Merge pull request JuliaLang#9308 from Wilfred/wh/julia_mode_lookback…

…_limit

julia-mode.el: Set a maximum lookback for finding enclosing parens/blocks

contrib/julia-mode.el

@@ -322,6 +322,8 @@ Do not move back beyond position MIN."
 (defun julia-last-open-block (min)
  "Move back and return indentation level for last open block.
 Do not move back beyond MIN."
+ ;; Ensure MIN is not before the start of the buffer.
+ (setq min (max min (point-min)))
  (let ((pos (julia-last-open-block-pos min)))
  (and pos
  (progn
@@ -334,12 +336,26 @@ beginning of the buffer."
  (unless (eq (point) (point-min))
  (backward-char)))
 
+(defvar julia-max-paren-lookback 400
+ "When indenting, don't look back more than this
+many characters to see if there are unclosed parens.
+
+This variable has a major effect on indent performance if set too
+high.")
+
+(defvar julia-max-block-lookback 5000
+ "When indenting, don't look back more than this
+many characters to see if there are unclosed blocks.
+
+This variable has a moderate effect on indent performance if set too
+high.")
+
 (defun julia-paren-indent ()
  "Return the column position of the innermost containing paren
 before point. Returns nil if we're not within nested parens."
  (save-excursion
- (let ((min-pos (or (julia-last-open-block-pos (point-min))
- (point-min)))
+ (let ((min-pos (max (- (point) julia-max-paren-lookback)
+  (point-min)))
  (open-count 0))
  (while (and (> (point) min-pos)
  (not (plusp open-count)))
@@ -383,7 +399,7 @@ before point. Returns nil if we're not within nested parens."
  (beginning-of-line)
  (forward-to-indentation 0)
  (let ((endtok (julia-at-keyword julia-block-end-keywords)))
- (ignore-errors (+ (julia-last-open-block (point-min))
+ (ignore-errors (+ (julia-last-open-block (- (point) julia-max-block-lookback))
  (if endtok (- julia-basic-offset) 0)))))
  ;; Otherwise, use the same indentation as previous line.
  (save-excursion (forward-line -1)
@@ -394,6 +410,136 @@ before point. Returns nil if we're not within nested parens."
  (when (>= point-offset 0)
  (move-to-column (+ (current-indentation) point-offset)))))
 
+;; Emacs 23.X doesn't include ert, so we ignore any errors that occur
+;; when we define tests.
+(ignore-errors
+ (require 'ert)
+
+ (defmacro julia--should-indent (from to)
+ "Assert that we indent text FROM producing text TO in `julia-mode'."
+ `(with-temp-buffer
+ (julia-mode)
+ (insert ,from)
+ (indent-region (point-min) (point-max))
+ (should (equal (buffer-substring-no-properties (point-min) (point-max))
+ ,to))))
+
+ (ert-deftest julia--test-indent-if ()
+ "We should indent inside if bodies."
+ (julia--should-indent
+ "
+if foo
+bar
+end"
+ "
+if foo
+ bar
+end"))
+
+ (ert-deftest julia--test-indent-else ()
+ "We should indent inside else bodies."
+ (julia--should-indent
+ "
+if foo
+ bar
+else
+baz
+end"
+ "
+if foo
+ bar
+else
+ baz
+end"))
+
+ (ert-deftest julia--test-indent-toplevel ()
+ "We should not indent toplevel expressions. "
+ (julia--should-indent
+ "
+foo()
+bar()"
+ "
+foo()
+bar()"))
+
+ (ert-deftest julia--test-indent-nested-if ()
+ "We should indent for each level of indentation."
+ (julia--should-indent
+ "
+if foo
+ if bar
+bar
+ end
+end"
+ "
+if foo
+ if bar
+ bar
+ end
+end"))
+
+ (ert-deftest julia--test-indent-function ()
+ "We should indent function bodies."
+ (julia--should-indent
+ "
+function foo()
+bar
+end"
+ "
+function foo()
+ bar
+end"))
+
+ (ert-deftest julia--test-indent-begin ()
+ "We should indent after a begin keyword."
+ (julia--should-indent
+ "
+@async begin
+bar
+end"
+ "
+@async begin
+ bar
+end"))
+
+ (ert-deftest julia--test-indent-paren ()
+ "We should indent to line up with open parens."
+ (julia--should-indent
+ "
+foobar(bar,
+baz)"
+ "
+foobar(bar,
+ baz)"))
+
+ (ert-deftest julia--test-indent-equals ()
+ "We should increase indent on a trailing =."
+ (julia--should-indent
+ "
+foo() =
+bar"
+ "
+foo() =
+ bar"))
+
+ (ert-deftest julia--test-indent-ignores-blank-lines ()
+ "Blank lines should not affect indentation of non-blank lines."
+ (julia--should-indent
+ "
+if foo
+ 
+bar
+end"
+ "
+if foo
+ 
+ bar
+end"))
+
+ (defun julia--run-tests ()
+ (interactive)
+ (ert-run-tests-interactively "julia--test")))
+
 (defalias 'julia-mode-prog-mode
  (if (fboundp 'prog-mode)
  'prog-mode