class Unicode

In reports whether the rune is a member of one of the ranges.

IsControl reports whether the rune is a control character. The C (Other) Unicode category includes more code points such as surrogates; use Is(C, r) to test for them.

IsDigit reports whether the rune is a decimal digit.

IsGraphic reports whether the rune is defined as a Graphic by Unicode. Such characters include letters, marks, numbers, punctuation, symbols, and spaces, from categories L, M, N, P, S, Zs.

IsLetter reports whether the rune is a letter (category L).

IsLower reports whether the rune is a lower case letter.

IsMark reports whether the rune is a mark character (category M).

IsNumber reports whether the rune is a number (category N).

IsOneOf reports whether the rune is a member of one of the ranges. The function "In" provides a nicer signature and should be used in preference to IsOneOf.

IsPrint reports whether the rune is defined as printable by Go. Such characters include letters, marks, numbers, punctuation, symbols, and the ASCII space character, from categories L, M, N, P, S and the ASCII space character. This categorization is the same as IsGraphic except that the only spacing character is ASCII space, U+0020.

IsPunct reports whether the rune is a Unicode punctuation character (category P).

IsSpace reports whether the rune is a space character as defined by Unicode's White Space property; in the Latin-1 space this is

'\t', '\n', '\v', '\f', '\r', ' ', U+0085 (NEL), U+00A0 (NBSP).

Other definitions of spacing characters are set by category Z and property Pattern_White_Space.

IsSymbol reports whether the rune is a symbolic character.

IsTitle reports whether the rune is a title case letter.

IsUpper reports whether the rune is an upper case letter.

Is reports whether the rune is in the specified table of ranges.

SimpleFold iterates over Unicode code points equivalent under the Unicode-defined simple case folding. Among the code points equivalent to rune (including rune itself), SimpleFold returns the smallest rune > r if one exists, or else the smallest rune >= 0. If r is not a valid Unicode code point, SimpleFold(r) returns r.

For example:

SimpleFold('A') = 'a'
SimpleFold('a') = 'A'

SimpleFold('K') = 'k'
SimpleFold('k') = '\u212A' (Kelvin symbol, K)
SimpleFold('\u212A') = 'K'

SimpleFold('1') = '1'

SimpleFold(-2) = -2

To maps the rune to the specified case: UpperCase, LowerCase, or TitleCase.

ToLower maps the rune to lower case.

ToTitle maps the rune to title case.

ToUpper maps the rune to upper case.