Lexical Analysis

Introduction

A program written in high level language produce output in low level language is called compiler.

Cross Compiler

A compiler that runs on one machine 'A' and produces a code for another machine 'B'.

Example: (a) Suppose Compiler runs on machine A, which takes language X as input and produces output in Y language.

(b) Suppose Compiler runs on machine A and produces code Y for another machine B.

Compiler Parts

There are two major parts of a compiler:

1. Analysis Phase: It breaks up the source program into constant piece and creates an intermediate representation of the source program.

(i) Lexical Analyzer

(ii) Syntax Analyzer

(iii) Semantic Analyzer

2. Synthesis Phase: It constructs the desired target program from the intermediate representation. 

(i) Intermediate Code Generator

(ii) Code Generator

(iii) Code Optimizer

Language Processing System

Lexical Analysis

Lexical analyzer reads a source program character by character to produce tokens.