I don't know of any way to find the caller without turning on debug.
If you need a third operand to a verb, you can make the verb an adverb:
vb =: adverb define
and then you could call it with
x ('caller' vb) y
(where the parens are optional).
In the old days, turning on debug made my big apps crash. I think it's
been fixed now, but I'm still like Mark Twain's cat.
Henry Rich
PS Oops. I see you don't want to change the caller. I have no help then.
hhr
On 1/25/2011 10:06 PM, Ian Clark wrote:
>> The question is why you are doing this.
>
> I'd rather not go into that. You have to study the middleware I'm
> porting from APL to relate to why I need a function which knows the
> name of its caller. And without the caller having to go to the trouble
> of telling it. The tool makes heavy use of two utility functions:
> "myname" and "mycaller", whose function should be obvious, even if
> their application isn't. And please don't ask why a function might
> conceivably need to discover its own name: the requirement has been
> known to arise.
>
> In APL the solution is easy: the stack is always available for a
> function to inspect while it's running. In J you have to switch the
> suspension stack on. Is this because the facility is quirky and
> inefficient, or simply because a lot of people don't need it or want
> it -- as I don't, as a rule?
>
> "mycaller", implemented the APL way, is working fine (touch-wood). But
> if there's a slick J technique without enabling the suspension stack
> then it would simplify the code considerably and I can lose a few
> heavily-looping saddle-functions.
>
>
>
> 2011/1/25 Björn Helgason<[email protected]>:
>> The question is why you are doing this.
>>
>> If it is because of development or something you want for when the system is
>> running.
>>
>> You can of course make sure the caller sends its name in as part of
>> arguments passed.
>>
>> During development I usually pepper smoutput all over the code.
>>
>> For a running application I usually write out stuff in logfiles and/or use
>> wdstatus to see if everything is running ok.
>>
>>
>> 2011/1/25 Ian Clark<[email protected]>
>>
>>> If I define two or more verbs tacitly like this:
>>>
>>> act1 =: action
>>> act2 =: action
>>> ...
>>>
>>> how, inside the verb: action, can I identify the calling verb --
>>> ideally as the literal name, eg 'act1'?
>>>
>>> I can solve the problem ...
>>>
>>> (a) by having the caller pass its own name as an argument in a rather
>>> more complex tacit expression, eg
>>>
>>> act1 =: action bind 'act1'
>>> act2 =: action bind 'act2'
>>> ...
>>>
>>> (b) by enabling suspension with: (13!:0)1 (in the caller of act1,
>>> act2) and then inspecting the stack within action by means of 0{"1
>>> (13!:13 '')
>>> ...which is what I'm using at present.
>>>
>>> (a) is not out of the question, but complicates the code, especially
>>> generated code.
>>> And I don't like (b) -- besides being clumsy I anticipate gotchas in
>>> the long term.
>>>
>>> Am I right to feel edgy about (b), for general application?
>>>
>>> Is there a neater way?
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>>
>>
>>
>> --
>> Björn Helgason, Verkfræðingur
>> Fornustekkum II
>> 781 Hornafirði,
>> t-póst: [email protected]
>> gsm: +3546985532
>> sími: +3544781286
>> http://groups.google.com/group/J-Programming
>>
>>
>> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans
>>
>> góður kennari getur stigið á tær án þess að glansinn fari af skónum
>> /|_ .-----------------------------------.
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>> ,--' _,' | Dagurinn í dag |
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>> ( -. | `-----------------------------------'
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>> (`-. '--.) (='.'=) ♖♘♗♕♔♙
>> `. )----' (")_(") ☃☠
>> ----------------------------------------------------------------------
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