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Add doctest example for ApplicativeError.raiseError #2122

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Dec 20, 2017
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Add doctest example for ApplicativeError.raiseError #2122

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Add doctest example for ApplicativeError.raiseError
ceedubs Dec 20, 2017
0df42a9
Fix scaladoc interpretation issue in raiseError example
ceedubs Dec 20, 2017
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19 changes: 19 additions & 0 deletions core/src/main/scala/cats/ApplicativeError.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -10,8 +10,27 @@ import scala.util.control.NonFatal
* This type class allows one to abstract over error-handling applicatives.
*/
trait ApplicativeError[F[_], E] extends Applicative[F] {

/**
* Lift an error into the `F` context.
*
* Example:
* {{{
* scala> import cats.implicits._
*
* // integer-rounded division
* scala> def divide[F[_]](dividend: Int, divisor: Int)(implicit F: ApplicativeError[F, String]): F[Int] =
* | if (divisor === 0) F.raiseError(s"division by zero: $dividend / 0")
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@kailuowang kailuowang Dec 20, 2017 •
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/home/travis/build/typelevel/cats/core/src/main/scala/cats/ApplicativeError.scala:23: Variable dividend undefined in comment for method raiseError in trait ApplicativeError

[error] * | if (divisor === 0) F.raiseError(s"division by zero: $dividend / 0")

Scaladocs seems to be parsing $XXXX token, the easiest thing to do is probably to let it win and remove it.

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Oh right I've dealt with this before. There's a trick to fix it, but the string interpolation isn't adding much to the example anyway so I'll just remove it.

* | else F.pure(dividend / divisor)
*
* scala> type ErrorOr[A] = Either[String, A]
*
* scala> divide[ErrorOr](6, 3)
* res0: ErrorOr[Int] = Right(2)
*
* scala> divide[ErrorOr](6, 0)
* res1: ErrorOr[Int] = Left(division by zero: 6 / 0)
* }}}
*/
def raiseError[A](e: E): F[A]

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