junkion

Junkion

Dedication

Take some wooden nickles / Look for Mr. Goodbar / Get your mojo working now / I'll show you how / You can dare to be stupid!

-- "Weird Al" Yankovich, "Dare To Be Stupid"

Overview

Doing I/O in Scala is usually junky -- you often end up writing Java-esque code using a wide constellation of types from the java.io and java.nio packages. It never looks attractive, and it's often hard to be sure if it's the "right way" or not.

Writing a library that supports all possible types of I/O (from small text files up to gigabytes of binary data) is hard. Instead Junkion is designed to be used when you mostly aren't worried about supporting gigantic files, or a specific use case, but just want an easy-to-use library that is efficient in "normal" cases.

Getting Junkion

Junkion supports Scala 2.10, 2.11, and 2.12. If you use SBT, you can include Junkion via the following build.sbt snippet:

libraryDependencies += "org.spire-math" %% "junkion" % "0.2.0"

Recipes

Junkion is really just a collection of very simple implicit methods that should make the humdrum business of opening and working with small files a bit easier. (I just mean a file that you don't necessarily mind loading into memory all at once. 50 MB probably qualifies as small, while 5 GB probably doesn't.)

import junkion.implicits._

val file = "/some/example/file.txt".file

val s1: String = file.string

val bytes: Array[Byte] = file.bytes.array
val bb: ByteBuffer = file.bytes.byteBuffer
val bbs: Stream[ByteBuffer] = file.bytes.chunked
val s2: String = file.bytes.string

val chars: Array[Char] = file.chars.array
val cb: CharBuffer = file.chars.charBuffer
val s3: String = file.chars.string

val it: Iterator[String] = file.lines.iterator
val stream: Stream[String] = file.lines.stream
val seq: IndexedSeq[String] = file.lines.indexedSeq
val array: Array[String] = file.lines.array
val list: List[String] = file.lines.list
val vector: Vector[String] = file.lines.vector

val lineCount: Int = file.lines.foldLeft(0)((n, _) => n + 1)
val wordCount: Int = file.lines.foldLeft(0)((n, s) => n + s.split(" +").length)

By default all operations involving String and Char use the UTF-8 encoding, but alternate character encodings can be provided explicitly using .as:

val s1: String = file.as("Big5").string
val s2: String = file.as("ISO-8859-1").bytes.string
val chars: Array[Char] = file.as("KOI8-R").chars.array
val lines: Iterator[String] = file.as("UTF-16").lines.iterator

You can also write simple strings and characters to files using .write and .writelines:

val file = "/tmp/data.txt".file

file.write(s)     // s: String
file.write(arr)   // arr: Array[String]
file.write(it)    // it: Iterator[String]
file.write(seq)   // seq: Iterable[String]

// append a newline after each string to be written
file.writelines(s)
file.writelines(arr)
file.writelines(it)
file.writelines(seq)

// optionally specify encodings
file.as("Big5").write(s)
file.as("ISO-8859-1").write(arr)
file.as("KOI8-R").write(it)
file.as("UTF-16").write(seq)

// optionally work directly with (w: BufferedWriter)
file.as("UTF-8").writing { w =>
  ... /* writes to w, which is automatically closed */
}

Disclaimers

Any project named after robots living in a junkyard, and inspired by Dare To Be Stupid should not need this section, but:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Copyright and License

All code is available to you under the MIT license, available at http://opensource.org/licenses/mit-license.php and also in the COPYING file.

non / junkion 0.2.0