dict.org

The DICT Development Group


Search for:
Search type:
Database:

Database copyright information
Server information
Wiki: Resources, links, and other information


3 definitions found
 for idempotent
From WordNet (r) 3.0 (2006) :

  idempotent
      adj 1: unchanged in value following multiplication by itself;
             "this matrix is idempotent"

From The Jargon File (version 4.4.7, 29 Dec 2003) :

  idempotent
   adj.
  
      [from mathematical techspeak] Acting as if used only once, even if used
      multiple times. This term is often used with respect to C header files,
      which contain common definitions and declarations to be included by several
      source files. If a header file is ever included twice during the same
      compilation (perhaps due to nested #include files), compilation errors can
      result unless the header file has protected itself against multiple
      inclusion; a header file so protected is said to be idempotent. The term
      can also be used to describe an initialization subroutine that is arranged
      to perform some critical action exactly once, even if the routine is called
      several times.
  

From The Free On-line Dictionary of Computing (18 March 2015) :

  idempotent
  
     1. A function f : D -> D is idempotent if
  
     	f (f x) = f x  for all x in D.
  
     I.e. repeated applications have the same effect as one.  This
     can be extended to functions of more than one argument,
     e.g. Boolean & has x & x = x.  Any value in the image of an
     idempotent function is a fixed point of the function.
  
     2. This term can be used to describe C header files, which
     contain common definitions and declarations to be included by
     several source files.  If a header file is ever included twice
     during the same compilation (perhaps due to nested #include
     files), compilation errors can result unless the header file
     has protected itself against multiple inclusion; a header file
     so protected is said to be idempotent.
  
     3. The term can also be used to describe an initialisation
     subroutine that is arranged to perform some critical action
     exactly once, even if the routine is called several times.
  
     [{Jargon File]
  
     (1995-01-11)
  

Questions or comments about this site? Contact webmaster@dict.org