Procesadores de Lenguajes

3º. 2º cuatrimestre. Itinerario de Computación. Grado en Ingeniería Informática. ULL

Organization ULL-ESIT-PL-1920   Github Classroom ULL-ESIT-PL-1920   Campus Virtual PL   Chat Chat   Profesor Casiano

Table of Contents

What is a Compiler

What is a Linker

<i>An illustration of the linking process. Object files and static libraries are assembled into a new library or executable</i>
An illustration of the linking process. Object files and static libraries are assembled into a new library or executable
Rear Admiral (then Commodore) Grace M. Hopper, 1984. By 1952, Hopper had finished her program linker (originally called a compiler), which was written for the A-0 System.
Rear Admiral (then Commodore) Grace M. Hopper, 1984. By 1952, Hopper had finished her program linker (originally called a compiler), which was written for the A-0 System.

Esprima/Espree Examples

Espree started out as a fork of Esprima v1.2.2, the last stable published released of Esprima before work on ECMAScript 6 began. Espree is now built on top of Acorn, which has a modular architecture that allows extension of core functionality. The goal of Espree is to produce output that is similar to Esprima with a similar API so that it can be used in place of Esprima.

REPL example

> esprima = require('esprima')
{ parse: [Function: parse],
  parseModule: [Function: parseModule],
  parseScript: [Function: parseScript],
  tokenize: [Function: tokenize],
  Syntax: 
   { ... },
  version: '4.0.1' }

> esprima.tokenize('answer = 42', { range: true })
[ { type: 'Identifier', value: 'answer', range: [ 0, 6 ] },
  { type: 'Punctuator', value: '=', range: [ 7, 8 ] },
  { type: 'Numeric', value: '42', range: [ 9, 11 ] } ]

> esprima.parseScript('const answer = 42', { tokens: true })
Script {
  type: 'Program',
  body: 
   [ VariableDeclaration {
       type: 'VariableDeclaration',
       declarations: [Array],
       kind: 'const' } ],
  sourceType: 'script',
  tokens: 
   [ { type: 'Keyword', value: 'const' },
     { type: 'Identifier', value: 'answer' },
     { type: 'Punctuator', value: '=' },
     { type: 'Numeric', value: '42' } ] }

> inspect = require('util')
{ ... }

> console.log(util.inspect(esprima.parseScript('answer = 42'), {depth: null}))
Script {
  type: 'Program',
  body: 
   [ ExpressionStatement {
       type: 'ExpressionStatement',
       expression: 
        AssignmentExpression {
          type: 'AssignmentExpression',
          operator: '=',
          left: Identifier { type: 'Identifier', name: 'answer' },
          right: Literal { type: 'Literal', value: 42, raw: '42' } } } ],
  sourceType: 'script' }
undefined
>

PEG.js Example

altjs.coffee is the code for the “AltJS language in 5 minutes” section presented in the second half of the talk.

Extra Special Bonus!

idgrep.coffee (and idgrep.js) is another example of using Esprima to do static analysis on JavaScript code.

ASTExplorer

Repo

En el Repo ULL-ESIT-GRADOII-PL/esprima-pegjs-jsconfeu-talk encontrará el material de esta lección

Talk Master the Art of the AST and Take Control of Your JS by Yonatan Mevorach

ASTExplorer

ESLint Piggyback example

Babel remove “debugger” example

jscodeshift example

Repositorios interesantes de cowchimp

AST: Awesome Super Tool - JS Roundabout - April 2019

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