
    <<MesaPS.mesa>>
        <<Copyright © 1986 by Xerox Corporation.  All rights reserved.>>
        <<Doug Wyatt, October 10, 1986 6:29:16 pm PDT>>

    DIRECTORY
        CountedVM USING [Handle],
        Imager USING [Context],
        Random USING [RandomStream];

    PS: DEFINITIONS
    ~ BEGIN
<<Types>>
    Any: TYPE ~ RECORD [
        executable: BOOL,
        variant: SELECT type: Type FROM
            null => [],
            integer => [int: INT],
            real => [real: REAL],
            boolean => [bool: BOOL],
            array => [access: Access, finger: ArrayFinger, start, length: ArrayIndex],
            string => [access: Access, finger: StringFinger, start, length: StringIndex],
            name => [id: NameID],
            dict => [finger: DictFinger],
            operator => [op: Op],
            file => [access: Access, id: StreamID],
            mark => [stop: BOOL _ FALSE],
            save => [level: Level],
            fontID => [],
            ENDCASE
        ];

    null: Any ~ [executable: FALSE, variant: null[]];

    Array: TYPE ~ Any[array];
    Proc: TYPE ~ Array; -- executable
    String: TYPE ~ Any[string];
    Name: TYPE ~ Any[name];
    Dict: TYPE ~ Any[dict];
    Operator: TYPE ~ Any[operator];
    File: TYPE ~ Any[file];

    Type: TYPE ~ {null, integer, real, boolean, array, string, name, dict, operator, file, mark, save, fontID, stop};

    Access: TYPE ~ {none, executeOnly, readOnly, unlimited}; 

    Level: TYPE ~ CARDINAL;

    ArrayIndex: TYPE ~ CARDINAL;
    ArrayFinger: TYPE ~ LONG POINTER TO ArrayDescriptor;
    ArrayDescriptor: TYPE ~ RECORD [pointer: ArrayPointer, size: ArrayIndex];
    ArrayPointer: TYPE ~ LONG POINTER TO ArrayBody;
    ArrayBody: TYPE ~ RECORD [SEQUENCE COMPUTED ArrayIndex OF Any];

    StringIndex: TYPE ~ CARDINAL;
    StringFinger: TYPE ~ LONG POINTER TO StringDescriptor;
    StringDescriptor: TYPE ~ RECORD [pointer: StringPointer, size: StringIndex];
    StringPointer: TYPE ~ LONG POINTER TO StringBody;
    StringBody: TYPE ~ RECORD [PACKED SEQUENCE COMPUTED StringIndex OF CHAR];

    DictIndex: TYPE ~ CARDINAL;
    DictFinger: TYPE ~ LONG POINTER TO DictPointer;
    DictPointer: TYPE ~ LONG POINTER TO DictBody;
    DictBody: TYPE ~ RECORD [access: Access, maxLength, length: DictIndex, 
    tuples: SEQUENCE COMPUTED DictIndex OF Tuple];
    TuplePointer: TYPE ~ LONG POINTER TO Tuple;
    Tuple: TYPE ~ RECORD [key: Any, value: Any];

    NameID: TYPE ~ CARDINAL;
    StreamID: TYPE ~ CARDINAL;

    Op: TYPE ~ PROC [self: Root];

    Error: ERROR [errorName: Name];
    ErrorType: TYPE ~ {dictfull, dictstackoverflow, dictstackunderflow, execstackoverflow, handleerror, interrupt, invalidaccess, 
    invalidexit, invalidfileaccess, invalidfont, invalidrestore, ioerror, limitcheck, nocurrentpoint, rangecheck, stackoverflow, 
    stackunderflow, syntaxerror, timeout, typecheck, undefined, undefinedfilename, undefinedresult, unmatchedmark, unregistered, 
    VMerror};

    Stack: TYPE ~ LONG POINTER TO StackDescriptor;
    StackDescriptor: TYPE ~ RECORD [
        pointer: ArrayPointer,
        count, size: ArrayIndex,
        underflow, overflow: Name
        ];

    Root: TYPE ~ REF RootRep;
    RootRep: TYPE ~ RECORD [
        zone: UNCOUNTED ZONE,
        vm: CountedVM.Handle,
        pointer: LONG POINTER,
        ostack, estack, dstack: Stack,
        xfor: Operator,
        xrepeat: Operator,
        xloop: Operator,
        xforall: Operator,
        random: Random.RandomStream,
        imager: Imager.Context
        ];

    Path: TYPE ~ REF PathRep;
    PathRep: TYPE ~ RECORD [subPaths: LIST OF SubPath];
    SubPath: TYPE ~ REF SubPathRep;
    SubPathRep: TYPE ~ RECORD [closed: BOOL, points: LIST OF PathPoint];
    PathPoint: TYPE ~ REF PathPointRep;
    PathPointRep: TYPE ~ RECORD [control: BOOL, p: VEC];

    LineCap: TYPE ~ Imager.StrokeEnd; -- {butt, round, square}
    LineJoin: TYPE ~ Imager.StrokeJoint; -- {miter, round, bevel}

    DashIndex: TYPE ~ [0..dashLimit);
    DashArray: TYPE ~ ARRAY [0..dashLimit) OF REAL;

    GState: TYPE ~ REF GStateRep;
    GStateRep: TYPE ~ RECORD [
        CTM: Imager.Transformation,
        color: Imager.ConstantColor,
        position: VEC,
        path: Path,
        clipPath: Path,
        font: Dict,
        lineWidth: REAL,
        lineCap: LineCap,
        lineJoin: LineJoin,
        screen: HalftoneScreen,
        transfer: Proc, -- proc
        flatness: REAL,
        miterLimit: REAL,
        dashPatternLength: ArrayIndex,
        dashPatternArray: REF DashArray,
        device: xxx
        ];


    END.