Rule Based Switch Buffers for Emacs

Switch paired files (ex; production code and test code) quickly based rules that written by yourself.

Installation

You can install via ELPA, or manually by downloading ruled-switch-buffer and adding the following to your init file:

(add-to-list 'load-path "/path/to/ruled-switch-buffer")
(require ruled-switch-buffer)

Usage

First, you must write rules. Here is some examples:

;; rules for c/c++
(ruled-switch-buffer-define h-to-c
  :matcher (lambda (fn) (string-match ".h$" fn))
  :mappers ((lambda (fn) (replace-regexp-in-string "\\.h$" ".c" fn))
            (lambda (fn) (replace-regexp-in-string "\\.h$" ".cc" fn))
            (lambda (fn) (replace-regexp-in-string "\\.h$" ".cxx" fn))))

(ruled-switch-buffer-define c-to-h
  :matcher (lambda (fn) (string-match ".c\\(c\\|xx\\)?$" fn))
  :mappers (lambda (fn) (replace-regexp-in-string "\\.c.*$" ".h" fn)))

;; rules for toggle production code and rspec code
(ruled-switch-buffer-define app-rb-to-spec-rb
  :matcher (lambda (fn) (string-match "/app/.*.rb$" fn))
  :mappers (lambda (fn) (replace-regexp-in-string "\\(.*\\)/app/\\(.*\\).rb$" "\\1/spec/\\2_spec.rb" fn)))

(ruled-switch-buffer-define spec-rb-to-app-rb
  :matcher (lambda (fn) (string-match "/spec/.*_spec.rb$" fn))
  :mappers (lambda (fn) (replace-regexp-in-string "\\(.*\\)/spec/\\(.*\\)_spec.rb$" "\\1/app/\\2.rb" fn)))

;; rules for viewcomponent gem
(ruled-switch-buffer-define view-component-rb
  :matcher (lambda (fn) (string-match "_component.rb$" fn))
  :mappers ((lambda (fn) (replace-regexp-in-string "\\.rb$" ".html.haml" fn))
            (lambda (fn) (replace-regexp-in-string "\\.rb$" ".html.erb" fn))))

(ruled-switch-buffer-define view-component-haml
  :matcher (lambda (fn) (string-match "_component.html.haml$" fn))
  :mappers (lambda (fn) (replace-regexp-in-string "\\.html.haml$" ".rb" fn)))

(ruled-switch-buffer-define view-component-erb
  :matcher (lambda (fn) (string-match "_component.html.erb$" fn))
  :mappers (lambda (fn) (replace-regexp-in-string "\\.html.erb$" ".rb" fn)))

Once the rules are ready, open any file and execute M-x ruled-switch-buffer. If the file name of current buffer matches some rules, a list of possible destination files will be displayed and you will be asked to select one. If there is only one candidate, it will be selected automatically.

For example, if you have a file like the following:

foo.c
foo.cc
foo.h

Execute M-x ruled-switch-buffer on foo.c or foo.cc will open foo.h immediately.

Execute M-x ruled-switch-buffer on foo.h will ask you to choice whether to open foo.c or foo.cc.