DIRECTORYBasics, DABasics, 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: DABasics.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: DABasics.Position] 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: DABasics.Position] = {SELECT pDir FROMhorizontal => pos _ [pqPos.p, pqPos.q];vertical => pos _ [pqPos.q, pqPos.p];ENDCASE};Overlap: PUBLIC PROC [r1, r2: RTBasic.Range] RETURNS [overlap: RTBasic.Range] = {IF r2.l <= r1.l AND r1.l <= r2.r THENoverlap _ [r1.l, MIN[r1.r, r2.r]]ELSE IF r1.l <= r2.l AND r2.l <= r1.r THENoverlap _ [r2.l, MIN[r1.r, r2.r]]ELSEoverlap _ [MAX[r1.r, r2.r], MIN[r1.r, r2.r]]};Gap: PUBLIC PROC [r1, r2: RTBasic.Range] RETURNS [gap: RTBasic.Range] = {IF r2.r < r1.l  THENgap _ [r2.r, r1.l]ELSE IF r1.r < r2.l THENgap _ [r1.r, r2.l]ELSE gap _ [MAX[r1.r, r2.r], MIN[r1.r, r2.r]]};Span: PUBLIC PROC [r1, r2: RTBasic.Range] RETURNS [result: RTBasic.Range] = {result _ [MIN[r1.l, r2.l], MAX[r1.r, r2.r]]};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.  К  RTBasicImpl.mesaCopyright ╙ 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PQ Proceduresconvert a position from x-y to p-q space.convert a position from p-q to x-y space.Range Proceduresget the overlap of seg1, seg2get the gap of seg1, seg2determnie span of ranges 1 and 2VariablesЭ╩)  Ш ЪЬЩIcodeЪЬBЩBJЪЬ:Щ:ЧJШ Ъ╧k	Ш	JЪЬ Ш JШ ЧЪЬЭЬЭШJЪЭЬ
ЭШЧheadЩJЪ╧nЬЭЬЭЬ@ЭЬЭЬЭЬШfJЪЮЬЭЬЭЬAЭЬЭЬЭЬШiЧЪЬ
Щ
ЪЮ	ЬЭЬШ0ЪЭЬШJЪЬШЧJШ ЧЪЮЬЭЬШ?ЪЭЬШJЪЬ#Ш#ЧJШ ЧЪЮЬЭЬ%ШDЪЭЬШ"JЪЬ%Ш%ЧJШ ЧЪЮЬЭЬ$ШCЪЭЬ Ш'JШ JЪЬ	ЭЬЭЬШ'JЪЭЬЭЬЭЬШ&JЪЭЬШЧЧЧLЩШ ЪЮЬЭЬ3ЭЬШhJЩ)JШ ЪЭЬЭШJЪЬ%Ш%JЪЬ#Ш#JЪЭЬШ	ЧJЩ ЧЪЮЬЭЬ1ЭЬШhJЩ)JШ ЪЭЬЭШJЪЬ'Ш'JЪЬЭЬШ%JЪЭЬШ	ЧЧЧЩЪЮЬЭЬЭЬЭЬШQKЪЬЩKШ ЪЭЬЭЬЭШ%KЪЬЭЬШ!ЧЪЭЬЭЬЭЬЭШ*KЪЬЭЬШ!ЧЪЭШKЪЬЭЬЭЬШ.ЧKШ ЧЪЮЬЭЬЭЬЭЬШIKЪЬЩKШ ЪЭЬЭШKЪЬШЧЪЭЬЭЬЭШKЪЬШЧKЪЭЬЭЬЭЬШ/KШ ЧЪЮЬЭЬЭЬЭЬШMKЩ KШ KЪЬ
ЭЬЭЬШ-ЧЧЩ	JЪЬ
ЭЬЭЬЭЬ&ШVJЪЬSШSJЪЬЭЬЭЬ,ШVJЪЬЭЬЭЬ+ШKJЪЭЬШJШ ЧJШ Ч ЕЧ    ╪  Л  