<> <> <> <> <<>> DIRECTORY Rope, TextNode, WalnutDocumentRope; WalnutDocumentRopeImpl: CEDAR PROGRAM IMPORTS TextNode, Rope EXPORTS WalnutDocumentRope = BEGIN ROPE: TYPE = Rope.ROPE; Create: PUBLIC PROC [doc: TextNode.Ref] RETURNS [r: ROPE] = { docSize: INT _ TextNode.LocOffset[[doc,0], TextNode.LastLocWithin[doc]]; r _ Rope.MakeRope[base: doc, size: docSize, fetch: Fetch]; IF docSize > 0 THEN { loc0: TextNode.Location = TextNode.LocRelative[[doc,0], 0]; loc1: TextNode.Location = TextNode.LocRelative[[doc,0], 1]; IF loc0 = loc1 THEN { <> r _ Rope.Substr[r, 1]; }; }; }; Fetch: PROC [data: REF, index: INT] RETURNS [CHAR] = { doc: TextNode.Ref _ NARROW[data]; loc: TextNode.Location = TextNode.LocRelative[[doc,0], index]; n: TextNode.RefTextNode = TextNode.NarrowToTextNode[loc.node]; IF n=NIL THEN ERROR; IF loc.where >= Rope.Size[n.rope] THEN RETURN ['\n]; RETURN [Rope.Fetch[n.rope, loc.where]] }; END.