ltake ( n list -- result )
Lazy lists » Manipulating lazy lists

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lmerge ( list1 list2 -- result )

Vocabulary
lists.lazy

Inputs

n	a non negative integer
list	a cons object

Outputs

result

resulting cons object

Word description
Outputs a lazy list containing the first n items in the list. This is done a lazy manner. No evaluation of the list elements occurs initially but a lazy-take object is returned which conforms to the list protocol. Calling car, cdr or nil? on this will evaluate elements as required.

See also
leach, foldl, lmap-lazy, lfilter, lappend-lazy, lfrom, lfrom-by, lconcat, lcartesian-product, lcartesian-product*, lcartesian-map, lcartesian-map*, lmerge, lwhile, luntil

Definition

USING: kernel lists math ;

IN: lists.lazy

: ltake ( n list -- result )
    over zero? [ 2drop nil ] [ <lazy-take> ] if ;