Rules engine written in golang with the help of antlr.
This package will be very helpful in situations where you have a generic rule and want to verify if your values (specified using map[string]interface{}
) satisfy the rule.
Here are some examples:
type obj map[string]interface{}
parser.Evaluate("x eq 1", obj{"x": 1})
parser.Evaluate("x == 1", obj{"x": 1})
parser.Evaluate("x lt 1", obj{"x": 1})
parser.Evaluate("x < 1", obj{"x": 1})
parser.Evaluate("x gt 1", obj{"x": 1})
parser.Evaluate("x.a == 1 and x.b.c <= 2", obj{
"x": obj{
"a": 1,
"b": obj{
"c": 2,
},
},
})
parser.Evaluate("y == 4 and (x > 1)", obj{"x": 1})
parser.Evaluate("y == 4 and (x IN [1,2,3])", obj{"x": 1})
parser.Evaluate("y == 4 and (x eq 1.2.3)", obj{"x": "1.2.3"})
All the operations can be written capitalized or lowercase (ex: eq
or EQ
can be used)
Logical Operations supported are AND OR
Compare Expression and their definitions (a|b means you can use either one of the two a or b):
eq|==: equals to
ne|!=: not equals to
lt|<: less than
gt|>: greater than
le|<=: less than equal to
ge|>=: greater than equal to
co: contains
sw: starts with
ew: ends with
in: in a list
pr: present
not: not of a logical expression