From: Sam Roberts <sroberts@...>
Date: 2003-06-24T02:26:08+09:00
Subject: Re: Runtime interpretation

[ensemble] ~ $ ri eval
----------------------------------------------------------- Kernel::eval
     eval( aString [, aBinding [file [line]]]) -> anObject
------------------------------------------------------------------------
     Evaluates the Ruby expression(s) in aString. If aBinding is given,
     the evaluation is performed in its context. The binding may be a
     Binding object or a Proc object. If the optional file and line
     parameters are present, they will be used when reporting syntax
     errors.
        def getBinding(str)
          return binding
        end
        str = "hello"
        eval "str + ' Fred'"                      #=> "hello Fred"
        eval "str + ' Fred'", getBinding("bye")   #=> "bye Fred"


Cheers,
Sam


Quoteing orion2480@hotmail.com, on Tue, Jun 24, 2003 at 02:21:45AM +0900:
> I want to know how to interpret something from a string, so as to be used 
> directly by the interpreter at runtime.  A simplified example:
> 
> $> ruby myprogram.rb
> Enter object information:> Array.new(4)
> object created:> [nil, nil, nil, nil]
> Enter object information:> Hash.new()
> object created:> {}
> Enter object information:> MyObject.new(2,4,6)
> etc., etc.
> 
> I know that, as an interpreted language, Ruby can load new classes, 
> function definitions, etc. at runtime.  But is the above possible? If the 
> object creation was limited to Arrays and Hash's, it would be simple enough 
> just to parse the string and go from there... but that severly limits the 
> funcationality with such specificity.  I was hoping to be able to directly 
> _interpret_ the information in the input string.  Is this possible?
> 
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