Splitted the mapping resolve into a secondary method that only does r…

…esolve the url

src/horseman/mapping.py

@@ -42,7 +42,7 @@ def __call__(self, environ: Environ, start_response: StartResponse):
         try:
             iterable = self.resolve(path_info, environ)
             yield from iterable(environ, start_response)
-        except Exception:
+        except Exception as exc:
             iterable = self.handle_exception(sys.exc_info(), environ)
             if iterable is None:
                 raise
@@ -60,20 +60,28 @@ def __call__(self, environ: Environ, start_response: StartResponse):
                         raise
 
 
-class Mapping(RootNode, UserDict, t.Mapping[str, WSGICallable]):
+class Mapping(RootNode, UserDict[str, WSGICallable]):
 
     def __setitem__(self, path: str, script: WSGICallable):
         super().__setitem__(str('/' / PurePosixPath(path)), script)
 
-    def resolve(self, path_info: str, environ: Environ) -> WSGICallable:
+    def match(self, path_info: str):
         uri = PurePosixPath(path_info)
         for current in (uri, *uri.parents):
             if (script := self.get(str(current))) is not None:
-                if current.parents:
-                    environ['SCRIPT_NAME'] += str(current)
+                name = str(current) if current.parents else None
                 if current != uri:
-                    environ['PATH_INFO'] = f'/{uri.relative_to(current)}'
+                    return script, name, f'/{uri.relative_to(current)}'
                 else:
-                    environ['PATH_INFO'] = '/'
-                return script
-        raise HTTPError(404)
+                    return script, name, '/'
+        return None, None, None
+
+    def resolve(self, path_info: str, environ: Environ) -> WSGICallable:
+        script, name, path = self.match(path_info)
+        if script is None:
+            raise HTTPError(404)
+        if name:
+            environ['SCRIPT_NAME'] += name
+        environ['PATH_INFO'] = path
+        return script
+