Univac

API and CLI to generate Abstract Syntax Trees (AST) of several well-known programming languages using antlr4 grammars

Playground - Demo

Playground (WIP)

Features

• JavaScript API for node.js and browser.
• Command line tool
• TypeScript
• ASTs for C, golang, ruby, java, python, scala, erlang, lua, dart2, rust, antlr4, kotlin, smalltalk, fortran77, VisualBasic6, less wat, and more...

A word of caution

A word of caution regarding generated ASTs:

• Not guaranteed to support 100% of Language's features
• Not guaranteed to render 100% of given source code semantics
• AST structure is not official
  • Was built using antlr4 which is not a tool oriented to generate AST
    • So some grammars needed to be post-processed to remove redundant nodes.

Install

npm i univac

JavaScript API

import { parseAst } from 'univac'

const ast = await parseAst({
  input: 'int main() {}',
  language: 'c'
})
console.log(JSON.stringify(ast, null, 2))

Command line

univac --input src/file.py --language python3 --output file-ast.json
univac --listLanguages
univac --input "int main() {}" --language c > ast.json

Supported Languages

The idea is to support all languages in antlr4 grammars

Status

THis is a very new project, WIP, this is the current status:

• tests for Node.js API
• tests to make sure it runs in the browser
• C language
• Golang
• C++
• scala
• ruby
• java
• lua
• python3
• erlang
• dart2
• kotlin
• Fortran77
• Smalltalk
• VisualBasic6
• wat
• less
• java9 (very slow)
• CLI
• Basic Playground
• playground improved with many examples, syntax hihgiling,different kind of ast viewers.
• antlr4 grammar
• c++ grammar (cppAntlr) - slow
• introduced second kind of parser : tree-sitting. These return a "real" ast - not visitor.
  • declared adaptor interfaces
  • visitor is now a normalizer Normalizer
  • tree-sitter tests for node
  • async call parseAst()
• rust (tree-sitter)
• sexpressions (antlr4)
• abnf (antlr4)
• julia (tree-sitter)

Language grammars notes

Smalltalk

Grammar taken from official readline-smalltalk project: https://github.com/redline-smalltalk/redline-smalltalk

Ruby

Is not Ruby, is Ruby-like. Doesn't support Object Oriented features.

TODO: rename it or remove it. Notes from the author:

Ruby-like language (Corundum) grammar written in ANTLR v4. Was developed just for fun to use with Parrot VM (basically it compiles into PIR - parrot intermediate representation)

It has some specific stuff like inline pir and for loop :) And won't ever have OOP features, sorry.

Java9

It's very very slow, just use the java one. notes form the author:

A Java 8 grammar for ANTLR 4 derived from the Java Language Specification chapter 19.

NOTE: This grammar results in a generated parser that is much slower than the Java 7 grammar in the grammars-v4/java directory. This one is, however, extremely close to the spec.