listless


Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.
Related to listless: restless

listless

(programming)
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).
References in classic literature ?
The result of the long strain was seen later in the afternoon, when he sat locked within the turret-room before the still baffling trunk, distrait, listless and yet agitated, sunk in a settled gloom.
With my body in one easy-chair and my legs upon another, I had surrounded myself with a cloud of newspapers until at last, saturated with the news of the day, I tossed them all aside and lay listless, watching the huge crest and monogram upon the envelope upon the table and wondering lazily who my friend's noble correspondent could be.
Rather odd to enter a drawing-room carrying a large luminous cod," continued the stranger, in his listless way.
Holmes sat silently, with his head thrown back and his eyes closed, in an attitude which might seem listless to a stranger, but which I knew betokened the most intense self-absorption.
At last, however, her listless walk brought her up alongside him, and still he said nothing.
I should lie out in the garden in a hammock and read sentimental novels with a melancholy ending, until the books should fall from my listless hand, and I should recline there, dreamily gazing into the deep blue of the firmament, watching the fleecy clouds floating like white-sailed ships across its depths, and listening to the joyous song of the birds and the low rustling of the trees.
She was no longer the listless creature who had lived at his side in a state of sullen self-absorption, but a mysterious alien presence, an evil energy secreted from the long years of silent brooding.
Arthur's cheery acceptance of the news that she received invitations from others had been like a blow, leaving her numb and listless.
As he approached he was struck by her listless attitude: she sat there as if she had nothing else to do.
He noticed that, whereas the Protestant church was nearly empty and the congregation had a listless air, the Jesuit on the other hand was crowded and the worshippers seemed to pray with all their hearts.
I suppose I was breathing hard, or perhaps I was crying, for after a time I heard a listless voice that had never been listless before say, 'Is that you?
I knew my strength was declining, my appetite had failed, and I was grown listless and desponding;--and if, indeed, he could never care for me, and I could never see him more--if I was forbidden to minister to his happiness--forbidden, for ever, to taste the joys of love, to bless, and to be blessed--then, life must be a burden, and if my heavenly Father would call me away, I should be glad to rest.