abstract-syntax-tree

Is it possible to access the Abstract Syntax Tree(AST) inside the javac.exe programmatically? Could you provide an example? jamesh Yes, it is possible, but only since Java 6. Peter von der Ahé talks about the two JSRs in this interview . Of JSR 199: The JSR 199 Compiler API consists of three things: The first one basically allows you to invoke a compiler via the API. Second, the API allows you to customize how the compiler finds and writes out files. I mean files in the abstract sense, since the files the compiler deals with aren't necessarily on the file system. JSR 199's file abstraction

I had read "whole internet", but can't find any examples about getting syntax tree (just like in Esprima) from TypeScrypt source. I mean how can i get object like this ( Esprima Parser example) { "type": "Program", "body": [ { "type": "VariableDeclaration", "declarations": [ { "type": "VariableDeclarator", "id": { "type": "Identifier", "name": "answer" }, "init": { "type": "BinaryExpression", "operator": "*", "left": { "type": "Literal", "value": 6, "raw": "6" }, "right": { "type": "Literal", "value": 7, "raw": "7" } } } ], "kind": "var" } ] } from javascript code var answer = 6 * 7; only for

I found the two terms in a compiler design book, and I'd like to know what each stands for, and how they are different. I searched on the internet and found that parse trees are also called concrete syntax trees (CSTs). 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 : multExpr (( '+'^ | '-'^ ) multExpr)* ; multExpr : atom ('*'^ atom)* ; atom

I'm trying to write Python expression evaluation visualizer, that will show how Python expressions are evaluated step by step (for education purposes). Philip Guo's Python Tutor is great, but it evaluates Python program line by line, and I found that students sometimes do not understand how one-line expressions like sorted([4, 2, 3, 1] + [5, 6])[1] == 2 are evaluated and I'd like to visualize this process. (It seems that nobody did it yet — at least I found nothing.) The ideal solution will create a sequence of strings like this: sorted([4, 2, 3, 1] + [5, 6])[1] == 2 sorted( >> [4, 2, 3, 1] +

I've found a sample template in the ANTLR website, its the Javatreeparser.g, which the site says could produce the AST that I need, but since I'm new to ANTLR, how do I make it show? What I've done so far is placing the grammar file together with my existing java grammar. But I have no idea on how to use and output the AST that I need from the file. How do I do it? Bart Kiers I've found a sample template in the ANTLR website, its the Javatreeparser.g, which the site says could produce the AST that I need, No, the combined grammar Java.g from the ANTLR wiki produces a lexer and parser for Java

I have an AST (abstract syntax tree) and now i want to test my compiler by giving it 2 or more numbers and expect an output with the result of math operations (like a calculator). My question is, what is the best way to build the interpreter? The visiting of the AST nodes is recursive, so i don't know how many encapsulated calculations exists until i get to the end of the tree. But since this is done iteration by iteration, how can i make all the operations in the end? Thank you Intepreters are pretty easy to code, once you have an AST: int interpret(tree t) { /* left to right, top down scan

My collegue suggested me to write a visitor pattern to navigate the AST. Can anyone tell me more how would I start writing it? As far as I understand, each Node in AST would have visit() method (?) that would somehow get called (from where?). That about concludes my understanding. To simplify everything, suppose I have nodes Root , Expression , Number , Op and the tree looks like this: Root | Op(+) / \ / \ Number(5) \ Op(*) / \ / \ / \ Number(2) Number(444) Can anyone think of how the visitor pattern would visit this tree to produce output: 5 + 2 * 444 Thanks, Boda Cydo. Wikipedia has a great