eager evaluation

1 definition found

eager evaluation - Free On-line Dictionary of Computing (26 May 2007) :

  eager evaluation
  
     Any evaluation strategy where evaluation of some or all
     function arguments is started before their value is required.
     A typical example is call-by-value, where all arguments are
     passed evaluated.  The opposite of eager evaluation is
     call-by-need where evaluation of an argument is only started
     when it is required.
  
     The term "speculative evaluation" is very close in meaning
     to eager evaluation but is applied mostly to parallel
     architectures whereas eager evaluation is used of both
     sequential and parallel evaluators.
  
     Eager evaluation does not specify exactly when argument
     evaluation takes place - it might be done fully speculatively
     (all redexes in the program reduced in parallel) or may be
     done by the caller just before the function is entered.
  
     The term "eager evaluation" was invented by Carl Hewitt and
     Henry Baker <hbaker@netcom.com> and used in their paper ["The
     Incremental Garbage Collection of Processes", Sigplan Notices,
     Aug 1977.
     (ftp://ftp.netcom.com/pub/hb/hbaker/Futures.html)].  It was
     named after their "eager beaver" evaluator.
  
     See also conservative evaluation, lenient evaluation,
     strict evaluation.
  
     (1994-12-22)