Filter für die Historie II

VirtualTour.om

PROCEDURE ProcessCommand; VAR ch1, ch2: CHAR; index1, index2: INTEGER; currentPos: Streams.Count; len: Streams.Count; ok: BOOLEAN; (* ... *) BEGIN (* ProcessCommand *) Streams.GetPos(history, currentPos); ch1 := line[1]; ch2 := line[2]; IF (ch1 >= "a") & (ch1 <= "z") THEN index1 := ORD(ch1) - ORD("a"); IF ch2 = 0X THEN marks[index1] := currentPos; ELSIF (ch2 >= "a") & (ch2 <= "z") THEN index2 := ORD(ch2) - ORD("a"); IF (marks[index1] >= 0) & (marks[index2] > marks[index1]) THEN len := marks[index2] - marks[index1]; Write.String("*** copying "); Write.Int(len, 1); Write.Line(" bytes from history:"); Streams.SetPos(history, marks[index1]); ok := Streams.Copy(history, out, len); ASSERT(ok); Write.Line("*** copying finished"); Streams.SetPos(history, currentPos); ELSE Write.Line("Invalid range!"); END; ELSE Help; END; ELSE Help; END; END ProcessCommand;