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@guilgaly
Last active June 2, 2024 19:50
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Scala compiler options I typically use
val scalacOptions = Seq(
"-encoding",
"utf-8", // Specify character encoding used by source files.
"-Ybackend-parallelism", //
"8",
"-explaintypes", // Explain type errors in more detail.
"-feature", // Emit warning and location for usages of features that should be imported explicitly.
"-unchecked", // Enable additional warnings where generated code depends on assumptions.
"-Xcheckinit", // Wrap field accessors to throw an exception on uninitialized access.
// "-Ymacro-annotations", // Enable support for macro annotations, formerly in macro paradise.
// ********** -language: Enable or disable language features *****************
// "-language:dynamics", //Allow direct or indirect subclasses of scala.Dynamic
// "-language:existentials", // Existential types (besides wildcard types) can be written and inferred
// "-language:higherKinds", // Allow higher-kinded types
// "-language:implicitConversions", // Allow definition of implicit functions called views
// "-language:postfixOps", // Allow postfix operator notation, such as 1 to 10 toList (not recommended)
// "-language:reflectiveCalls", // Allow reflective access to members of structural types
// "-language:experimental.macros", // Allow macro definition (besides implementation and application)
// ********** Warning Settings ***********************************************
"-Werror", // Fail the compilation if there are any warnings.
"-Wdead-code", // Warn when dead code is identified.
"-Wextra-implicit", // Warn when more than one implicit parameter section is defined.
// "-Wmacros:none", // Do not inspect expansions or their original trees when generating unused symbol warnings.
// "-Wmacros:before", // Only inspect unexpanded user-written code for unused symbols. (Default)
"-Wmacros:after", // Only inspect expanded trees when generating unused symbol warnings.
// "-Wmacros:both", // Inspect both user-written code and expanded trees when generating unused symbol warnings.
"-Wnumeric-widen", // Warn when numerics are widened.
"-Woctal-literal", // Warn on obsolete octal syntax.
// "-Wself-implicit", // Warn when an implicit resolves to an enclosing self-definition.
"-Wunused:imports", //Warn if an import selector is not referenced.
"-Wunused:patvars", // Warn if a variable bound in a pattern is unused.
"-Wunused:privates", // Warn if a private member is unused.
"-Wunused:locals", // Warn if a local definition is unused.
"-Wunused:explicits", // Warn if an explicit parameter is unused.
"-Wunused:implicits", // Warn if an implicit parameter is unused.
"-Wunused:params", // Enable -Wunused:explicits,implicits.
"-Wvalue-discard", // Warn when non-Unit expression results are unused.
// ********** -Xlint: Enable recommended warnings ****************************
"-Xlint:adapted-args", // Warn if an argument list is modified to match the receiver.
"-Xlint:nullary-unit", // Warn when nullary methods return Unit.
"-Xlint:inaccessible", // Warn about inaccessible types in method signatures.
"-Xlint:infer-any", // Warn when a type argument is inferred to be Any.
// "-Xlint:missing-interpolator", // A string literal appears to be missing an interpolator id.
"-Xlint:doc-detached", // A Scaladoc comment appears to be detached from its element.
"-Xlint:private-shadow", // A private field (or class parameter) shadows a superclass field.
"-Xlint:type-parameter-shadow", // A local type parameter shadows a type already in scope.
"-Xlint:poly-implicit-overload", // Parameterized overloaded implicit methods are not visible as view bounds.
"-Xlint:option-implicit", // Option.apply used implicit view.
"-Xlint:delayedinit-select", // Selecting member of DelayedInit.
"-Xlint:package-object-classes", // Class or object defined in package object.
"-Xlint:stars-align", // Pattern sequence wildcard must align with sequence component.
"-Xlint:constant", // Evaluation of a constant arithmetic expression results in an error.
"-Xlint:nonlocal-return", // A return statement used an exception for flow control.
"-Xlint:implicit-not-found", // Check @implicitNotFound and @implicitAmbiguous messages.
"-Xlint:serial", // @SerialVersionUID on traits and non-serializable classes.
"-Xlint:valpattern", // Enable pattern checks in val definitions.
"-Xlint:eta-zero", // Warn on eta-expansion (rather than auto-application) of zero-ary method.
"-Xlint:eta-sam", // Warn on eta-expansion to meet a Java-defined functional interface that is not explicitly annotated with @FunctionalInterface.
"-Xlint:deprecation", // Enable linted deprecations.
)
val scalacOptions = Seq(
"-encoding",
"utf-8", // Specify character encoding used by source files.
"-Ybackend-parallelism", // maximum worker threads for backend
"8",
"-explaintypes", // Explain type errors in more detail.
"-feature", // Emit warning and location for usages of features that should be imported explicitly.
"-unchecked", // Enable additional warnings where generated code depends on assumptions.
"-Xcheckinit", // Wrap field accessors to throw an exception on uninitialized access.
"-Ypartial-unification", // Enable partial unification in type constructor inference.
"-Yno-adapted-args", // Do not adapt an argument list (either by inserting () or creating a tuple) to match the receiver.
"-deprecation", // Emit warning and location for usages of deprecated APIs.
// ********** -language: Enable or disable language features *****************
// "-language:dynamics", //Allow direct or indirect subclasses of scala.Dynamic
// "-language:existentials", // Existential types (besides wildcard types) can be written and inferred
// "-language:higherKinds", // Allow higher-kinded types
// "-language:implicitConversions", // Allow definition of implicit functions called views
// "-language:postfixOps", // Allow postfix operator notation, such as 1 to 10 toList (not recommended)
// "-language:reflectiveCalls", // Allow reflective access to members of structural types
// "-language:experimental.macros", // Allow macro definition (besides implementation and application)
// ********** Warning Settings ***********************************************
"-Xfatal-warnings", // Fail the compilation if there are any warnings.
"-Ywarn-dead-code", // Warn when dead code is identified.
"-Ywarn-extra-implicit", // Warn when more than one implicit parameter section is defined.
// "-Ywarn-macros:none", // Do not inspect expansions or their original trees when generating unused symbol warnings.
// "-Ywarn-macros:before", // Only inspect unexpanded user-written code for unused symbols. (Default)
"-Ywarn-macros:after", // Only inspect expanded trees when generating unused symbol warnings.
// "-Ywarn-macros:both", // Inspect both user-written code and expanded trees when generating unused symbol warnings.
"-Ywarn-numeric-widen", // Warn when numerics are widened.
"-Ywarn-unused:implicits", // Warn if an implicit parameter is unused.
"-Ywarn-unused:imports", // Warn if an import selector is not referenced.
"-Ywarn-unused:locals", // Warn if a local definition is unused.
"-Ywarn-unused:params", // Warn if a value parameter is unused.
"-Ywarn-unused:patvars", // Warn if a variable bound in a pattern is unused.
"-Ywarn-unused:privates", // Warn if a private member is unused.
"-Ywarn-value-discard", // Warn when non-Unit expression results are unused.
// ********** -Xlint: Enable recommended warnings ****************************
"-Xlint:adapted-args", // Warn if an argument list is modified to match the receiver.
"-Xlint:nullary-unit", // Warn when nullary methods return Unit.
"-Xlint:inaccessible", // Warn about inaccessible types in method signatures.
"-Xlint:nullary-override", // Warn when non-nullary `def f()' overrides nullary `def f'.
"-Xlint:infer-any", // Warn when a type argument is inferred to be `Any`.
// "-Xlint:missing-interpolator", // A string literal appears to be missing an interpolator id.
"-Xlint:doc-detached", // A Scaladoc comment appears to be detached from its element.
"-Xlint:private-shadow", // A private field (or class parameter) shadows a superclass field.
"-Xlint:type-parameter-shadow", // A local type parameter shadows a type already in scope.
"-Xlint:poly-implicit-overload", // Parameterized overloaded implicit methods are not visible as view bounds.
"-Xlint:option-implicit", // Option.apply used implicit view.
"-Xlint:delayedinit-select", // Selecting member of DelayedInit.
"-Xlint:package-object-classes", // Class or object defined in package object.
"-Xlint:stars-align", // Pattern sequence wildcard must align with sequence component.
"-Xlint:constant", // Evaluation of a constant arithmetic expression results in an error.
"-Xlint:by-name-right-associative", // By-name parameter of right associative operator.
"-Xlint:unsound-match", // Pattern match may not be typesafe.
)
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