Compiler & Parser

Javascript compiler

The JavaScript compiler translates JavaScript source into Java class files. The resulting Java class files can then be loaded and executed at another time, providing a convenient method for transferring JavaScript, and for avoiding translation cost.

JavaScript JIT compilers

The first JavaScript JIT compiler was Mozilla’s TraceMonkey This was a “tracing jit" so-called because it traces a path through your code looking for commonly executed code loops.

These “hot loops” are then compiled into machine code. With this optimisation alone Mozilla were able to achieve performance gains of 20% to 40% over their previous engine.

Shortly after TraceMonkey launched Google debuted its Chrome browser along with it’s new V8 JavaScript engine.

V8 had been designed specifically to execute at speed. A key design decision was to skip bytecode generation entirely and instead have the translator emit native code.

This increased the overall speed of their JavaScript execution by 150%.





Parser

The word "parse" means to analyze an object specifically. It is commonly used in computer science to refer to reading program code.

Before the engine can execute the code, it has to feed the source into its parser The purpose of the parser is to perform the syntactic analysis and to produce an abstract syntax tree (AST). 

 PEG.js is a simple parser generator for JavaScript that produces fast parsers with excellent error reporting. You can use it to process complex data or computer languages and build transformers, interpreters, compilers and other tools easily.

Features


  • Simple and expressive grammar syntax
  • Integrates both lexical and syntactical analysis
  • Parsers have excellent error reporting out of the box
  • Based on parsing expression grammar formalism — more powerful than traditional LL(k) and LR(k) parsers
  • Usable from browser, from the command line, or via JavaScript API
Compiler & Parser Compiler & Parser Reviewed by Unknown on 06:46:00 Rating: 5

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