A TextSub.T represents a subsequence of another text.
INTERFACETextSub ; TYPE TT <: Public; Public = TEXT OBJECT base : TEXT; start : CARDINAL; len : CARDINAL; END; PROCEDURE New (t: TEXT; start, length: CARDINAL): TEXT;
Return a sub-sequence oft: empty ifstart >= Length(t)orlength = 0; otherwise the subsequence ranging fromstartto the minimum ofstart+length-1andLength(t)-1.
END TextSub.