name.lakhin.eliah.projects.papacarlo.lexis.TokenReference.scala Maven / Gradle / Ivy
/*
Copyright 2013 Ilya Lakhin (Илья Александрович Лахин)
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 name.lakhin.eliah.projects
package papacarlo.lexis
import name.lakhin.eliah.projects.papacarlo.utils.Signal
final class TokenReference(val collection: TokenCollection,
var index: Int) {
private[lexis] var fragment = Option.empty[Fragment]
private var removed: Boolean = false
val onUpdate = new Signal[TokenReference]
val onRemove = new Signal[TokenReference]
def exists = !removed
def token = {
if (removed) throw new RuntimeException("Token was removed")
collection.descriptions(index)
}
def getFragment = fragment
private[lexis] def remove() {
removed = true
onRemove.trigger(this)
}
override def toString =
if (removed) "removed"
else {
val cursor = collection.cursor(index)
cursor._1 + ":" + cursor._2
}
}