(tested with MRI 1.8.7 and newer)
Description
This project was originally inspired by Smalltalk's Method Finder, but additonal features were added over time.
Usage
MethodFinder.find
Provided with a receiver, the desired result and possibly some
arguments, MethodFinder.find
will list all methods that produce the
given result when called on the receiver with the provided arguments.
>> MethodFinder.find(10,1,3)
=> [:%, :<=>, :>>, :[], :modulo, :remainder]
>> MethodFinder.find("abc","ABC")
=> [:swapcase, :swapcase!, :upcase, :upcase!]
>> MethodFinder.find(10,100,2)
=> [:**]
>> MethodFinder.find(['a','b','c'],['A','B','C']) { |x| x.upcase }
=> [:collect, :collect!, :map, :map!]
Object#find_method
This gem also adds Object#find_method
, which besides offering an
alternate interface to pretty much the same functionality as
MethodFinder.find
, also allows you to test for state other than
the return value of the method.
>> %w[a b c].find_method { |a| a.unknown(1) ; a == %w[a c] }
=> [:delete_at, :slice!]
>> 10.find_method { |n| n.unknown(3) == 1 }
=> [:%, :<=>, :>>, :[], :gcd, :modulo, :remainder]
Inside find_method
's block, the receiver is available as block
argument and the special method unknown
is used as a placeholder for
the desired method.
You can also call find_method
without passing a block. This is the
same as calling MethodFinder.find
.
>> 10.find_method(1,3)
[:%, :<=>, :>>, :[], :modulo, :remainder]
Blacklists
You can exclude methods from being tried by editing the hashes
MethodFinder::INSTANCE_METHOD_BLACKLIST
and
MethodFinder::CLASS_METHOD_BLACKLIST
. Both use the class/module
as key and an array of method names as values (note that class, module
and method names have to be symbols).
For example, to blacklist the instance method shutdown
of Object
,
you would do
MethodFinder::INSTANCE_METHOD_BLACKLIST[:Object] << :shutdown
This might come in handy when using MethodFinder
together with other
gems as such as interactive_editor
.
MethodFinder.find_classes_and_modules
A simple method to return all currently defined modules and classes.
>> MethodFinder.find_classes_and_modules
=> [ArgumentError, Array, BasicObject, Bignum ... ZeroDivisionError]
MethodFinder.find_in_class_or_module
Searches for a given name within a class. The first parameter can either be a class object, a symbol or a string whereas the optional second parameter can be a string or a regular expression:
>> MethodFinder.find_in_class_or_module('Array', 'shuff')
=> [:shuffle, :shuffle!]
>> MethodFinder.find_in_class_or_module(Float, /^to/)
=> [:to_f, :to_i, :to_int, :to_r, :to_s]
If the second parameter is omitted, all methods of the class or module will be returned.
>> MethodFinder.find_in_class_or_module(Math)
=> [:acos, :acosh, :asin ... :tanh]
Warning
Common sense not included!
While I never had any problems with this, it's still better to be safe than sorry, so use this with caution and maybe not on production data.
I initially wrote this for the students of the core Ruby course on
RubyLearning, so Rails is not of interest
to me (not saying it doesn't work there, just that I test in plain
IRB, not with script/console
).
Thanks
- Matthew Lucas for first packaging this as a gem.
- Ryan Bates for
suggesting
what eventually became
Object#find_method
. - Jan Lelis for implementing blacklists.
- Brian Morearty for pointing out an
incompatibility with Ruby 1.8.7
and adding the blockless version of
Object#find_method
.
License
Copyright (c) 2011 Michael Kohl
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.