help in understanding eval function

[Ravi Kanth]

Hi
I am new to ruby I am having trouble in understanding the eval function

can you suggest me a good reference to look at the various classes and
methods available.


thanx in advance.

 

[7stud --]

Hi
I am new to ruby I am having trouble in understanding the eval function

can you suggest me a good reference to look at the various classes and
methods available.

Programming Ruby(2nd ed.) for ruby 1.8.x.
Programming Ruby(3rd ed.) for ruby 1.9.x.

or...

$ri eval
------------------------------------------------------------ Kernel#eval
eval(string [, binding [, filename [,lineno]]]) => obj
------------------------------------------------------------------------
Evaluates the Ruby expression(s) in _string_. If _binding_ is
given, the evaluation is performed in its context. The binding may
be a +Binding+ object or a +Proc+ object. If the optional
_filename_ and _lineno_ 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"
------------------

 

[7stud --]

Programming Ruby(2nd ed.) for ruby 1.8.x.
Programming Ruby(3rd ed.) for ruby 1.9.x.

I guess I should explain: the second half of those books is a complete
ruby reference, which as far as I know is the only language reference in
print.

 

[Gary Wright]

I guess I should explain: the second half of those books is a complete
ruby reference, which as far as I know is the only language
reference in
print.

I think that "The Ruby Programming Language" by David Flanagan and
Matz could be fairly considered as a 'language reference'. Personally
I think that David and Matz's style is better suited for experienced
programmers than Dave Thomas's style in Programming Ruby, which I
think is better for beginner/novice programmers.

Gary Wright

 

[imdwalrus]

Hi
I am new to ruby I am having trouble in understanding the eval function

can you suggest me a good reference to look at the various classes and
methods available.

thanx in advance.

Dave Thomas provides as thorough an explanation as you could ask for
in his Ruby Metaprogramming screencasts:
http://www.pragprog.com/screencasts/v-dtrubyom/the-ruby-object-model-and-metaprogramming
.. The fourth one in that series is dedicated to eval, but the first
three are useful in helping you to understand it thoroughly. Also,
David Black does a good job explaining eval (and everything else he
addresses) in The Well-Grounded Rubyist.