Go pattern matching
It's just another implementation of pattern matching in Go. I have been inspired by Python pattern matching, that's why I wanted to try writing something similar in Go :) For now the following matching are implemented :
- Simple types (like int, int64, float, float64, bool..).
- Struct type.
- Slices (with HEAD, TAIL, OneOf patterns).
- Dictionary (with ANY, OneOf pattern).
- Regexp.
- Additional custom matching (ability to add special matching for some, structs for example).
Usages
Fibonacci example:
func fib(n int) int {
_, res := match.Match(n).
When(1, 1).
When(2, 1).
When(match.ANY, func() int { return fib(n-1) + fib(n-2) }).
Result()
return res.(int)
}
Simple types:
isMatched, mr := match.Match(42).
When(42, 10).
Result()
// isMatched - true, mr - 10
With Structs:
- Simple check value by type
val := TestStruct{1}
isMatched, _ := Match(val).
When(func(TestStruct) {}, 1).
Result()
- Check value by type and condition
val := TestStruct{1}
isMatched, _ := Match(val).
When(func(ts TestStruct) bool { return ts.value == 42 }, 1).
When(func(ts AnotherStruct) bool { return ts.stringValue == "hello" }, 2).
Result()
With Maps:
isMatched, mr := match.Match(map[string]int{
"rsc": 3711,
"r": 2138,
"gri": 1908,
"adg": 912,
}).
When(map[string]interface{}{
"rsc": 3711,
"r": 2138,
"gri": 1908,
"adg": match.ANY,
}, true).
Result()
With Slices:
isMatched, mr := match.Match([]int{1, 2, 3, 4, 5, 6}).
When([]interface{}{match.HEAD, 3, match.OneOf(3, 4), 5, 6}, 125).
Result()
With regexps:
isMatched, mr := match.Match("gophergopher").
When("gophergopher", func() interface{} { return true }).
Result()
Without result:
func main() {
Match(val).
When(42, func() { fmt.Println("You found the answer to life, universe and everything!") }).
When(ANY, func() { fmt.Println("No.. It's not an answer.") }).
Result()
}
Installation
Just go get this repository in the following way:
go get github.com/alexpantyukhin/go-pattern-match
Full example
package main
import (
"fmt"
"github.com/alexpantyukhin/go-pattern-match"
)
func main() {
isMatched, mr := match.Match([]int{1, 2, 3}).
When(42, false).
When([]interface{}{match.HEAD, 2, 3}, true).
Result()
if isMatched {
fmt.Println(mr)
}
}
