    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    @Override
    031    public Symbol mapMethod(String namespace, Method method)
    032    {
    033        return mapMethodName(namespace, method.getName());
    034    }
    035
    036    private Symbol mapMethodName(String namespace, String name)
    037    {
    038        return Symbol.create(namespace, transformName(name));
    039    }
    040
    041    private final Pattern transition = Pattern.compile("(\\p{Lower}\\p{Upper})");
    042
    043    private String transformName(String name)
    044    {
    045
    046        Matcher matcher = transition.matcher(name);
    047
    048        StringBuilder builder = new StringBuilder();
    049
    050        int lastx = 0;
    051
    052        while (matcher.find())
    053        {
    054            MatchResult matchResult = matcher.toMatchResult();
    055
    056            int start = matchResult.start();
    057            int end = matchResult.end();
    058
    059            builder.append(name.substring(lastx, start + 1));
    060            builder.append('-');
    061            // TODO: An acronym (such as "URL") should not be lower cased here.
    062            builder.append(name.substring(end - 1, end).toLowerCase());
    063
    064            lastx = end;
    065        }
    066
    067        if (lastx == 0)
    068        {
    069            return name;
    070        }
    071
    072        builder.append(name.substring(lastx));
    073
    074        return builder.toString();
    075    }
    076
    077}