Re: R-alpha: is.function(..) 'lies' sometimes ...

Ross & (ihaka@stat.auckland.ac.nz)
Mon, 1 Jul 1996 12:43:39 +1200


Date: Mon, 1 Jul 1996 12:43:39 +1200
Message-Id: <199607010043.MAA27604@stat.auckland.ac.nz>
From: Ross & <ihaka@stat.auckland.ac.nz>
To: R-testers@stat.math.ethz.ch
Subject: Re: R-alpha: is.function(..)  'lies' sometimes ...
In-Reply-To: <199606281659.SAA11799@bush.kubism.ku.dk>
 <199606281659.SAA11799@bush.kubism.ku.dk>

(1)  We have fixed is.function.  It was an oversight.

(2)  The problem

> z<-"plot"
> UseMethod(z,x)
Error in UseMethod(z, x) : first argument must be a method name
> UseMethod("plot",x)
> 

is easily fixed.  We just need to evaluate the first argument.

We can't easily get rid of the need for explicit arguments in
UseMethod however.  This would require having an explicit list of call
frames and some knowledge of where the arguments sit in the frame, and
we don't do things that way.  The present setup bends things about as
far as they will go without breaking.
	Ross
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