src/main/java/com/google/devtools/build/docgen/BuildEncyclopediaProcessor.java - bazel - Git at Google

 // Copyright 2014 Google Inc. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package com.google.devtools.build.docgen;

 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Predicate;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Ordering;
 import com.google.common.collect.Sets;
 import com.google.devtools.build.docgen.DocgenConsts.RuleType;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
 import com.google.devtools.build.lib.packages.RuleClass;

 import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;

 /**
  * A class to assemble documentation for the Build Encyclopedia. This class uses
  * {@link BuildDocCollector} to extract documentation fragments from rule classes.
  */
 public class BuildEncyclopediaProcessor {
   private static final Predicate<String> RULE_WORTH_DOCUMENTING = new Predicate<String>() {
     @Override
     public boolean apply(String name) {
       return !name.contains("$");
     }
   };

   private ConfiguredRuleClassProvider ruleClassProvider;

   /**
    * Creates the BuildEncyclopediaProcessor instance. The ruleClassProvider parameter
    * is used for rule class hierarchy and attribute checking.
    *
    */
   public BuildEncyclopediaProcessor(ConfiguredRuleClassProvider ruleClassProvider) {
     this.ruleClassProvider = Preconditions.checkNotNull(ruleClassProvider);
   }

   /**
    * Collects and processes all the rule and attribute documentation in inputDirs and
    * generates the Build Encyclopedia into the outputRootDir.
    */
   public void generateDocumentation(String[] inputDirs, String outputRootDir)
       throws BuildEncyclopediaDocException, IOException {
     File buildEncyclopediaPath = setupDirectories(outputRootDir);

     Page page = TemplateEngine.newPage(
         "com/google/devtools/build/docgen/templates/build-encyclopedia.vm");

     BuildDocCollector collector = new BuildDocCollector(ruleClassProvider, false);
     Map<String, RuleDocumentation> ruleDocEntries = collector.collect(inputDirs);
     warnAboutUndocumentedRules(
         Sets.difference(ruleClassProvider.getRuleClassMap().keySet(), ruleDocEntries.keySet()));
     writeRuleClassDocs(ruleDocEntries.values(), page);
     page.write(buildEncyclopediaPath);
   }


   /**
    * Categorizes, checks and prints all the rule-class documentations.
    */
   private void writeRuleClassDocs(Iterable<RuleDocumentation> docEntries, Page page)
       throws BuildEncyclopediaDocException, IOException {
     Set<RuleDocumentation> binaryDocs = new TreeSet<>();
     Set<RuleDocumentation> libraryDocs = new TreeSet<>();
     Set<RuleDocumentation> testDocs = new TreeSet<>();
     Set<RuleDocumentation> otherDocs = new TreeSet<>();

     for (RuleDocumentation doc : docEntries) {
       RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(doc.getRuleName());
       if (!ruleClass.isDocumented()) {
         continue;
       }

       if (doc.isLanguageSpecific()) {
         switch(doc.getRuleType()) {
           case BINARY:
             binaryDocs.add(doc);
             break;
           case LIBRARY:
             libraryDocs.add(doc);
             break;
           case TEST:
             testDocs.add(doc);
             break;
           case OTHER:
             otherDocs.add(doc);
             break;
         }
       } else {
         otherDocs.add(doc);
       }
     }

     renderBeHeader(docEntries, page);

     page.add(DocgenConsts.VAR_SECTION_BINARY, getRuleDocs(binaryDocs));
     page.add(DocgenConsts.VAR_SECTION_LIBRARY, getRuleDocs(libraryDocs));
     page.add(DocgenConsts.VAR_SECTION_TEST, getRuleDocs(testDocs));
     page.add(DocgenConsts.VAR_SECTION_OTHER, getRuleDocs(otherDocs));
   }

   private void renderBeHeader(Iterable<RuleDocumentation> docEntries, Page page)
       throws BuildEncyclopediaDocException {
     // Separate rule families into language-specific and generic ones.
     Set<String> languageSpecificRuleFamilies = new TreeSet<>();
     Set<String> genericRuleFamilies = new TreeSet<>();
     separateRuleFamilies(docEntries, languageSpecificRuleFamilies, genericRuleFamilies);

     // Create a mapping of rules based on rule type and family.
     Map<String, ListMultimap<RuleType, RuleDocumentation>> ruleMapping = new HashMap<>();
     createRuleMapping(docEntries, ruleMapping);

     String languageSpecificTable;
     {
       StringBuilder sb = new StringBuilder();

       sb.append("<colgroup span=\"6\" width=\"20%\"></colgroup>\n")
         .append("<tr><th>Language</th><th>Binary rules</th><th>Library rules</th>"
           + "<th>Test rules</th><th>Other rules</th><th></th></tr>\n");

       // Generate the table.
       for (String ruleFamily : languageSpecificRuleFamilies) {
         generateHeaderTableRuleFamily(sb, ruleMapping.get(ruleFamily), ruleFamily);
       }
       languageSpecificTable = sb.toString();
     }

     String otherRulesTable;
     {
       StringBuilder sb = new StringBuilder();

       sb.append("<colgroup span=\"6\" width=\"20%\"></colgroup>\n");
       for (String ruleFamily : genericRuleFamilies) {
         generateHeaderTableRuleFamily(sb, ruleMapping.get(ruleFamily), ruleFamily);
       }
       otherRulesTable = sb.toString();
     }
     page.add(DocgenConsts.VAR_LANG_SPECIFIC_HEADER_TABLE, languageSpecificTable);
     page.add(DocgenConsts.VAR_OTHER_RULES_HEADER_TABLE, otherRulesTable);
     page.add(DocgenConsts.VAR_COMMON_ATTRIBUTE_DEFINITION,
         generateCommonAttributeDocs(
             PredefinedAttributes.COMMON_ATTRIBUTES, DocgenConsts.COMMON_ATTRIBUTES));
     page.add(DocgenConsts.VAR_TEST_ATTRIBUTE_DEFINITION,
         generateCommonAttributeDocs(
             PredefinedAttributes.TEST_ATTRIBUTES, DocgenConsts.TEST_ATTRIBUTES));
     page.add(DocgenConsts.VAR_BINARY_ATTRIBUTE_DEFINITION,
         generateCommonAttributeDocs(
             PredefinedAttributes.BINARY_ATTRIBUTES, DocgenConsts.BINARY_ATTRIBUTES));
     page.add(DocgenConsts.VAR_LEFT_PANEL, generateLeftNavigationPanel(docEntries));
   }

   /**
    * Create a mapping of rules based on rule type and family.
    */
   private void createRuleMapping(Iterable<RuleDocumentation> docEntries,
       Map<String, ListMultimap<RuleType, RuleDocumentation>> ruleMapping)
       throws BuildEncyclopediaDocException {
     for (RuleDocumentation ruleDoc : docEntries) {
       RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(ruleDoc.getRuleName());
       if (ruleClass != null) {
         String ruleFamily = ruleDoc.getRuleFamily();
         if (!ruleMapping.containsKey(ruleFamily)) {
           ruleMapping.put(ruleFamily, LinkedListMultimap.<RuleType, RuleDocumentation>create());
         }
         if (ruleClass.isDocumented()) {
           ruleMapping.get(ruleFamily).put(ruleDoc.getRuleType(), ruleDoc);
         }
       } else {
         throw ruleDoc.createException("Can't find RuleClass for " + ruleDoc.getRuleName());
       }
     }
   }

   /**
    * Separates all rule families in docEntries into language-specific rules and generic rules.
    */
   private void separateRuleFamilies(Iterable<RuleDocumentation> docEntries,
       Set<String> languageSpecificRuleFamilies, Set<String> genericRuleFamilies)
       throws BuildEncyclopediaDocException {
     for (RuleDocumentation ruleDoc : docEntries) {
       if (ruleDoc.isLanguageSpecific()) {
         if (genericRuleFamilies.contains(ruleDoc.getRuleFamily())) {
           throw ruleDoc.createException("The rule is marked as being language-specific, but other "
               + "rules of the same family have already been marked as being not.");
         }
         languageSpecificRuleFamilies.add(ruleDoc.getRuleFamily());
       } else {
         if (languageSpecificRuleFamilies.contains(ruleDoc.getRuleFamily())) {
           throw ruleDoc.createException("The rule is marked as being generic, but other rules of "
               + "the same family have already been marked as being language-specific.");
         }
         genericRuleFamilies.add(ruleDoc.getRuleFamily());
       }
     }
   }

   private String generateLeftNavigationPanel(Iterable<RuleDocumentation> docEntries) {
     // Order the rules alphabetically. At this point they are ordered according to
     // RuleDocumentation.compareTo() which is not alphabetical.
     TreeMap<String, String> ruleNames = new TreeMap<>();
     for (RuleDocumentation ruleDoc : docEntries) {
       String ruleName = ruleDoc.getRuleName();
       ruleNames.put(ruleName.toLowerCase(), ruleName);
     }
     StringBuilder sb = new StringBuilder();
     for (String ruleName : ruleNames.values()) {
       RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(ruleName);
       Preconditions.checkNotNull(ruleClass);
       if (ruleClass.isDocumented()) {
         sb.append(String.format("<a href=\"#%s\">%s</a><br/>\n", ruleName, ruleName));
       }
     }
     return sb.toString();
   }

   private String generateCommonAttributeDocs(Map<String, RuleDocumentationAttribute> attributes,
       String attributeGroupName) throws BuildEncyclopediaDocException {
     RuleDocumentation ruleDoc = new RuleDocumentation(
         attributeGroupName, "OTHER", null, null, 0, null, ImmutableSet.<String>of(),
         ruleClassProvider);
     for (RuleDocumentationAttribute attribute : attributes.values()) {
       ruleDoc.addAttribute(attribute);
     }
     return ruleDoc.generateAttributeDefinitions();
   }

   private void generateHeaderTableRuleFamily(StringBuilder sb,
       ListMultimap<RuleType, RuleDocumentation> ruleTypeMap, String ruleFamily) {
     sb.append("<tr>\n")
       .append(String.format("<td class=\"lang\">%s</td>\n", ruleFamily));
     boolean otherRulesSplitted = false;
     for (RuleType ruleType : DocgenConsts.RuleType.values()) {
       sb.append("<td>");
       int i = 0;
       List<RuleDocumentation> ruleDocList = ruleTypeMap.get(ruleType);
       for (RuleDocumentation ruleDoc : ruleDocList) {
         if (i > 0) {
           if (ruleType.equals(RuleType.OTHER)
               && ruleDocList.size() >= 4 && i == (ruleDocList.size() + 1) / 2) {
             // Split 'other rules' into two columns if there are too many of them.
             sb.append("</td>\n<td>");
             otherRulesSplitted = true;
           } else {
             sb.append("<br/>");
           }
         }
         String ruleName = ruleDoc.getRuleName();
         String deprecatedString = ruleDoc.hasFlag(DocgenConsts.FLAG_DEPRECATED)
             ? " class=\"deprecated\"" : "";
         sb.append(String.format("<a href=\"#%s\"%s>%s</a>", ruleName, deprecatedString, ruleName));
         i++;
       }
       sb.append("</td>\n");
     }
     // There should be 6 columns.
     if (!otherRulesSplitted) {
       sb.append("<td></td>\n");
     }
     sb.append("</tr>\n");
   }

   private String getRuleDocs(Iterable<RuleDocumentation> docEntries) {
     StringBuilder sb = new StringBuilder();
     for (RuleDocumentation doc : docEntries) {
       sb.append(doc.getHtmlDocumentation());
     }
     return sb.toString();
   }

   private File setupDirectories(String outputRootDir) {
     if (outputRootDir != null) {
       File outputRootPath = new File(outputRootDir);
       outputRootPath.mkdirs();
       return new File(outputRootDir + File.separator + DocgenConsts.BUILD_ENCYCLOPEDIA_NAME);
     } else {
       return new File(DocgenConsts.BUILD_ENCYCLOPEDIA_NAME);
     }
   }

   private static void warnAboutUndocumentedRules(Iterable<String> rulesWithoutDocumentation) {
       Iterable<String> undocumentedRules = Iterables.filter(rulesWithoutDocumentation,
           RULE_WORTH_DOCUMENTING);
       System.err.printf("WARNING: The following rules are undocumented: [%s]\n",
           Joiner.on(", ").join(Ordering.<String>natural().immutableSortedCopy(undocumentedRules)));
   }
 }
	// Copyright 2014 Google Inc. All rights reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package com.google.devtools.build.docgen;

	import com.google.common.base.Joiner;
	import com.google.common.base.Preconditions;
	import com.google.common.base.Predicate;
	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.Iterables;
	import com.google.common.collect.LinkedListMultimap;
	import com.google.common.collect.ListMultimap;
	import com.google.common.collect.Ordering;
	import com.google.common.collect.Sets;
	import com.google.devtools.build.docgen.DocgenConsts.RuleType;
	import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
	import com.google.devtools.build.lib.packages.RuleClass;

	import java.io.File;
	import java.io.IOException;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.TreeMap;
	import java.util.TreeSet;

	/**
	* A class to assemble documentation for the Build Encyclopedia. This class uses
	* {@link BuildDocCollector} to extract documentation fragments from rule classes.
	*/
	public class BuildEncyclopediaProcessor {
	private static final Predicate<String> RULE_WORTH_DOCUMENTING = new Predicate<String>() {
	@Override
	public boolean apply(String name) {
	return !name.contains("$");
	}
	};

	private ConfiguredRuleClassProvider ruleClassProvider;

	/**
	* Creates the BuildEncyclopediaProcessor instance. The ruleClassProvider parameter
	* is used for rule class hierarchy and attribute checking.
	*
	*/
	public BuildEncyclopediaProcessor(ConfiguredRuleClassProvider ruleClassProvider) {
	this.ruleClassProvider = Preconditions.checkNotNull(ruleClassProvider);
	}

	/**
	* Collects and processes all the rule and attribute documentation in inputDirs and
	* generates the Build Encyclopedia into the outputRootDir.
	*/
	public void generateDocumentation(String[] inputDirs, String outputRootDir)
	throws BuildEncyclopediaDocException, IOException {
	File buildEncyclopediaPath = setupDirectories(outputRootDir);

	Page page = TemplateEngine.newPage(
	"com/google/devtools/build/docgen/templates/build-encyclopedia.vm");

	BuildDocCollector collector = new BuildDocCollector(ruleClassProvider, false);
	Map<String, RuleDocumentation> ruleDocEntries = collector.collect(inputDirs);
	warnAboutUndocumentedRules(
	Sets.difference(ruleClassProvider.getRuleClassMap().keySet(), ruleDocEntries.keySet()));
	writeRuleClassDocs(ruleDocEntries.values(), page);
	page.write(buildEncyclopediaPath);
	}


	/**
	* Categorizes, checks and prints all the rule-class documentations.
	*/
	private void writeRuleClassDocs(Iterable<RuleDocumentation> docEntries, Page page)
	throws BuildEncyclopediaDocException, IOException {
	Set<RuleDocumentation> binaryDocs = new TreeSet<>();
	Set<RuleDocumentation> libraryDocs = new TreeSet<>();
	Set<RuleDocumentation> testDocs = new TreeSet<>();
	Set<RuleDocumentation> otherDocs = new TreeSet<>();

	for (RuleDocumentation doc : docEntries) {
	RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(doc.getRuleName());
	if (!ruleClass.isDocumented()) {
	continue;
	}

	if (doc.isLanguageSpecific()) {
	switch(doc.getRuleType()) {
	case BINARY:
	binaryDocs.add(doc);
	break;
	case LIBRARY:
	libraryDocs.add(doc);
	break;
	case TEST:
	testDocs.add(doc);
	break;
	case OTHER:
	otherDocs.add(doc);
	break;
	}
	} else {
	otherDocs.add(doc);
	}
	}

	renderBeHeader(docEntries, page);

	page.add(DocgenConsts.VAR_SECTION_BINARY, getRuleDocs(binaryDocs));
	page.add(DocgenConsts.VAR_SECTION_LIBRARY, getRuleDocs(libraryDocs));
	page.add(DocgenConsts.VAR_SECTION_TEST, getRuleDocs(testDocs));
	page.add(DocgenConsts.VAR_SECTION_OTHER, getRuleDocs(otherDocs));
	}

	private void renderBeHeader(Iterable<RuleDocumentation> docEntries, Page page)
	throws BuildEncyclopediaDocException {
	// Separate rule families into language-specific and generic ones.
	Set<String> languageSpecificRuleFamilies = new TreeSet<>();
	Set<String> genericRuleFamilies = new TreeSet<>();
	separateRuleFamilies(docEntries, languageSpecificRuleFamilies, genericRuleFamilies);

	// Create a mapping of rules based on rule type and family.
	Map<String, ListMultimap<RuleType, RuleDocumentation>> ruleMapping = new HashMap<>();
	createRuleMapping(docEntries, ruleMapping);

	String languageSpecificTable;
	{
	StringBuilder sb = new StringBuilder();

	sb.append("<colgroup span=\"6\" width=\"20%\"></colgroup>\n")
	.append("<tr><th>Language</th><th>Binary rules</th><th>Library rules</th>"
	+ "<th>Test rules</th><th>Other rules</th><th></th></tr>\n");

	// Generate the table.
	for (String ruleFamily : languageSpecificRuleFamilies) {
	generateHeaderTableRuleFamily(sb, ruleMapping.get(ruleFamily), ruleFamily);
	}
	languageSpecificTable = sb.toString();
	}

	String otherRulesTable;
	{
	StringBuilder sb = new StringBuilder();

	sb.append("<colgroup span=\"6\" width=\"20%\"></colgroup>\n");
	for (String ruleFamily : genericRuleFamilies) {
	generateHeaderTableRuleFamily(sb, ruleMapping.get(ruleFamily), ruleFamily);
	}
	otherRulesTable = sb.toString();
	}
	page.add(DocgenConsts.VAR_LANG_SPECIFIC_HEADER_TABLE, languageSpecificTable);
	page.add(DocgenConsts.VAR_OTHER_RULES_HEADER_TABLE, otherRulesTable);
	page.add(DocgenConsts.VAR_COMMON_ATTRIBUTE_DEFINITION,
	generateCommonAttributeDocs(
	PredefinedAttributes.COMMON_ATTRIBUTES, DocgenConsts.COMMON_ATTRIBUTES));
	page.add(DocgenConsts.VAR_TEST_ATTRIBUTE_DEFINITION,
	generateCommonAttributeDocs(
	PredefinedAttributes.TEST_ATTRIBUTES, DocgenConsts.TEST_ATTRIBUTES));
	page.add(DocgenConsts.VAR_BINARY_ATTRIBUTE_DEFINITION,
	generateCommonAttributeDocs(
	PredefinedAttributes.BINARY_ATTRIBUTES, DocgenConsts.BINARY_ATTRIBUTES));
	page.add(DocgenConsts.VAR_LEFT_PANEL, generateLeftNavigationPanel(docEntries));
	}

	/**
	* Create a mapping of rules based on rule type and family.
	*/
	private void createRuleMapping(Iterable<RuleDocumentation> docEntries,
	Map<String, ListMultimap<RuleType, RuleDocumentation>> ruleMapping)
	throws BuildEncyclopediaDocException {
	for (RuleDocumentation ruleDoc : docEntries) {
	RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(ruleDoc.getRuleName());
	if (ruleClass != null) {
	String ruleFamily = ruleDoc.getRuleFamily();
	if (!ruleMapping.containsKey(ruleFamily)) {
	ruleMapping.put(ruleFamily, LinkedListMultimap.<RuleType, RuleDocumentation>create());
	}
	if (ruleClass.isDocumented()) {
	ruleMapping.get(ruleFamily).put(ruleDoc.getRuleType(), ruleDoc);
	}
	} else {
	throw ruleDoc.createException("Can't find RuleClass for " + ruleDoc.getRuleName());
	}
	}
	}

	/**
	* Separates all rule families in docEntries into language-specific rules and generic rules.
	*/
	private void separateRuleFamilies(Iterable<RuleDocumentation> docEntries,
	Set<String> languageSpecificRuleFamilies, Set<String> genericRuleFamilies)
	throws BuildEncyclopediaDocException {
	for (RuleDocumentation ruleDoc : docEntries) {
	if (ruleDoc.isLanguageSpecific()) {
	if (genericRuleFamilies.contains(ruleDoc.getRuleFamily())) {
	throw ruleDoc.createException("The rule is marked as being language-specific, but other "
	+ "rules of the same family have already been marked as being not.");
	}
	languageSpecificRuleFamilies.add(ruleDoc.getRuleFamily());
	} else {
	if (languageSpecificRuleFamilies.contains(ruleDoc.getRuleFamily())) {
	throw ruleDoc.createException("The rule is marked as being generic, but other rules of "
	+ "the same family have already been marked as being language-specific.");
	}
	genericRuleFamilies.add(ruleDoc.getRuleFamily());
	}
	}
	}

	private String generateLeftNavigationPanel(Iterable<RuleDocumentation> docEntries) {
	// Order the rules alphabetically. At this point they are ordered according to
	// RuleDocumentation.compareTo() which is not alphabetical.
	TreeMap<String, String> ruleNames = new TreeMap<>();
	for (RuleDocumentation ruleDoc : docEntries) {
	String ruleName = ruleDoc.getRuleName();
	ruleNames.put(ruleName.toLowerCase(), ruleName);
	}
	StringBuilder sb = new StringBuilder();
	for (String ruleName : ruleNames.values()) {
	RuleClass ruleClass = ruleClassProvider.getRuleClassMap().get(ruleName);
	Preconditions.checkNotNull(ruleClass);
	if (ruleClass.isDocumented()) {
	sb.append(String.format("<a href=\"#%s\">%s</a><br/>\n", ruleName, ruleName));
	}
	}
	return sb.toString();
	}

	private String generateCommonAttributeDocs(Map<String, RuleDocumentationAttribute> attributes,
	String attributeGroupName) throws BuildEncyclopediaDocException {
	RuleDocumentation ruleDoc = new RuleDocumentation(
	attributeGroupName, "OTHER", null, null, 0, null, ImmutableSet.<String>of(),
	ruleClassProvider);
	for (RuleDocumentationAttribute attribute : attributes.values()) {
	ruleDoc.addAttribute(attribute);
	}
	return ruleDoc.generateAttributeDefinitions();
	}

	private void generateHeaderTableRuleFamily(StringBuilder sb,
	ListMultimap<RuleType, RuleDocumentation> ruleTypeMap, String ruleFamily) {
	sb.append("<tr>\n")
	.append(String.format("<td class=\"lang\">%s</td>\n", ruleFamily));
	boolean otherRulesSplitted = false;
	for (RuleType ruleType : DocgenConsts.RuleType.values()) {
	sb.append("<td>");
	int i = 0;
	List<RuleDocumentation> ruleDocList = ruleTypeMap.get(ruleType);
	for (RuleDocumentation ruleDoc : ruleDocList) {
	if (i > 0) {
	if (ruleType.equals(RuleType.OTHER)
	&& ruleDocList.size() >= 4 && i == (ruleDocList.size() + 1) / 2) {
	// Split 'other rules' into two columns if there are too many of them.
	sb.append("</td>\n<td>");
	otherRulesSplitted = true;
	} else {
	sb.append("<br/>");
	}
	}
	String ruleName = ruleDoc.getRuleName();
	String deprecatedString = ruleDoc.hasFlag(DocgenConsts.FLAG_DEPRECATED)
	? " class=\"deprecated\"" : "";
	sb.append(String.format("<a href=\"#%s\"%s>%s</a>", ruleName, deprecatedString, ruleName));
	i++;
	}
	sb.append("</td>\n");
	}
	// There should be 6 columns.
	if (!otherRulesSplitted) {
	sb.append("<td></td>\n");
	}
	sb.append("</tr>\n");
	}

	private String getRuleDocs(Iterable<RuleDocumentation> docEntries) {
	StringBuilder sb = new StringBuilder();
	for (RuleDocumentation doc : docEntries) {
	sb.append(doc.getHtmlDocumentation());
	}
	return sb.toString();
	}

	private File setupDirectories(String outputRootDir) {
	if (outputRootDir != null) {
	File outputRootPath = new File(outputRootDir);
	outputRootPath.mkdirs();
	return new File(outputRootDir + File.separator + DocgenConsts.BUILD_ENCYCLOPEDIA_NAME);
	} else {
	return new File(DocgenConsts.BUILD_ENCYCLOPEDIA_NAME);
	}
	}

	private static void warnAboutUndocumentedRules(Iterable<String> rulesWithoutDocumentation) {
	Iterable<String> undocumentedRules = Iterables.filter(rulesWithoutDocumentation,
	RULE_WORTH_DOCUMENTING);
	System.err.printf("WARNING: The following rules are undocumented: [%s]\n",
	Joiner.on(", ").join(Ordering.<String>natural().immutableSortedCopy(undocumentedRules)));
	}
	}