Comments on: Scala exercise http://blog.tmorris.net/scala-exercise/ The weblog of Tony Morris Sat, 04 Feb 2012 12:22:40 +0000 http://wordpress.org/?v=2.6 By: oxbow http://blog.tmorris.net/scala-exercise/#comment-37830 oxbow Thu, 25 Feb 2010 18:40:36 +0000 http://blog.tmorris.net/?p=649#comment-37830 Well, that was easier than I was expecting Well, that was easier than I was expecting

]]> By: Tony Morris http://blog.tmorris.net/scala-exercise/#comment-37196 Tony Morris Thu, 11 Feb 2010 08:53:55 +0000 http://blog.tmorris.net/?p=649#comment-37196 Hi Arnaud, I compiled against Scala 2.8.0 which will make quite a difference. Hi Arnaud,
I compiled against Scala 2.8.0 which will make quite a difference.

]]> By: Arnaud Bailly http://blog.tmorris.net/scala-exercise/#comment-37189 Arnaud Bailly Thu, 11 Feb 2010 06:19:46 +0000 http://blog.tmorris.net/?p=649#comment-37189 Thanks for the exercises. I tried to solve this one but got a compilation error: <pre> scalac -Xprint:typer -explaintypes exercise.scala; scala tony.Main exercise.scala:62: error: inferred the kinds of the type arguments (Array[String],String) do not conform to the expected kinds of the type parameters (type F,type A). Array[String]'s type parameters do not match type F's expected parameters: class Array has one type parameter, but type F has one val i = minimum(args, StringOrder, ArrayFoldable) ^ exercise.scala:62: error: type mismatch; found : java.lang.Object with tony.Foldable[Array] required: tony.Foldable[Array[String]] val i = minimum(args, StringOrder, ArrayFoldable) ^ java.lang.Object with tony.Foldable[Array] < tony.Foldable[Array[String]]? java.lang.Object < tony.Foldable[Array[String]]? < tony.Foldable[Array[String]]? false false tony.Foldable[Array] < tony.Foldable[Array[String]]? Array[String] < Array? false false false </pre> What am I doing wrong ? Note that I am using scala 2.7.7 on Linux. Best regards, Arnaud Thanks for the exercises. I tried to solve this one but got a compilation error:

scalac -Xprint:typer -explaintypes exercise.scala; scala tony.Main
exercise.scala:62: error: inferred the kinds of the type arguments (Array[String],String) do not conform to the expected kinds of the type parameters (type F,type A).
Array[String]'s type parameters do not match type F's expected parameters: class Array has one type parameter, but type F has one
    val i = minimum(args, StringOrder, ArrayFoldable)
            ^
exercise.scala:62: error: type mismatch;
 found   : java.lang.Object with tony.Foldable[Array]
 required: tony.Foldable[Array[String]]
    val i = minimum(args, StringOrder, ArrayFoldable)
                                       ^
java.lang.Object with tony.Foldable[Array] < tony.Foldable[Array[String]]?
  java.lang.Object < tony.Foldable[Array[String]]?
     < tony.Foldable[Array[String]]?
    false
  false
  tony.Foldable[Array] < tony.Foldable[Array[String]]?
    Array[String] < Array?
    false
  false
false

What am I doing wrong ? Note that I am using scala 2.7.7 on Linux.

Best regards,
Arnaud

]]> By: Steven Shaw http://blog.tmorris.net/scala-exercise/#comment-37064 Steven Shaw Sun, 07 Feb 2010 00:58:15 +0000 http://blog.tmorris.net/?p=649#comment-37064 Thanks for making this an easy one :) Thanks for making this an easy one :)

]]>