is* testing methods for testing the state of
> receiver, but instance variable is named without the is prefix.
>
> I.e. if you want to determine the visibility of an object, you name
the