README.md

Golang Rules Engine

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 lt 1", obj{"x": 1})
  parser.Evaluate("x gt 1", obj{"x": 1})
  
  parser.Evaluate("x.a eq 1 and x.b.c le 2", obj{
    "x": obj{
       "a": 1,
       "b": obj{
          "c": 2,
       },
    },
  })
  

  parser.Evaluate("y eq 4 and (x gt 1)", obj{"x": 1})

  parser.Evaluate("y eq 4 and (x IN [1 2 3])", obj{"x": 1})

  parser.Evaluate("y eq 4 and (x eq 1.2.3)", obj{"x": "1.2.3"})
  

Operations

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:

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