[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: For-each adds whitespace per iteration: why?

Subject: Re: For-each adds whitespace per iteration: why?
From: Eliot Kimber <ekimber@xxxxxxxxxx>
Date: Fri, 10 Jan 2014 12:59:44 -0600
Re:  For-each adds whitespace per iteration: why?
Ah, that explains it. I have gotten in the habit of preferring
+ADw-xsl:sequence+AD4- over +ADw-xsl:value-of+AD4- but this is apparently one
place where
I should not have.

A subtle aspect of the spec.

I+IBk-m glad my understanding of +IBw-concatenation+IB0- in this context was
incorrect.

The key bit from 5.7.1 appears to step 3 of the sequence processing rules:

+ACI-3. Any consecutive sequence of strings within the result sequence is
converted to a single text node, whose string value
+ADw-http://www.w3.org/TR/xslt20/+ACM-dt-string-value+AD4- contains the
content of
each of the strings in turn, with a single space (+ACM-x20) used as a
separator between successive strings.+ACI-

That makes things clear.

Cheers,

Eliot


--
Eliot Kimber
Senior Solutions Architect
+ACI-Bringing Strategy, Content, and Technology Together+ACI-
Main: 512.554.9368
www.reallysi.com
www.rsuitecms.com




On 1/10/14, 11:27 AM, +ACI-Michael Kay+ACI- +ADw-mike+AEA-saxonica.com+AD4-
wrote:

+AD4-
+AD4-On 10 Jan 2014, at 17:05, Eliot Kimber +ADw-ekimber+AEA-rsicms.com+AD4-
wrote:
+AD4-
+AD4APg- In the context of writing an XSLT to generate DTD syntax from RNGs
(for
+AD4APg- DITA 1.3) I discovered that for-each results in whitespace being
emitted
+AD4APg- for each iteration. This came as a surprise. Reading the spec it
says,
+AD4APg- under clause 7, Repetition:
+AD4APg-
+AD4APg- +ACI-For each item in the input sequence, evaluating the sequence
+AD4APg-constructor
+AD4APg- +ADw-http://www.w3.org/TR/xslt20/+ACM-dt-sequence-constructor+AD4-
produces a
+AD4APg-sequence
+AD4APg- of items (see 5.7 Sequence Constructors
+AD4APg- +ADw-http://www.w3.org/TR/xslt20/+ACM-sequence-constructors+AD4-).
These output
+AD4APg- sequences are concatenated+ADs- ...
+AD4APg-
+AD4APg- I understand +ACI-These output sequences are concatenated+IB0- to
mean that
+AD4APg-string
+AD4APg- concatenation rules are applied, which explains the white space.
+AD4-
+AD4-No, this is a concatenation of two or more sequences to produce a single
+AD4-sequence. No whitespace is added at this point.
+AD4-
+AD4APg-
+AD4APg- My question: why is for-each defined in this way?
+AD4-
+AD4-It isn't.
+AD4APg-
+AD4APg-
+AD4APg- I tested this with this little XSLT transform:
+AD4APg-
+AD4APg- +ADw-?xml version+AD0AIg-1.0+ACI- encoding+AD0AIg-UTF-8+ACI-?+AD4-
+AD4APg- +ADw-xsl:stylesheet
xmlns:xsl+AD0AIg-http://www.w3.org/1999/XSL/Transform+ACI-
+AD4APg-  xmlns:xs+AD0AIg-http://www.w3.org/2001/XMLSchema+ACI-
+AD4APg-  xmlns:xd+AD0AIg-http://www.oxygenxml.com/ns/doc/xsl+ACI-
+AD4APg-  exclude-result-prefixes+AD0AIg-xs xd+ACI-
+AD4APg-  version+AD0AIg-2.0+ACIAPg-
+AD4APg-
+AD4APg-  +ADw-xsl:output method+AD0AIg-text+ACI-/+AD4-
+AD4APg-
+AD4APg-  +ADw-xsl:template name+AD0AIg-test-for-each+ACIAPg-
+AD4APg-    +ADw-xsl:variable name+AD0AIg-strings+ACI- select+AD0AIg-('one',
'two', 'three',
+AD4APg-'four')+ACI-/+AD4-
+AD4APg- value-of +ACQ-strings+AD0APA-xsl:value-of
select+AD0AIgAk-strings+ACI-/+AD4-
+AD4APg- for +ACQ-str in +ACQ-strings return concat('/', +ACQ-str,
'/')+AD0APA-xsl:sequence
+AD4APg- select+AD0AIg-for +ACQ-str in +ACQ-strings return concat('/',
+ACQ-str, '/')+ACI-/+AD4-
+AD4APg- string-join(+ACQ-strings, '')+AD0APA-xsl:sequence
select+AD0AIg-string-join(+ACQ-strings,
+AD4APg- '')+ACI-/+AD4-
+AD4APg- for-each over strings: +ACIAPA-xsl:for-each
select+AD0AIgAk-strings+ACIAPg-
+AD4APg-  +ADw-xsl:sequence select+AD0AIg-concat('/',.,'/')+ACI-/+AD4-
+AD4APg- +ADw-/xsl:for-each+AD4AIg-
+AD4APg-  +ADw-/xsl:template+AD4-
+AD4APg-
+AD4APg- +ADw-/xsl:stylesheet+AD4-
+AD4APg-
+AD4APg-
+AD4APg-
+AD4APg- Which produces this output using Saxon 9.5.1.2:
+AD4APg-
+AD4APg- value-of +ACQ-strings+AD0-one two three four
+AD4APg- for +ACQ-str in +ACQ-strings return concat('/', +ACQ-str,
'/')+AD0-/one/ /two/ /three/
+AD4APg- /four/
+AD4APg- string-join(+ACQ-strings, '')+AD0-onetwothreefour
+AD4APg- for-each over strings: +ACI-/one/ /two/ /three/ /four/+ACI-
+AD4APg-
+AD4-The whitespace is being added as part of the process of constructing
your
+AD4-final result tree from a sequence of strings. The result tree is
+AD4-constructed as a document node, following the rules of 5.7.1
Constructing
+AD4-Complex Content
+AD4-
+AD4-http://www.w3.org/TR/2009/PER-xslt20-20090421/+ACM-constructing-complex-
conten
+AD4-t
+AD4-
+AD4-or equivalently the rules applied by the Serializer
+AD4-
+AD4-http://www.w3.org/TR/xslt-xquery-serialization/+ACM-serdm
+AD4-
+AD4-The simplest way to avoid the space separation is to construct text
nodes
+AD4-rather than strings, which happens if you replace xsl+ADs-sequence by
+AD4-xsl:value-of in
+AD4-
+AD4APg- +ADw-xsl:sequence select+AD0AIg-concat('/',.,'/')+ACI-/+AD4-
+AD4-
+AD4-Michael Kay
+AD4-Saxonica
+AD4-
+AD4APg-
+AD4APg- I see that the for-each result is consistent with the flowr
expression.
+AD4APg-
+AD4APg- Is my analysis correct that the only way to construct a string with
no
+AD4APg- extra whitespace using a loop is to use string-join() as in my test
+AD4APg-case?
+AD4APg-
+AD4APg- For my DTD-generation application that would mean using the for-each
+AD4APg-loop
+AD4APg- to construct a sequence of strings and then using string-join on the
+AD4APg- sequence to avoid additional whitespace. Of course I can simply
account
+AD4APg- for the space inserted by the concatenation and get the correct
+AD4APg-indention
+AD4APg- and keep my code a bit simpler.
+AD4APg-
+AD4APg- Cheers,
+AD4APg-
+AD4APg- Eliot
+AD4APg-
+AD4APg- --
+AD4APg- Eliot Kimber
+AD4APg- Senior Solutions Architect
+AD4APg- +ACI-Bringing Strategy, Content, and Technology Together+ACI-
+AD4APg- Main: 512.554.9368
+AD4APg- www.reallysi.com
+AD4APg- www.rsuitecms.com
+AD4APg-
+AD4APg-
+AD4APg-
+AD4APg-
--+//0-------------------------------------------------------------------
+AD4APg- XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
+AD4APg- To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
+AD4APg- or e-mail:
+ADw-mailto:xsl-list-unsubscribe+AEA-lists.mulberrytech.com+AD4-
+AD4APg- --+//0---
+AD4APg-
+AD4-
+AD4-
+AD4---+AH4------------------------------------------------------------------
-
+AD4-XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
+AD4-To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
+AD4-or e-mail:
+ADw-mailto:xsl-list-unsubscribe+AEA-lists.mulberrytech.com+AD4-
+AD4---+AH4---
+AD4-

Current Thread

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
Email
First Name
Last Name
Company
Subscribe in XML format
RSS 2.0
Atom 0.3
Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.