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Scala example source code file (HasFlags.scala)
The HasFlags.scala Scala example source codepackage scala package reflect package internal import Flags._ /** Common code utilized by Modifiers (which carry the flags associated * with Trees) and Symbol. */ trait HasFlags { type AccessBoundaryType type AnnotationType /** Though both Symbol and Modifiers widen this method to public, it's * defined protected here to give us the option in the future to route * flag methods through accessors and disallow raw flag manipulation. * And after that, perhaps, on some magical day: a typesafe enumeration. */ protected def flags: Long /** Access level encoding: there are three scala flags (PRIVATE, PROTECTED, * and LOCAL) which combine with value privateWithin (the "foo" in private[foo]) * to define from where an entity can be accessed. The meanings are as follows: * * PRIVATE access restricted to class only. * PROTECTED access restricted to class and subclasses only. * LOCAL can only be set in conjunction with PRIVATE or PROTECTED. * Further restricts access to the same object instance. * * In addition, privateWithin can be used to set a visibility barrier. * When set, everything contained in the named enclosing package or class * has access. It is incompatible with PRIVATE or LOCAL, but is additive * with PROTECTED (i.e. if either the flags or privateWithin allow access, * then it is allowed.) * * The java access levels translate as follows: * * java private: hasFlag(PRIVATE) && !hasAccessBoundary * java package: !hasFlag(PRIVATE | PROTECTED) && (privateWithin == enclosing package) * java protected: hasFlag(PROTECTED) && (privateWithin == enclosing package) * java public: !hasFlag(PRIVATE | PROTECTED) && !hasAccessBoundary */ def privateWithin: AccessBoundaryType /** A list of annotations attached to this entity. */ def annotations: List[AnnotationType] /** Whether this entity has a "privateWithin" visibility barrier attached. */ def hasAccessBoundary: Boolean /** Whether this entity has ANY of the flags in the given mask. */ def hasFlag(flag: Long): Boolean /** Whether this entity has ALL of the flags in the given mask. */ def hasAllFlags(mask: Long): Boolean /** Whether this entity has NONE of the flags in the given mask. */ def hasNoFlags(mask: Long): Boolean = !hasFlag(mask) /** The printable representation of this entity's flags and access boundary, * restricted to flags in the given mask. */ def flagString: String = flagString(flagMask) def flagString(mask: Long): String = calculateFlagString(flags & mask) /** The default mask determining which flags to display. */ def flagMask: Long = AllFlags /** The string representation of a single bit, seen from this * flag carrying entity. */ def resolveOverloadedFlag(flag: Long): String = Flags.flagToString(flag) // Tests which come through cleanly: both Symbol and Modifiers use these // identically, testing for a single flag. def hasAbstractFlag = hasFlag(ABSTRACT) def hasAccessorFlag = hasFlag(ACCESSOR) def hasDefault = hasFlag(DEFAULTPARAM) && hasFlag(METHOD | PARAM) // Second condition disambiguates with TRAIT def hasEnumFlag = hasFlag(ENUM) @deprecated("Use isLocalToThis instead", "2.11.0") def hasLocalFlag = hasFlag(LOCAL) def isLocalToThis = hasFlag(LOCAL) def hasModuleFlag = hasFlag(MODULE) def hasPackageFlag = hasFlag(PACKAGE) def hasStableFlag = hasFlag(STABLE) def hasStaticFlag = hasFlag(STATIC) def isAbstractOverride = hasFlag(ABSOVERRIDE) def isAnyOverride = hasFlag(OVERRIDE | ABSOVERRIDE) def isCase = hasFlag(CASE) def isCaseAccessor = hasFlag(CASEACCESSOR) def isDeferred = hasFlag(DEFERRED) def isFinal = hasFlag(FINAL) def isArtifact = hasFlag(ARTIFACT) def isImplicit = hasFlag(IMPLICIT) def isInterface = hasFlag(INTERFACE) def isJavaDefined = hasFlag(JAVA) def isLabel = hasAllFlags(LABEL | METHOD) && !hasAccessorFlag def isLazy = hasFlag(LAZY) def isLifted = hasFlag(LIFTED) def isMacro = hasFlag(MACRO) def isMutable = hasFlag(MUTABLE) def isOverride = hasFlag(OVERRIDE) def isParamAccessor = hasFlag(PARAMACCESSOR) def isPrivate = hasFlag(PRIVATE) @deprecated ("Use `hasPackageFlag` instead", "2.11.0") def isPackage = hasFlag(PACKAGE) def isPrivateLocal = hasAllFlags(PrivateLocal) def isProtected = hasFlag(PROTECTED) def isProtectedLocal = hasAllFlags(ProtectedLocal) def isPublic = hasNoFlags(PRIVATE | PROTECTED) && !hasAccessBoundary def isSealed = hasFlag(SEALED) def isSpecialized = hasFlag(SPECIALIZED) def isSuperAccessor = hasFlag(SUPERACCESSOR) def isSynthetic = hasFlag(SYNTHETIC) def isTrait = hasFlag(TRAIT) && !hasFlag(PARAM) def isDeferredOrDefault = hasFlag(DEFERRED | DEFAULTMETHOD) def isDeferredNotDefault = isDeferred && !hasFlag(DEFAULTMETHOD) def flagBitsToString(bits: Long): String = { // Fast path for common case if (bits == 0L) "" else { var sb: StringBuilder = null var i = 0 while (i <= MaxBitPosition) { val flag = Flags.rawFlagPickledOrder(i) if ((bits & flag) != 0L) { val s = resolveOverloadedFlag(flag) if (s.length > 0) { if (sb eq null) sb = new StringBuilder append s else if (sb.length == 0) sb append s else sb append " " append s } } i += 1 } if (sb eq null) "" else sb.toString } } def accessString: String = { val pw = if (hasAccessBoundary) privateWithin.toString else "" if (pw == "") { if (hasAllFlags(PrivateLocal)) "private[this]" else if (hasAllFlags(ProtectedLocal)) "protected[this]" else if (hasFlag(PRIVATE)) "private" else if (hasFlag(PROTECTED)) "protected" else "" } else if (hasFlag(PROTECTED)) "protected[" + pw + "]" else "private[" + pw + "]" } protected def calculateFlagString(basis: Long): String = { val access = accessString val nonAccess = flagBitsToString(basis & ~AccessFlags) if (access == "") nonAccess else if (nonAccess == "") access else nonAccess + " " + access } // Guess this can't be deprecated seeing as it's in the reflect API. def isParameter = hasFlag(PARAM) } Other Scala source code examplesHere is a short list of links related to this Scala HasFlags.scala source code file: |
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