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Scaladoc update for collection.mutable.MultiMap

Addition of source code example on how to use a MultiMap and its
defined methods. Minor correction in documentation for method
`removeBinding`.
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1 parent 2d62ab2 commit af8b45fe354adb03d9b7a9012fb8885bffdd1a45 @sschaef sschaef committed Nov 15, 2012
Showing with 32 additions and 3 deletions.
  1. +32 −3 src/library/scala/collection/mutable/MultiMap.scala
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35 src/library/scala/collection/mutable/MultiMap.scala
@@ -15,8 +15,36 @@ package mutable
/** A trait for mutable maps with multiple values assigned to a key.
*
* This class is typically used as a mixin. It turns maps which map `A`
- * to `Set[B]` objects into multi maps which map `A` to
- * `B` objects.
+ * to `Set[B]` objects into multimaps that map `A` to `B` objects.
+ *
+ * @example {{{
+ * // first import all necessary types from package `collection.mutable`
+ * import collection.mutable.{ HashMap, MultiMap, Set }
+ *
+ * // to create a `MultiMap` the easiest way is to mixin it into a normal
+ * // `Map` instance
+ * val mm = new HashMap[Int, Set[String]] with MultiMap[Int, String]
+ *
+ * // to add key-value pairs to a multimap it is important to use
+ * // the method `addBinding` because standard methods like `+` will
+ * // overwrite the complete key-value pair instead of adding the
+ * // value to the existing key
+ * mm.addBinding(1, "a")
+ * mm.addBinding(2, "b")
+ * mm.addBinding(1, "c")
+ *
+ * // mm now contains `Map(2 -> Set(b), 1 -> Set(c, a))`
+ *
+ * // to check if the multimap contains a value there is method
+ * // `entryExists`, which allows to traverse the including set
+ * mm.entryExists(1, _ == "a") == true
+ * mm.entryExists(1, _ == "b") == false
+ * mm.entryExists(2, _ == "b") == true
+ *
+ * // to remove a previous added value there is the method `removeBinding`
+ * mm.removeBinding(1, "a")
+ * mm.entryExists(1, _ == "a") == false
+ * }}}
*
* @define coll multimap
* @define Coll `MultiMap`
@@ -57,7 +85,8 @@ trait MultiMap[A, B] extends Map[A, Set[B]] {
this
}
- /** Removes the binding of `value` to `key` if it exists.
+ /** Removes the binding of `value` to `key` if it exists, otherwise this
+ * operation doesn't have any effect.
*
* If this was the last value assigned to the specified key, the
* set assigned to that key will be removed as well.

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