The Unicode character \xFFFD, safely (but unrecoverably) representing an illegal, invalid, or otherwise unknown character.

Infra: ASCII whitespace

The ASCII characters defined as whitespace in the HTML standard. Unlike Haskell's isSpace and anything following that example, does not include \x11 (VT).

Infra: ASCII alpha

Test whether the character is an alphabetic character in the ASCII range ([A-Za-z]).

Infra: ASCII alphanumeric

Test whether the character is either an alphabetic character or a digit in the ASCII range ([A-Za-z0-9]).

Infra: ASCII whitespace

Test whether the character fits the spec's definition of asciiWhitespace.

Convert an uppercase, alphabetic, ASCII character to its lowercase form. This has the same semantics within the ASCII range as toLower, but leaves any non-ASCII characters unchanged.

>>> toAsciiLower 'A'
'a'

>>> toAsciiLower 'Á'
'Á'

Convert a lowercase, alphabetic, ASCII character to its uppercase form. This has the same semantics within the ASCII range as toUpper, but leaves any non-ASCII characters unchanged.

>>> toAsciiUpper 'a'
'A'

>>> toAsciiUpper 'á'
'á'