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Re: [xsl] One-based indexes in XPath


Subject: Re: [xsl] One-based indexes in XPath
From: "Colin Adams" <colinpauladams@xxxxxxxxxxxxxx>
Date: Tue, 20 May 2008 17:48:46 +0100

Zero is NOT the norm for modern programming languages. It might well
be for ancient ones. It is a very poor choice, justifiable only when
trying to squeeze the last ounce of speed in a highly
numerically-intensive application.

And even there it is not justified - you simply use data structures
that have an unused first element, and so avoid the subtract one
operation in that way.

2008/5/20 Justin Johansson <procode@xxxxxxxxxxx>:
> Trusting this question is relevant to the XSL List.
>
> Would someone please give me advice as to why "1-based" indexes are used in
> XPath, such as para[1] instead of para[0] for the first para item/element?
>
> Why does the spec for XPath (and its/XQuery operator/function library) go
> against the norm for modern programming languages in which zero is the base
> for array-like collections?
>
> The reason for my question is to do with reconciling XPath and XSLT with an
> implementation in Javascript in which zero is the base index for arrays.
> My users may well be perplexed by having to decide whether an index number
> is in XPath/XSLT-world or Javascript-world.
>
> Thanks for comments,
>
> Justin Johansson


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