@glimmer/syntax

What is @glimmer/syntax?

@glimmer/syntax is a library for parsing, traversing, and transforming Glimmer templates. It provides tools to work with the syntax tree of Glimmer templates, which are used in Ember.js applications.

What are @glimmer/syntax's main functionalities?

Parsing Templates

This feature allows you to parse a Glimmer template string into an Abstract Syntax Tree (AST). The `preprocess` function takes a template string and returns its AST representation.

const { preprocess } = require('@glimmer/syntax');
const template = '<div>{{hello}}</div>';
const ast = preprocess(template);
console.log(ast);

Traversing AST

This feature allows you to traverse the AST of a Glimmer template. The `traverse` function takes an AST and a visitor object, which defines the functions to be called for different node types.

const { traverse } = require('@glimmer/syntax');
const ast = preprocess('<div>{{hello}}</div>');
traverse(ast, {
  MustacheStatement(node) {
    console.log('Found a mustache statement:', node);
  }
});

Transforming AST

This feature allows you to transform the AST of a Glimmer template. You can modify nodes in the AST and then convert it back to a template string using the `print` function.

const { preprocess, print, builders } = require('@glimmer/syntax');
let ast = preprocess('<div>{{hello}}</div>');
traverse(ast, {
  MustacheStatement(node) {
    node.path = builders.path('goodbye');
  }
});
const transformedTemplate = print(ast);
console.log(transformedTemplate);

Other packages similar to @glimmer/syntax

handlebars

Handlebars is a popular templating engine that provides similar functionality for parsing, traversing, and transforming Handlebars templates. It is more general-purpose compared to @glimmer/syntax, which is specifically designed for Glimmer templates.

esprima

Esprima is a high-performance, standard-compliant ECMAScript parser. It provides similar functionality for parsing JavaScript code into an AST and traversing it. Like babel-parser, it is not specific to templates but is useful for general JavaScript code analysis and transformation.