AST explorer
Paste or drop code into the editor and inspect the generated AST on https://astexplorer.net/
The AST explorer provides following code parsers:
- CSS:
- GraphQL
- Graphviz:
- Handlebars:
- HTML:
- ICU
- JavaScript:
- JSON
- Lua:
- Markdown:
- MDX:
- PHP
- Pug
- Regular Expressions:
- Scala
- Solidity:
- SQL:
- WebIDL
- YAML:
Experimental / custom syntax
Depending on the parser settings, it not only supports ES5/CSS3 but also
- ES6: arrow functions, destructuring,
classes, ... - ES7 proposals: async/await, object rest / spread, ...
- JSX, known through React.
- Typed JavaScript (Flow and TypeScript)
- SASS
Transforms
Since future syntax is supported, the AST explorer is a useful tool for
developers who want to create AST transforms. In fact, following transformers
are included so you can prototype your own plugins:
- JavaScript
- babel (v5, v6)
- ESLint (v1, v2, v3)
- jscodeshift
- tslint
- HTML
- CSS
- MDX
- Regular Expressions
- Handlebars
More Features
- Save and fork code snippets. Copy the URL to share them.
- Copying an AST or dropping a file containing an AST into the window will
parse the AST and update the code using escodegen. - Otherwise, the content of text editor will be replaced with the content of the
file (i.e. you can drag and drop JS files). - Choose between multiple parsers and configure them.
- shift+click on a node expands the full subtree.
- Hovering over a node highlights the corresponding text in the source code
- Editing the source or moving the cursor around will automatically highlight
the corresponding AST node (or its ancestors of it isn't expanded) - You can use
$nodein the console to refer to the last opened/toggled AST
node.
Contributions
I'm happy about any feedback, feature request or PR to make this tool as useful
as possible!
How to add a new parser
- Go to
website/. - Install the new parser as dependency:
yarn add theParser(ornpm install -S theParser) - Copy one of the existing examples in
src/parsers/{language}. - Adjust the code as necessary:
- Update metadata.
- Load the right parser (
loadParser). - Call the right parsing method with the right/necessary options in
parse. - Implement the
nodeToRangemethod (this is for highlighting). - Implement the
getNodeNamemethod (this is for quick look through the tree). - Implement
opensByDefaultmethod for auto-expansion of specific properties. - Define
_ignoredPropertiesset or implementforEachPropertygenerator method for filtering. - Provide a
renderSettingsmethod if applicable.
How to add a new transformer
- Go to
website/. - Install the new transformer as dependency.
- Copy one of the existing examples in
src/parsers/{language}/transformers. - Adjust the code as necessary:
- Update metadata and
defaultParserID. - Load the right transformer (
loadTransformer). - Call the transformation method in
transform. - Change sample transformation code in
codeExample.txt.
Build your own version for development
- Clone the repository.
- Go to
website/. - Install all dependencies with
yarn install(you can runnpm installas
well).
Run yarn run build for the final minimized version.
Run yarn run watch for incremental builds.
Run yarn start to start a simple static webserver.