From: John Carter <john.carter@...>
Date: 2008-03-11T13:31:11+09:00
Subject: Re: Best practices for Ruby Meta-programming

On Mon, 10 Mar 2008, Robert Dober wrote:

> attr_reader e.g. is nothing less than MP.

I'd still be happier if I could flick a switch and see the
intermediate vanilla code that was generated.

> FWIAC metaprogramming is here to do things at runtime and nothing else
> in the world can replace it.

I suspect we've overloaded the term "meta-programming".

There are "programs that write programs".

There is a common subset of that ... "programs that instantiate
generic template code by substituting template variables with concrete
text."

If by meta-programming you mean one of the meanings above this line,
seeing a concrete vanilla ruby intermediate representation is
invaluable.

----------------------------------------------------------------------

If by meta-programming you mean one of the following, creating
concrete intermediate representations is harder..., but certainly not
impossible.

There are "programs that query & display the current run time state of
the program". (Profiling, debugging, coverage, memory profiling & leak
detection, object creation hotspot detection...)

There are _very_ hairy programs "that query the current run time state
of the program and modify the code 'on-the-fly' accordingly."

> You know sometimes it is just the right tool to use, *sometimes*.

Their are times and places where on-the-fly self-modifying code is
appropriate.

They are clearly marked on the map as "Here be Dragons".

John Carter                             Phone : (64)(3) 358 6639
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