2.5 - Translators

2.5 - Translators

1. Low Level Language

   • Similar to how computers actually work.
   • Machine orientated.
   • Requires extensive knowledge of computer hardware & its configuration.
   • Machine language
     • Written in the language of the computer.
     • No need for translation.
     • 1st generation.
   • Assembly language
     • Translated by an assembler.
     • Easier for humans to understand, still difficult however.
     • 2nd generation.

2. High Level Language

   • AKA source code.
   • Programming language using English-like language and mathematics symbols.
   • Advantages
     • Closer to English language.
     • Code is portable.
       • Can be used on any computer.
     • Aimed at humans.
   • Has to be translated using a compiler or interpreter.

3. Compiler

   • Program that translates a program written in a high-level language to the machine language of a computer.
   • Turns source code to machine code.
     • Inputs are processed when program is always running.
   • Entire source code has to be completed when compiled.
   • Faster.
   • Doesn't reveal source code.
   • An analogy would be subtitles on a film - all is subtitled before the film is released.

4. Interpreter

   • More flexible.
   • Translates line by line.
   • Interprets inputs at the same time as source code.
   • An analogy would be interpreting a speech line by line.

5. Generations of code

   • 1st generation
     • Machine code.
     • Directly executable.
     • Hard to find errors, hard to understand, difficult to program.
     • Non-portable.
   • 2nd generation
     • Assembly code.
     • Uses mnemonics.
     • Easier to program but still difficult.
     • Uses an assembler to convert to 1st generation.
     • Hard to debug.
     • Used in device drivers.
       • Printers, etc.
   • 3rd generation
     • Easier to understand, debug and find errors.
     • Translated using compiler/interpreter.
   • 4th generation
     • States facts and rules.
     • Describes what should be performed but NOT how to perform it.
     • Examples include SQL, Expert system and AI.

6. IDE

   • Integrated Development Environment.
   • Assists with:
     • Editing (when writing the code)
     • Error diagnostics
     • Run-time environment
     • Translators
     • Debugging

7. Language translators

   • Used to translate language into a form that can be directly executed.
   • Examples Include:
     • Compiler
     • Interpreter
     • Assembler