001// Copyright 2012 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.clojure;
016
017import clojure.lang.Symbol;
018import org.apache.tapestry5.clojure.MethodToFunctionSymbolMapper;
019
020import java.lang.reflect.Method;
021import java.util.regex.MatchResult;
022import java.util.regex.Matcher;
023import java.util.regex.Pattern;
024
025/**
026 * Default implementation that transforms a camelCased method-name to a clojure-style function name.
027 */
028public class DefaultMapper implements MethodToFunctionSymbolMapper
029{
030    public Symbol mapMethod(String namespace, Method method)
031    {
032        return mapMethodName(namespace, method.getName());
033    }
034
035    private Symbol mapMethodName(String namespace, String name)
036    {
037        return Symbol.create(namespace, transformName(name));
038    }
039
040    private final Pattern transition = Pattern.compile("(\\p{Lower}\\p{Upper})");
041
042    private String transformName(String name)
043    {
044
045        Matcher matcher = transition.matcher(name);
046
047        StringBuilder builder = new StringBuilder();
048
049        int lastx = 0;
050
051        while (matcher.find())
052        {
053            MatchResult matchResult = matcher.toMatchResult();
054
055            int start = matchResult.start();
056            int end = matchResult.end();
057
058            builder.append(name.substring(lastx, start + 1));
059            builder.append("-");
060            // TODO: An acronym (such as "URL") should not be lower cased here.
061            builder.append(name.substring(end - 1, end).toLowerCase());
062
063            lastx = end;
064        }
065
066        if (lastx == 0)
067        {
068            return name;
069        }
070
071        builder.append(name.substring(lastx));
072
073        return builder.toString();
074    }
075
076}