1.2.2 Applications Generation

1.2.2 Applications Generation

1. Software Types

   • Applications Software
     • Software that allows a user to perform a task or produce something
     • Browsers
     • Spreadsheet
     • Communications
   • Utility Software
     • Small program that usually has one purpose normally maintainance
     • Disk Defragmentation
     • Anti virus
     • Compression
   • Open Source
     • Source code is publicly available // users can modify
   • Closed Source
     • Source code is not publicly available // users cannot modify

2. Translators

   • Assemblers
     • Used to convert low level assembly language into machine code
   • Compliers
     • Translates high level source code into executable machine code
   • Interpreters
     • Translates high level level programming languages into machine code

3. Stages of Compilation

   • Lexical Analysis
     • Commands and white spaces removed
     • High level code = Tokens
     • Symbol table created
   • Syntax Analysis
     • Checks code for valid syntax
     • Checks against language rules
     • Produces an Abstract Syntax Tree
   • Code Generation
     • Program is represented in Abstract Syntax tree
     • Then converts into object code
   • Optimization
     • finds code that can be replaced with more alternatives to improve speed

4. Linkers and loaders

   • Linker
     • Links to library files
   • Loader
     • Part of the OS that loads the libraries