A compiler is a program that converts source code (in a programming language) to a machine language form (object code) that a computer can execute. Some compilers output assembly language which is then converted to machine language by a separate assembler.
Description
A compiler is distinguished from an assembler by the fact that each input statement does not, in general, correspond to a single machine instruction or fixed sequence of instructions. A compiler may support such features as automatic allocation of variables, arbitrary arithmetic expressions, control structures such as FOR and WHILE loops, variable scope, input/ouput operations, higher-order functions and portability of source code.[1]
History
Autocode, written by Alick Glennie for the Manchester Mark 1 in 1952, is considered to be one of the first primitive compilers. The Laning and Zierler system, written around the same time for the Whirlwind I, was one of the first working algebraic compilers.[1] Steve Wozniak, when writing Integer BASIC for the Apple I in 1975-1976, had to hand assemble the instructions directly into machine language for the MOS 6502 processor because he could not afford a compiler at the time.[2]
Compilers used by Apple
Integrated development environments (IDEs) provided by Apple for their operating systems typically include a compiler.
- Macintosh Programmer's Workshop (MPW), for classic Mac OS.
- CodeWarrior (from Metrowerks), for PowerPC.
- Xcode, for iOS, iPadOS, macOS (formerly Mac OS X), tvOS, and watchOS.
References
- ↑ 1.0 1.1 Compiler at the Free On-Line Dictionary Of Computing. 1998-05-08.
- ↑ Restoring Woz's Original Apple BASIC by James Grahame, Retro Thing. 2008-07-16.
External links
- Compiler at Wikipedia
