m3tk-gast.2 package -- created Fri Mar 20 09:20:13 PST 1992 by mjordan
current owner mjordan

This package provides basic facilities for specifying an Abstract Syntax
Tree. It defines a basic node type AST.NODE, and in separate interfaces,
specifies a set of standard methods applicable to an AST node.
Language specific ASTs are defined by subtyping AST.NODE and providing
implementations for the standard methods. 

AST             defines AST.NODE and explains the basic framework
AST_Init        adds an "init" method to AST.NODE
AST_Name        adds a "name" method to AST.NODE
AST_Iter        adds an iterator for node children
AST_WalkRep     adds support for tree walks with client callback
AST_CopyRep     adds support for tree copies with client callback
AST_DisplayRep  adds support for "displaying" a tree node
AST_LAST        defines the "last" interface to extend AST.NODE

The interfaces AST_{Walk.Copy,Display}Rep are not intended to be
used by AST clients, they provide support for the following interfaces:

ASTWalk         walk a tree with callback to client
ASTCopy         copy a tree with callback to client

Display is inherently language specific, so does not appear at this level.

ASTName         just a veneer on the "name" method.

ASTNodeArray    presents the children of a node as an array