Programming language: Difference between revisions

Revision as of 01:37, 25 July 2002

Revision as of 04:58, 27 July 2002

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Since programming languages are artificial languages, they require a high degree of discipline to accurately specify which operations are desired. Programming languages are not error tolerant; however, the burden of recognising and using the special vocabulary is reduced by help messages generated by the programming language implementation.

There are a few languages which offer a high degree of freedom in allowing self-modification in which a program re-writes parts of itself to handle new cases. Typically, only machine language and members of the [[LISP programming language|Lisp family]] ([[Common Lisp]], [[Scheme programming language|Scheme]]) provide this capability; Some languages such as [[MUMPS]] and [[Perl]] allow modification of data structures that contain program fragments, and provide methods to transfer program control to those data structures; languages that support dynamic linking and loading such as [[C programming language|C]], [[C plus plus|C++]], and the [[Java programming language]]

can fake self-modification by either embedding a small compiler or calling a full compiler and linking in the resulting object code. Interpreting code by recompiling it in real time is called [[dynamic recompilation]]; [[emulator]]s and other [[virtual machine]]s exploit this technique for greater performance.