On Emacs modes

Presentation about Emacs modes, given at London Emacs meetup 20th May 2014

Transcript

1. M-x emacs-meetup London 20th May 2014 by @dotemacs
2. About modes
3. What are modes?
4. "...encapsulate a set of editing behaviours." - Bob Glickstein
5. Yukihiro Matz chief designer of the Ruby programming language
6. "I started Ruby development with influence from Emacs implementation"
7. "But as an Emacs addict I needed a language mode"
8. "auto-indent was a must"
9. "Back in 1993, there was no auto-indenting language mode for a language with such syntax"
10. "I somehow succeeded in implementing auto-indent for a language with 'end' delimiters"
11. "If I couldn't make ruby-mode work the syntax of Ruby would have changed to more C-like one, too similar to other scripting languages and as a result, Ruby would not have gained current popularity"
12. How was it done before?
13. Bob Glickstein & Scott Andrew Borton
14. Modes
15. two types
16. minor & major
17. Minor mode
18. Definition (define-minor-mode <name>-mode ....)
19. name :lighter
20. keymap Specific for the minor-mode :keymap
21. variable <name>-mode
22. command called <name>-mode that can toggle the mode on/off
23. Add it to a hook (add-hook 'some-mode 'your-mode)
24. Major mode
25. name
26. hooks <name>-mode-hook
27. syntax table
28. Entry function <name>-mode
29. Which should do the following:
30. syntax highlighting write optimised regexps or use regexp-opt
31. indentation
32. syntax table "behaviour" & movement
33. remove all buffer-local variables (kill-all-local-variable)
34. set the variables major-mode to <name>-mode mode-name to string "<name>"
35. install mode specific keymap
36. Options for keymap sparse-keymap define your own
37. bind mode to files (add-to-list 'auto-mode-alist '("\\.BAR\\'" . FOO-mode))
38. run user defined hooks for the mode Defined with <name>-mode-hook
39. provide mode (provide '<name>)
40. cookies ;;;###autoload
41. This sounds like a lot of work. Why re-invent the wheel?
42. Cookie cutter sample-mode - 2001 derived-mode
43. checkdoc
44. Thank you ❤
45. Notes » Yukihiro Matz's notes on Ruby syntax design » How to write a minor mode » Book "Writing GNU Emacs Extensions" by Bob Glickstein » Mode Tutorial » sample-mode » checkdoc