/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package typechecker
/** Mode constants.
*/
trait Modes {
/** NOmode, EXPRmode and PATTERNmode are mutually exclusive.
*/
final val NOmode = 0x000
final val EXPRmode = 0x001
final val PATTERNmode = 0x002
/** TYPEmode needs a comment. <-- XXX.
*/
final val TYPEmode = 0x004
/** SCCmode is orthogonal to above. When set we are
* in the this or super constructor call of a constructor.
*/
final val SCCmode = 0x008
/** FUNmode is orthogonal to above.
* When set we are looking for a method or constructor.
*/
final val FUNmode = 0x010
/** POLYmode is orthogonal to above.
* When set expression types can be polymorphic.
*/
final val POLYmode = 0x020
/** QUALmode is orthogonal to above. When set
* expressions may be packages and Java statics modules.
*/
final val QUALmode = 0x040
/** TAPPmode is set for the function/type constructor
* part of a type application. When set we do not decompose PolyTypes.
*/
final val TAPPmode = 0x080
/** SUPERCONSTRmode is set for the super
* in a superclass constructor call super.<init>.
*/
final val SUPERCONSTRmode = 0x100
/** SNDTRYmode indicates that an application is typed for the 2nd time.
* In that case functions may no longer be coerced with implicit views.
*/
final val SNDTRYmode = 0x200
/** LHSmode is set for the left-hand side of an assignment.
*/
final val LHSmode = 0x400
/** STARmode is set when star patterns are allowed.
* (This was formerly called REGPATmode.)
*/
final val STARmode = 0x1000
/** ALTmode is set when we are under a pattern alternative.
*/
final val ALTmode = 0x2000
/** HKmode is set when we are typing a higher-kinded type.
* adapt should then check kind-arity based on the prototypical type's
* kind arity. Type arguments should not be inferred.
*/
final val HKmode = 0x4000 // @M: could also use POLYmode | TAPPmode
/** BYVALmode is set when we are typing an expression
* that occurs in a by-value position. An expression e1 is in by-value
* position within expression e2 iff it will be reduced to a value at that
* position during the evaluation of e2. Examples are by-value function
* arguments or the conditional of an if-then-else clause.
* This mode has been added to support continuations.
*/
final val BYVALmode = 0x8000
/** TYPEPATmode is set when we are typing a type in a pattern.
*/
final val TYPEPATmode = 0x10000
/** RETmode is set when we are typing a return expression.
*/
final val RETmode = 0x20000
final private val StickyModes = EXPRmode | PATTERNmode | TYPEmode | ALTmode
final def onlyStickyModes(mode: Int) =
mode & StickyModes
final def forFunMode(mode: Int) =
mode & (StickyModes | SCCmode) | FUNmode | POLYmode | BYVALmode
final def forTypeMode(mode: Int) =
if (inAnyMode(mode, PATTERNmode | TYPEPATmode)) TYPEmode | TYPEPATmode
else TYPEmode
final def inAllModes(mode: Int, required: Int) = (mode & required) == required
final def inAnyMode(mode: Int, required: Int) = (mode & required) != 0
final def inNoModes(mode: Int, prohibited: Int) = (mode & prohibited) == 0
final def inHKMode(mode: Int) = (mode & HKmode) != 0
final def inFunMode(mode: Int) = (mode & FUNmode) != 0
final def inPolyMode(mode: Int) = (mode & POLYmode) != 0
final def inPatternMode(mode: Int) = (mode & PATTERNmode) != 0
final def inExprModeOr(mode: Int, others: Int) = (mode & (EXPRmode | others)) != 0
final def inExprModeButNot(mode: Int, prohibited: Int) =
(mode & (EXPRmode | prohibited)) == EXPRmode
/** Translates a mask of mode flags into something readable.
*/
private val modeNameMap = Map[Int, String](
(1 << 0) -> "EXPRmode",
(1 << 1) -> "PATTERNmode",
(1 << 2) -> "TYPEmode",
(1 << 3) -> "SCCmode",
(1 << 4) -> "FUNmode",
(1 << 5) -> "POLYmode",
(1 << 6) -> "QUALmode",
(1 << 7) -> "TAPPmode",
(1 << 8) -> "SUPERCONSTRmode",
(1 << 9) -> "SNDTRYmode",
(1 << 10) -> "LHSmode",
(1 << 11) -> "<DOES NOT EXIST mode>",
(1 << 12) -> "STARmode",
(1 << 13) -> "ALTmode",
(1 << 14) -> "HKmode",
(1 << 15) -> "BYVALmode",
(1 << 16) -> "TYPEPATmode"
)
def modeString(mode: Int): String =
if (mode == 0) "NOmode"
else (modeNameMap filterKeys (bit => inAllModes(mode, bit))).values mkString " "
}
