---
title: "Ruby 2.6 adds RubyVM::AST module"
description: "Ruby 2.6 adds RubyVM::AST module"
canonical_url: "https://www.bigbinary.com/blog/ruby-2-6-adds-rubyvm-ast-module"
markdown_url: "https://www.bigbinary.com/blog/ruby-2-6-adds-rubyvm-ast-module.md"
---

# Ruby 2.6 adds RubyVM::AST module

Ruby 2.6 adds RubyVM::AST module

- Author: Amit Choudhary
- Published: October 2, 2018
- Categories: Ruby 2.6, Ruby

Ruby 2.6 added `RubyVM::AST` to generate the
[Abstract Syntax Tree](https://en.wikipedia.org/wiki/Abstract_syntax_tree) of
code. Please note, this feature is experimental and under active development.

As of now, `RubyVM::AST` supports two methods: `parse` and `parse_file`.

`parse` method takes a string as a parameter and returns the root node of the
tree in the form of the object, RubyVM::AST::Node (Link is not available).

`parse_file` method takes the file name as a parameter and returns the root node
of the tree in the form of the object,
[RubyVM::AST::Node](https://ruby-doc.org/core-2.6.0.preview2/RubyVM/AST/Node.html).

#### Ruby 2.6.0-preview2

```ruby
irb> RubyVM::AST.parse("(1..100).select { |num| num % 5 == 0 }")
=> #<RubyVM::AST::Node(NODE_SCOPE(0) 1:0, 1:38): >

irb> RubyVM::AST.parse_file("/Users/amit/app.rb")
=> #<RubyVM::AST::Node(NODE_SCOPE(0) 1:0, 1:38): >
```

[RubyVM::AST::Node](https://ruby-doc.org/core-2.6.0.preview2/RubyVM/AST/Node.html)
has seven public instance methods - `children`, `first_column`, `first_lineno`,
`inspect`, `last_column`, `last_lineno` and `type`.

#### Ruby 2.6.0-preview2

```ruby
irb> ast_node = RubyVM::AST.parse("(1..100).select { |num| num % 5 == 0 }")
=> #<RubyVM::AST::Node(NODE_SCOPE(0) 1:0, 1:38): >

irb> ast_node.children
=> [nil, #<RubyVM::AST::Node(NODE_ITER(9) 1:0, 1:38): >]

irb> ast_node.first_column
=> 0

irb> ast_node.first_lineno
=> 1

irb> ast_node.inspect
=> "#<RubyVM::AST::Node(NODE_SCOPE(0) 1:0, 1:38): >"

irb> ast_node.last_column
=> 38

irb> ast_node.last_lineno
=> 1

irb> ast_node.type
=> "NODE_SCOPE"
```

This module will majorly help in building a static code analyzer and formatter.

## Links

- [Human page](https://www.bigbinary.com/blog/ruby-2-6-adds-rubyvm-ast-module)