Adding scala.io.Target

text/0000-io-target.md

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+# SLIP-NNN - IO Target
+
+**By: Omid Bakhshandeh**
+This is a proposal for adding `scala.io.Target` to Scala std.
+
+## History
+
+| Date          | Version       |
+|---------------|---------------|
+| Jun 18th 2015 | Initial Draft |
+
+## Motivation
+
+`scala.io.Source` is one of the most used part of `Scala std`. For many people that are new
+to the language and programming IO play an important role.
+Scala std doesn't have any support for generating output. Scala programmers use `Java.io`
+or `Java.nio` for writing on disk. On the other hand, the incopatibility between Java File
+and Scala File makes it hard to have nice Scala code.
+
+Here, I propose `Scala.io.Target` to be added to std. This part of library could implement the
+output version `Scala.io.Source`.
+
+
+### Examples
+
+An example could be something like this:
+
+```scala
+def fromFile(file: File, bufferSize: Int)(implicit codec: Codec): BufferedSource
+
+def toFile(file: File, bufferSize: Int)(implicit codec: Codec): BufferedTarget
+
+```
+It's important to investigate the parts that are a little bit tricky to implement or even impossible like:
+
+```scala
+fromURL(url: URL)(implicit codec: Codec): BufferedSource
+
+toURL(url: URL)(implicit codec: Codec): BufferedTarget // is it possible to start a simple webserver
+                                                       //or something like that?
+```
+
+### Example in Java
+
+Here is a simple example from java:
+
+```java
+impor java.io.*
+Charset charset = Charset.forName("US-ASCII");
+File file = new File(...);
+String s = ...;
+try (BufferedWriter writer = Files.newBufferedWriter(file, charset)) {
+    writer.write(s, 0, s.length());
+} catch (IOException x) {
+    System.err.format("IOException: %s%n", x);
+}
+```
+and scala version could be something like:
+
+```scala
+impor scala.io.Target._
+String s = ...
+Target.toFile(new File(...), s) // File is Scala file, not Java file
+```
+
+## Drawbacks
+
+The only reason that this library shouldn't be implemented is the richness of Java IO library. If this library
+is not good enough that people use it and cannot provide all Java.IO functionality like `ByteWriter` or `Channels`,
+then implemeting this library could be a waste of time.
+
+## Alternatives
+There are some alternatives like `Scalaz` and others, but I think this should be really part of Scala std.