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From: adrianb@elk.stat.washington.edu (Adrian Baddeley)
Newsgroups: comp.lang.c++
Subject: Re: Named arguments?
Message-ID: <2180@uw-entropy.ms.washington.edu>
Date: 15 Aug 89 20:47:41 GMT
References: <612@windy.dsir.govt.nz> <2179@uw-entropy.ms.washington.edu> 
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Reply-To: adrianb@castor.ms.washington.edu
Organization: UW Statistics, Seattle
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In article  Neal Gafter writes:

>I have not seen a good syntax proposed for named arguments, so let me
>make a specific proposal that is upwardly-compatible with C++, seems
>natural (at least to me), and introduces no ambiguities:
>
>extern int distance(int x, int y, int z, float scale = 1.0);
>	int result = distance(scale: scale1, x: x1, y: y1, z: z1);
>
>Opinions?

	Looks good. 
	The calling syntax resembles an interpreter that I once wrote 
	for image processing. (It didn't have your nice declaration syntax.) 
		y = subset(x, margin:10)
		z = transform(x, table: y )
		print(x, copies:2, title:"Image X", pipe:"lpr -Pps")
	This seemed to satisfy users (as does 'S'). 

	'S' has a mechanism for testing in the function body
	whether a named argument was present in the function call, 
	even if it was assigned the default value. 
	Is this a good idea???

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adrianb@castor.ms.washington.edu	(until 21 august 1989)
Adrian Baddeley, visiting Department of Statistics GN-22,
University of Washington, Seattle WA 98195, USA.
	tel (U of W): +1 206 545-2617 / 543-7237