mux

mux

Lightweight, dependency-free HTTP router

Quick example:

package main

import (
  "net/http"
  "github.com/GreedyKomodoDragon/mux"
)

func main() {
  r := mux.New()
  r.Get("/users/{id}", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    id := mux.Param(r, "id")
    w.Write([]byte(id))
  }))
  http.ListenAndServe(":8080", r)
}

Features:

• Named params: {name}
• Explicit wildcard: {*path} (must be last segment)
• Subrouter groups: Group(prefix, func(sub *Router) { ... })
• Per-router middleware with Use(...)
• Prefix middleware with UsePrefix(prefix, ...)
• Convenience methods: Get/Post/Put/Patch/Delete
• Trailing slash behaviour mirrors net/http/ServeMux (redirects to add/remove trailing slash when a nearby route exists)

How it works:

• Route registration compiles a pattern into typed path segments (static, param, wildcard) and inserts it into an internal trie.
• Request matching walks the trie by path segment with precedence: static -> param -> wildcard.
• Handlers are pre-wrapped at registration time (not per request), so serving stays fast.
• URL params are stored on request context only when needed, and read with Param(r, name) / Params(r).
• Internal trie details are documented in mux/TRIE.md.

Pattern rules:

• {name} captures one segment.
• {*name} captures the remaining path and must be the final segment.
• Duplicate param names inside one route pattern are invalid and panic at registration.
• Empty segments (for example /a//b) are invalid and panic at registration.

Middleware model:

• UsePrefix(prefix, ...) applies middleware to matching routes by path prefix.
• Prefix matching is segment-aware: /v2 matches /v2/users, not /v21/users.
• Literal prefix segments only match static route segments (not param segments).
• Wildcard route segments ({*name}) can satisfy deeper prefix matches.
• Middleware execution order is: UsePrefix(...) -> Use(...) -> handler.
• UsePrefix(...) rewraps existing matching routes immediately and also affects future matching routes.
• Use(...) is registration-time only; adding it later does not rewrap existing routes.

Groups:

• Group(prefix, fn) creates a subrouter with inherited Use(...) middleware and combined prefix.
• Routes registered in a group are inserted into the root router trie with the group prefix applied.
• UsePrefix(...) called inside a group is interpreted relative to that group prefix.

HTTP behavior:

• If path matches but method does not, router returns 405 and sets Allow.
• Not found routes use the configured NotFound handler (default http.NotFound).
• Trailing slash redirect semantics follow net/http/ServeMux behavior.

Notes:

• Register routes at startup; the router is optimized for serving and does not expect frequent runtime registration.
• Duplicate registrations (same method+pattern) are allowed; the last registration wins.