Go pattern matching

It's just another approach for using pattern matching in Go. I have been inspired by python pattern matching that's why I wanted to make an attempt to rewrite 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.
• Adding 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:

val := TestStruct{1}

isMatched, _ := Match(val).
    When(func(TestStruct) {},  1).
    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()

Plans:

• I would like to implement a recursive pattern matching (for matching inner elements of objects)
• Possibly to have matching without result.

Installation

Just go get this repository with 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)
    }
}