What’s the difference between parse trees and abstract syntax trees (ASTs)?

This is based on the Expression Evaluator grammar by Terrence Parr. The grammar for this example: grammar Expr002; options { output=AST; ASTLabelType=CommonTree; // type of $stat.tree ref etc… } prog : ( stat )+ ; stat : expr NEWLINE -> expr | ID ‘=’ expr NEWLINE -> ^(‘=’ ID expr) | NEWLINE -> ; expr … Read more

Learning Resources on Parsers, Interpreters, and Compilers [closed]

The best paper I ever read on compilers is dated 1964 “META II a syntax-oriented compiler writing language” by Val Schorre. (http://doi.acm.org/10.1145/800257.808896) In 10 pages, he shows you how to build an astoundingly simple but very effective compiler-compiler, provides you with with the compiler-compiler grammar and provides you with enough details for you to hand … Read more