编译sbt时找不到隐式值

Question

我有一个sbt项目，该项目配置有Dependencias.scala、build.sbt和plugins.sbt，并且我具有以下依赖关系：https://christopherdavenport.github.io/cormorant/

lazy val `cormorant-core`         = "io.chrisdavenport"       %% "cormorant-core"           % Version.cormorant
lazy val `cormorant-generic`      = "io.chrisdavenport"       %% "cormorant-generic"        % Version.cormorant
lazy val `cormorant-parser`       = "io.chrisdavenport"       %% "cormorant-parser"         % Version.cormorant
lazy val `cormorant-http4s`       = "io.chrisdavenport"       %% "cormorant-http4s"         % Version.cormorant
lazy val `cormorant-refined`      = "io.chrisdavenport"       %% "cormorant-refined"        % Version.cormorant

当我编译它时：sbt-compile，它出现了这个错误：

[error] /home/javier/IdeaProjects/ERPFetcherJavs/src/main/scala/com/arkondata/bipo/utils/CSVHandler.scala:11:53: could not find implicit value for parameter gen: shapeless.LabelledGeneric.Aux[A,H]
[error]   private implicit val lr: LabelledRead[ItemData] = deriveLabelledRead
[error]                                                     ^
[error] /home/javier/IdeaProjects/ERPFetcherJavs/src/main/scala/com/arkondata/bipo/utils/CSVHandler.scala:13:54: could not find implicit value for parameter gen: shapeless.LabelledGeneric.Aux[A,H]
[error]   private implicit val lw: LabelledWrite[ItemData] = deriveLabelledWrite
[error]                                                      ^
[error] two errors found
[error] (Compile / compileIncremental) Compilation failed

我该怎么修？？

Answer 1

假设ItemData是一个简单的case类，例如：

case class ItemData(a: String)

然后，当运行上面的代码时，上面的错误会再次出现。为什么会发生这种情况？

deriveLabelledRead是package io.chrisdavenport.cormorant.generic的一种方法，它包含两个隐含项：

def deriveLabelledRead[A, H <: HList](
implicit gen: LabelledGeneric.Aux[A, H],
hlw: Lazy[LabelledRead[H]])

在阅读了文档后，我们需要做一堆导入：

import io.chrisdavenport.cormorant._
import io.chrisdavenport.cormorant.generic.semiauto._
import io.chrisdavenport.cormorant.parser._
import io.chrisdavenport.cormorant.implicits._
import cats.implicits._
import java.util.UUID
import java.time.Instant

导入这些内容时，deriveLabelledRead具有正确创建所需的隐含项。