Translators

Translator software

This is software that allows new programs to be written and run on computers, by converting source code into machine code.

Assembler

An assembler translates assembly language into machine code. Assembly language consists of mnemonics for machine opcodes so assemblers perform a 1:1 translation from mnemonics to a direct instruction. For example:

LDA #4 converts to 0001001000100100

Conversely, one instruction in a high level language will translate to one or more instructions at machine level.

Advantages of using an Assembler:

Very fast in translating assembly language to machine code as 1 to 1 relationship
Assembly code is often very efficient (and therefore fast) because it is a low level language
Assembly code is fairly easy to understand due to the use of English-like mnemonics

Disadvantages of using Assembler:

Assembly language is written for a certain instruction set and/or processor
Assembly tends to be optimised for the hardware it's designed for, meaning it is often incompatible with different hardware
Lots of assembly code is needed to do relatively simple tasks, and complex programs require lots of programming time

Compiler

A Compiler is a computer program that translates code written in a high level language to a lower level language, object/machine code. The most common reason for translating source code is to create an executable program (converting from a high level language into machine language).

Advantages of using a compiler

Source code is not included, therefore compiled code is more secure than interpreted code
Tends to produce faster code than interpreting source code
Produces an executable file, and therefore the program can be run without need of the source code

Disadvantages of using a compiler

Object code needs to be produced before a final executable file, this can be a slow process
The source code must be 100% correct for the executable file to be produced

Interpreter

An interpreter program executes other programs directly, running through program code and executing it line-by-line. As it analyses every line, an interpreter is slower than running compiled code but it can take less time to interpret program code than to compile and then run it — this is very useful when prototyping and testing code. Interpreters are written for multiple platforms, this means code written once can be run immediately on different systems without having to recompile for each. Examples of this include flash based web programs that will run on your PC, MAC, games console and Mobile phone.

Advantages of using an Interpreter

Easier to debug(check errors) than a compiler
Easier to create multi-platform code, as each different platform would have an interpreter to run the same code
Useful for prototyping software and testing basic program logic

Disadvantages of using an Interpreter

Source code is required for the program to be executed, and this source code can be read making it insecure
Interpreters are generally slower than compiled programs due to the per-line translation method