[elpa] master b4072c1 14/47: Trivial refactoring for clarity.

[Jackson Ray Hamilton]

branch: master
commit b4072c1481873e4274cd187a76ae9d4afffae52c
Author: Jackson Ray Hamilton <address@hidden>
Commit: Jackson Ray Hamilton <address@hidden>

    Trivial refactoring for clarity.
---
 context-coloring.el |  149 +++++++++++++++++++++++++++-----------------------
 1 files changed, 80 insertions(+), 69 deletions(-)

diff --git a/context-coloring.el b/context-coloring.el
index 9c31314..9e1e1ed 100644
--- a/context-coloring.el
+++ b/context-coloring.el
@@ -324,7 +324,7 @@ generated by `js2-mode'."
         (setq level (context-coloring-scope-get-level scope)))
        (t
         (setq scope-stack (cdr scope-stack)))))
-    ;; Assume global
+    ;; Assume a global variable.
     (or level 0)))
 
 (defun context-coloring-make-backtick (end enabled)
@@ -341,37 +341,58 @@ generated by `js2-mode'."
 (defun context-coloring-backtick-enabled-p (backtick-stack)
   (context-coloring-backtick-get-enabled (car backtick-stack)))
 
-(defun context-coloring-make-let-value (end)
-  (list
-   :end end))
+(defun context-coloring-forward-sws ()
+  "Move forward through whitespace and comments."
+  (while (forward-comment 1)))
 
-(defun context-coloring-let-value-get-end (let-value)
-  (plist-get let-value :end))
+(defun context-coloring-forward-sexp-position ()
+  (scan-sexps (point) 1))
 
 (defun context-coloring-emacs-lisp-identifier-syntax-p (syntax-code)
   (or (= 2 syntax-code)
       (= 3 syntax-code)))
 
-(defun context-coloring-forward-sws ()
-  "Move forward through whitespace and comments."
-  (while (forward-comment 1)))
+(defun context-coloring-open-parenthesis-p (syntax-code)
+  (= 4 syntax-code))
+
+(defun context-coloring-close-parenthesis-p (syntax-code)
+  (= 5 syntax-code))
 
-(defun context-coloring-at-open-parenthesis ()
+(defun context-coloring-expression-prefix-p (syntax-code)
+  (= 6 syntax-code))
+
+(defun context-coloring-at-open-parenthesis-p ()
   (= 4 (logand #xFFFF (car (syntax-after (point))))))
 
+(defun context-coloring-ppss-depth (ppss)
+  ;; Same as (nth 0 ppss).
+  (car ppss))
+
+(defconst context-coloring-defun-regexp
+  "\\`defun\\'\\|\\`defmacro\\'\\|\\`defsubst\\'")
+
+(defconst context-coloring-arglist-arg-regexp
+  "\\`[^&:]")
+
+(defconst context-coloring-unbindable-constant-regexp
+  "\\`[-+]?[0-9]\\|\\`t\\'\\|\\`nil\\'")
+
+(defconst context-coloring-COMMA-CHAR 44)
+(defconst context-coloring-BACKTICK-CHAR 96)
+
 (defun context-coloring-emacs-lisp-colorize ()
   "Color the current buffer by parsing emacs lisp sexps."
   (with-silent-modifications
     (save-excursion
-      ;; TODO: Can probably make this lazy to the nearest defun
+      ;; TODO: Can probably make this lazy to the nearest defun.
       (goto-char (point-min))
       (let* ((inhibit-point-motion-hooks t)
              (end (point-max))
              (last-ppss-pos (point))
              (ppss (syntax-ppss))
-             (scope-stack `(,(context-coloring-make-scope -1 0))) ; -1 never 
matches a depth
-             (backtick-stack `(,(context-coloring-make-backtick -1 nil)))
-             (let-value-stack `(,(context-coloring-make-let-value -1)))
+             ; -1 never matches a depth.  This is a minor optimization.
+             (scope-stack `(,(context-coloring-make-scope -1 0)))
+             (backtick-stack '())
              one-word-found-p
              in-defun-p
              in-lambda-p
@@ -403,17 +424,13 @@ generated by `js2-mode'."
                              (point)))
           (setq token-pos (point))
           (setq token-syntax (syntax-after token-pos))
+          (setq token-syntax-code (logand #xFFFF (car token-syntax)))
+          (setq token-char (char-after))
           (setq ppss (parse-partial-sexp last-ppss-pos token-pos nil nil ppss))
           (setq last-ppss-pos token-pos)
-          ;; `skip-syntax-forward' leaves the point at the delimiter, move past
-          ;; it.
-          (setq token-syntax-code (logand #xFFFF (car token-syntax)))
-          (setq token-char (string-to-char (buffer-substring-no-properties
-                                            token-pos
-                                            (1+ token-pos))))
           (cond
 
-           ;; Resolve invalid state
+           ;; Resolve an invalid state.
            ((cond
              ;; Inside string?
              ((nth 3 ppss)
@@ -422,54 +439,49 @@ generated by `js2-mode'."
               t)
              ;; Inside comment?
              ((nth 4 ppss)
-              (skip-syntax-forward "^>" end) ; comment ender
+              (skip-syntax-forward "^>" end)
               t)))
 
-           ;; Expression prefix
-           ;; Has to come first in case of commas
-           ((= 6 token-syntax-code)
+           ;; Need to check early in case there's a comma.
+           ((context-coloring-expression-prefix-p token-syntax-code)
             (forward-char)
             (cond
-             ;; Just outright skip top-level symbols
-             ((not (or (cadr backtick-stack)
-                       (= token-char 96))) ; 96 = '`'
-              (goto-char (scan-sexps (point) 1)))
-             ((or (= token-char 96)  ; 96 = '`'
-                  (= token-char 44)) ; 44 = ','
-              ;; Have to manage backticks
+             ;; Skip top-level symbols.
+             ((not (or backtick-stack
+                       (= token-char context-coloring-BACKTICK-CHAR)))
+              (goto-char (context-coloring-forward-sexp-position)))
+             ;; Push a backtick state.
+             ((or (= token-char context-coloring-BACKTICK-CHAR)
+                  (= token-char context-coloring-COMMA-CHAR))
               (setq backtick-stack (cons (context-coloring-make-backtick
-                                          (scan-sexps (point) 1) ; End of the 
backtick
-                                          (= token-char 96)) ; 96 = '`'
+                                          
(context-coloring-forward-sexp-position)
+                                          (= token-char 
context-coloring-BACKTICK-CHAR))
                                          backtick-stack)))))
 
-           ;; End backtick
-           ((and (cadr backtick-stack)
+           ;; Pop a backtick state.
+           ((and backtick-stack
                  (>= (point) (context-coloring-backtick-get-end (car 
backtick-stack))))
             (setq backtick-stack (cdr backtick-stack)))
 
-           ;; Restricted by backtick
-           ((and (cadr backtick-stack)
+           ;; Restricted by an enabled backtick.
+           ((and backtick-stack
                  (context-coloring-backtick-enabled-p backtick-stack))
             (forward-char))
 
-           ;; Opening delimiter
-           ((= 4 token-syntax-code)
+           ((context-coloring-open-parenthesis-p token-syntax-code)
             (forward-char)
-            ;; Lookahead for scopes / function calls
+            ;; Look for function calls.
             (context-coloring-forward-sws)
             (setq child-0-pos (point))
             (setq child-0-syntax (syntax-after child-0-pos))
             (setq child-0-syntax-code (logand #xFFFF (car child-0-syntax)))
             (cond
-             ;; Word
              ((context-coloring-emacs-lisp-identifier-syntax-p 
child-0-syntax-code)
               (setq one-word-found-p t)
               (setq child-0-end (scan-sexps child-0-pos 1))
               (setq child-0-string (buffer-substring-no-properties child-0-pos 
child-0-end))
               (cond
-               ((string-match-p
-                 "\\`defun\\'\\|\\`defmacro\\'\\|\\`defsubst\\'"
-                 child-0-string)
+               ((string-match-p context-coloring-defun-regexp child-0-string)
                 (setq in-defun-p t))
                ((string-match-p "\\`lambda\\'" child-0-string)
                 (setq in-lambda-p t))
@@ -482,11 +494,11 @@ generated by `js2-mode'."
                       in-let-p
                       in-let*-p)
               (setq scope-stack (cons (context-coloring-make-scope
-                                       (nth 0 ppss)
+                                       (context-coloring-ppss-depth ppss)
                                        (1+ (context-coloring-scope-get-level
                                             (car scope-stack))))
                                       scope-stack)))
-            ;; TODO: Probably redundant and wasteful
+            ;; TODO: Probably redundant and wasteful.
             (context-coloring-colorize-region token-pos
                                               (scan-sexps token-pos 1)
                                               (context-coloring-scope-get-level
@@ -496,48 +508,49 @@ generated by `js2-mode'."
                   in-lambda-p)
               (goto-char child-0-end)
               (when in-defun-p
-                ;; Lookahead for defun name
+                ;; Look for a function name.
                 (context-coloring-forward-sws)
                 (setq child-1-pos (point))
                 (setq child-1-syntax (syntax-after child-1-pos))
                 (setq child-1-syntax-code (logand #xFFFF (car child-1-syntax)))
                 (cond
-                 ;; Word
                  ((context-coloring-emacs-lisp-identifier-syntax-p 
child-1-syntax-code)
                   (setq child-1-end (scan-sexps child-1-pos 1))
-                  ;; defuns are global so use level 0
+                  ;; Defuns are global, so use level 0.
                   (context-coloring-colorize-region child-1-pos child-1-end 0)
                   (goto-char child-1-end))))
-              ;; Lookahead for parameters
+              ;; Look for an arglist.
               (context-coloring-forward-sws)
-              (when (context-coloring-at-open-parenthesis)
-                ;; Actually it should be `child-1-end' for `lambda'.
-                (setq child-2-end (scan-sexps (point) 1))
+              (when (context-coloring-at-open-parenthesis-p)
+                ;; (Actually it should be `child-1-end' for `lambda'.)
+                (setq child-2-end (context-coloring-forward-sexp-position))
                 (setq defun-arglist (read (buffer-substring-no-properties
                                            (point)
                                            child-2-end)))
                 (while defun-arglist
                   (setq defun-arg (car defun-arglist))
                   (when (and (symbolp defun-arg)
-                             (string-match-p "\\`[^&:]" (symbol-name 
defun-arg)))
+                             (string-match-p
+                              context-coloring-arglist-arg-regexp
+                              (symbol-name defun-arg)))
                     (context-coloring-scope-add-variable
                      (car scope-stack)
                      defun-arg))
                   (setq defun-arglist (cdr defun-arglist)))
                 (goto-char child-2-end))
-              ;; Cleanup
+              ;; Cleanup.
               (setq in-defun-p nil)
               (setq in-lambda-p nil))
              ((or in-let-p
                   in-let*-p)
               (goto-char child-0-end)
-              ;; Lookahead for bindings
+              ;; Look for bindings.
               (context-coloring-forward-sws)
               (setq child-1-pos (point))
               (setq child-1-syntax (syntax-after child-1-pos))
               (setq child-1-syntax-code (logand #xFFFF (car child-1-syntax)))
               (when (= 4 child-1-syntax-code)
-                (setq child-1-end (scan-sexps (point) 1))
+                (setq child-1-end (context-coloring-forward-sexp-position))
                 (setq let-varlist (read (buffer-substring-no-properties
                                          (point)
                                          child-1-end)))
@@ -552,11 +565,11 @@ generated by `js2-mode'."
                     (context-coloring-scope-add-variable
                      (car scope-stack)
                      (car let-var))
-                    ;; TODO: Recurse or use stack to eval var value
+                    ;; TODO: Recurse or use stack to eval var value.
                     ))
                   (setq let-varlist (cdr let-varlist)))
                 (goto-char child-1-end))
-              ;; Cleanup
+              ;; Cleanup.
               (setq in-let-p nil)
               (setq in-let*-p nil))
              (t
@@ -566,19 +579,18 @@ generated by `js2-mode'."
                            (1+ child-0-end))
                           (t
                            (1+ token-pos))))))
-            ;; Cleanup
+            ;; Cleanup.
             (setq one-word-found-p nil))
 
-           ;; Word (variable)
            ((context-coloring-emacs-lisp-identifier-syntax-p token-syntax-code)
-            (setq variable-end (scan-sexps (point) 1))
+            (setq variable-end (context-coloring-forward-sexp-position))
             (setq variable-string (buffer-substring-no-properties
                                    token-pos
                                    variable-end))
             (cond
-             ;; Ignore constants such as numbers, keywords, t, nil. These can't
+             ;; Ignore constants such as numbers, keywords, t, nil.  These 
can't
              ;; be rebound, so they should be treated like syntax.
-             ((string-match-p "\\`[-+]?[0-9]\\|\\`t\\'\\|\\`nil\\'" 
variable-string))
+             ((string-match-p context-coloring-unbindable-constant-regexp 
variable-string))
              ((keywordp (read variable-string)))
              (t
               (setq variable (intern variable-string))
@@ -592,13 +604,12 @@ generated by `js2-mode'."
                  variable-scope-level))))
             (goto-char variable-end))
 
-           ;; Closing delimiter
-           ((= 5 token-syntax-code)
+           ((context-coloring-close-parenthesis-p token-syntax-code)
             (forward-char)
-            ;; End scope
             (setq ppss (parse-partial-sexp last-ppss-pos (point) nil nil ppss))
             (setq last-ppss-pos (point))
-            (when (= (nth 0 ppss) (context-coloring-scope-get-depth (car 
scope-stack)))
+            (when (= (context-coloring-ppss-depth ppss)
+                     (context-coloring-scope-get-depth (car scope-stack)))
               (setq scope-stack (cdr scope-stack))))
 
            ))))