Common parsers that can be used in many contexts.
Matches a "word", comprised of alphanumeric characters and _.
parse "hello world" word -- Ok "hello"Matches an alphabetic character.
Matches an alphanumeric character.
Matches a digit, e.g. 8.
Matches an uppercase alphabetic characters, e.g. A.
Matches a lowercase alphabetic characters, e.g. z.
Matches the space character, .
Matches the tab character, \t.
Matches either a space or a tab.
Matches a newline character.
Matches an integer.