I noticed recently that the javac scanner is making use of ArrayList.remove(0) when it consumes a buffer. Obviously this is an inefficient way to implement a buffer, so I thought I'd try to fix it [1]. ArrayDeque seems to provide just the behavior I need, with one fatal flaw: despite encoding its data with an array, the class exposes no random-access operations. For lookahead, I need to be able to call get(int).
This seems to be a fairly common complaint [2][3]. I found an old bug requesting that ArrayDeque be enhanced to implement List [4], as well as a thread from 2010 that included a proof-of-concept ArrayDeque+List [5] and had a note from Martin Buchholz saying he regrets that ArrayDeque doesn't already implement List [6]. Is there any hope of ArrayDeque being enhanced in the near future to provide random access? There's some risk that any such initiative would be derailed by a quest for an uber-collection. I think a lot of people would be quite happy just to have a (trivial) 'get(int)' method added to ArrayDeque. —Dan [1] https://bugs.openjdk.java.net/browse/JDK-8033158 [2] http://en.wikipedia.org/wiki/Deque#Language_support [3] https://www.google.com/#q=arraydeque+%22random+access%22 [4] https://bugs.openjdk.java.net/browse/JDK-6368844 [5] http://mail.openjdk.java.net/pipermail/core-libs-dev/2010-April/004038.html [6] http://mail.openjdk.java.net/pipermail/core-libs-dev/2010-April/004031.html
