https://github.com/saintedlama/estools

Provides a set of utility function to traverse, filter and map esprima ASTs
https://github.com/saintedlama/estools

Last synced: 2 months ago
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Provides a set of utility function to traverse, filter and map esprima ASTs

• Host: GitHub
• URL: https://github.com/saintedlama/estools
• Owner: saintedlama
• License: mit
• Created: 2014-08-15T08:12:57.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2017-05-31T21:36:43.000Z (over 7 years ago)
• Last Synced: 2024-10-12T12:25:40.763Z (3 months ago)
• Language: JavaScript
• Size: 18.6 KB
• Stars: 6
• Watchers: 2
• Forks: 0
• Open Issues: 15
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# estools [![Build Status](https://travis-ci.org/saintedlama/estools.svg?branch=master)](https://travis-ci.org/saintedlama/estools) [![Coverage Status](https://coveralls.io/repos/saintedlama/estools/badge.png?branch=master)](https://coveralls.io/r/saintedlama/estools?branch=master)

Estools provides a set of utility functions to traverse, filter and map esprima ASTs.

    npm install estools --save

    var estools = require('estools')

# API

## traverse(ast, visitor)

Traverses all tree nodes of an AST and calls visitor functions passing the AST node.

ast is the result of esprima.parse, visitor may be a function or a visitor object.

The visitor object may define the following functions

### enter(node, parent)

Called when entering a node. The current node and parent node are passed as parameter

Example

    traverse(ast, {

      enter : function(node, parent) {

        console.log(node.type);  // Print the node type to std out

      }

    });

### leave(node, parent)

Called when leaving a node. The current node and parent node are passed as parameter

Example

    traverse(ast, {

      leave : function(node, parent) {

        console.log(node.type);  // Print the node type to std out

      }

    });

### visit(node, parent, next)

Called after `enter` and before `leave`. The current node and a parent node are passed as parameter. Additionally

a function `next` is passed. The `visit` function is responsible to call `next` to visit child nodes. To skip

child nodes just omit the call to `visit`.

Example

    traverse(ast, {

      visit : function(node, parent, next) {

        next();

      }

    });

Example skipping nodes

    traverse(ast, {

      visit : function(node, parent, next) {

        if (node.type != 'FunctionExpression') { // Skip child nodes of function expressions

          next();

        }

      }

    });

## filter(ast, filterObj)

Filters AST nodes and returns matching AST nodes as a flat list.

## map(ast, mappingFunction)

Maps ASTs and nodes to a normalized tree with node having child nodes stored in a nodes field array.