toLower package:unicode-data

Convert a letter to the corresponding lower-case letter, if any. Any other character is returned unchanged. It uses the character property Simple_Lowercase_Mapping. See: lowerCaseMapping and toLowerString for full lower case conversion.

toLower c == Data.Char.toLower c

Convert a character to full lower case if defined, else to itself. The result string may have more than one character. For instance, “İ” (U+0130 Latin capital letter I with dot above) maps to the sequence: “i” (U+0069 Latin small letter I) followed by “ ̇” (U+0307 combining dot above). It uses the character property Lowercase_Mapping. See: toLower for simple lower case conversion.

toLowerString c == foldMap toLowerString (toLowerString c)