CODEWITHSUNDEEP
javaabstract-syntax-treejavaparser
ivan
ivan

Reputation: 297

JavaParser - Get typed AST

I want to get typed AST from JavaParser or another parser of Java code. It means I would be able to get the type for a specific variable or parameters+returning type of a method. I googled a lot about this feature of JavaParser, but didn't find anything, I assume this is because JavaParser makes untyped AST. So, advise me how I can get this. But please don't say to parse all the code and make my own set of types, I tried and this is very hard, I think this is harder than making my own AST parser.

Upvotes: 1

Views: 1591

Answers (1)

Federico Tomassetti
Federico Tomassetti

Reputation: 2248

I am a JavaParser contributor and I just did that in Clojure, on top of JavaParser. I explain how implement that in one post How to build a symbol solver for Java, in Clojure

JavaParser, or any other parser just build an Abstract Syntax Tree (AST) of the code, then you have to resolve symbols to understand which references are associated to which declarations.

Suppose you have in your code something like:

a = 1;

Now, to understand the type of a you should find where it is declared. It could be a reference to a parameter, to a local variable, to field declared in a current class or to a field inherited. If it is a field inherited you should find the code (or the bytecode) of the parent class and look there for the declaration of a. A parser does not do that, a parse just take a string (or a file) and build an AST.

Build a symbol resolver is not rocket science but it requires a bit of work. The solution I described in the post linked above is available on GitHub and I would be glad to help you use it if you want (even if it is written in Clojure you can call it from Java quite easily)

Upvotes: 2

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