Re: Support for decimal type

Erik wrote:

> I would vote for `format-number()` so we don't have to reinvent the wheel.

I agree.

From: <ebruchez@gmail.com> on behalf of Erik Bruchez <ebruchez@orbeon.com>
Date: Tuesday, 23 January 2018 at 17:15
To: Steven Pemberton <steven.pemberton@cwi.nl>
Cc: XForms <public-xformsusers@w3.org>
Subject: Re: Support for decimal type
Resent-From: <public-xformsusers@w3.org>
Resent-Date: Tuesday, 23 January 2018 at 17:14

I was making a banking app, and realised that there is insufficient support for using the decimal type.

On summing a series of amounts I was getting values like 136.6000000345,

If you deal with xs:decimal throughout, you shouldn't get that kind of results in the first place unless you do divisions, assuming the source data is good.

so I was having to do things like

        round(amount*100) div 100

Ideally I would have liked the XPath3 function round(d, precision)
https://www.w3.org/TR/xpath-functions/#func-round


Funnily enough we have an issue and StackOverflow question about this rounding:

    https://stackoverflow.com/questions/44304839/orbeon-xforms-round-when-formatting-true

    https://github.com/orbeon/orbeon-forms/issues/3226


It's definitely an omission from XPath 2.

but that still doesn't solve my problem of formatting 25 as 25.00 or 25.6 as 25.60

XPath3 format-number is a bit heavyweight for my needs
https://www.w3.org/TR/xpath-functions/#func-format-number


It comes from XSLT 2, and it's a decent formatting function. We use this for formatting in our number component.

How about a function decimal(d, 2) yielding a string with 2 places of accuracy?

The thing is, you quickly have to decide whether you want thousands separators, how you want to represent negative numbers, etc. I would vote for `format-number()` so we don't have to reinvent the wheel.

-Erik