Hi Folks,

Thank you very much Martin, Michael, and Eliot. Simply superb.

Below I summarize the problem and the solution.

-----------------------------
Problem Statement:
-----------------------------

The below XSLT program loops over each value in a sequence and separates the
sequence values by a tab (hex 9) character. When the output file is opened in
a hex editor we see 3 characters separating the sequence values:

	space (hex 20), tab (hex 9), and space (hex 20)

Problem: How can we avoid getting space characters surrounding the tab?

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                           version="2.0">

    <xsl:output method="text" />

    <xsl:variable name="headers" select="('A', 'B')"/>
    <xsl:variable name="field-separator" select="codepoints-to-string(9)"/>

    <xsl:template match="/">
        <xsl:for-each select="$headers">
            <xsl:sequence select="." />
            <xsl:sequence select="$field-separator"/>
        </xsl:for-each>
    </xsl:template>

</xsl:stylesheet>

--------------
Solution:
--------------

The following value-of element will generate the desired output, without space
(hex 20) characters surrounding the tab (hex A) character:

      <xsl:value-of select="$headers" separator="{$field-separator}"/>

Here is an alternate (equivalent) solution which uses XPath to solve the
problem:

      <xsl:sequence select="string-join($headers, $field-separator)"/>

------------------
Problem #2:
------------------

Unlike the above case, in this case there is not a predetermined sequence of
values to be output. Rather, the sequence of values to be output are
determined at run-time. We need to loop over some values, compute an
appropriate value to output, and then follow the output value with a tab (hex
9). Like this:

<xsl:for-each select="foo">
	<xsl:variable name="value" select="f:compute-value(.)"/>
	<xsl:sequence select="$value" />
	<xsl:sequence select="$field-separator"/>
</xsl:for-each>

Problem: How can we output a tab (hex 9) without also getting the space (hex
20) characters surrounding the tab character?

--------------
Solution:
--------------

Replace the above loop with this value-of element:

      <xsl:value-of select="f:get-sequence($foo)"
separator="{$field-separator}"/>

Create a function which returns just the sequence of values (no field
separators):

<xsl:function name="f:get-sequence" as="xs:string*">
	<xsl:param name="foo" />

	<xsl:for-each select="foo">
		<xsl:variable name="value" select="f:compute-value(.)"/>
		<xsl:sequence select="$value" />
	</xsl:for-each>

</xsl:function>