如何将`sbt`配置为不显示警告“警告对象*中的私有默认参数从未使用”

Question

我有一个 scala 编译器 2.12.11，编译器会打印一些警告，例如：
private default argument in class SomeClass is never used 在使用时。

我见过Scala 2.12.2 emits a ton of useless "Warning: parameter value ... in method ... is never used" warnings. How to get rid of them?，但它对我没有帮助，因为不可能否定params。
你能帮我取消这个警告，但保存另一个unused 警告吗？目前，我有-Xlint 选项。

Answer 1

您可以手动打开特定选项，而不是批处理-Xlint。在 2.13 中，我可以打印这样的可用选项：

scalac -Xlint:help
Enable recommended warnings
  adapted-args            An argument list was modified to match the receiver.
  nullary-unit            `def f: Unit` looks like an accessor; add parens to look side-effecting.
  inaccessible            Warn about inaccessible types in method signatures.
  infer-any               A type argument was inferred as Any.
  missing-interpolator    A string literal appears to be missing an interpolator id.
  doc-detached            When running scaladoc, warn if a doc comment is discarded.
  private-shadow          A private field (or class parameter) shadows a superclass field.
  type-parameter-shadow   A local type parameter shadows a type already in scope.
  poly-implicit-overload  Parameterized overloaded implicit methods are not visible as view bounds.
  option-implicit         Option.apply used an implicit view.
  delayedinit-select      Selecting member of DelayedInit.
  package-object-classes  Class or object defined in package object.
  stars-align             In a pattern, a sequence wildcard `_*` should match all of a repeated parameter.
  strict-unsealed-patmat  Pattern match on an unsealed class without a catch-all.
  constant                Evaluation of a constant arithmetic expression resulted in an error.
  unused                  Enable -Wunused:imports,privates,locals,implicits,nowarn.
  nonlocal-return         A return statement used an exception for flow control.
  implicit-not-found      Check @implicitNotFound and @implicitAmbiguous messages.
  serial                  @SerialVersionUID on traits and non-serializable classes.
  valpattern              Enable pattern checks in val definitions.
  eta-zero                Usage `f` of parameterless `def f()` resulted in eta-expansion, not empty application `f()`.
  eta-sam                 The Java-defined target interface for eta-expansion was not annotated @FunctionalInterface.
  deprecation             Enable -deprecation and also check @deprecated annotations.
  byname-implicit         Block adapted by implicit with by-name parameter.
  recurse-with-default    Recursive call used default argument.
  unit-special            Warn for specialization of Unit in parameter position.
  multiarg-infix          Infix operator was defined or used with multiarg operand.
  implicit-recursion      Implicit resolves to an enclosing definition.
Default: All choices are enabled by default.

所以我可以例如启用-Xlint:inaccessible -Xlint:adapted-args -Wunused:privates,locales 或我想要的任何东西，而不是一切。对于 2.12，这个列表会有所不同。 （也可以查看scalac -X、scalac -Y和scalac -W）。

另一种方法是在您有意识地“破坏”某些内容时启用警告并抑制它们。对于未使用的，您有 @scala.annotation.unused，对于 2.12 和之前的其他警告，有 silencer 插件，从 2.13 开始有 @scala.annotation.nowarn 注释。