Straw man case-insensitive serve mux

insensitiveMux.go

package main

import "net/http"
import pathpkg "path"
import "strings"

type InsensitiveMux struct {
	handlers map[string]http.Handler
	isDir    map[string]bool
}

func (m *InsensitiveMux) Handle(path string, handler http.Handler) {
	if m.handlers == nil {
		m.handlers = map[string]http.Handler{}
	}

	if path[0] != '/' {
		panic("invalid path")
	}
	dir := path[len(path)-1] == '/'
	path = pathpkg.Clean(path)
	m.handlers[path] = handler
	m.isDir[path] = dir
}

func (m *InsensitiveMux) HandleFunc(path string, f func(w http.ResponseWriter, r *http.Request)) {
	m.Handle(path, http.HandlerFunc(f))
}

func (m *InsensitiveMux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	path := r.URL.Path

	// Try case sensitive
	var best = m.handlers["/"]
	for i, r := range path {
		if r != '/' {
			continue
		}
		if h, ok := m.handlers[path[:i]]; ok {
			best = h
		}
	}
	if best != nil {
		best.ServeHTTP(w, r)
		return
	}

	// Try case insensitive
	path = strings.ToLower(path)
	for i, r := range path {
		if r != '/' {
			continue
		}
		if h, ok := m.handlers[path[:i]]; ok {
			best = h
		}
	}
	if best != nil {
		http.Redirect(w, r, path, http.StatusMovedPermanently)
		return
	}

	http.NotFound(w, r)
}

func main() {
}