V putIfAbsent(K key, V ifAbsent()) { if (key == null) throw new ArgumentError(key); int comp = _splay(key); if (comp == 0) { return _root.value; } int modificationCount = _modificationCount; int splayCount = _splayCount; V value = ifAbsent(); if (modificationCount != _modificationCount) { throw new ConcurrentModificationError(this); } if (splayCount != _splayCount) { comp = _splay(key); // Key is still not there, otherwise _modificationCount would be changed. assert(comp != 0); } _addNewRoot(new _SplayTreeMapNode(key, value), comp); return value; }
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/2.0.0/dart-collection/SplayTreeMap/putIfAbsent.html