mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

rollup merge of #19913: KOMON/rust-mode-emacs-indentation

Browse Source 
I added an option to auto-indent method chains to line up along their '.' operators. Like so:

```
let input = io::stdin().readline()
                       .ok()
                       .expect("Failed to read line");
```

The old default would indent like so:
```
let input = io::stdin().readme()
    .ok()
    .expect("Failed to read line");
```

The Rust guide explicitly condones the former, so I thought it would be nice for the emacs mode to support it. It's off by default, you have to set ```rust-indent-method-chain``` to ```t``` via your .emacs or the customize menu
This commit is contained in:
Alex Crichton 2015-01-21 09:13:36 -08:00
commit 83af23ea49
1 changed files with 30 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
src/etc/emacs/rust-mode.el
View File

@ -54,6 +54,11 @@
:type 'integer
:group 'rust-mode)
(defcustom rust-indent-method-chain nil
"Indent Rust method chains, aligned by the '.' operators"
:type 'boolean
:group 'rust-mode)
(defun rust-paren-level () (nth 0 (syntax-ppss)))
(defun rust-in-str-or-cmnt () (nth 8 (syntax-ppss)))
(defun rust-rewind-past-str-cmnt () (goto-char (nth 8 (syntax-ppss))))
@ -73,10 +78,19 @@
;; open bracket ends the line
(when (not (looking-at "[[:blank:]]*\\(?://.*\\)?$"))
(when (looking-at "[[:space:]]")
(forward-word 1)
(backward-word 1))
(forward-word 1)
(backward-word 1))
(current-column))))
(defun rust-align-to-method-chain ()
(save-excursion
(previous-line)
(end-of-line)
(backward-word 1)
(backward-char)
(when (looking-at "\\..+\(.*\)\n")
(- (current-column) rust-indent-offset))))
(defun rust-rewind-to-beginning-of-current-level-expr ()
(let ((current-level (rust-paren-level)))
(back-to-indentation)
@ -99,10 +113,13 @@
;; the inside of it correctly relative to the outside.
(if (= 0 level)
0
(or
(when rust-indent-method-chain
(rust-align-to-method-chain))
(save-excursion
(backward-up-list)
(rust-rewind-to-beginning-of-current-level-expr)
(+ (current-column) rust-indent-offset)))))
(+ (current-column) rust-indent-offset))))))
(cond
;; A function return type is indented to the corresponding function arguments
((looking-at "->")
@ -114,6 +131,16 @@
;; A closing brace is 1 level unindended
((looking-at "}") (- baseline rust-indent-offset))
;;Line up method chains by their .'s
((when (and rust-indent-method-chain
(looking-at "\..+\(.*\);?\n"))
(or
(let ((method-indent (rust-align-to-method-chain)))
(when method-indent
(+ method-indent rust-indent-offset)))
(+ baseline rust-indent-offset))))
;; Doc comments in /** style with leading * indent to line up the *s
((and (nth 4 (syntax-ppss)) (looking-at "*"))
(+ 1 baseline))