<<>>
    <<VersionMap2Implr.Mesa>>
        <<Copyright Ó 1990 by Xerox Corporation.  All rights reserved.>>
        <<Last tweaked by Mike Spreitzer on August 16, 1990 12:08:59 pm PDT>>

    DIRECTORY IO, Rope, VersionMap2;

    VersionMap2Implr: CEDAR DEFINITIONS = {OPEN VersionMap2;
        <<Stuff useful to implementors of MapClasses.>>

        FillinDefaults: PROC [functional: BOOL, mutability: Mutability, classRep: MapClassRep] RETURNS [MapClass];

        AlwaysFunctional: PROC [map: Map] RETURNS [BOOL];
        NeverFunctional: PROC [map: Map] RETURNS [BOOL];
        AlwaysConstant: PROC [map: Map] RETURNS [Mutability];
        AlwaysReadonly: PROC [map: Map] RETURNS [Mutability];
        AlwaysWritable: PROC [map: Map] RETURNS [Mutability];
        HasByScan: PROC [map: Map, elt: VersionTuple] RETURNS [BOOL];

        ScanProc: TYPE ~ PROC [map: Map, Consume: TupleConsumer, inOrder: BOOL, pfml: PatternFactoredMapList] RETURNS [MaybeTuple];
        ScanByGenerate: ScanProc;
        SortScan: PROC [map: Map, Scan: ScanProc, Consume: TupleConsumer, pfml: PatternFactoredMapList] RETURNS [MaybeTuple];
        FilterScan: PROC [map: Map, Scan: ScanProc, Consume: TupleConsumer, inOrder: BOOL, pfml: PatternFactoredMapList] RETURNS 
        [MaybeTuple];
        CantScan: ScanProc;

        GenerateByScan: PROC [map: Map, inOrder: BOOL, pfml: PatternFactoredMapList] RETURNS [Generator];
        CantGenerate: PROC [map: Map, inOrder: BOOL, pfml: PatternFactoredMapList] RETURNS [Generator];

        SizeByScan: PROC [map: Map, limit: INT] RETURNS [INT];
        FullSize: PROC [map: Map, limit: INT] RETURNS [INT];
        DefaultPatternFactorMap: PROC [map: Map] RETURNS [PatternFactoredMap];
        CantAddTuple: PROC [map: Map, t: VersionTuple, if: IfHads] RETURNS [had: Hads];
        AddTupleBySingleton: PROC [map: Map, t: VersionTuple, if: IfHads] RETURNS [had: Hads];
        CantAddMap: PROC [map, other: Map, if: IfHads] RETURNS [some: HadSets];
        AddMapByTuples: PROC [map, other: Map, if: IfHads] RETURNS [some: HadSets];
        CantRemTuple: PROC [map: Map, t: VersionTuple] RETURNS [had: Hads];
        RemTupleBySingleton: PROC [map: Map, t: VersionTuple] RETURNS [had: Hads];
        CantRemMap: PROC [map, other: Map] RETURNS [some: HadSets];
        RemMapByTuples: PROC [map, other: Map] RETURNS [some: HadSets];
        DefaultNegate: PROC [map: Map] RETURNS [Map];
        DefaultIsNegation: PROC [map: Map] RETURNS [MaybeMap];
        DefaultIntersect: PROC [map, other: Map] RETURNS [Map];
        DefaultIsIntersection: PROC [map: Map] RETURNS [Maybe2Maps];
        DefaultUnion: PROC [map, other: Map, test: UnionTest, ordered: BOOL] RETURNS [Map];
        DefaultIsUnion: PROC [map: Map] RETURNS [Maybe2Maps];
        DefaultDifference: PROC [map, other: Map] RETURNS [Map];
        DefaultIsDifference: PROC [map: Map] RETURNS [Maybe2Maps];
        DefaultSymmetricDifference: PROC [map, other: Map] RETURNS [Map];
        DefaultIsSymmetricDifference: PROC [map: Map] RETURNS [Maybe2Maps];

        NamePatternAcceptsAll: PROC [pattern: Name, minDirBoundaries: NAT] RETURNS [BOOL];
            <<Returns TRUE iff the given pattern matches every tuple whose name has at least the given number of internal directory boundaries.>>

        CountAvailable: PROC [gen: Generator, limit: INT _ INT.LAST] RETURNS [INT];

        OcFromHad: PROC [had: Hads] RETURNS [OldCase]
            ~ INLINE {RETURN [ocFromHad[had[created]][had[stamp]]]};
            ocFromHad: ARRAY --created:--Had OF ARRAY --stamp:--Had OF OldCase
                = [
                    same: [same: same, different: stampDifferent, none: new],
                    different: [same: createdDifferent, different: bothDifferent, none: new],
                    none: ALL[new] ];

        Cant: PROC [info: REF ANY, fmt: ROPE, v1, v2, v3, v4, v5: IO.Value _ [null[]]];
            <<Raises the error that means unimplemented.>>

        DullClose: PROC [Generator];

        }.