toupper package:unicode-data

Convert a letter to the corresponding upper-case letter, if any. Any other character is returned unchanged. It uses the character property Simple_Uppercase_Mapping. See: upperCaseMapping and toUpperString for full upper case conversion.

toUpper c == Data.Char.toUpper c

Convert a character to full upper case if defined, else to itself. The result string may have more than one character. For instance, the German “ß” (U+00DF Eszett) maps to the two-letter sequence “SS”. It uses the character property Uppercase_Mapping. See: toUpper for simple upper case conversion.

toUpperString c == foldMap toUpperString (toUpperString c)