Introduction
This package was created with inspiration from Thomas' go-ruler to run a simple set of rules against an entity.
This version includes a couple more features including, AND and OR composites and the ability to add custom comparators.
Note: This package only compares two types: string and float64, this plays nicely with encoding/json.
Example
// Create a new instance of an engine with some default comparators
e, err := NewJSONEngine(json.RawMessage(`{"composites":[{"operator":"or","rules":[{"comparator":"always-false","path":"user.name","value":"Trevor"},{"comparator":"eq","path":"user.name","value":"Trevor"}]}]}`))
if err != nil {
panic(err)
}
// Add a new, custom comparator
e = e.AddComparator("always-false", func(a, b interface{}) bool {
return false
})
// Give some properties, this map can be deeper and supports interfaces
props := map[string]interface{}{
"user": map[string]interface{}{
"name": "Trevor",
}
}
// Run the engine on the props
res := e.Evaluate(props)
// res == true
Comparators
eqwill return true ifa == bneqwill return true ifa != bltwill return true ifa < bltewill return true ifa <= bgtwill return true ifa > bgtewill return true ifa >= bcontainswill return true ifacontainsboneofwill return true ifais one ofbregexwill return true ifamatchesb
contains is different than oneof in that contains expects the first argument to be a slice, and oneof expects the second argument to be a slice.
Benchmarks, Benchmark, N, Speed, Used, Allocs, --------------------------------, ----------, ------------, ---------, ------------, BenchmarkEqual-12, 1000000000, 5.22 ns/op, 0 B/op, 0 allocs/op, BenchmarkNotEqual-12, 2000000000, 3.77 ns/op, 0 B/op, 0 allocs/op, BenchmarkLessThan-12, 2000000000, 2.20 ns/op, 0 B/op, 0 allocs/op, BenchmarkLessThanEqual-12, 2000000000, 1.95 ns/op, 0 B/op, 0 allocs/op, BenchmarkGreaterThan-12, 5000000000, 1.95 ns/op, 0 B/op, 0 allocs/op, BenchmarkGreaterThanEqual-12, 2000000000, 1.97 ns/op, 0 B/op, 0 allocs/op, BenchmarkRegex-12, 10000000, 712 ns/op, 740 B/op, 11 allocs/op, BenchmarkRegexPhone-12, 1000000, 3025 ns/op, 3192 B/op, 30 allocs/op, BenchmarkContains-12, 1000000000, 5.66 ns/op, 0 B/op, 0 allocs/op, BenchmarkContainsLong50000-12, 30000, 157679 ns/op, 0 B/op, 0 allocs/op, BenchmarkNotContains-12, 500000000, 11.5 ns/op, 0 B/op, 0 allocs/op, BenchmarkNotContainsLong50000-12, 30000, 157437 ns/op, 0 B/op, 0 allocs/op, BenchmarkOneOf-12, 500000000, 0.53 ns/op, 0 B/op, 0 allocs/op, BenchmarkNoneOf-12, 500000000, 0.53 ns/op, 0 B/op, 0 allocs/op, BenchmarkPluckShallow-12, 100000000, 42.4 ns/op, 16 B/op, 1 allocs/op, BenchmarkPluckDeep-12, 30000000, 174 ns/op, 112 B/op, 1 allocs/op, BenchmarkRule_evaluate-12, 100000000, 51.7 ns/op, 16 B/op, 1 allocs/op, BenchmarkComposite_evaluate-12, 100000000, 58.9 ns/op, 16 B/op, 1 allocs/op, BenchmarkEngine_Evaluate-12, 100000000, 69.9 ns/op, 16 B/op, 1 allocs/op, To run benchmarks:
go test -run none -bench . -benchtime 3s -benchmem
All benchmarks were run on:
MacOS High Sierra 2.6Ghz Intel Core i7 16 GB 2400 MHz DDR4
License
Copyright © 2019 Trevor Hutto
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. You may obtain a copy of the License in the LICENSE file, or at:
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.