relationship to ast library

[machow]

siu	role	notes
Symbolic	Quick AST creation	Can be thought of as alternative to ast.parse, or manual node creation
Call	Callable AST	Can hold literal python objects (e.g. a list vs the AST representation of a list)
Tree visitor	Processing and transforming AST	Subclass of NodeVisitor, dispatches on function name (Call.func) not class name
Generic function dispatch	Functions can return lazy versions of themselves