Summary

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	File:     pdae.icn

	Subject:  Procedures for programmer-defined argument evaluation

	Author:   Ralph E. Griswold

	Date:     January 18, 1994

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   This file is in the public domain.

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  These procedures use co-expressions to model the built-in argu-
  ment evaluation regime of Icon and also provide new ones.
  
       Allpar{e1,e2, ...}   parallel evaluation with last result
                            used for short sequences
  
       Extract{e1,e2, ...}  extract results of even-numbered argu-
                            ments according to odd-numbered values
  
       Lifo{e1,e2, ...}     models standard Icon ``lifo'' evalua-
                            tion
  
       Parallel{e1,e2, ...} parallel evaluation terminating on
                            shortest sequence
  
       Reverse{e1,e2, ...}  left-to-right reversal of lifo evalua-
                            tion
  
       Rotate{e1,e2, ...}   parallel evaluation with shorter
                            sequences re-evaluated
  
       Simple{e1,e2, ...}   simple evaluation with only success or
                            failure

  In all cases, the first argument is "applied".

  Comments:

     Because of the handling of the scope of local identif-
  iers in co-expressions, expressions in programmer-defined argu-
  ment evaluation regimes cannot communicate through local identif-
  iers.  Some constructions, such as break and return, cannot be
  used in arguments to programmer-defined argument evaluation
  regimes.
  
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  Requires:  co-expressions

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This file is part of the (main) package.

Allpar(L)

Extract(L)

Lifo(L)

Parallel(L)

Reverse(L)

Rotate(L)

Simple(L)