DIRECTORYBasics, D2Basic, Rope, RTBasic;RTBasicImpl: CEDAR PROGRAMEXPORTS RTBasic = BEGINError: PUBLIC ERROR[errorType: RTBasic.ErrorType _ callingError, explanation: Rope.ROPE _ NIL] = CODE;Signal: PUBLIC SIGNAL[signalType: RTBasic.ErrorType _ callingError, explanation: Rope.ROPE _ NIL] = CODE;OtherSide: PUBLIC PROCEDURE [side: RTBasic.Side]RETURNS [RTBasic.Side] = {RETURN[otherSide[side]]};OtherDirection: PUBLIC PROCEDURE [direction: RTBasic.Direction]RETURNS [RTBasic.Direction] = {RETURN[otherDirection[direction]]};OtherRelation: PUBLIC PROCEDURE [aboveOrBelow: RTBasic.AboveOrBelow]RETURNS [RTBasic.AboveOrBelow] = {RETURN[otherRelation[aboveOrBelow]]};SimpleCompare: PUBLIC PROCEDURE [result1, result2: D2Basic.Number]RETURNS [result: Basics.Comparison] = {result _ IF result1 < result2 THEN lessELSE IF result1 > result2 THEN greaterELSE equal};XYToPQ: PUBLIC PROC [pDir: RTBasic.Direction, pos: D2Basic.Vector] RETURNS [pqPos: RTBasic.PQPos] = {SELECT pDir FROMhorizontal => pqPos _ [pos.x, pos.y];vertical => pqPos _ [pos.y, pos.x];ENDCASE};PQToXY: PUBLIC PROC [pDir: RTBasic.Direction, pqPos: RTBasic.PQPos] RETURNS [pos: D2Basic.Vector] = {SELECT pDir FROMhorizontal => pos _ [pqPos.p, pqPos.q];vertical => pos _ [pqPos.q, pqPos.p];ENDCASE};sideName: PUBLIC ARRAY RTBasic.Side OF Rope.ROPE _ ["bottom", "top", "left", "right"];otherRelation: ARRAY RTBasic.AboveOrBelow OF RTBasic.AboveOrBelow _ [below, above];otherDirection: ARRAY RTBasic.Direction OF RTBasic.Direction _ [vertical, horizontal];otherSide: ARRAY RTBasic.Side OF RTBasic.Side _ [top, bottom, right, left];END.     RTBasicImpl.mesaCopyright Ó 1986, 1987 by Xerox Corporation.  All rights reserved.last edited by Bryan Preas   April 19, 1987 4:08:10 pm PDTSignals and ErrorsProceduresconvert a position from x-y to p-q space.convert a position from p-q to x-y space.Variables Ê$  ˜ šœ™IcodešœB™BJšœ:™:—J˜ šÏk	˜	Jšœ˜J˜ —šœœ˜Jšœ
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