listless

adj 1: lacking zest or vivacity; "he was listless and bored"

2: marked by low spirits; showing no enthusiasm; "a dispirited

and divided Party"; "reacted to the crisis with listless

resignation" [syn: {dispirited}]

listless

In {functional programming}, a property of a

{function} which allows it to be combined with other functions

in a way that eliminates intermediate data structures,

especially lists.

{Phil Wadler}'s thesis gives the conditions for a function to

be in listless form: each input list is traversed only once,

one element at a time, from left to right. Each output list

is generated once, one element at a time, from left to right.

No other lists are generated or traversed.

Not all functions can be expressed in listless form

(e.g. reverse).

(1995-02-22)