Pattern matching

pattern_matching.rego

# First name may be either "joe" or "jane" for function to evaluate
# No rule body needed as argument passed will be matched for equality
allowed_firstname("joe")
allowed_firstname("jane")

# This works with multiple arguments too, where only some are matched
# statically
alcohol_allowed("Sweden", age) if age > 18
alcohol_allowed("USA",    age) if age > 21
alcohol_allowed(country,  age) if {
    # for any other country, we'll need to look up the rules for the country
    # provided, perhaps by using http.send
}