The `match()` function applies the given regular expression pattern on
the given subject value.

Depending on whether the given regular expression sets the global (`g`)
modifier, either an array of match groups or the first match group is
returned.

Returns `null` if the given pattern argument is not a regular expression
value, or if the subject is `null` or unspecified.

-- Testcase --
{%
	print(join("\n", [
		// match all key=value pairs
		match("kind=fruit name=strawberry color=red", /([[:alpha:]]+)=([^= ]+)/g),

		// match any word
		match("The quick brown fox jumps over the lazy dog", /[[:alpha:]]+/g),

		// match the first three lowercase words
		match("The quick brown fox jumps over the lazy dog", / ([[:lower:]]+) ([[:lower:]]+) ([[:lower:]]+)/),

		// special case: match any empty string sequence
		match("foo", /()/g),

		// special case: match first empty string sequence
		match("foo", /()/),

		// subject is implictly converted to string
		match(true, /u/)
	]), "\n");
%}
-- End --

-- Expect stdout --
[ [ "kind=fruit", "kind", "fruit" ], [ "name=strawberry", "name", "strawberry" ], [ "color=red", "color", "red" ] ]
[ [ "The" ], [ "quick" ], [ "brown" ], [ "fox" ], [ "jumps" ], [ "over" ], [ "the" ], [ "lazy" ], [ "dog" ] ]
[ " quick brown fox", "quick", "brown", "fox" ]
[ [ "", "" ], [ "", "" ], [ "", "" ], [ "", "" ] ]
[ "", "" ]
[ "u" ]
-- End --


Omitting the subject yields `null`.

-- Testcase --
{%
	printf("%.J\n", match(null, /u/));
%}
-- End --

-- Expect stdout --
null
-- End --