How to loop through the alphabet with XSLT? - xslt

Question

I need to create a dynamic XSL-FO table in XSLT 2.0, that looks similar to this:
+------+------+------+------+------+------+
| | 1 | 2 | 3 | 4 | 5 |
+------+------+------+------+------+------+
| A | | | | | |
+------+------+------+------+------+------+
| B | | | | | |
+------+------+------+------+------+------+
| C | | | | | |
+------+------+------+------+------+------+
| D | | | | | |
+------+------+------+------+------+------+
| E | | | | | |
+------+------+------+------+------+------+
Both end-stops (rows, columns) are dynamic and specified with the last number/letter in the source data.
<input>
<end-stop-column>5</end-stop-column>
<end-stop-row>E</end-stop-row>
</input>
I thought of an for-each approach (pseudo code):
<fo:table>
<fo:table-body>
<fo:table-row>
<fo:table-cell><fo:block></fo:block></fo:table-cell>
<xsl:for-each select="1 to 5">
<xsl:variable name="colid" select="current()"/>
<fo:table-cell><fo:block><xsl:value-of select="$colid"/></fo:block></fo:table-cell>
</xsl:for-each>
</fo:table-row>
<xsl:for-each select="A to E">
<xsl:variable name="rowid" select="current()"/>
<fo:table-row>
<fo:table-cell><fo:block><xsl:value-of select="$rowid"/></fo:block></fo:table-cell> <xsl:for-each select="1 to 5">
<xsl:variable name="colid" select="current()"/>
<fo:table-cell>
<fo:block>
<xsl:text>Value for </xsl:text>
<xsl:value-of select="$rowid"/>
<xsl:text> </xsl:text>
<xsl:value-of select="$colid"/>
</fo:block>
</fo:table-cell>
</xsl:for-each>
</fo:table-row>
</xsl:for-each>
</fo:table-body>
</fo:table>
The above XSLT does not work, because for-each within the in context can only handle numbers.
How to handle the letters in the rows? The rows may not stop at Z and start again from ZA, ZB, ..., ZZ, ZZA, ....

Answer 1

Use a mapping from letters to numbers, if string-to-codepoints(end-stop-row) suffices (https://www.w3.org/TR/xpath-functions/#func-string-to-codepoints) (will depend on the alphabet you have in mind), use that. The formatting of numbers you process in a second step as letters can be handled by xsl:number or format-number.