golang: Just a quick test of a using github.com/google/btree using mixed types: string and int

btree.go

// Just a quick test of a using github.com/google/btree using
// mixed types (string) and (int)

package main

import (
	"fmt"
	"github.com/google/btree"
	"strconv"
)

type myString string

// There ought to be a better way
func (a myString) Less(b btree.Item) bool {
	switch b.(type) {
	case myString:
		return a < b.(myString)
	case Int:
		return string(a) < strconv.Itoa(int(b.(Int)))
	}
	return true

	// If we don't have type mixing/assertions, we'd just do a:
	return a < b.(myString)
}

func (s myString) String() string {
	return string(s)
}

type Int int

// There ought to be a better way
func (a Int) Less(b btree.Item) bool {
	switch b.(type) {
	case myString:
		return strconv.Itoa(int(a)) < string(b.(myString))
	case Int:
		return a < b.(Int)
	}
	return true
}

func main() {
	tree := btree.New(8)

	tree.ReplaceOrInsert(myString("Hello"))
	tree.ReplaceOrInsert(myString("World"))
	tree.ReplaceOrInsert(Int(42))
	tree.ReplaceOrInsert(myString("Happy"))
	tree.ReplaceOrInsert(myString("New"))
	tree.ReplaceOrInsert(myString("Year"))
	tree.ReplaceOrInsert(Int(2014))
	tree.ReplaceOrInsert(myString("1984 is a book"))

	// A bit silly, but we don't have non destructive reads on
	// trees in github.com/google/btree, unlike github.com/petar/gollrb
	for item := tree.DeleteMin(); item != nil; item = tree.DeleteMin() {
		fmt.Println(item)
	}
}