add example

Signed-off-by: George Lemon <[email protected]>

Author: georgelemon

README.md

@@ -17,6 +17,47 @@ Libevent additionally provides a sophisticated framework for buffered network IO
 - [Libevent](https://libevent.org/) 2.1.12 or later
 - Nim 2.0 or later
 
+## Create a simple HTTP server
+
+Using the bindings in this package, you can create a simple HTTP server like this:
+```nim
+import std/httpcore
+import pkg/libevent
+
+from std/net import Port
+
+let eventBase = event_base_new()
+assert eventBase != nil, "Could not create event base"
+
+let httpServer = evhttp_new(eventBase)
+assert httpServer != nil, "Could not create HTTP server"
+
+template respond(str: string, code: HttpCode = HttpCode(200)) =
+  let buf = evhttp_request_get_output_buffer(req)
+  assert buf != nil # should never be nil
+  assert evbuffer_add(buf, str.cstring, str.len.csize_t) == 0
+  evhttp_send_reply(req, code.cint, "", buf)
+  return
+
+proc onRequest(req: ptr evhttp_request, arg: pointer) {.cdecl.} =
+  let uri = evhttp_request_get_uri(req)
+  let path = if uri.len > 0: uri else: "/"
+  let httpMethod = evhttp_request_get_command(req)
+  case path
+  of "/":
+    respond("Hello, World!")
+  else:
+    respond("Not Found", HttpCode(404))
+  
+assert evhttp_bind_socket(httpServer, "0.0.0.0", uint16(8000)) == 0
+evhttp_set_gencb(httpServer, onRequest, nil)
+assert event_base_dispatch(eventBase) > -1, "Could not start event loop"
+
+# cleanup after event loop ends, which it never does in this example
+evhttp_free(httpServer)
+event_base_free(eventBase)
+```
+
 
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