package dotty.tools.dotc.core
/** A collection of mode bits that are part of a context */
case class Mode(val bits: Int) extends AnyVal {
import Mode._
def | (that: Mode) = Mode(bits | that.bits)
def & (that: Mode) = Mode(bits & that.bits)
def &~ (that: Mode) = Mode(bits & ~that.bits)
def is (that: Mode) = (bits & that.bits) == that.bits
def isExpr = (this & PatternOrType) == None
override def toString =
(0 until 31).filter(i => (bits & (1 << i)) != 0).map(modeName).mkString("Mode(", ",", ")")
}
object Mode {
val None = Mode(0)
private val modeName = new Array[String](32)
def newMode(bit: Int, name: String): Mode = {
modeName(bit) = name
Mode(1 << bit)
}
val Pattern = newMode(0, "Pattern")
val Type = newMode(1, "Type")
val ImplicitsEnabled = newMode(2, "ImplicitsEnabled")
val InferringReturnType = newMode(3, "InferringReturnType")
/** This mode bit is set if we collect information without reference to a valid
* context with typerstate and constraint. This is typically done when we
* cache the eligibility of implicits. Caching needs to be done across different constraints.
* Therefore, if TypevarsMissContext is set, subtyping becomes looser, and assumes
* that TypeParamRefs can be sub- and supertypes of anything. See TypeComparer.
*/
val TypevarsMissContext = newMode(4, "TypevarsMissContext")
val CheckCyclic = newMode(5, "CheckCyclic")
val InSuperCall = newMode(6, "InSuperCall")
/** Allow GADTFlexType labelled types to have their bounds adjusted */
val GADTflexible = newMode(8, "GADTflexible")
/** Allow dependent functions. This is currently necessary for unpickling, because
* some dependent functions are passed through from the front end(s?), even though they
* are technically speaking illegal.
*/
val AllowDependentFunctions = newMode(9, "AllowDependentFunctions")
/** We are currently printing something: avoid to produce more logs about
* the printing
*/
val Printing = newMode(10, "Printing")
/** We are currently typechecking an ident to determine whether some implicit
* is shadowed - don't do any other shadowing tests.
*/
val ImplicitShadowing = newMode(11, "ImplicitShadowing")
/** We are currently in a `viewExists` check. In that case, ambiguous
* implicits checks are disabled and we succeed with the first implicit
* found.
*/
val ImplicitExploration = newMode(12, "ImplicitExploration")
/** We are currently unpickling Scala2 info */
val Scala2Unpickling = newMode(13, "Scala2Unpickling")
/** Use Scala2 scheme for overloading and implicit resolution */
val OldOverloadingResolution = newMode(14, "OldOverloadingResolution")
/** Allow hk applications of type lambdas to wildcard arguments;
* used for checking that such applications do not normally arise
*/
val AllowLambdaWildcardApply = newMode(15, "AllowHKApplyToWildcards")
/** Read original positions when unpickling from TASTY */
val ReadPositions = newMode(16, "ReadPositions")
val PatternOrType = Pattern | Type
/** We are elaborating the fully qualified name of a package clause.
* In this case, identifiers should never be imported.
*/
val InPackageClauseName = newMode(17, "InPackageClauseName")
}
