How do I work with the AST in Irony now?

Question

I have a grammar that works and parses in the Irony console just fine, but I don\'t get anything in the AST treeview. I was following along with the BASIC->Javascript article f

Answer 1

In Irony parsing is done in 2 phases. First it creates a parse tree and then it creates your AST tree.

You are only seeing the first step. In order for Irony to create the AST you can:

1. Tell it how to to map your NonTerminals to AST nodes:

   E.g. looking at the Irony sample grammer ExpressionEvaluatorGrammar we see:

   var BinExpr = new NonTerminal("BinExpr", typeof(BinaryOperationNode));`    
   

   Here the we are telling Irony to map the BinExpr NonTerminal to a BinaryOperationNode which is our AST node.

2. Make it generate the AST when parsing:

   When you set this flag the AST tree will be generated when you parse.

   this.LanguageFlags = LanguageFlags.CreateAst;
   

The root of your AST tree will then be:

parseTree.Root.AstNode

I found this source a great starting point.