<XML><RECORDS><RECORD><REFERENCE_TYPE>3</REFERENCE_TYPE><REFNUM>7063</REFNUM><AUTHORS><AUTHOR>O'Donnell,J.T.</AUTHOR></AUTHORS><YEAR>1993</YEAR><TITLE>Bidirectional fold and scan</TITLE><PLACE_PUBLISHED>Functional Programming, Glasgow 1993, Springer Workshops in Computing </PLACE_PUBLISHED><PUBLISHER>Springer Verlag</PUBLISHER><PAGES>193-200</PAGES><LABEL>O'Donnell:1993:7063</LABEL><KEYWORDS><KEYWORD>fold</KEYWORD></KEYWORDS<ABSTRACT>Bidirectional fold generalises foldl and foldr to allow simultaneous communication in both directions across a list. Bidirectional scan calculates the list of partial results of a bidirectional fold, just as scanl and scanr calculate the partial results of a foldl or foldr. Mapping scans combine a map with a scan, and often simplify programs using scans. This family of functions is significant because it expresses important patterns of computation that arise repeatedly in circuit design and data parallel programming.</ABSTRACT></RECORD></RECORDS></XML>