Captures

A successful match along with any capture groups.

Captures values are returned by Regex.match and yielded by Regex.find. Coercing one with str produces the text of the overall match.

Implements: std.Index[Int | Str, Match | nil]

Fields

end @ Int

The byte offset of the end of the overall match within the haystack.

start @ Int

The byte offset of the start of the overall match within the haystack.

Methods

(index) key -> (Match | nil)

Reads a capture group by integer index or by name.

Index 0 is the overall match, 1 the first capture group, and so on. Named groups, written (?<name>...), are read by their name. A group that did not participate in the match, such as an optional one, reads as nil.

Parameters

Name	Type	Description
key	(Int | Str)	Group index or name.

Errors

IndexError if the pattern has no such group.

Example

let date = Regex r"(\d{4})-(\d{2})-(\d{2})"
let caps = date.match "2024-03-15"

echo $caps       # => 2024-03-15  (overall match)
echo $caps[0]    # => 2024-03-15  (overall match)
echo $caps[1]    # => 2024
echo $caps[2]    # => 03
echo $caps[3]    # => 15

let named = Regex r"(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})"
let caps = named.match "2024-03-15"

echo $caps["year"]   # => 2024
echo $caps["month"]  # => 03
echo $caps["day"]    # => 15

Open in playground