Further optimization in Tramp's file name decomposition

* lisp/net/tramp.el (tramp-syntax): Recompute all file name
components.  Call `custom-set-variables' after loading.
(tramp-build-prefix-format, tramp-build-prefix-regexp)
(tramp-build-method-regexp)
(tramp-build-postfix-method-format)
(tramp-build-postfix-method-regexp)
(tramp-build-prefix-ipv6-format)
(tramp-build-prefix-ipv6-regexp)
(tramp-build-postfix-ipv6-format)
(tramp-build-postfix-ipv6-regexp)
(tramp-build-postfix-host-format)
(tramp-build-postfix-host-regexp)
(tramp-build-file-name-regexp)
(tramp-build-completion-file-name-regexp): New defuns.
(tramp-prefix-format, tramp-prefix-regexp)
(tramp-method-regexp, tramp-postfix-method-format)
(tramp-postfix-method-regexp, tramp-prefix-ipv6-format)
(tramp-prefix-ipv6-regexp, tramp-postfix-ipv6-format)
(tramp-postfix-ipv6-regexp, tramp-postfix-host-format)
(tramp-postfix-host-regexp)
(tramp-remote-file-name-spec-regexp)
(tramp-file-name-structure, tramp-file-name-regexp)
(tramp-completion-file-name-regexp): Convert defuns into defvars.
(tramp-prefix-regexp-alist)
(tramp-postfix-method-regexp-alist)
(tramp-prefix-ipv6-regexp-alist)
(tramp-postfix-ipv6-regexp-alist)
(tramp-postfix-host-regexp-alist)
(tramp-remote-file-name-spec-regexp-alist): Remove.
(tramp-build-remote-file-name-spec-regexp)
(tramp-build-file-name-structure): Simplify.
(tramp-completion-file-name-regexp-alist): New defconst.
(tramp-tramp-file-p, tramp-dissect-file-name)
(tramp-make-tramp-file-name)
(tramp-completion-make-tramp-file-name)
(tramp-rfn-eshadow-update-overlay-regexp)
(tramp-register-file-name-handlers)
(tramp-completion-handle-file-name-all-completions)
(tramp-completion-dissect-file-name, tramp-clear-passwd):
* lisp/net/tramp-ftp.el (tramp-ftp-file-name-handler):
* lisp/net/tramp-sh.el (tramp-sh-handle-vc-registered)
(tramp-compute-multi-hops): Use variables but functions for
file name components.

* test/lisp/net/tramp-tests.el (tramp-test24-file-name-completion):
Use variables but functions for file name components.

4 files changed, 195 insertions, 205 deletions

diff --git a/lisp/net/tramp-ftp.el b/lisp/net/tramp-ftp.el
index 8e489eee801..85afd52bf42 100644
--- a/lisp/net/tramp-ftp.el
+++ b/lisp/net/tramp-ftp.el
@@ -121,10 +121,10 @@ pass to the OPERATION."
     (or (boundp 'ange-ftp-name-format)
         (let (file-name-handler-alist) (require 'ange-ftp)))
     (let ((ange-ftp-name-format
-           (list (nth 0 (tramp-file-name-structure))
-                 (nth 3 (tramp-file-name-structure))
-                 (nth 2 (tramp-file-name-structure))
-                 (nth 4 (tramp-file-name-structure))))
+           (list (nth 0 tramp-file-name-structure)
+                 (nth 3 tramp-file-name-structure)
+                 (nth 2 tramp-file-name-structure)
+                 (nth 4 tramp-file-name-structure)))
           ;; ange-ftp uses `ange-ftp-ftp-name-arg' and `ange-ftp-ftp-name-res'
           ;; for optimization in `ange-ftp-ftp-name'. If Tramp wasn't active,
           ;; there could be incorrect values from previous calls in case the
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 597ca6a6202..01fe335963b 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -3437,7 +3437,7 @@ the result will be a local, non-Tramp, file name."
         (let (tramp-vc-registered-file-names
               (remote-file-name-inhibit-cache (current-time))
               (file-name-handler-alist
-               `((,(tramp-file-name-regexp) . tramp-vc-file-name-handler))))
+               `((,tramp-file-name-regexp . tramp-vc-file-name-handler))))
 
           ;; Here we collect only file names, which need an operation.
           (tramp-with-demoted-errors
@@ -4468,7 +4468,7 @@ Goes through the list `tramp-inline-compress-commands'."
       (let ((user (tramp-file-name-user item))
             (host (tramp-file-name-host item))
             (proxy (concat
-                    (tramp-prefix-format) proxy (tramp-postfix-host-format))))
+                    tramp-prefix-format proxy tramp-postfix-host-format)))
         (tramp-message
          vec 5 "Add proxy (\"%s\" \"%s\" \"%s\")"
          (and (stringp host) (regexp-quote host))
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 118960be5ed..14624593e0c 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -689,11 +689,34 @@ Do not change the value by `setq', it must be changed only by
            (tramp-cleanup-all-buffers))
          ;; Set the value:
          (set-default symbol value)
-         ;; Reset `tramp-file-name-regexp'.
-         (setq tramp-file-name-regexp (tramp-file-name-regexp))
+         ;; Reset the depending variables.
+         (with-no-warnings
+           (setq tramp-prefix-format (tramp-build-prefix-format)
+                 tramp-prefix-regexp (tramp-build-prefix-regexp)
+                 tramp-method-regexp (tramp-build-method-regexp)
+                 tramp-postfix-method-format (tramp-build-postfix-method-format)
+                 tramp-postfix-method-regexp (tramp-build-postfix-method-regexp)
+                 tramp-prefix-ipv6-format (tramp-build-prefix-ipv6-format)
+                 tramp-prefix-ipv6-regexp (tramp-build-prefix-ipv6-regexp)
+                 tramp-postfix-ipv6-format (tramp-build-postfix-ipv6-format)
+                 tramp-postfix-ipv6-regexp (tramp-build-postfix-ipv6-regexp)
+                 tramp-postfix-host-format (tramp-build-postfix-host-format)
+                 tramp-postfix-host-regexp (tramp-build-postfix-host-regexp)
+                 tramp-remote-file-name-spec-regexp
+                 (tramp-build-remote-file-name-spec-regexp)
+                 tramp-file-name-structure (tramp-build-file-name-structure)
+                 tramp-file-name-regexp (tramp-build-file-name-regexp)
+                 tramp-completion-file-name-regexp
+                 (tramp-build-completion-file-name-regexp)))
          ;; Rearrange file name handlers.
          (tramp-register-file-name-handlers)))
 
+;; Initialize the Tramp syntax variables.  We want to override initial
+;; values of `tramp-file-name-regexp' and
+;; `tramp-completion-file-name-regexp'.
+(eval-after-load 'tramp
+  '(custom-set-variables `(tramp-syntax ',(tramp-compat-tramp-syntax))))
+
 (defun tramp-syntax-values ()
   "Return possible values of `tramp-syntax', a list"
   (let ((values (cdr (get 'tramp-syntax 'custom-type))))
@@ -712,22 +735,19 @@ Raise an error if `tramp-syntax' is invalid."
     (separate   . "/["))
   "Alist mapping Tramp syntax to strings beginning Tramp file names.")
 
-(defun tramp-prefix-format ()
-  "String matching the very beginning of Tramp file names.
-Used in `tramp-make-tramp-file-name'."
+(defun tramp-build-prefix-format ()
   (tramp-lookup-syntax tramp-prefix-format-alist))
 
-(defconst tramp-prefix-regexp-alist
-  (mapcar (lambda (x)
-            (cons (car x) (concat "^" (regexp-quote (cdr x)))))
-          tramp-prefix-format-alist)
-  "Alist of regexps matching the beginnings of Tramp file names.
-Keyed by Tramp syntax. Derived from `tramp-prefix-format-alist'.")
+(defvar tramp-prefix-format (tramp-build-prefix-format)
+  "String matching the very beginning of Tramp file names.
+Used in `tramp-make-tramp-file-name'.")
+
+(defun tramp-build-prefix-regexp ()
+  (concat "^" (regexp-quote tramp-prefix-format)))
 
-(defun tramp-prefix-regexp ()
+(defvar tramp-prefix-regexp (tramp-build-prefix-regexp)
   "Regexp matching the very beginning of Tramp file names.
-Should always start with \"^\". Derived from `tramp-prefix-format'."
-  (tramp-lookup-syntax tramp-prefix-regexp-alist))
+Should always start with \"^\". Derived from `tramp-prefix-format'.")
 
 (defconst tramp-method-regexp-alist
   '((default    . "[a-zA-Z0-9-]+")
@@ -735,34 +755,33 @@ Should always start with \"^\". Derived from `tramp-prefix-format'."
     (separate   . "[a-zA-Z0-9-]*"))
   "Alist mapping Tramp syntax to regexps matching methods identifiers.")
 
-(defun tramp-method-regexp ()
-  "Regexp matching methods identifiers.
-The `ftp' syntax does not support methods."
+(defun tramp-build-method-regexp ()
   (tramp-lookup-syntax tramp-method-regexp-alist))
 
+(defvar tramp-method-regexp (tramp-build-method-regexp)
+  "Regexp matching methods identifiers.
+The `ftp' syntax does not support methods.")
+
 (defconst tramp-postfix-method-format-alist
   '((default    . ":")
     (simplified . "")
     (separate   . "/"))
   "Alist mapping Tramp syntax to the delimiter after the method.")
 
-(defun tramp-postfix-method-format ()
+(defun tramp-build-postfix-method-format ()
+  (tramp-lookup-syntax tramp-postfix-method-format-alist))
+
+(defvar tramp-postfix-method-format (tramp-build-postfix-method-format)
   "String matching delimiter between method and user or host names.
 The `ftp' syntax does not support methods.
-Used in `tramp-make-tramp-file-name'."
-  (tramp-lookup-syntax tramp-postfix-method-format-alist))
+Used in `tramp-make-tramp-file-name'.")
 
-(defconst tramp-postfix-method-regexp-alist
-  (mapcar (lambda (x)
-            (cons (car x) (regexp-quote (cdr x))))
-          tramp-postfix-method-format-alist)
-  "Alist mapping Tramp syntax to regexp matching delimiter after method.
-Derived from `tramp-postfix-method-format-alist'.")
+(defun tramp-build-postfix-method-regexp ()
+  (regexp-quote tramp-postfix-method-format))
 
-(defun tramp-postfix-method-regexp ()
+(defvar tramp-postfix-method-regexp (tramp-build-postfix-method-regexp)
   "Regexp matching delimiter between method and user or host names.
-Derived from `tramp-postfix-method-format'."
-  (tramp-lookup-syntax tramp-postfix-method-regexp-alist))
+Derived from `tramp-postfix-method-format'.")
 
 (defconst tramp-user-regexp "[^/|: \t]+"
   "Regexp matching user names.")
@@ -772,8 +791,7 @@ Derived from `tramp-postfix-method-format'."
   "String matching delimiter between user and domain names.")
 
 ;;;###tramp-autoload
-(defconst tramp-prefix-domain-regexp
-  (regexp-quote tramp-prefix-domain-format)
+(defconst tramp-prefix-domain-regexp (regexp-quote tramp-prefix-domain-format)
   "Regexp matching delimiter between user and domain names.
 Derived from `tramp-prefix-domain-format'.")
 
@@ -790,8 +808,7 @@ Derived from `tramp-prefix-domain-format'.")
   "String matching delimiter between user and host names.
 Used in `tramp-make-tramp-file-name'.")
 
-(defconst tramp-postfix-user-regexp
-  (regexp-quote tramp-postfix-user-format)
+(defconst tramp-postfix-user-regexp (regexp-quote tramp-postfix-user-format)
   "Regexp matching delimiter between user and host names.
 Derived from `tramp-postfix-user-format'.")
 
@@ -804,28 +821,24 @@ Derived from `tramp-postfix-user-format'.")
     (separate   . ""))
   "Alist mapping Tramp syntax to strings prefixing IPv6 addresses.")
 
-(defun tramp-prefix-ipv6-format ()
-  "String matching left hand side of IPv6 addresses.
-Used in `tramp-make-tramp-file-name'."
+(defun tramp-build-prefix-ipv6-format ()
   (tramp-lookup-syntax tramp-prefix-ipv6-format-alist))
 
-(defconst tramp-prefix-ipv6-regexp-alist
-  (mapcar (lambda (x)
-            (cons (car x) (regexp-quote (cdr x))))
-          tramp-prefix-ipv6-format-alist)
-  "Alist mapping Tramp syntax to regexp matching prefix of IPv6 addresses.
-Derived from `tramp-prefix-ipv6-format-alist'")
+(defvar tramp-prefix-ipv6-format (tramp-build-prefix-ipv6-format)
+  "String matching left hand side of IPv6 addresses.
+Used in `tramp-make-tramp-file-name'.")
+
+(defun tramp-build-prefix-ipv6-regexp ()
+  (regexp-quote tramp-prefix-ipv6-format))
 
-(defun tramp-prefix-ipv6-regexp ()
+(defvar tramp-prefix-ipv6-regexp (tramp-build-prefix-ipv6-regexp)
   "Regexp matching left hand side of IPv6 addresses.
-Derived from `tramp-prefix-ipv6-format'."
-  (tramp-lookup-syntax tramp-prefix-ipv6-regexp-alist))
+Derived from `tramp-prefix-ipv6-format'.")
 
 ;; The following regexp is a bit sloppy.  But it shall serve our
 ;; purposes.  It covers also IPv4 mapped IPv6 addresses, like in
 ;; "::ffff:192.168.0.1".
-(defconst tramp-ipv6-regexp
-  "\\(?:\\(?:[a-zA-Z0-9]+\\)?:\\)+[a-zA-Z0-9.]+"
+(defconst tramp-ipv6-regexp "\\(?:\\(?:[a-zA-Z0-9]+\\)?:\\)+[a-zA-Z0-9.]+"
   "Regexp matching IPv6 addresses.")
 
 (defconst tramp-postfix-ipv6-format-alist
@@ -834,28 +847,24 @@ Derived from `tramp-prefix-ipv6-format'."
     (separate   . ""))
   "Alist mapping Tramp syntax to suffix for IPv6 addresses.")
 
-(defun tramp-postfix-ipv6-format ()
-  "String matching right hand side of IPv6 addresses.
-Used in `tramp-make-tramp-file-name'."
+(defun tramp-build-postfix-ipv6-format ()
   (tramp-lookup-syntax tramp-postfix-ipv6-format-alist))
 
-(defconst tramp-postfix-ipv6-regexp-alist
-  (mapcar (lambda (x)
-            (cons (car x) (regexp-quote (cdr x))))
-          tramp-postfix-ipv6-format-alist)
-  "Alist mapping Tramp syntax to regexps matching IPv6 suffixes.
-Derived from `tramp-postfix-ipv6-format-alist'.")
+(defvar tramp-postfix-ipv6-format (tramp-build-postfix-ipv6-format)
+  "String matching right hand side of IPv6 addresses.
+Used in `tramp-make-tramp-file-name'.")
+
+(defun tramp-build-postfix-ipv6-regexp ()
+  (regexp-quote tramp-postfix-ipv6-format))
 
-(defun tramp-postfix-ipv6-regexp ()
+(defvar tramp-postfix-ipv6-regexp (tramp-build-postfix-ipv6-regexp)
   "Regexp matching right hand side of IPv6 addresses.
-Derived from `tramp-postfix-ipv6-format'."
-  (tramp-lookup-syntax tramp-postfix-ipv6-format-alist))
+Derived from `tramp-postfix-ipv6-format'.")
 
 (defconst tramp-prefix-port-format "#"
   "String matching delimiter between host names and port numbers.")
 
-(defconst tramp-prefix-port-regexp
-  (regexp-quote tramp-prefix-port-format)
+(defconst tramp-prefix-port-regexp (regexp-quote tramp-prefix-port-format)
   "Regexp matching delimiter between host names and port numbers.
 Derived from `tramp-prefix-port-format'.")
 
@@ -871,8 +880,7 @@ Derived from `tramp-prefix-port-format'.")
 (defconst tramp-postfix-hop-format "|"
   "String matching delimiter after ad-hoc hop definitions.")
 
-(defconst tramp-postfix-hop-regexp
-  (regexp-quote tramp-postfix-hop-format)
+(defconst tramp-postfix-hop-regexp (regexp-quote tramp-postfix-hop-format)
   "Regexp matching delimiter after ad-hoc hop definitions.
 Derived from `tramp-postfix-hop-format'.")
 
@@ -882,22 +890,19 @@ Derived from `tramp-postfix-hop-format'.")
     (separate   . "]"))
   "Alist mapping Tramp syntax to strings between host and local names.")
 
-(defun tramp-postfix-host-format ()
-  "String matching delimiter between host names and localnames.
-Used in `tramp-make-tramp-file-name'."
+(defun tramp-build-postfix-host-format ()
   (tramp-lookup-syntax tramp-postfix-host-format-alist))
 
-(defconst tramp-postfix-host-regexp-alist
-  (mapcar (lambda (x)
-            (cons (car x) (regexp-quote (cdr x))))
-          tramp-postfix-host-format-alist)
-  "Alist mapping Tramp syntax to regexp matching name delimiters.
-Derived from `tramp-postfix-host-format-alist'.")
+(defvar tramp-postfix-host-format (tramp-build-postfix-host-format)
+  "String matching delimiter between host names and localnames.
+Used in `tramp-make-tramp-file-name'.")
 
-(defun tramp-postfix-host-regexp ()
+(defun tramp-build-postfix-host-regexp ()
+  (regexp-quote tramp-postfix-host-format))
+
+(defvar tramp-postfix-host-regexp (tramp-build-postfix-host-regexp)
   "Regexp matching delimiter between host names and localnames.
-Derived from `tramp-postfix-host-format'."
-  (tramp-lookup-syntax tramp-postfix-host-regexp-alist))
+Derived from `tramp-postfix-host-format'.")
 
 (defconst tramp-localname-regexp ".*$"
   "Regexp matching localnames.")
@@ -910,48 +915,35 @@ Derived from `tramp-postfix-host-format'."
 
 ;;; File name format:
 
-(defun tramp-build-remote-file-name-spec-regexp (syntax)
-  "Construct a regexp matching a Tramp file name for a Tramp SYNTAX."
-  (let ((tramp-syntax syntax))
-    (concat
-     "\\("   (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-     "\\(?:" "\\("   tramp-user-regexp     "\\)" tramp-postfix-user-regexp "\\)?"
-     "\\("   "\\(?:" tramp-host-regexp     "\\|"
-     (tramp-prefix-ipv6-regexp)
-     "\\(?:" tramp-ipv6-regexp "\\)?"
-     (tramp-postfix-ipv6-regexp) "\\)?"
-     "\\(?:" tramp-prefix-port-regexp    tramp-port-regexp "\\)?" "\\)?")))
-
-(defconst tramp-remote-file-name-spec-regexp-alist
-  `((default    . ,(tramp-build-remote-file-name-spec-regexp 'default))
-    (simplified . ,(tramp-build-remote-file-name-spec-regexp 'simplified))
-    (separate   . ,(tramp-build-remote-file-name-spec-regexp 'separate)))
-  "Alist mapping Tramp syntax to regexps matching Tramp file names.")
-
-(defun tramp-remote-file-name-spec-regexp ()
-  "Regular expression matching a Tramp file name between prefix and postfix."
-  (tramp-lookup-syntax tramp-remote-file-name-spec-regexp-alist))
-
-(defun tramp-build-file-name-structure (syntax)
-  "Construct the Tramp file name structure for SYNTAX.
+(defun tramp-build-remote-file-name-spec-regexp ()
+  "Construct a regexp matching a Tramp file name for a Tramp syntax.
+It is expected, that `tramp-syntax' has the proper value."
+  (concat
+           "\\("   tramp-method-regexp "\\)" tramp-postfix-method-regexp
+   "\\(?:" "\\("   tramp-user-regexp   "\\)" tramp-postfix-user-regexp   "\\)?"
+   "\\("   "\\(?:" tramp-host-regexp   "\\|"
+                   tramp-prefix-ipv6-regexp  "\\(?:" tramp-ipv6-regexp "\\)?"
+                                             tramp-postfix-ipv6-regexp "\\)"
+           "\\(?:" tramp-prefix-port-regexp  tramp-port-regexp "\\)?" "\\)?"))
+
+(defvar tramp-remote-file-name-spec-regexp
+  (tramp-build-remote-file-name-spec-regexp)
+  "Regular expression matching a Tramp file name between prefix and postfix.")
+
+(defun tramp-build-file-name-structure ()
+  "Construct the Tramp file name structure for a Tramp syntax.
+It is expected, that `tramp-syntax' has the proper value.
 See `tramp-file-name-structure'."
-  (let ((tramp-syntax syntax))
-    (list
-     (concat
-      (tramp-prefix-regexp)
-      "\\(" "\\(?:" (tramp-remote-file-name-spec-regexp)
-      tramp-postfix-hop-regexp "\\)+" "\\)?"
-      (tramp-remote-file-name-spec-regexp) (tramp-postfix-host-regexp)
-      "\\(" tramp-localname-regexp "\\)")
-     5 6 7 8 1)))
-
-(defconst tramp-file-name-structure-alist
-  `((default    . ,(tramp-build-file-name-structure 'default))
-    (simplified . ,(tramp-build-file-name-structure 'simplified))
-    (separate   . ,(tramp-build-file-name-structure 'separate)))
-  "Alist mapping Tramp syntax to the file name structure for that syntax.")
-
-(defun tramp-file-name-structure ()
+  (list
+   (concat
+    tramp-prefix-regexp
+    "\\(" "\\(?:" tramp-remote-file-name-spec-regexp
+                  tramp-postfix-hop-regexp "\\)+" "\\)?"
+    tramp-remote-file-name-spec-regexp tramp-postfix-host-regexp
+    "\\(" tramp-localname-regexp "\\)")
+   5 6 7 8 1))
+
+(defvar tramp-file-name-structure (tramp-build-file-name-structure)
   "List of six elements (REGEXP METHOD USER HOST FILE HOP), detailing \
 the Tramp file name structure.
 
@@ -969,25 +961,22 @@ cascade of several hops.
 These numbers are passed directly to `match-string', which see.  That
 means the opening parentheses are counted to identify the pair.
 
-See also `tramp-file-name-regexp'."
-  (tramp-lookup-syntax tramp-file-name-structure-alist))
+See also `tramp-file-name-regexp'.")
 
-(defun tramp-file-name-regexp ()
-  "Regular expression matching file names handled by Tramp.
-This regexp should match Tramp file names but no other file names."
-  (car (tramp-file-name-structure)))
+(defun tramp-build-file-name-regexp ()
+  (car tramp-file-name-structure))
 
 ;;;###autoload
 (defconst tramp-initial-file-name-regexp "\\`/.+:.*:"
   "Value for `tramp-file-name-regexp' for autoload.
 It must match the initial `tramp-syntax' settings.")
 
-;; External packages use constant `tramp-file-name-regexp'.  In order
-;; not to break them, we still provide it.  It is a variable now.
 ;;;###autoload
 (defvar tramp-file-name-regexp tramp-initial-file-name-regexp
-    "Value for `tramp-file-name-regexp' for autoload.
-It must match the initial `tramp-syntax' settings.")
+  "Regular expression matching file names handled by Tramp.
+This regexp should match Tramp file names but no other file
+names.  When calling `tramp-register-file-name-handlers', the
+initial value is overwritten by the car of `tramp-file-name-structure'.")
 
 ;;;###autoload
 (defconst tramp-completion-file-name-regexp-default
@@ -1031,7 +1020,17 @@ On W32 systems, the volume letter must be ignored.")
   "Value for `tramp-completion-file-name-regexp' for separate remoting.
 See `tramp-file-name-structure' for more explanations.")
 
-(defun tramp-completion-file-name-regexp ()
+(defconst tramp-completion-file-name-regexp-alist
+  `((default    . ,tramp-completion-file-name-regexp-default)
+    (simplified . ,tramp-completion-file-name-regexp-simplified)
+    (separate   . ,tramp-completion-file-name-regexp-separate))
+  "Alist mapping incomplete Tramp file names.")
+
+(defun tramp-build-completion-file-name-regexp ()
+  (tramp-lookup-syntax tramp-completion-file-name-regexp-alist))
+
+(defvar tramp-completion-file-name-regexp
+  (tramp-build-completion-file-name-regexp)
   "Regular expression matching file names handled by Tramp completion.
 This regexp should match partial Tramp file names only.
 
@@ -1040,14 +1039,7 @@ this file \(tramp.el) is loaded.  This means that this variable must be set
 before loading tramp.el.  Alternatively, `file-name-handler-alist' can be
 updated after changing this variable.
 
-Also see `tramp-file-name-structure'."
-  (cond ((eq (tramp-compat-tramp-syntax) 'default)
-         tramp-completion-file-name-regexp-default)
-        ((eq (tramp-compat-tramp-syntax) 'simplified)
-         tramp-completion-file-name-regexp-simplified)
-        ((eq (tramp-compat-tramp-syntax) 'separate)
-         tramp-completion-file-name-regexp-separate)
-        (t (error "Wrong `tramp-syntax' %s" tramp-syntax))))
+Also see `tramp-file-name-structure'.")
 
 ;;;###autoload
 (defconst tramp-initial-completion-file-name-regexp
@@ -1284,7 +1276,7 @@ entry does not exist, return nil."
                (if (memq system-type '(cygwin windows-nt))
                    "^/[[:alpha:]]?:" "^/:")
                name))
-         (string-match (tramp-file-name-regexp) name))))
+         (string-match tramp-file-name-regexp name))))
 
 (defun tramp-find-method (method user host)
   "Return the right method string to use.
@@ -1356,13 +1348,13 @@ values."
   (save-match-data
     (unless (tramp-tramp-file-p name)
       (tramp-compat-user-error nil "Not a Tramp file name: \"%s\"" name))
-    (if (not (string-match (nth 0 (tramp-file-name-structure)) name))
+    (if (not (string-match (nth 0 tramp-file-name-structure) name))
         (error "`tramp-file-name-structure' didn't match!")
-      (let ((method    (match-string (nth 1 (tramp-file-name-structure)) name))
-            (user      (match-string (nth 2 (tramp-file-name-structure)) name))
-            (host      (match-string (nth 3 (tramp-file-name-structure)) name))
-            (localname (match-string (nth 4 (tramp-file-name-structure)) name))
-            (hop       (match-string (nth 5 (tramp-file-name-structure)) name))
+      (let ((method    (match-string (nth 1 tramp-file-name-structure) name))
+            (user      (match-string (nth 2 tramp-file-name-structure) name))
+            (host      (match-string (nth 3 tramp-file-name-structure) name))
+            (localname (match-string (nth 4 tramp-file-name-structure) name))
+            (hop       (match-string (nth 5 tramp-file-name-structure) name))
             domain port)
         (when user
           (when (string-match tramp-user-with-domain-regexp user)
@@ -1373,9 +1365,9 @@ values."
           (when (string-match tramp-host-with-port-regexp host)
             (setq port (match-string 2 host)
                   host (match-string 1 host)))
-          (when (string-match (tramp-prefix-ipv6-regexp) host)
+          (when (string-match tramp-prefix-ipv6-regexp host)
             (setq host (replace-match "" nil t host)))
-          (when (string-match (tramp-postfix-ipv6-regexp) host)
+          (when (string-match tramp-postfix-ipv6-regexp host)
             (setq host (replace-match "" nil t host))))
 
         (unless nodefault
@@ -1400,42 +1392,41 @@ values."
     (method user domain host port localname &optional hop)
   "Constructs a Tramp file name from METHOD, USER, HOST and LOCALNAME.
 When not nil, optional DOMAIN, PORT and HOP are used."
-  (concat (tramp-prefix-format) hop
+  (concat tramp-prefix-format hop
           (unless (or (zerop (length method))
-                      (zerop (length (tramp-postfix-method-format))))
-            (concat method (tramp-postfix-method-format)))
+                      (zerop (length tramp-postfix-method-format)))
+            (concat method tramp-postfix-method-format))
           user
           (unless (zerop (length domain))
             (concat tramp-prefix-domain-format domain))
           (unless (zerop (length user))
-           tramp-postfix-user-format)
+            tramp-postfix-user-format)
           (when host
             (if (string-match tramp-ipv6-regexp host)
-                (concat
-                 (tramp-prefix-ipv6-format) host (tramp-postfix-ipv6-format))
+                (concat tramp-prefix-ipv6-format host tramp-postfix-ipv6-format)
               host))
           (unless (zerop (length port))
             (concat tramp-prefix-port-format port))
-          (tramp-postfix-host-format)
+          tramp-postfix-host-format
           (when localname localname)))
 
 (defun tramp-completion-make-tramp-file-name (method user host localname)
   "Constructs a Tramp file name from METHOD, USER, HOST and LOCALNAME.
 It must not be a complete Tramp file name, but as long as there are
 necessary only.  This function will be used in file name completion."
-  (concat (tramp-prefix-format)
+  (concat tramp-prefix-format
           (unless (or (zerop (length method))
-                      (zerop (length (tramp-postfix-method-format))))
-            (concat method (tramp-postfix-method-format)))
+                      (zerop (length tramp-postfix-method-format)))
+            (concat method tramp-postfix-method-format))
           (unless (zerop (length user))
             (concat user tramp-postfix-user-format))
           (unless (zerop (length host))
             (concat
              (if (string-match tramp-ipv6-regexp host)
                  (concat
-                  (tramp-prefix-ipv6-format) host (tramp-postfix-ipv6-format))
+                  tramp-prefix-ipv6-format host tramp-postfix-ipv6-format)
                host)
-             (tramp-postfix-host-format)))
+             tramp-postfix-host-format))
           (when localname localname)))
 
 (defun tramp-get-buffer (vec)
@@ -1947,7 +1938,7 @@ special handling of `substitute-in-file-name'."
                          'tramp-rfn-eshadow-setup-minibuffer)))
 
 (defun tramp-rfn-eshadow-update-overlay-regexp ()
-  (format "[^%s/~]*\\(/\\|~\\)" (tramp-postfix-host-format)))
+  (format "[^%s/~]*\\(/\\|~\\)" tramp-postfix-host-format))
 
 (defun tramp-rfn-eshadow-update-overlay ()
   "Update `rfn-eshadow-overlay' to cover shadowed part of minibuffer input.
@@ -2365,11 +2356,11 @@ remote file names."
   ;; property of `tramp-file-name-handler', this shall be done by the
   ;; respective foreign handlers.
   (add-to-list 'file-name-handler-alist
-               (cons (tramp-file-name-regexp) 'tramp-file-name-handler))
+               (cons tramp-file-name-regexp 'tramp-file-name-handler))
   (put 'tramp-file-name-handler 'safe-magic t)
 
   (add-to-list 'file-name-handler-alist
-               (cons (tramp-completion-file-name-regexp)
+               (cons tramp-completion-file-name-regexp
                      'tramp-completion-file-name-handler))
   (put 'tramp-completion-file-name-handler 'safe-magic t)
   ;; Mark `operations' the handler is responsible for.
@@ -2473,8 +2464,8 @@ not in completion mode."
     ;; Suppress hop from completion.
     (when (string-match
            (concat
-            (tramp-prefix-regexp)
-            "\\(" "\\(" (tramp-remote-file-name-spec-regexp)
+            tramp-prefix-regexp
+            "\\(" "\\(" tramp-remote-file-name-spec-regexp
                         tramp-postfix-hop-regexp
             "\\)+" "\\)")
            fullname)
@@ -2519,9 +2510,8 @@ not in completion mode."
     ;; Unify list, add hop, remove nil elements.
     (dolist (elt result)
       (when elt
-        (string-match (tramp-prefix-regexp) elt)
-        (setq elt
-              (replace-match (concat (tramp-prefix-format) hop) nil nil elt))
+        (string-match tramp-prefix-regexp elt)
+        (setq elt (replace-match (concat tramp-prefix-format hop) nil nil elt))
         (push
          (substring elt (length (tramp-drop-volume-letter directory)))
          result1)))
@@ -2569,58 +2559,58 @@ They are collected by `tramp-completion-dissect-file-name1'."
          (tramp-completion-ipv6-regexp
           (format
            "[^%s]*"
-           (if (zerop (length (tramp-postfix-ipv6-format)))
-               (tramp-postfix-host-format)
-             (tramp-postfix-ipv6-format))))
+           (if (zerop (length tramp-postfix-ipv6-format))
+               tramp-postfix-host-format
+             tramp-postfix-ipv6-format)))
          ;; "/method" "/[method"
          (tramp-completion-file-name-structure1
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) x-nil "\\)$")
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp x-nil "\\)$")
            1 nil nil nil))
          ;; "/method:user" "/[method/user"
          (tramp-completion-file-name-structure2
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-            "\\(" tramp-user-regexp x-nil     "\\)$")
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp "\\)" tramp-postfix-method-regexp
+            "\\(" tramp-user-regexp x-nil   "\\)$")
            1 2 nil nil))
          ;; "/method:host" "/[method/host"
          (tramp-completion-file-name-structure3
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-            "\\(" tramp-host-regexp x-nil     "\\)$")
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp "\\)" tramp-postfix-method-regexp
+            "\\(" tramp-host-regexp x-nil   "\\)$")
            1 nil 2 nil))
          ;; "/method:[ipv6" "/[method/ipv6"
          (tramp-completion-file-name-structure4
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-            (tramp-prefix-ipv6-regexp)
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp "\\)" tramp-postfix-method-regexp
+            tramp-prefix-ipv6-regexp
             "\\(" tramp-completion-ipv6-regexp x-nil "\\)$")
            1 nil 2 nil))
          ;; "/method:user@host" "/[method/user@host"
          (tramp-completion-file-name-structure5
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-            "\\(" tramp-user-regexp "\\)"     tramp-postfix-user-regexp
-            "\\(" tramp-host-regexp x-nil     "\\)$")
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp "\\)" tramp-postfix-method-regexp
+            "\\(" tramp-user-regexp "\\)"   tramp-postfix-user-regexp
+            "\\(" tramp-host-regexp x-nil   "\\)$")
            1 2 3 nil))
          ;; "/method:user@[ipv6" "/[method/user@ipv6"
          (tramp-completion-file-name-structure6
           (list
            (concat
-            (tramp-prefix-regexp)
-            "\\(" (tramp-method-regexp) "\\)" (tramp-postfix-method-regexp)
-            "\\(" tramp-user-regexp "\\)"     tramp-postfix-user-regexp
-            (tramp-prefix-ipv6-regexp)
+            tramp-prefix-regexp
+            "\\(" tramp-method-regexp "\\)" tramp-postfix-method-regexp
+            "\\(" tramp-user-regexp "\\)"   tramp-postfix-user-regexp
+            tramp-prefix-ipv6-regexp
             "\\(" tramp-completion-ipv6-regexp x-nil "\\)$")
            1 2 3 nil)))
     (delq
@@ -4479,10 +4469,10 @@ Invokes `password-read' if available, `read-passwd' else."
       (tramp-clear-passwd
        (tramp-dissect-file-name
         (concat
-         (tramp-prefix-format)
+         tramp-prefix-format
          (replace-regexp-in-string
           (concat tramp-postfix-hop-regexp "$")
-          (tramp-postfix-host-format) hop)))))
+          tramp-postfix-host-format hop)))))
     (auth-source-forget
      `(:max 1 ,(and user-domain :user) ,user-domain
        :host ,host-port :port ,method))
diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 4139d50ff01..13e2e30cab4 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2852,16 +2852,16 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
             (tramp-change-syntax syntax)
             (let ;; This is needed for the `simplified' syntax.
                 ((method-marker
-                  (if (zerop (length (tramp-method-regexp)))
+                  (if (zerop (length tramp-method-regexp))
                       "" tramp-default-method-marker))
                  ;; This is needed for the `separate' syntax.
-                 (prefix-format (substring (tramp-prefix-format) 1)))
+                 (prefix-format (substring tramp-prefix-format 1)))
               ;; Complete method name.
               (unless (or (zerop (length method))
-                          (zerop (length (tramp-method-regexp))))
+                          (zerop (length tramp-method-regexp)))
                 (should
                  (member
-                  (concat prefix-format method (tramp-postfix-method-format))
+                  (concat prefix-format method tramp-postfix-method-format)
                   (file-name-all-completions
                    (concat prefix-format (substring method 0 1)) "/"))))
               ;; Complete host name for default method.  With gvfs
@@ -2873,25 +2873,25 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
                   (should
                    (member
                     (concat
-                     prefix-format method-marker (tramp-postfix-method-format)
-                     host (tramp-postfix-host-format))
+                     prefix-format method-marker tramp-postfix-method-format
+                     host tramp-postfix-host-format)
                     (file-name-all-completions
                      (concat
-                      prefix-format method-marker (tramp-postfix-method-format)
+                      prefix-format method-marker tramp-postfix-method-format
                       (substring host 0 1))
                      "/")))))
               ;; Complete host name.
               (unless (or (zerop (length method))
-                          (zerop (length (tramp-method-regexp)))
+                          (zerop (length tramp-method-regexp))
                           (zerop (length host))
                           (tramp--test-gvfs-p method))
                 (should
                  (member
                   (concat
-                   prefix-format method (tramp-postfix-method-format)
-                   host (tramp-postfix-host-format))
+                   prefix-format method tramp-postfix-method-format
+                   host tramp-postfix-host-format)
                   (file-name-all-completions
-                   (concat prefix-format method (tramp-postfix-method-format))
+                   (concat prefix-format method tramp-postfix-method-format)
                    "/"))))))
 
         ;; Cleanup.