Created
November 25, 2011 13:00
-
-
Save dcsobral/1393475 to your computer and use it in GitHub Desktop.
WordCount
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Based on Fantom's word count example here: http://blog.joda.org/2011/11/guide-to-evaluating-fantom.html | |
// I'm commenting the lines that need changing, and leaving a few of them uncommented, | |
// as they are the same | |
// class WordCount { | |
object WordCount { | |
// Void main(Str[] args) { | |
def main(args: Array[String]) { | |
if (args.size != 1) { | |
// echo("usage: Wordcount <file>") | |
println("usage: WordCount <file>") | |
// Env.cur.exit(-1) | |
sys exit -1 | |
} | |
// Set up an empty map to count each word, setting default for each value to zero | |
// wordCounts := Str:Int[:] { def = 0 } | |
val wordCounts = collection.mutable.Map[String, Int]() withDefaultValue 0 | |
// Open the file, read each line in order | |
// file := Uri(args[0]).toFile | |
val file = io.Source fromFile args(0) | |
// file.eachLine |line| { | |
file.getLines foreach { line => | |
// skip empty lines | |
if (line.trim.isEmpty) return | |
// split and trim on whitespace into words | |
// words := line.split | |
val words = line split "\\s+" | |
// count each one | |
// words.each |word| { wordCounts[word] += 1 } | |
words foreach { word => wordCounts(word) += 1 } | |
} | |
// Show each word found, with its count, in alphabetical order | |
// wordCounts.keys.sort.each |key| { | |
wordCounts.keys.toSeq.sorted foreach { key => | |
// echo("$key ${wordCounts[key]}") | |
println(key+" "+wordCounts(key)) | |
} | |
} | |
} |
Thanks, @dcsobral and @kaja47.
learned two more things about scala:
- Predef.identity
- mapValues
And here is the par version:
file.getLines.filterNot(_.trim.isEmpty).toStream.par.flatMap(_ split """\s+""").groupBy(identity).map{case (word, wordList) => (word, wordList.size)}.toStream.sortBy(_._1).foreach{case (word, count) => println(word + " " + count)}
We love single line :-)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
fixed version:
file.getLines.filterNot(.trim.isEmpty).flatMap( split """\s+""").toSeq.groupBy(identity).mapValues(.size).toSeq.sortBy(._1).foreach{ case (word, count) => println(word+" "+count) }
call to
toSeq
creates Stream