bug#16593: 24.3.50; ruby-mode: align chained method calls on multiple lines

[Dmitry Gutov]

Tags: patch

For background:
http://lists.gnu.org/archive/html/emacs-devel/2014-01/msg01889.html

I have a working patch, but I can't get rid of the warnings on startup:

Warning (smie): Conflict: . </= .
Warning (smie): Conflict: . </= .

=== modified file 'lisp/progmodes/ruby-mode.el'
--- lisp/progmodes/ruby-mode.el 2014-01-17 03:15:02 +0000
+++ lisp/progmodes/ruby-mode.el 2014-01-30 04:18:54 +0000
@@ -264,6 +264,13 @@
   :safe 'listp
   :version "24.4")
 
+(defcustom ruby-align-chained-calls nil
+  "If non-nil, chained method calls on multiple lines will be
+aligned to the same column."
+  :type 'boolean
+  :group 'ruby
+  :safe 'booleanp)
+
 (defcustom ruby-deep-arglist t
   "Deep indent lists in parenthesis when non-nil.
 Also ignores spaces after parenthesis when `space'.
@@ -351,7 +358,7 @@
              (exp "and" exp) (exp "or" exp))
        (exp  (exp1) (exp "," exp) (exp "=" exp)
              (id " @ " exp)
-             (exp "." id))
+             (id "." exp))
        (exp1 (exp2) (exp2 "?" exp1 ":" exp1))
        (exp2 ("def" insts "end")
              ("begin" insts-rescue-insts "end")
@@ -399,7 +406,8 @@
        (nonassoc ">" ">=" "<" "<=")
        (nonassoc "==" "===" "!=")
        (nonassoc "=~" "!~")
-       (left "<<" ">>"))))))
+       (left "<<" ">>")
+       (assoc "."))))))
 
 (defun ruby-smie--bosp ()
   (save-excursion (skip-chars-backward " \t")
@@ -609,7 +617,18 @@
         ;; When after `.', let's always de-indent,
         ;; because when `.' is inside the line, the
         ;; additional indentation from it looks out of place.
-        ((smie-rule-parent-p ".") (smie-rule-parent (- ruby-indent-level)))
+        ((smie-rule-parent-p ".")
+         (let (smie--parent)
+           (save-excursion
+             ;; Traverse up the parents until the parent is "." at
+             ;; indentation, or any other token.
+             (while (and (progn
+                           (goto-char (1- (cadr (smie-indent--parent))))
+                           (not (ruby-smie--bosp)))
+                         (progn
+                           (setq smie--parent nil)
+                           (smie-rule-parent-p "."))))
+             (smie-rule-parent))))
         (t (smie-rule-parent))))))
     (`(:after . ,(or `"(" "[" "{"))
      ;; FIXME: Shouldn't this be the default behavior of
@@ -622,7 +641,10 @@
        (unless (or (eolp) (forward-comment 1))
          (cons 'column (current-column)))))
     (`(:before . "do") (ruby-smie--indent-to-stmt))
-    (`(:before . ".") ruby-indent-level)
+    (`(:before . ".")
+     (if (smie-rule-sibling-p)
+         (and ruby-align-chained-calls 0)
+       ruby-indent-level))
     (`(:after . "=>") ruby-indent-level)
     (`(:before . ,(or `"else" `"then" `"elsif" `"rescue" `"ensure"))
      (smie-rule-parent))

=== modified file 'test/automated/ruby-mode-tests.el'
--- test/automated/ruby-mode-tests.el   2014-01-01 07:43:34 +0000
+++ test/automated/ruby-mode-tests.el   2014-01-30 04:15:02 +0000
@@ -333,6 +333,20 @@
      |      42
      |    end")))
 
+(ert-deftest ruby-align-chained-calls ()
+  (let ((ruby-align-chained-calls t))
+    (ruby-should-indent-buffer
+     "one.two.three
+     |       .four
+     |
+     |my_array.select { |str| str.size > 5 }
+     |        .map    { |str| str.downcase }"
+     "one.two.three
+     |  .four
+     |
+     |my_array.select { |str| str.size > 5 }
+     |   .map    { |str| str.downcase }")))
+
 (ert-deftest ruby-move-to-block-stops-at-indentation ()
   (ruby-with-temp-buffer "def f\nend"
     (beginning-of-line)

=== modified file 'test/indent/ruby.rb'
--- test/indent/ruby.rb 2014-01-17 03:15:02 +0000
+++ test/indent/ruby.rb 2014-01-30 04:15:30 +0000
@@ -257,8 +257,8 @@
   bar
 
 foo_bar_tee(1, 2, 3)
-  .qux
-  .bar
+  .qux.bar
+  .tee
 
 foo do
   bar
@@ -348,7 +348,7 @@
 
 zoo
   .lose(
-  q, p)
+    q, p)
 
 foo(bar:
       tee)