I've been caught by the hook in the *present* (and I thought I understood them!). My go-to example for hooks is a dyadic function followed by a monadic one: So for example, the monadic hook (+!) would be interpretted as argument + !argument which gives a nice intuitive meaning to (+!) , viz. the argument plus its factorial.
However, in the case cited by the OP, the first part of the hook pair is a monadic function, since the LHS has already bound to 3. So I would have expected an error message, because I thought the first verb in a hook /must/be dyadic. Is this not the case? Can you still prefix a left-hand argument, say N, and expect the hook to be executed N times? Wow! Back to the desk... detention for not doing homework. On 3 May 2014 00:23, Don Kelly <[email protected]> wrote: > try func3=. [:(3&+) 2&- > or > func4=.3+2&- > > I've been caught by the hook in the past. > > Don Kelly+ > > > On 30/04/2014 8:42 AM, Jon Hough wrote: > >> I can't understand why >> func1 =. 3&+ @: (2&-) >> func2 =. (3&+) (2&-) >> >> give different results as mondaic verbs. >> func1 5 gives 0, which is what I would expect. >> func2 5 gives 12, which I can't understand. >> I would like to know what the difference is between func1 and func2. It >> is my understanding that for monadic verbs @: is optional, so doesn't add >> anything to the meaning of the whole verb. >> Regards. >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
