[bison.git] / data / xslt / xml2xhtml.xsl

<?xml version="1.0" encoding="UTF-8"?>

<!--
    xml2html.xsl - transform Bison XML Report into XHTML.
    $Id$

    Copyright (C) 2007 Free Software Foundation, Inc.

    This file is part of Bison, the GNU Compiler Compiler.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Written by Wojciech Polak <polak@gnu.org>.
  -->

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns="http://www.w3.org/1999/xhtml"
  xmlns:bison="http://www.gnu.org/software/bison/">

<xsl:import href="bison.xsl"/>

<xsl:output method="xml" encoding="UTF-8"
	    doctype-public="-//W3C//DTD XHTML 1.0 Strict//EN"
	    doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
	    indent="yes"/>

<xsl:template match="/">
  <html>
    <head>
      <title>GNU Bison XML Automaton Report</title>
      <style type="text/css"><![CDATA[
      body {
        font-family: "Nimbus Sans L", Arial, sans-serif;
	font-size: 9pt;
      }
      a:link {
 	color: #1f00ff;
	text-decoration: none;
      }
      a:visited {
 	color: #1f00ff;
	text-decoration: none;
      }
      a:hover {
 	color: red;
      }
      #menu a {
        text-decoration: underline;
      }
      .i {
        font-style: italic;
      }
      .pre {
        font-family: monospace;
        white-space: pre;
      }
      ol.decimal {
        list-style-type: decimal;
      }
      ol.lower-alpha {
        list-style-type: lower-alpha;
      }
      .point {
        color: #cc0000;
      }
      #footer {
        margin-top: 3.5em;
        font-size: 7pt;
      }
      ]]></style>
    </head>
    <body>
      <xsl:apply-templates select="bison-xml-report"/>
      <xsl:text>&#10;&#10;</xsl:text>
      <div id="footer"><hr />
      <a href="http://www.gnu.org/software/bison/" title="GNU Bison">
      GNU Bison <xsl:value-of select="/bison-xml-report/@version"/></a>
      XML Automaton Report, written by
      <a href="http://www.gnu.org.ua/~polak/" title="Wojciech Polak">Wojciech Polak</a>.
      Copyright (C) 2007 Free Software Foundation, Inc.<br />
      Verbatim copying and distribution of this entire page is permitted
      in any medium, provided this notice is preserved.</div>
    </body>
  </html>
</xsl:template>

<xsl:template match="bison-xml-report">
  <h1>GNU Bison XML Automaton Report</h1>
  <p>
    input grammar: <span class="i"><xsl:value-of select="filename"/></span>
  </p>

  <xsl:text>&#10;&#10;</xsl:text>
  <h3>Table of Contents</h3>
  <ul id="menu">
    <li>
      <a href="#reductions">Reductions</a>
      <ul class="lower-alpha">
	<li><a href="#nonterminals_useless_in_grammar">Nonterminals useless in grammar</a></li>
	<li><a href="#terminals_unused_in_grammar">Terminals unused in grammar</a></li>
	<li><a href="#rules_useless_in_grammar">Rules useless in grammar</a></li>
	<xsl:if test="grammar/rules/rule[@usefulness='useless-in-parser']">
	  <li><a href="#rules_useless_in_parser">Rules useless in parser due to conflicts</a></li>
	</xsl:if>
      </ul>
    </li>
    <li><a href="#conflicts">Conflicts</a></li>
    <li>
      <a href="#grammar">Grammar</a>
      <ul class="lower-alpha">
	<li><a href="#grammar">Itemset</a></li>
	<li><a href="#terminals">Terminal symbols</a></li>
	<li><a href="#nonterminals">Nonterminal symbols</a></li>
      </ul>
    </li>
    <li><a href="#automaton">Automaton</a></li>
  </ul>
  <xsl:apply-templates select="grammar" mode="reductions"/>
  <xsl:apply-templates select="grammar" mode="useless-in-parser"/>
  <xsl:apply-templates select="automaton" mode="conflicts"/>
  <xsl:apply-templates select="grammar"/>
  <xsl:apply-templates select="automaton"/>
</xsl:template>

<xsl:template match="grammar" mode="reductions">
  <h2>
    <a name="reductions"/>
    <xsl:text> Reductions</xsl:text>
  </h2>
  <xsl:apply-templates select="nonterminals" mode="useless-in-grammar"/>
  <xsl:apply-templates select="terminals" mode="unused-in-grammar"/>
  <xsl:apply-templates select="rules" mode="useless-in-grammar"/>
</xsl:template>

<xsl:template match="nonterminals" mode="useless-in-grammar">
  <h3>
    <a name="nonterminals_useless_in_grammar"/>
    <xsl:text> Nonterminals useless in grammar</xsl:text>
  </h3>
  <xsl:text>&#10;&#10;</xsl:text>
  <xsl:if test="nonterminal[@usefulness='useless-in-grammar']">
    <p class="pre">
      <xsl:for-each select="nonterminal[@usefulness='useless-in-grammar']">
	<xsl:text>   </xsl:text>
	<xsl:value-of select="@name"/>
	<xsl:text>&#10;</xsl:text>
      </xsl:for-each>
      <xsl:text>&#10;&#10;</xsl:text>
    </p>
  </xsl:if>
</xsl:template>

<xsl:template match="terminals" mode="unused-in-grammar">
  <h3>
    <a name="terminals_unused_in_grammar"/>
    <xsl:text> Terminals unused in grammar</xsl:text>
  </h3>
  <xsl:text>&#10;&#10;</xsl:text>
  <xsl:if test="terminal[@usefulness='unused-in-grammar']">
    <p class="pre">
      <xsl:for-each select="terminal[@usefulness='unused-in-grammar']">
        <xsl:sort select="@symbol-number" data-type="number"/>
	<xsl:text>   </xsl:text>
	<xsl:value-of select="@name"/>
	<xsl:text>&#10;</xsl:text>
      </xsl:for-each>
      <xsl:text>&#10;&#10;</xsl:text>
    </p>
  </xsl:if>
</xsl:template>

<xsl:template match="rules" mode="useless-in-grammar">
  <h3>
    <a name="rules_useless_in_grammar"/>
    <xsl:text> Rules useless in grammar</xsl:text>
  </h3>
  <xsl:text>&#10;</xsl:text>
  <xsl:variable name="set" select="rule[@usefulness='useless-in-grammar']"/>
  <xsl:if test="$set">
    <p class="pre">
      <xsl:call-template name="style-rule-set">
        <xsl:with-param name="rule-set" select="$set"/>
      </xsl:call-template>
      <xsl:text>&#10;&#10;</xsl:text>
    </p>
  </xsl:if>
</xsl:template>

<xsl:template match="grammar" mode="useless-in-parser">
  <xsl:variable
    name="set" select="rules/rule[@usefulness='useless-in-parser']"
  />
  <xsl:if test="$set">
    <h2>
      <a name="rules_useless_in_parser"/>
      <xsl:text> Rules useless in parser due to conflicts</xsl:text>
    </h2>
    <xsl:text>&#10;</xsl:text>
    <p class="pre">
      <xsl:call-template name="style-rule-set">
        <xsl:with-param name="rule-set" select="$set"/>
      </xsl:call-template>
    </p>
    <xsl:text>&#10;&#10;</xsl:text>
  </xsl:if>
</xsl:template>

<xsl:template match="grammar">
  <h2>
    <a name="grammar"/>
    <xsl:text> Grammar</xsl:text>
  </h2>
  <xsl:text>&#10;</xsl:text>
  <p class="pre">
    <xsl:call-template name="style-rule-set">
      <xsl:with-param
        name="rule-set" select="rules/rule[@usefulness!='useless-in-grammar']"
      />
    </xsl:call-template>
  </p>
  <xsl:text>&#10;&#10;</xsl:text>
  <xsl:apply-templates select="terminals"/>
  <xsl:apply-templates select="nonterminals"/>
</xsl:template>

<xsl:template name="style-rule-set">
  <xsl:param name="rule-set"/>
  <xsl:for-each select="$rule-set">
    <xsl:apply-templates select=".">
      <xsl:with-param name="pad" select="'3'"/>
      <xsl:with-param name="prev-lhs">
        <xsl:if test="position()>1">
          <xsl:variable name="position" select="position()"/>
          <xsl:value-of select="$rule-set[$position - 1]/lhs"/>
        </xsl:if>
      </xsl:with-param>
    </xsl:apply-templates>
  </xsl:for-each>
</xsl:template>

<xsl:template match="automaton" mode="conflicts">
  <h2>
    <a name="conflicts"/>
    <xsl:text> Conflicts</xsl:text>
  </h2>
  <xsl:text>&#10;&#10;</xsl:text>
  <xsl:variable name="conflict-report">
    <xsl:apply-templates select="state" mode="conflicts"/>
  </xsl:variable>
  <xsl:if test="string-length($conflict-report) != 0">
    <p class="pre">
      <xsl:copy-of select="$conflict-report"/>
      <xsl:text>&#10;&#10;</xsl:text>
    </p>
  </xsl:if>
</xsl:template>

<xsl:template match="state" mode="conflicts">
  <xsl:variable name="conflict-counts">
    <xsl:apply-templates select="." mode="bison:count-conflicts" />
  </xsl:variable>
  <xsl:variable
    name="sr-count" select="substring-before($conflict-counts, ',')"
  />
  <xsl:variable
    name="rr-count" select="substring-after($conflict-counts, ',')"
  />
  <xsl:if test="$sr-count > 0 or $rr-count > 0">
    <a>
      <xsl:attribute name="href">
        <xsl:value-of select="concat('#state_', @number)"/>
      </xsl:attribute>
      <xsl:value-of select="concat('State ', @number)"/>
    </a>
    <xsl:text> conflicts:</xsl:text>
    <xsl:if test="$sr-count > 0">
      <xsl:value-of select="concat(' ', $sr-count, ' shift/reduce')"/>
      <xsl:if test="$rr-count > 0">
        <xsl:value-of select="(',')"/>
      </xsl:if>
    </xsl:if>
    <xsl:if test="$rr-count > 0">
      <xsl:value-of select="concat(' ', $rr-count, ' reduce/reduce')"/>
    </xsl:if>
    <xsl:value-of select="'&#10;'"/>
  </xsl:if>
</xsl:template>

<xsl:template match="grammar/terminals">
  <h3>
    <a name="terminals"/>
    <xsl:text> Terminals, with rules where they appear</xsl:text>
  </h3>
  <xsl:text>&#10;&#10;</xsl:text>
  <p class="pre">
    <xsl:apply-templates select="terminal"/>
  </p>
  <xsl:text>&#10;&#10;</xsl:text>
</xsl:template>

<xsl:template match="grammar/nonterminals">
  <h3>
    <a name="nonterminals"/>
    <xsl:text> Nonterminals, with rules where they appear</xsl:text>
  </h3>
  <xsl:text>&#10;&#10;</xsl:text>
  <p class="pre">
    <xsl:apply-templates
      select="nonterminal[@usefulness!='useless-in-grammar']"
    />
  </p>
</xsl:template>

<xsl:template match="terminal">
  <b><xsl:value-of select="@name"/></b>
  <xsl:value-of select="concat(' (', @token-number, ')')"/>
  <xsl:for-each select="key('bison:ruleByRhs', @name)">
    <xsl:apply-templates select="." mode="number-link"/>
  </xsl:for-each>
  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="nonterminal">
  <b><xsl:value-of select="@name"/></b>
  <xsl:value-of select="concat(' (', @symbol-number, ')')"/>
  <xsl:text>&#10;    </xsl:text>
  <xsl:if test="key('bison:ruleByLhs', @name)">
    <xsl:text>on left:</xsl:text>
    <xsl:for-each select="key('bison:ruleByLhs', @name)">
      <xsl:apply-templates select="." mode="number-link"/>
    </xsl:for-each>
  </xsl:if>
  <xsl:if test="key('bison:ruleByRhs', @name)">
    <xsl:if test="key('bison:ruleByLhs', @name)">
      <xsl:text>&#10;    </xsl:text>
    </xsl:if>
    <xsl:text>on right:</xsl:text>
    <xsl:for-each select="key('bison:ruleByRhs', @name)">
      <xsl:apply-templates select="." mode="number-link"/>
    </xsl:for-each>
  </xsl:if>
  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="rule" mode="number-link">
  <xsl:text> </xsl:text>
  <a>
    <xsl:attribute name="href">
      <xsl:value-of select="concat('#rule_', @number)"/>
    </xsl:attribute>
    <xsl:value-of select="@number"/>
  </a>
</xsl:template>

<xsl:template match="automaton">
  <h2>
    <a name="automaton"/>
    <xsl:text> Automaton</xsl:text>
  </h2>
  <xsl:apply-templates select="state">
    <xsl:with-param name="pad" select="'3'"/>
  </xsl:apply-templates>
</xsl:template>

<xsl:template match="automaton/state">
  <xsl:param name="pad"/>
  <xsl:text>&#10;&#10;</xsl:text>
  <h3>
    <a>
      <xsl:attribute name="name">
	<xsl:value-of select="concat('state_', @number)"/>
      </xsl:attribute>
    </a>
    <xsl:text>state </xsl:text>
    <xsl:value-of select="@number"/>
  </h3>
  <xsl:text>&#10;&#10;</xsl:text>
  <p class="pre">
    <xsl:apply-templates select="itemset/item">
      <xsl:with-param name="pad" select="$pad"/>
    </xsl:apply-templates>
    <xsl:apply-templates select="actions/transitions">
      <xsl:with-param name="type" select="'shift'"/>
    </xsl:apply-templates>
    <xsl:apply-templates select="actions/errors"/>
    <xsl:apply-templates select="actions/reductions"/>
    <xsl:apply-templates select="actions/transitions">
      <xsl:with-param name="type" select="'goto'"/>
    </xsl:apply-templates>
    <xsl:apply-templates select="solved-conflicts"/>
  </p>
</xsl:template>

<xsl:template match="actions/transitions">
  <xsl:param name="type"/>
  <xsl:if test="transition[@type = $type]">
    <xsl:text>&#10;</xsl:text>
    <xsl:apply-templates select="transition[@type = $type]">
      <xsl:with-param name="pad">
	<xsl:call-template name="max-width-symbol">
	  <xsl:with-param name="node" select="transition[@type = $type]"/>
	</xsl:call-template>
      </xsl:with-param>
    </xsl:apply-templates>
  </xsl:if>
</xsl:template>

<xsl:template match="actions/errors">
  <xsl:if test="error">
    <xsl:text>&#10;</xsl:text>
    <xsl:apply-templates select="error">
      <xsl:with-param name="pad">
	<xsl:call-template name="max-width-symbol">
	  <xsl:with-param name="node" select="error"/>
	</xsl:call-template>
      </xsl:with-param>
    </xsl:apply-templates>
  </xsl:if>
</xsl:template>

<xsl:template match="actions/reductions">
  <xsl:if test="reduction">
    <xsl:text>&#10;</xsl:text>
    <xsl:apply-templates select="reduction">
      <xsl:with-param name="pad">
	<xsl:call-template name="max-width-symbol">
	  <xsl:with-param name="node" select="reduction"/>
	</xsl:call-template>
      </xsl:with-param>
    </xsl:apply-templates>
  </xsl:if>
</xsl:template>

<xsl:template match="item">
  <xsl:param name="pad"/>
  <xsl:param name="prev-rule-number"
	     select="preceding-sibling::item[1]/@rule-number"/>
  <xsl:apply-templates
    select="key('bison:ruleByNumber', current()/@rule-number)"
  >
    <xsl:with-param name="itemset" select="'true'"/>
    <xsl:with-param name="pad" select="$pad"/>
    <xsl:with-param name="prev-lhs"
      select="key('bison:ruleByNumber', $prev-rule-number)/lhs[text()]"
   />
    <xsl:with-param name="point" select="@point"/>
    <xsl:with-param name="lookaheads">
      <xsl:apply-templates select="lookaheads"/>
    </xsl:with-param>
  </xsl:apply-templates>
</xsl:template>

<xsl:template match="rule">
  <xsl:param name="itemset"/>
  <xsl:param name="pad"/>
  <xsl:param name="prev-lhs"/>
  <xsl:param name="point"/>
  <xsl:param name="lookaheads"/>

  <xsl:if test="$itemset != 'true' and not($prev-lhs = lhs[text()])">
    <xsl:text>&#10;</xsl:text>
  </xsl:if>

  <xsl:if test="$itemset != 'true'">
    <a>
      <xsl:attribute name="name">
	<xsl:value-of select="concat('rule_', @number)"/>
      </xsl:attribute>
    </a>
  </xsl:if>
  <xsl:text>  </xsl:text>

  <xsl:choose>
    <xsl:when test="$itemset = 'true'">
      <a>
	<xsl:attribute name="href">
	  <xsl:value-of select="concat('#rule_', @number)"/>
	</xsl:attribute>
	<xsl:call-template name="lpad">
	  <xsl:with-param name="str" select="string(@number)"/>
	  <xsl:with-param name="pad" select="number($pad)"/>
	</xsl:call-template>
      </a>
    </xsl:when>
    <xsl:otherwise>
      <xsl:call-template name="lpad">
	<xsl:with-param name="str" select="string(@number)"/>
	<xsl:with-param name="pad" select="number($pad)"/>
      </xsl:call-template>
    </xsl:otherwise>
  </xsl:choose>
  <xsl:text> </xsl:text>

  <!-- LHS -->
  <xsl:choose>
    <xsl:when test="$itemset != 'true' and $prev-lhs = lhs[text()]">
      <xsl:call-template name="lpad">
	<xsl:with-param name="str" select="'|'"/>
	<xsl:with-param name="pad" select="number(string-length(lhs[text()])) + 2"/>
      </xsl:call-template>
    </xsl:when>
    <xsl:when test="$itemset = 'true' and $prev-lhs = lhs[text()]">
      <xsl:call-template name="lpad">
	<xsl:with-param name="str" select="'|'"/>
	<xsl:with-param name="pad" select="number(string-length(lhs[text()])) + 2"/>
      </xsl:call-template>
    </xsl:when>
    <xsl:otherwise>
      <span class="i">
	<xsl:value-of select="lhs"/>
      </span>
      <xsl:text> &#8594;</xsl:text>
    </xsl:otherwise>
  </xsl:choose>

  <!-- RHS -->
  <xsl:for-each select="rhs/*">
    <xsl:if test="position() = $point + 1">
      <xsl:text> </xsl:text>
      <span class="point">.</span>
    </xsl:if>
    <xsl:if test="$itemset = 'true' and name(.) != 'empty'">
      <xsl:apply-templates select="."/>
    </xsl:if>
    <xsl:if test="$itemset != 'true'">
      <xsl:apply-templates select="."/>
    </xsl:if>
    <xsl:if test="position() = last() and position() = $point">
      <xsl:text> </xsl:text>
      <span class="point">.</span>
    </xsl:if>
  </xsl:for-each>
  <xsl:if test="$lookaheads">
    <xsl:value-of select="$lookaheads"/>
  </xsl:if>

  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="symbol">
  <xsl:text> </xsl:text>
  <xsl:choose>
    <xsl:when test="name(key('bison:symbolByName', .)) = 'nonterminal'">
      <span class="i"><xsl:value-of select="."/></span>
    </xsl:when>
    <xsl:otherwise>
      <b><xsl:value-of select="."/></b>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template match="empty">
  <xsl:text> &#949;</xsl:text>
</xsl:template>

<xsl:template match="lookaheads">
  <xsl:text>  [</xsl:text>
  <xsl:apply-templates select="symbol"/>
  <xsl:text>]</xsl:text>
</xsl:template>

<xsl:template match="lookaheads/symbol">
  <xsl:value-of select="."/>
  <xsl:if test="position() != last()">
    <xsl:text>, </xsl:text>
  </xsl:if>
</xsl:template>

<xsl:template match="transition">
  <xsl:param name="pad"/>
  <xsl:text>    </xsl:text>
  <xsl:call-template name="rpad">
    <xsl:with-param name="str" select="string(@symbol)"/>
    <xsl:with-param name="pad" select="number($pad) + 2"/>
  </xsl:call-template>
  <xsl:choose>
    <xsl:when test="@type = 'shift'">
      <a>
	<xsl:attribute name="href">
	  <xsl:value-of select="concat('#state_', @state)"/>
	</xsl:attribute>
	<xsl:value-of select="concat('shift, and go to state ', @state)"/>
      </a>
    </xsl:when>
    <xsl:when test="@type = 'goto'">
      <a>
	<xsl:attribute name="href">
	  <xsl:value-of select="concat('#state_', @state)"/>
	</xsl:attribute>
	<xsl:value-of select="concat('go to state ', @state)"/>
      </a>
    </xsl:when>
  </xsl:choose>
  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="error">
  <xsl:param name="pad"/>
  <xsl:text>    </xsl:text>
  <xsl:call-template name="rpad">
    <xsl:with-param name="str" select="string(@symbol)"/>
    <xsl:with-param name="pad" select="number($pad) + 2"/>
  </xsl:call-template>
  <xsl:text>error</xsl:text>
  <xsl:text> (</xsl:text>
  <xsl:value-of select="text()"/>
  <xsl:text>)</xsl:text>
  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="reduction">
  <xsl:param name="pad"/>
  <xsl:text>    </xsl:text>
  <xsl:call-template name="rpad">
    <xsl:with-param name="str" select="string(@symbol)"/>
    <xsl:with-param name="pad" select="number($pad) + 2"/>
  </xsl:call-template>
  <xsl:if test="@enabled = 'false'">
    <xsl:text>[</xsl:text>
  </xsl:if>
  <xsl:choose>
    <xsl:when test="@rule = 'accept'">
      <xsl:text>accept</xsl:text>
    </xsl:when>
    <xsl:otherwise>
      <a>
	<xsl:attribute name="href">
	  <xsl:value-of select="concat('#rule_', @rule)"/>
	</xsl:attribute>
	<xsl:value-of select="concat('reduce using rule ', @rule)"/>
      </a>
      <xsl:text> (</xsl:text>
      <xsl:value-of
        select="key('bison:ruleByNumber', current()/@rule)/lhs[text()]"
      />
      <xsl:text>)</xsl:text>
    </xsl:otherwise>
  </xsl:choose>
  <xsl:if test="@enabled = 'false'">
    <xsl:text>]</xsl:text>
  </xsl:if>
  <xsl:text>&#10;</xsl:text>
</xsl:template>

<xsl:template match="solved-conflicts">
  <xsl:if test="resolution">
    <xsl:text>&#10;</xsl:text>
    <xsl:apply-templates select="resolution"/>
  </xsl:if>
</xsl:template>

<xsl:template match="resolution">
  <xsl:text>    Conflict between </xsl:text>
  <a>
    <xsl:attribute name="href">
      <xsl:value-of select="concat('#rule_', @rule)"/>
    </xsl:attribute>
    <xsl:value-of select="concat('rule ',@rule)"/>
  </a>
  <xsl:text> and token </xsl:text>
  <xsl:value-of select="@symbol"/>
  <xsl:text> resolved as </xsl:text>
  <xsl:if test="@type = 'error'">
    <xsl:text>an </xsl:text>
  </xsl:if>
  <xsl:value-of select="@type"/>
  <xsl:text> (</xsl:text>
  <xsl:value-of select="."/>
  <xsl:text>).&#10;</xsl:text>
</xsl:template>

<xsl:template name="max-width-symbol">
  <xsl:param name="node"/>
  <xsl:variable name="longest">
    <xsl:for-each select="$node">
      <xsl:sort data-type="number" select="string-length(@symbol)"
		order="descending"/>
      <xsl:if test="position() = 1">
	<xsl:value-of select="string-length(@symbol)"/>
      </xsl:if>
    </xsl:for-each>
  </xsl:variable>
  <xsl:value-of select="$longest"/>
</xsl:template>

<xsl:template name="lpad">
  <xsl:param name="str" select="''"/>
  <xsl:param name="pad" select="0"/>
  <xsl:variable name="diff" select="$pad - string-length($str)" />
  <xsl:choose>
    <xsl:when test="$diff &lt; 0">
      <xsl:value-of select="$str"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:call-template name="space">
	<xsl:with-param name="repeat" select="$diff"/>
      </xsl:call-template>
      <xsl:value-of select="$str"/>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template name="rpad">
  <xsl:param name="str" select="''"/>
  <xsl:param name="pad" select="0"/>
  <xsl:variable name="diff" select="$pad - string-length($str)"/>
  <xsl:choose>
    <xsl:when test="$diff &lt; 0">
      <xsl:value-of select="$str"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$str"/>
      <xsl:call-template name="space">
	<xsl:with-param name="repeat" select="$diff"/>
      </xsl:call-template>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template name="space">
  <xsl:param name="repeat">0</xsl:param>
  <xsl:param name="fill" select="' '"/>
  <xsl:if test="number($repeat) &gt;= 1">
    <xsl:call-template name="space">
      <xsl:with-param name="repeat" select="$repeat - 1"/>
      <xsl:with-param name="fill" select="$fill"/>
    </xsl:call-template>
    <xsl:value-of select="$fill"/>
  </xsl:if>
</xsl:template>

</xsl:stylesheet>