Peter Eisentraut's Blog

Since it's pgindent season, here's a small related tip for Emacs users.

(setq fill-column 79)

This will set the maximum line length for filling commands such as M-q to the same length that pgindent uses. That is especially useful when you want to reformat block comments nicely. The default is 70, which will cause perpetual conflicts between Emacs and pgindent.

The commit shows various other ways to include this in your Emacs configuration. (I use the c-add-style approach, personally.)

Hardly anything ruins a glorious day of coding like fat-fingering the commit message late at night as you doze off, and then pushing it out for the world to see. To prevent that, I have equipped my Emacs configuration with a few little tools now.

First, I found the git-commit-mode, a special mode for Git commit messages. This helps you format the commit messages according to convention, and will use ugly colors if, for example, you write lines that are too long or you do not keep the second line blank. It also allows the use of things like M-q without shredding the whole file template.

Second, I integrated on-the-fly spell checking into the git-commit-mode. It won't stop you from writing nonsense, but it will catch the silly mistakes.

Here's a simple configuration snippet:

(require 'git-commit)
(add-hook 'git-commit-mode-hook 'turn-on-flyspell)
(add-hook 'git-commit-mode-hook (lambda () (toggle-save-place 0)))

The last line is handy if you have save-place on by default. When you make a new commit, it would then normally place the cursor where a previously edited commit message was finished, because to the save-place functionality, it looks as though it's the same file.

Flymake is an on-the-fly syntax checker for Emacs. Here is how you can use it for editing the PostgreSQL source code. Add this to your src/Makefile.custom:

check-syntax:
        $(COMPILE.c) -fsyntax-only $(CHK_SOURCES)

Then you can activate the flymake minor mode either manually using M-x flymake-mode, or by adding it to your Emacs customization for PostgreSQL. I use:

(defun pgsql-c-mode ()
  "C mode adjusted for PostgreSQL project"
  (interactive)
  (c-mode)
  (flymake-mode)

  ; .. and the rest ...
)

Here is a screenshot:
Notice the marked line with the syntax error and the tooltip/popup with the error message, which appears when the mouse hovers over the marked line.

Note, however, that since activating flymake will essentially cause a compiler to be running continuously in the background, this is not what you want to use when hacking PostgreSQL on the road. ;-)