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-rw-r--r--examples/src/main/scala/decode.scala53
1 files changed, 30 insertions, 23 deletions
diff --git a/examples/src/main/scala/decode.scala b/examples/src/main/scala/decode.scala
index 8603b9e..0332427 100644
--- a/examples/src/main/scala/decode.scala
+++ b/examples/src/main/scala/decode.scala
@@ -11,9 +11,11 @@ trait Decoder[T] { def decode(str: String): T }
/** derivation object (and companion object) for [[Decoder]] instances */
object Decoder {
-
+
/** decodes strings */
- implicit val string: Decoder[String] = new Decoder[String] { def decode(str: String): String = str }
+ implicit val string: Decoder[String] = new Decoder[String] {
+ def decode(str: String): String = str
+ }
/** decodes ints */
implicit val int: Decoder[Int] = new Decoder[Int] { def decode(str: String): Int = str.toInt }
@@ -23,12 +25,14 @@ object Decoder {
/** type constructor for new instances of the typeclass */
type Typeclass[T] = Decoder[T]
-
+
/** defines how new [[Decoder]]s for case classes should be constructed */
def combine[T](ctx: CaseClass[Decoder, T]): Decoder[T] = new Decoder[T] {
def decode(value: String) = {
val (name, values) = parse(value)
- ctx.construct { param => param.typeclass.decode(values(param.label)) }
+ ctx.construct { param =>
+ param.typeclass.decode(values(param.label))
+ }
}
}
@@ -45,25 +49,29 @@ object Decoder {
private def parse(value: String): (String, Map[String, String]) = {
val end = value.indexOf('(')
val name = value.substring(0, end)
-
- def parts(value: String, idx: Int = 0, depth: Int = 0, collected: List[String] = List("")): List[String] = {
- def plus(char: Char): List[String] = collected.head+char :: collected.tail
-
- if(idx == value.length) collected
- else value(idx) match {
- case '(' =>
- parts(value, idx + 1, depth + 1, plus('('))
- case ')' =>
- if(depth == 1) plus(')')
- else parts(value, idx + 1, depth - 1, plus(')'))
- case ',' =>
- if(depth == 0) parts(value, idx + 1, depth, "" :: collected)
- else parts(value, idx + 1, depth, plus(','))
- case char =>
- parts(value, idx + 1, depth, plus(char))
- }
+
+ def parts(value: String,
+ idx: Int = 0,
+ depth: Int = 0,
+ collected: List[String] = List("")): List[String] = {
+ def plus(char: Char): List[String] = collected.head + char :: collected.tail
+
+ if (idx == value.length) collected
+ else
+ value(idx) match {
+ case '(' =>
+ parts(value, idx + 1, depth + 1, plus('('))
+ case ')' =>
+ if (depth == 1) plus(')')
+ else parts(value, idx + 1, depth - 1, plus(')'))
+ case ',' =>
+ if (depth == 0) parts(value, idx + 1, depth, "" :: collected)
+ else parts(value, idx + 1, depth, plus(','))
+ case char =>
+ parts(value, idx + 1, depth, plus(char))
+ }
}
-
+
def keyValue(str: String): (String, String) = {
val List(label, value) = str.split("=", 2).to[List]
(label, value)
@@ -72,4 +80,3 @@ object Decoder {
(name, parts(value.substring(end + 1, value.length - 1)).map(keyValue).toMap)
}
}
-