= evalmimic

• http://github.com/tario/evalmimic

== DESCRIPTION:

Evalmimic allow the implementation of eval like methods, solves the common problem of binding retrieve: in ruby you can't obtain the binding of the caller, or if you can, is some tricky

== INSTALL:

sudo gem install evalmimic

== USAGE

Use define_eval_method to add a eval like method to the class or as global function:

class X define_eval_method :my_eval ... end

Define a method named internal_eval to handle the calls

class X define_eval_method :my_eval

def internal_eval(binding_, args)
   # binding_ is the original binding of the caller of my_eval
   # args is an array of the arguments passed to my_eval
end

end

Also, it can be use outside of a class, in analog way:

define_eval_method :my_eval

def internaleval(binding, args)

binding_ is the original binding of the caller of my_eval

 # args is an array of the arguments passed to my_eval

end

=== Example 1

Creating your own implementation of eval

require "rubygems" require "evalmimic"

define_eval_method :my_eval

def internaleval(b, args) b_.eval("a+b") end

def foo a = 4 b = 5

my_eval

end

print foo," "

=== Example 2

Creating an Evaluator class

require "rubygems" require "evalmimic"

class MyEvaluator define_eval_method :eval

def internal_eval(b_, args)
  b_.eval(args[0])
end

end

def foo m = MyEvaluator.new

a = 4
b = 5

m.eval "a+b"

end

print foo," "

=== Example 3

Hooking/monkey patching of the original eval

require "rubygems" require "evalmimic"

alias original_eval eval define_eval_method :eval

def internaleval(b, args) print "eval called with code = #{args[0].inspect} "

args[1] = args[1] || b_

original_eval(*args)

end

def foo a = 4 eval "a" end

print foo," "

== LICENSE:

Copyright (c) 2011 Roberto Dario Seminara [email protected]

evalhook is free software: you can redistribute it and/or modify it under the terms of the gnu general public license as published by the free software foundation, either version 3 of the license, or (at your option) any later version.

evalhook is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. see the gnu general public license for more details.

you should have received a copy of the gnu general public license along with evalhook. if not, see http://www.gnu.org/licenses/.