ReQL command: match

Command syntax

string.match(regexp) → null/object

Description

Match a string against a regular expression. If there is a match, returns an object with the fields:

• str: The matched string
• start: The matched string’s start
• end: The matched string’s end
• groups: The capture groups defined with parentheses

If no match is found, returns null.

Accepts RE2 syntax. You can enable case-insensitive matching by prefixing the regular expression with (?i). See the linked RE2 documentation for more flags.

The match command does not support backreferences.

Example: Get all users whose name starts with “A”. Because null evaluates to false in filter, you can use the result of match for the predicate.

r.table("users").filter(doc -> doc.g("name").match("^A")).run(conn);

Example: Get all users whose name ends with “n.”

r.table("users").filter(doc -> doc.g("name").match("n$")).run(conn);

Example: Get all users whose name contains “li.”

r.table("users").filter(doc -> doc.g("name").match("li")).run(conn);

Example: Get all users whose name is “John,” performing a case-insensitive search.

r.table("users").filter(doc -> doc.g("name").match("(?i)^john$")).run(conn);

Example: Retrieve the domain of a basic email.

r.expr("[email protected]").match(".*@(.*)").run(conn);

Result:

{
    "start": 0,
    "end": 20,
    "str": "[email protected]",
    "groups": [
        {
            "end": 17,
            "start": 7,
            "str": "domain.com"
        }
    ]
}

You can then retrieve only the domain with g() and nth.

r.expr("[email protected]").match(".*@(.*)").g("groups").nth(0)
 .g("str").run(conn);

Returns domain.com.

Example: A failure to parse out the domain name will return null.

r.expr("name[at]domain.com").match(".*@(.*)").run(conn);