Re: Length of actual parameters in a function call.
- To: mathgroup at smc.vnet.net
- Subject: [mg47498] Re: Length of actual parameters in a function call.
- From: Torben Winther Graversen <immtwg at bohr.gbar.dtu.dk>
- Date: Wed, 14 Apr 2004 07:16:56 -0400 (EDT)
- Organization: UNI-C
- References: <email@example.com>
- Sender: owner-wri-mathgroup at wolfram.com
E. Martin-Serrano <eMartinSerrano at houston.rr.com> wrote: : Hi, : A few weeks ago, reviewing some tutorials on pattern matching and error : handling, I came across an undocumented function to monitor the number of : parameters submitted to a function in a call; but somehow I lost its track : later. I guess that it must be something well-known by our specialists. Any : help about where to locate it? : The undocumented feature helps in tracking situations as when we define : "MyFunction[a_,b_,c_]:= something" and then it is called as "myFunction[a]" : leaving the function unevaluated. Hi, Perhaps the one you are looking for is ArgumentCountQ ? I stumbled on it a few days ago on Ted Ersek's Tricks page: http://www.verbeia.com/mathematica/tips/HTMLLinks/Tricks_210.html The documentation on Wolfram's site is at: http://support.wolfram.com/mathematica/kernel/Symbols/System/ArgumentCountQ.html ArgumentCountQ[head,len,min,max] tests whether the number len of arguments of a function head is between min and max. Regards, Torben