Re: Code generation architecture question
On Nov 13, 7:16 pm, Alex_Gaynor [EMAIL PROTECTED] wrote: I'm trying to figure out what the best architecture for doing code generation would be. I have a set of ASTs that define a program, so what should I do to for code generation. As I see it the 2 choices are to have the ASTs have a generate code method that returns the correct code for themselves, or to have a seperate class that generates code for a given AST. The problem with the first is that it isn't very flexible if I want to generate code for a new language/ platform, as well as the fact that it is very tightly coupled. However the issue with the other approach is that I can't think of a good way to write it without have a ton of if isinstance() calls. Any thoughts on what the best appraoch would be? I think you are seeking the Visitor Pattern. class A: def meth( self, visitor ): visitor.visit_classA( self ) class B: def meth( self, visitor ): visitor.visit_classB( self ) class Visitor: def visit_classA( self, objinst ): #handle classA def visit_classB( self, objinst ): #handle classB then A().meth( v ) gets around to getting v.visit_classA called. The code is moderately repetitive. I believe the Transformer class in the 'ast' module uses the visitor pattern, possibly called NodeWalker or something. -- http://mail.python.org/mailman/listinfo/python-list
Re: Code generation architecture question
On Nov 14, 3:04 am, Aaron Brady [EMAIL PROTECTED] wrote: On Nov 13, 7:16 pm, Alex_Gaynor [EMAIL PROTECTED] wrote: I'm trying to figure out what the best architecture for doing code generation would be. I have a set of ASTs that define a program, so what should I do to for code generation. As I see it the 2 choices are to have the ASTs have a generate code method that returns the correct code for themselves, or to have a seperate class that generates code for a given AST. The problem with the first is that it isn't very flexible if I want to generate code for a new language/ platform, as well as the fact that it is very tightly coupled. However the issue with the other approach is that I can't think of a good way to write it without have a ton of if isinstance() calls. Any thoughts on what the best appraoch would be? I think you are seeking the Visitor Pattern. class A: def meth( self, visitor ): visitor.visit_classA( self ) class B: def meth( self, visitor ): visitor.visit_classB( self ) class Visitor: def visit_classA( self, objinst ): #handle classA def visit_classB( self, objinst ): #handle classB then A().meth( v ) gets around to getting v.visit_classA called. The code is moderately repetitive. I believe the Transformer class in the 'ast' module uses the visitor pattern, possibly called NodeWalker or something. Ah this is great, the Visitor class knows how to transform everything into code, and each AST knows which method it is on the Visitor, thanks a ton! -- http://mail.python.org/mailman/listinfo/python-list
Code generation architecture question
I'm trying to figure out what the best architecture for doing code generation would be. I have a set of ASTs that define a program, so what should I do to for code generation. As I see it the 2 choices are to have the ASTs have a generate code method that returns the correct code for themselves, or to have a seperate class that generates code for a given AST. The problem with the first is that it isn't very flexible if I want to generate code for a new language/ platform, as well as the fact that it is very tightly coupled. However the issue with the other approach is that I can't think of a good way to write it without have a ton of if isinstance() calls. Any thoughts on what the best appraoch would be? -- http://mail.python.org/mailman/listinfo/python-list
