From: Sam Barton <sambarton919@...>
Date: 2011-02-22T20:28:17+09:00
Subject: Re: LiveAST: a pure Ruby 1.9.2 library for obtaining live abstract syntax trees

Marc Heiler wrote in post #982809:
> Hello,
>
> Can someone explain to me what one could do with this?
>
> It sounds very useful to be able and access the ASTs of methods and so
> forth, I am just not completely sure what I can do with this new
> information afterwards.

My favorite example is transforming

  db.select { |job, city| job == "spelunker" and city == "Miami" }

into a database query.  The ruby code you see does not actually execute 
-- some generated code does instead.  Ruby syntax is transformed into 
SQL syntax.

Syntax abstraction is very powerful and has thousands of uses, and 
though it is normally a lisp thing, any language can do it with sexp 
tools.

There are some grumps out there who tut-tut these approaches -- they 
want nothing beyond a certain level of abstraction.  "No, no, no!" they 
say when they encounter anything Lisp-like.  Can't you see them wagging 
their fingers at us now?

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