[Python-Dev] AST manipulation and source code generation

[Jeremy Hylton]

On 5/26/05, Chad Whitacre <chad at zetaweb.com> wrote:
> > Would there be any interest in extending the compiler package with tools
> > for AST transformations and for emitting Python source code from ASTs?
> 
> Heh, so I guess the answer is "yes."
> 
> BTW, how does the concept of AST transformations relate to the concept
> of (Lisp) macros? Am I right to think that they are similar?

I think they are similar, but two key differences are:

 - An AST transformation can transform existing syntax but doesn't allow you
   to create new syntax.

 - An AST transformation has to be explicitly invoked.  A macro is
part of the language
   proper and has a semantics for how and when macros are evaluated.

Jeremy