> Can you/anyone please explain the name=: 'body' (1 :) syntax? Sure, : is a conjunction, so the bident (1 :) is an adverb and 'body' (1 :) resolves as 1 : 'body' just as,
1 2 3 (+&) +&1 2 3 does. The other way around works similarly, 1 2 3 (&+) 1 2 3&+ ________________________________ From: Richard Donovan <[email protected]> To: J Programming <[email protected]> Sent: Fri, December 4, 2009 4:36:32 PM Subject: Re: [Jprogramming] newbie question As you were; I forgot the y in the verb so it DOES work! The other questions still apply. > From: [email protected] > To: [email protected] > Date: Fri, 4 Dec 2009 21:33:35 +0000 > Subject: Re: [Jprogramming] newbie question > > > Hi Jose Mario! > > Can you/anyone please explain the name=: 'body' (1 :) syntax? > I have never seen this before. Where is it documented? > > It doesn't seem to work with verbs: > > v=: '^' (3 :) > v > 3 : (,'^') > v 5 > |syntax error: v > | v 5 > > Thanks in advance > > > > Date: Thu, 3 Dec 2009 19:29:12 -0800 > > From: [email protected] > > To: [email protected] > > Subject: Re: [Jprogramming] newbie question > > > > >To pull out the even numbers. So filter takes a predicate and a > > >collection basically. I was thinking > > > > You can define filter as an adverb explicitly, > > > > filter=. '#~ x &>' (1 :) > > > > (2&|) filter i.11 > > 1 3 5 7 9 > > or tacitly, > > > > filter=. &> (#~`) (`:6) > > > > (0=2&|) filter i.11 > > 0 2 4 6 8 10 > > > > This version also deals with boxed lists: > > > > palindrome=. -: |. > > > > ]WORDS=. ;:'Yesterday dad did buy mom a madam reviver 4-rotor engine > >racecar with a radar detector' > > ┌─────────┬───┬───┬───┬───┬─┬─────┬───────┬─┬─┬─────┬──────┬───────┬────┬─┬─────┬────────┐ > > │Yesterday│dad│did│buy│mom│a│madam│reviver│4│-│rotor│engine│racecar│with│a│radar│detector│ > > └─────────┴───┴───┴───┴───┴─┴─────┴───────┴─┴─┴─────┴──────┴───────┴────┴─┴─────┴────────┘ > > > > palindrome filter WORDS > > ┌───┬───┬───┬─┬─────┬───────┬─┬─┬─────┬───────┬─┬─────┐ > > │dad│did│mom│a│madam│reviver│4│-│rotor│racecar│a│radar│ > > └───┴───┴───┴─┴─────┴───────┴─┴─┴─────┴───────┴─┴─────┘ > > > > palindrome filter (;:'blessed are they that belive that they are > >blessed');'palindrome';'rats live on no evil star' > > ┌────────────────────────────────────────────────────┬─────────────────────────┐ > > │┌───────┬───┬────┬────┬──────┬────┬────┬───┬───────┐│rats live on no evil > > star│ > > ││blessed│are│they│that│belive│that│they│are│blessed││ > > │ > > │└───────┴───┴────┴────┴──────┴────┴────┴───┴───────┘│ > > │ > > └────────────────────────────────────────────────────┴─────────────────────────┘ > > > > palindrome filter > > #~ palindrome&> > > > > > > > > > > > > ________________________________ > > From: Lau B. Jensen <[email protected]> > > To: Programming forum <[email protected]> > > Sent: Wed, December 2, 2009 6:28:08 AM > > Subject: Re: [Jprogramming] newbie question > > > > > > > > W.Ch Lin wrote: > > > Does J have filter function like clojure's ? > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > I definitely want to hear what the J crowd says, but just to be sure, in > > Clojure you could say > > > > (filter #(zero? (rem % 2)) (range 1 11)) > > > 2 4 6 8 10 > > > > To pull out the even numbers. So filter takes a predicate and a > > collection basically. I was thinking > > in J I'd to something like > > > > ,.((|~ & 2) 1 + i. 10) ;, 1 + i.10 > > +--------------------+ > > |1 0 1 0 1 0 1 0 1 0 | > > +--------------------+ > > |1 2 3 4 5 6 7 8 9 10| > > +--------------------+ > > > > Where as you can see all even values get a 0 return from (|~ & 2), but > > that leaves 2 questions > > > > 1) Is that how you would do it with J at all? > > 2) Disregarding 1, how would you pick those 0 values out from the > > original list 1 + i.10 ? > > > > Thanks > > Lau > > > > > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > _________________________________________________________________ > View your other email accounts from your Hotmail inbox. Add them now. > http://clk.atdmt.com/UKM/go/186394592/direct/01/ > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm _________________________________________________________________ Have more than one Hotmail account? Link them together to easily access both http://clk.atdmt.com/UKM/go/186394591/direct/01/ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
