map $ span $ toHtml "foo"Result:
<map><span>foo</span></map>
map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
map id = cat map (g . f) = map f >-> map g