Alan K. Stebbens wrote:
>A programming comparison on the web had this question:
>> The problem: Write a function foo that takes a number n and returns
>> a function that takes a number i, and returns n incremented by i.
Problem?!? A something that takes a number n and returns a function is
an adverb (or rather: "adnoun") in J. This one is very easy:
Welcome to J! (ctrl+d to quit) 4.05+GDS changes/Feb 16 2008/19:19:49
inc_by =. &+ NB. adnoun; 1 : 'm&+' if you
NB. are versionally challenged.
plusnine =. 9 inc_by Nb. applied to noun creates a verb
plusnine 6 NB. does it work?
15 NB. sure.
> The concept of embedding context within a function definition is
> called a "closure". Is there a "standard" way to accomplish
> closures in J?
I don't see any need to force Lisp/Scheme jargon onto J but if
you insist, I'd say that adnouns fit the bill.
plusnine
9&+
Martin
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