org.apache.usergrid.utils.Inflector.java Source code

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.usergrid.utils;

import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Transforms words to singular, plural, humanized (human readable), underscore, camel case, or ordinal form. This is
 * inspired by the <a href="http://api.rubyonrails.org/classes/Inflector.html">Inflector</a> class in <a
 * href="http://www.rubyonrails.org">Ruby on Rails</a>, which is distributed under the <a
 * href="http://wiki.rubyonrails.org/rails/pages/License">Rails license</a>.
 */
public class Inflector {

    protected static final Inflector INSTANCE = new Inflector();

    public static Inflector getInstance() {
        return INSTANCE;
    }

    protected class Rule {

        protected final String expression;
        protected final Pattern expressionPattern;
        protected final String replacement;

        protected Rule(String expression, String replacement) {
            this.expression = expression;
            this.replacement = replacement != null ? replacement : "";
            expressionPattern = Pattern.compile(this.expression, Pattern.CASE_INSENSITIVE);
        }

        /**
         * Apply the rule against the input string, returning the modified string or null if the rule didn't apply (and
         * no modifications were made)
         *
         * @param input the input string
         *
         * @return the modified string if this rule applied, or null if the input was not modified by this rule
         */
        protected String apply(String input) {
            Matcher matcher = expressionPattern.matcher(input);
            if (!matcher.find()) {
                return null;
            }
            return matcher.replaceAll(replacement);
        }

        @Override
        public int hashCode() {
            return expression.hashCode();
        }

        @Override
        public boolean equals(Object obj) {
            if (obj == this) {
                return true;
            }
            if ((obj != null) && (obj.getClass() == this.getClass())) {
                final Rule that = (Rule) obj;
                if (expression.equalsIgnoreCase(that.expression)) {
                    return true;
                }
            }
            return false;
        }

        @Override
        public String toString() {
            return expression + ", " + replacement;
        }
    }

    private final LinkedList<Rule> plurals = new LinkedList<Rule>();
    private final LinkedList<Rule> singulars = new LinkedList<Rule>();
    /**
     * The lowercase words that are to be excluded and not processed. This map can be modified by the users via {@link
     * #getUncountables()}.
     */
    private final Set<String> uncountables = new HashSet<String>();

    public Inflector() {
        initialize();
    }

    protected Inflector(Inflector original) {
        plurals.addAll(original.plurals);
        singulars.addAll(original.singulars);
        uncountables.addAll(original.uncountables);
    }

    @Override
    @SuppressWarnings("all")
    public Inflector clone() {
        return new Inflector(this);
    }

    // ------------------------------------------------------------------------------------------------
    // Usage functions
    // ------------------------------------------------------------------------------------------------

    /**
     * Returns the plural form of the word in the string. <p> Examples: <p/>
     * <pre>
     *   inflector.pluralize(&quot;post&quot;)               #=&gt; &quot;posts&quot;
     *   inflector.pluralize(&quot;octopus&quot;)            #=&gt; &quot;octopi&quot;
     *   inflector.pluralize(&quot;sheep&quot;)              #=&gt; &quot;sheep&quot;
     *   inflector.pluralize(&quot;words&quot;)              #=&gt; &quot;words&quot;
     *   inflector.pluralize(&quot;the blue mailman&quot;)   #=&gt; &quot;the blue mailmen&quot;
     *   inflector.pluralize(&quot;CamelOctopus&quot;)       #=&gt; &quot;CamelOctopi&quot;
     * </pre>
     * <p/> </p> <p> Note that if the {@link Object#toString()} is called on the supplied object, so this method works
     * for non-strings, too. </p>
     *
     * @param word the word that is to be pluralized.
     *
     * @return the pluralized form of the word, or the word itself if it could not be pluralized
     *
     * @see #singularize(Object)
     */
    public String pluralize(Object word) {
        if (word == null) {
            return null;
        }
        String wordStr = word.toString().trim();
        if (wordStr.length() == 0) {
            return wordStr;
        }
        if (isUncountable(wordStr)) {
            return wordStr;
        }
        for (Rule rule : plurals) {
            String result = rule.apply(wordStr);
            if (result != null) {
                return result;
            }
        }
        return wordStr;
    }

    public String pluralize(Object word, int count) {
        if (word == null) {
            return null;
        }
        if ((count == 1) || (count == -1)) {
            return word.toString();
        }
        return pluralize(word);
    }

    public boolean isPlural(Object word) {
        if (word == null) {
            return false;
        }
        return pluralize(word).equals(word.toString());
    }

    /**
     * Returns the singular form of the word in the string. <p> Examples: <p/>
     * <pre>
     *   inflector.singularize(&quot;posts&quot;)             #=&gt; &quot;post&quot;
     *   inflector.singularize(&quot;octopi&quot;)            #=&gt; &quot;octopus&quot;
     *   inflector.singularize(&quot;sheep&quot;)             #=&gt; &quot;sheep&quot;
     *   inflector.singularize(&quot;words&quot;)             #=&gt; &quot;word&quot;
     *   inflector.singularize(&quot;the blue mailmen&quot;)  #=&gt; &quot;the blue mailman&quot;
     *   inflector.singularize(&quot;CamelOctopi&quot;)       #=&gt; &quot;CamelOctopus&quot;
     * </pre>
     * <p/> </p> <p> Note that if the {@link Object#toString()} is called on the supplied object, so this method works
     * for non-strings, too. </p>
     *
     * @param word the word that is to be pluralized.
     *
     * @return the pluralized form of the word, or the word itself if it could not be pluralized
     *
     * @see #pluralize(Object)
     */
    public String singularize(Object word) {
        if (word == null) {
            return null;
        }
        String wordStr = word.toString().trim();
        if (wordStr.length() == 0) {
            return wordStr;
        }
        if (isUncountable(wordStr)) {
            return wordStr;
        }
        for (Rule rule : singulars) {
            String result = rule.apply(wordStr);
            if (result != null) {
                return result;
            }
        }
        return wordStr;
    }

    public boolean isSingular(Object word) {
        if (word == null) {
            return false;
        }
        return singularize(word).equals(word.toString());
    }

    /**
     * By default, this method converts strings to UpperCamelCase. If the <code>uppercaseFirstLetter</code> argument to
     * false, then this method produces lowerCamelCase. This method will also use any extra delimiter characters to
     * identify word boundaries. <p> Examples: <p/>
     * <pre>
     *   inflector.camelCase(&quot;active_record&quot;,false)    #=&gt; &quot;activeRecord&quot;
     *   inflector.camelCase(&quot;active_record&quot;,true)     #=&gt; &quot;ActiveRecord&quot;
     *   inflector.camelCase(&quot;first_name&quot;,false)       #=&gt; &quot;firstName&quot;
     *   inflector.camelCase(&quot;first_name&quot;,true)        #=&gt; &quot;FirstName&quot;
     *   inflector.camelCase(&quot;name&quot;,false)             #=&gt; &quot;name&quot;
     *   inflector.camelCase(&quot;name&quot;,true)              #=&gt; &quot;Name&quot;
     * </pre>
     * <p/> </p>
     *
     * @param lowerCaseAndUnderscoredWord the word that is to be converted to camel case
     * @param uppercaseFirstLetter true if the first character is to be uppercased, or false if the first character is
     * to be lowercased
     * @param delimiterChars optional characters that are used to delimit word boundaries
     *
     * @return the camel case version of the word
     *
     * @see #underscore(String, char[])
     */
    public String camelCase(String lowerCaseAndUnderscoredWord, boolean uppercaseFirstLetter,
            char... delimiterChars) {
        if (lowerCaseAndUnderscoredWord == null) {
            return null;
        }
        lowerCaseAndUnderscoredWord = lowerCaseAndUnderscoredWord.trim();
        if (lowerCaseAndUnderscoredWord.length() == 0) {
            return "";
        }
        if (uppercaseFirstLetter) {
            String result = lowerCaseAndUnderscoredWord;
            // Replace any extra delimiters with underscores (before the
            // underscores are converted in the next step)...
            if (delimiterChars != null) {
                for (char delimiterChar : delimiterChars) {
                    result = result.replace(delimiterChar, '_');
                }
            }

            // Change the case at the beginning at after each underscore ...
            return replaceAllWithUppercase(result, "(^|_)(.)", 2);
        }
        if (lowerCaseAndUnderscoredWord.length() < 2) {
            return lowerCaseAndUnderscoredWord;
        }
        return "" + Character.toLowerCase(lowerCaseAndUnderscoredWord.charAt(0))
                + camelCase(lowerCaseAndUnderscoredWord, true, delimiterChars).substring(1);
    }

    /**
     * Makes an underscored form from the expression in the string (the reverse of the {@link #camelCase(String,
     * boolean, char[]) camelCase} method. Also changes any characters that match the supplied delimiters into
     * underscore. <p> Examples: <p/>
     * <pre>
     *   inflector.underscore(&quot;activeRecord&quot;)     #=&gt; &quot;active_record&quot;
     *   inflector.underscore(&quot;ActiveRecord&quot;)     #=&gt; &quot;active_record&quot;
     *   inflector.underscore(&quot;firstName&quot;)        #=&gt; &quot;first_name&quot;
     *   inflector.underscore(&quot;FirstName&quot;)        #=&gt; &quot;first_name&quot;
     *   inflector.underscore(&quot;name&quot;)             #=&gt; &quot;name&quot;
     *   inflector.underscore(&quot;The.firstName&quot;)    #=&gt; &quot;the_first_name&quot;
     * </pre>
     * <p/> </p>
     *
     * @param camelCaseWord the camel-cased word that is to be converted;
     * @param delimiterChars optional characters that are used to delimit word boundaries (beyond capitalization)
     *
     * @return a lower-cased version of the input, with separate words delimited by the underscore character.
     */
    public String underscore(String camelCaseWord, char... delimiterChars) {
        if (camelCaseWord == null) {
            return null;
        }
        String result = camelCaseWord.trim();
        if (result.length() == 0) {
            return "";
        }
        result = result.replaceAll("([A-Z]+)([A-Z][a-z])", "$1_$2");
        result = result.replaceAll("([a-z\\d])([A-Z])", "$1_$2");
        result = result.replace('-', '_');
        if (delimiterChars != null) {
            for (char delimiterChar : delimiterChars) {
                result = result.replace(delimiterChar, '_');
            }
        }
        return result.toLowerCase();
    }

    /**
     * Returns a copy of the input with the first character converted to uppercase and the remainder to lowercase.
     *
     * @param words the word to be capitalized
     *
     * @return the string with the first character capitalized and the remaining characters lowercased
     */
    public String capitalize(String words) {
        if (words == null) {
            return null;
        }
        String result = words.trim();
        if (result.length() == 0) {
            return "";
        }
        if (result.length() == 1) {
            return result.toUpperCase();
        }
        return "" + Character.toUpperCase(result.charAt(0)) + result.substring(1).toLowerCase();
    }

    // ------------------------------------------------------------------------------------------------
    // Management methods
    // ------------------------------------------------------------------------------------------------

    /**
     * Determine whether the supplied word is considered uncountable by the {@link #pluralize(Object) pluralize} and
     * {@link #singularize(Object) singularize} methods.
     *
     * @param word the word
     *
     * @return true if the plural and singular forms of the word are the same
     */
    public boolean isUncountable(String word) {
        if (word == null) {
            return false;
        }
        String trimmedLower = word.trim().toLowerCase();
        return uncountables.contains(trimmedLower);
    }

    /**
     * Get the set of words that are not processed by the Inflector. The resulting map is directly modifiable.
     *
     * @return the set of uncountable words
     */
    public Set<String> getUncountables() {
        return uncountables;
    }

    public void addPluralize(String rule, String replacement) {
        final Rule pluralizeRule = new Rule(rule, replacement);
        plurals.addFirst(pluralizeRule);
    }

    public void addSingularize(String rule, String replacement) {
        final Rule singularizeRule = new Rule(rule, replacement);
        singulars.addFirst(singularizeRule);
    }

    public void addIrregular(String singular, String plural) {
        if (org.apache.commons.lang.StringUtils.isEmpty(singular)) {
            throw new IllegalArgumentException("singular rule may not be empty");
        }
        if (org.apache.commons.lang.StringUtils.isEmpty(plural)) {
            throw new IllegalArgumentException("plural rule may not be empty");
        }
        String singularRemainder = singular.length() > 1 ? singular.substring(1) : "";
        String pluralRemainder = plural.length() > 1 ? plural.substring(1) : "";
        addPluralize("(" + singular.charAt(0) + ")" + singularRemainder + "$", "$1" + pluralRemainder);
        addSingularize("(" + plural.charAt(0) + ")" + pluralRemainder + "$", "$1" + singularRemainder);
    }

    public void addUncountable(String... words) {
        if ((words == null) || (words.length == 0)) {
            return;
        }
        for (String word : words) {
            if (word != null) {
                uncountables.add(word.trim().toLowerCase());
            }
        }
    }

    /**
     * Utility method to replace all occurrences given by the specific backreference with its uppercased form, and
     * remove all other backreferences. <p> The Java {@link Pattern regular expression processing} does not use the
     * preprocessing directives <code>\l</code>, <code>&#92;u</code>, <code>\L</code>, and <code>\U</code>. If so, such
     * directives could be used in the replacement string to uppercase or lowercase the backreferences. For example,
     * <code>\L1</code> would lowercase the first backreference, and <code>&#92;u3</code> would uppercase the 3rd
     * backreference. </p>
     *
     * @return the input string with the appropriate characters converted to upper-case
     */
    protected static String replaceAllWithUppercase(String input, String regex, int groupNumberToUppercase) {
        Pattern underscoreAndDotPattern = Pattern.compile(regex);
        Matcher matcher = underscoreAndDotPattern.matcher(input);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, matcher.group(groupNumberToUppercase).toUpperCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }

    /** Completely remove all rules within this inflector. */
    public void clear() {
        uncountables.clear();
        plurals.clear();
        singulars.clear();
    }

    protected void initialize() {
        Inflector inflect = this;
        inflect.addPluralize("$", "s");
        inflect.addPluralize("s$", "s");
        inflect.addPluralize("(ax|test)is$", "$1es");
        inflect.addPluralize("(octop|vir)us$", "$1i");
        inflect.addPluralize("(octop|vir)i$", "$1i"); // already plural
        inflect.addPluralize("(alias|status)$", "$1es");
        inflect.addPluralize("(bu)s$", "$1ses");
        inflect.addPluralize("(buffal|tomat)o$", "$1oes");
        inflect.addPluralize("([ti])um$", "$1a");
        inflect.addPluralize("([ti])a$", "$1a"); // already plural
        inflect.addPluralize("sis$", "ses");
        inflect.addPluralize("(?:([^f])fe|([lr])f)$", "$1$2ves");
        inflect.addPluralize("(hive)$", "$1s");
        inflect.addPluralize("([^aeiouy]|qu)y$", "$1ies");
        inflect.addPluralize("(x|ch|ss|sh)$", "$1es");
        inflect.addPluralize("(matr|vert|ind)ix|ex$", "$1ices");
        inflect.addPluralize("([m|l])ouse$", "$1ice");
        inflect.addPluralize("([m|l])ice$", "$1ice");
        inflect.addPluralize("^(ox)$", "$1en");
        inflect.addPluralize("(quiz)$", "$1zes");
        // Need to check for the following words that are already pluralized:
        inflect.addPluralize("(people|men|children|sexes|moves|stadiums)$", "$1"); // irregulars
        inflect.addPluralize("(oxen|octopi|viri|aliases|quizzes)$", "$1"); // special
        // rules

        inflect.addSingularize("s$", "");
        inflect.addSingularize("(s|si|u)s$", "$1s"); // '-us' and '-ss' are
        // already singular
        inflect.addSingularize("(n)ews$", "$1ews");
        inflect.addSingularize("([ti])a$", "$1um");
        inflect.addSingularize("((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$", "$1$2sis");
        inflect.addSingularize("(^analy)ses$", "$1sis");
        inflect.addSingularize("(^analy)sis$", "$1sis"); // already singular,
        // but ends in 's'
        inflect.addSingularize("([^f])ves$", "$1fe");
        inflect.addSingularize("(hive)s$", "$1");
        inflect.addSingularize("(tive)s$", "$1");
        inflect.addSingularize("([lr])ves$", "$1f");
        inflect.addSingularize("([^aeiouy]|qu)ies$", "$1y");
        inflect.addSingularize("(s)eries$", "$1eries");
        inflect.addSingularize("(m)ovies$", "$1ovie");
        inflect.addSingularize("(x|ch|ss|sh)es$", "$1");
        inflect.addSingularize("([m|l])ice$", "$1ouse");
        inflect.addSingularize("(bus)es$", "$1");
        inflect.addSingularize("(o)es$", "$1");
        inflect.addSingularize("(shoe)s$", "$1");
        inflect.addSingularize("(cris|ax|test)is$", "$1is"); // already
        // singular, but
        // ends in 's'
        inflect.addSingularize("(cris|ax|test)es$", "$1is");
        inflect.addSingularize("(octop|vir)i$", "$1us");
        inflect.addSingularize("(octop|vir)us$", "$1us"); // already singular,
        // but ends in 's'
        inflect.addSingularize("(alias|status)es$", "$1");
        inflect.addSingularize("(alias|status)$", "$1"); // already singular,
        // but ends in 's'
        inflect.addSingularize("^(ox)en", "$1");
        inflect.addSingularize("(vert|ind)ices$", "$1ex");
        inflect.addSingularize("(matr)ices$", "$1ix");
        inflect.addSingularize("(quiz)zes$", "$1");

        inflect.addIrregular("person", "people");
        inflect.addIrregular("man", "men");
        inflect.addIrregular("child", "children");
        inflect.addIrregular("sex", "sexes");
        inflect.addIrregular("move", "moves");
        inflect.addIrregular("stadium", "stadiums");

        inflect.addUncountable("equipment", "information", "rice", "money", "species", "series", "fish", "sheep",
                "data", "analytics");
    }
}