/*
 * Copyright 2009-2010 Yuichiro Moriguchi
 *
 * 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 net.morilib.lisp.file;

import net.morilib.lisp.ConsIterator;
import net.morilib.lisp.ConsListBuilder;
import net.morilib.lisp.Datum;
import net.morilib.lisp.Environment;
import net.morilib.lisp.LispMessage;
import net.morilib.lisp.Subr;
import net.morilib.lisp.subr.SubrUtils;
import net.morilib.lisp.subr.UnaryArgs;

/**
 *
 *
 * @author MORIGUCHI, Yuichiro 2011/04/29
 */
public class LispListBuffer extends LispLineBuffer {

	/**
	 * 
	 *
	 *
	 * @author MORIGUCHI, Yuichiro 2011/04/29
	 */
	public static class OpenListBuffer extends Subr {

		/* (non-Javadoc)
		 * @see net.morilib.lisp.Subr#eval(net.morilib.lisp.Datum, net.morilib.lisp.Environment, net.morilib.lisp.LispMessage)
		 */
		@Override
		public Datum eval(
				Datum body, Environment env, LispMessage mesg) {
			ConsIterator itr = new ConsIterator(body);

			SubrUtils.checkTerminated(itr, body, mesg);
			return new LispListBuffer();
		}

	}

	
	public static class GetListFromBuffer extends UnaryArgs {

		/* (non-Javadoc)
		 * @see net.morilib.lisp.subr.UnaryArgs#execute(net.morilib.lisp.Datum, net.morilib.lisp.Environment, net.morilib.lisp.LispMessage)
		 */
		@Override
		protected Datum execute(
				Datum c1a, Environment env, LispMessage mesg) {
			if(c1a instanceof LispListBuffer) {
				return ((LispListBuffer)c1a).buf.get();
			} else {
				throw mesg.getError(
						"err.file.require.listbuffer", c1a);
			}
		}

	}

	//
	private ConsListBuilder buf;

	/**
	 * 
	 */
	public LispListBuffer() {
		buf = new ConsListBuilder();
	}

	/**
	 * 
	 * @return
	 */
	public void putLine(Datum s) {
		buf.append(s);
	}

	/**
	 * 
	 */
	public void close() {
		// do nothing
	}

	/* (non-Javadoc)
	 * @see net.morilib.lisp.Datum2#toDisplayString(java.lang.StringBuilder)
	 */
	@Override
	public void toDisplayString(StringBuilder buf) {
		buf.append("#<list-buffer>");
	}

}
