summary of point lambdafication survey

[Stuart Marks]

Brian has asked me to summarize the results of the point lambdafication survey 
he sent out a few weeks ago:

   http://mail.openjdk.java.net/pipermail/lambda-dev/2011-August/003919.html

There were 27 responses. Several responses were from the same individual, and 
some respondents didn't provide a name (and in at least one case a response was 
intended to supersede an earlier response) so it's hard to tell how many people 
responded. Perhaps there were twenty different individuals. Thanks to all who 
contributed.

Below is a brief summary of the responses. For the sake of brevity, I've taken 
some liberties in this summary; some of you typed a lot of code! My opinions 
and comments on the results will follow in a separate message.

* java.util.logging.Logger -- log(level, Callable<String>) -- 3 requests
   - pass a function that generates a log message
   - avoids overhead of string creation if level isn't enabled
   - variations for finest(), info(), etc.
   - need to deal with Exception thrown from Callable.call()

* BufferedReader.eachLine(block) -- 3 requests
   - run a block on each line read
   - variations with filtering

* java.util.concurrent.locks.Lock -- withLock(block) -- 2 requests
   - runs block with lock held, release lock in finally-clause
   - variations for lock with timeout, tryLock

* java.util.regex -- each() on Pattern, Matcher, or String -- 2 requests
   - run a block on each match, possibly returning a replacement

* java.sql.ResultSet -- each(block) -- 2 requests
   - run a block for each row in a ResultSet

* java.nio.Buffer family -- forEach(block)
   - runs block on each buffer element

* Swing/AWT event listeners -- multiple requests
   - rearrange non-SAM listeners to be suitable for lambdas

* SwingUtilities executeAndWait(callable), invokeAndWait(callable)
   - convenience functions for current APIs, possibly also returning a value

* SwingWorker(callable)
   - convenience method for creating a SwingWorker
   - callable supplies implementation of doInBackground()

* java.nio.channels.FileChannel -- lockDuring(block)
   - runs block with file lock held, release lock in finally-clause
   - variation for tryLock

* java.nio.file.Files -- eachFile(block)
   - run block for each file in a directory

* Collections.toMap(keyGen)
   - for each element in a Collection, generate a key, store into a Map
   - could be a static utility method or an extension method

* Process.onExit(block)
   - execute block when the process exits

* Integer.times(block) -- execute block N times

* Objects.equals(obj1, obj2, fieldGetters...)
   - helper method for writing equals() methods
   - handles identity, casting, field-by-field comparisons

* Throwable.visitCauses(block)
   - run block for each throwable in the chain of causes

* ThreadLocal(callable)
   - callable supplies the implementation of initialValue()
   - provides lazy initialization of thread-locals

s'marks