• Rune Literals
• Conversions
• Concatenating
• Methods

A rune, rune, is an unsigned 32-bit integer representing a Unicode code point.

$rune(arg: i64) -> rune

Converts arg to a rune. Panics if the argument is out of range.

Rune Literals

Rune literals use single quotes, e.g.

var c1 = 'a';
var c2 = '€';
var c3 = '🔥';

A rune literal should contain either a single UTF-8 encoded code point or a backslashed escape sequence representing a code point, e.g.

assert '\x61' == 'a';
assert '\u20AC' == '€';

Rune literals support the same backslashed escape sequences as strings.

Conversions

You can convert a rune to a string using the $str() function — this returns a string containing the UTF-8 encoded representation of the code point, e.g.

assert $str('a') == "a";
assert $str('a') == "\x61";

assert $str('🔥') == "🔥";
assert $str('🔥') == "\xF0\x9F\x94\xA5";

You can convert a rune to an integer using the $i64() function:

assert $i64('a') == 97;

You can convert an integer to a rune using the $rune() function:

assert $rune(97) == 'a';

Concatenating

If you add two runes together using the + operator, the result will be a UTF-8 encoded string, e.g.

assert 'x' + 'y' == "xy";

Similarly, you can prepend or append a rune to a string using the + operator, e.g.

assert 'x' + "yz" == "xyz";
assert "xy" + 'z' == "xyz";

You can multiply a rune by an integer n to produce a string containing n UTF-8 encoded copies of the rune, e.g.

assert 'x' * 3 == "xxx";
assert '🔥' * 3 == "🔥🔥🔥";

Methods

:is_ascii() -> bool

Returns true if the rune is in the ASCII range.

:is_ascii_alpha() -> bool

Returns true if the rune is in the range of ASCII alphabetical characters.

:is_ascii_decimal() -> bool

Returns true if the rune is an ASCII decimal digit.

:is_ascii_hex() -> bool

Returns true if the rune is an ASCII hexadecimal digit.

:is_ascii_octal() -> bool

Returns true if the rune is an ASCII octal digit.

:is_ascii_printable() -> bool

Returns true if the rune is in the range of ASCII printable characters.

:is_ascii_ws() -> bool

Returns true if the rune is an ASCII whitespace character.

:is_unicode_ws() -> bool

Returns true if the rune is a Unicode whitespace codepoint.