eval

Evaluates the given formula resulting in unit interval 0, 1, the frequency of returning true. 0 is always false, 1 is always true, 0.5 is true ~50% of the time, depending on the environment.

Example formulas:

• Always true: 1 or true

• True for half of the contexts: 0.5

• True for an email domain: `matches("*@doist.com", env"user.email")

• True for specific UTC offsets: contains(["+01:00", "+02:00"], env["user.utc_offset"])

• True after a date/time: gte(now(), datetime("2038-01-19T04:14:07+01:00")

• True if the user is logged in: not(isblank(env["user.email"]))

• Gradual rollout: map(datetime("2021-11-08"), datetime("2021-11-16"), 0, 1, now())

See also

Parameters