Syntactic Analysis

Syntactic Analysis takes the tokens (from Lexical Analysis and reformats them into a representation that describes each part of the syntax and their relation to one another. This is known as an intermediate representation or Abstract Syntax Tree. An Abstract Syntax Tree, or AST for short, is a deeply nested object that represents code in a way that is both easy to work with and tells us a lot of information.

(add 2 (subtract 4 2))

which when first tokenised (using Lexical Analysis and then transformed in to an Abstract Syntax Tree would look like this:

{
    type: 'Program',
    body: [{
      type: 'CallExpression',
      name: 'add',
      params: [{
        type: 'NumberLiteral',
        value: '2',
      }, {
        type: 'CallExpression',
        name: 'subtract',
        params: [{
          type: 'NumberLiteral',
          value: '4',
        }, {
          type: 'NumberLiteral',
          value: '2',
        }]
      }]
    }]
  }