emacs-ipython-notebook/ein-utils.el

;;; ein-utils.el --- Utility module

;; Copyright (C) 2012- Takafumi Arakaki

;; Author: Takafumi Arakaki

;; This file is NOT part of GNU Emacs.

;; ein-utils.el is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; ein-utils.el is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with ein-utils.el.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;

;;; Code:

(eval-when-compile (require 'cl))
(require 'json)

(defvar ein:url-or-port '(8888)
  "List of possible url-or-port values.")


(defmacro ein:aif (test-form then-form &rest else-forms)
  "Anaphoric IF."
  (declare (debug (form form &rest form)))
  `(let ((it ,test-form))
     (if it ,then-form ,@else-forms)))
(put 'ein:aif 'lisp-indent-function 2)

(defmacro ein:aand (test &rest rest)
  "Anaphoric AND."
  (declare (debug (form &rest form)))
  `(let ((it ,test))
     (if it ,(if rest (macroexpand-all `(ein:aand ,@rest)) 'it))))


(defmacro ein:deflocal (name &optional initvalue docstring)
  "Define permanent buffer local variable named NAME.
INITVALUE and DOCSTRING are passed to `defvar'."
  (declare (indent defun)
           (doc-string 3))
  `(progn
     (defvar ,name ,initvalue ,docstring)
     (make-variable-buffer-local ',name)
     (put ',name 'permanent-local t)))

(defmacro ein:with-read-only-buffer (buffer &rest body)
  (declare (indent 1))
  `(with-current-buffer ,buffer
     (setq buffer-read-only t)
     (save-excursion
       (let ((inhibit-read-only t))
         ,@body))))

(defvar ein:dotty-syntax-table
  (let ((table (make-syntax-table c-mode-syntax-table)))
    (modify-syntax-entry ?. "w" table)
    (modify-syntax-entry ?_ "w" table)
    table)
  "Adapted from `python-dotty-syntax-table'.")

(defun ein:object-at-point ()
  "Return dotty.words.at.point, just before previous opening parenthesis."
  (save-excursion
    (unless (looking-at "(")
      (search-backward "(" (point-at-bol) t))
    (with-syntax-table ein:dotty-syntax-table
      (thing-at-point 'word))))


;;; URL utils

(defvar ein:url-localhost-template "http://127.0.0.1:%s")

(defun ein:url (url-or-port &rest paths)
  (loop with url = (if (integerp url-or-port)
                       (format ein:url-localhost-template url-or-port)
                     url-or-port)
        for p in paths
        do (setq url (concat (ein:trim-right url "/")
                             "/"
                             (ein:trim-left p "/")))
        finally return url))

(defun ein:url-no-cache (url)
  "Imitate `cache=false' of `jQuery.ajax'.
See: http://api.jquery.com/jQuery.ajax/"
  (concat url (format-time-string "?_=%s")))


;;; JSON utils

(defmacro ein:with-json-setting (&rest body)
  `(let ((json-object-type 'plist)
         (json-array-type 'list))
     ,@body))

(defun ein:json-read ()
  "Read json from `url-retrieve'-ed buffer.

* `json-object-type' is `plist'. This is mainly for readability.
* `json-array-type' is `list'.  Notebook data is edited locally thus
  data type must be edit-friendly.  `vector' type is not."
  (goto-char (point-max))
  (backward-sexp)
  (ein:with-json-setting
   (json-read)))

(defun ein:json-read-from-string (string)
  (ein:with-json-setting
   (json-read-from-string string)))


;;;

(defun ein:propertize-read-only (string)
  (propertize string 'read-only t 'front-sticky t))

(defun ein:insert-read-only (string)
  (insert (ein:propertize-read-only string)))


;;; String manipulation

(defun ein:trim (string &optional regexp)
  (ein:trim-left (ein:trim-right string regexp) regexp))

(defun ein:trim-left (string &optional regexp)
  (unless regexp (setq regexp "\\s-\\|\n"))
  (ein:trim-regexp string (format "^\\(%s\\)+" regexp)))

(defun ein:trim-right (string &optional regexp)
  (unless regexp (setq regexp "\\s-\\|\n"))
  (ein:trim-regexp string (format "\\(%s\\)+$" regexp)))

(defun ein:trim-regexp (string regexp)
  (if (string-match regexp string)
      (replace-match "" t t string)
    string))

(defun ein:join-str (sep strings)
  (mapconcat 'identity strings sep))

(defun ein:join-path (paths)
  (mapconcat 'file-name-as-directory paths ""))

(defmacro ein:case-equal (str &rest clauses)
  "Similar to `case' but comparison is done by `equal'.
Adapted from twittering-mode.el's `case-string'."
  (declare (indent 1))
  `(cond
    ,@(mapcar
       (lambda (clause)
	 (let ((keylist (car clause))
	       (body (cdr clause)))
	   `(,(if (listp keylist)
		  `(or ,@(mapcar (lambda (key) `(equal ,str ,key))
				 keylist))
		't)
	     ,@body)))
       clauses)))


;;

(defun ein:plist-iter (plist)
  "Return list of (key . value) in PLIST."
  (loop for p in plist
        for i from 0
        for key-p = (= (% i 2) 0)
        with key = nil
        if key-p do (setq key p)
        else collect `(,key . ,p)))

(defun ein:get-value (obj)
  "Get value from obj if it is a variable or function."
  (cond
   ((not (symbolp obj)) obj)
   ((boundp obj) (eval obj))
   ((fboundp obj) (funcall obj))))

(defun ein:choose-setting (symbol value)
  "Choose setting in stored in SYMBOL based on VALUE.
The value of SYMBOL can be string, alist or function."
  (let ((setting (eval symbol)))
    (cond
     ((stringp setting) setting)
     ((functionp setting) (funcall setting value))
     ((listp setting)
      (ein:get-value (or (assoc-default value setting)
                         (assoc-default 'default setting))))
     (t (error "Unsupported type of `%s': %s" symbol (type-of setting))))))

(defmacro ein:setf-default (place val)
  "Set VAL to PLACE using `setf' if the value of PLACE is `nil'."
  `(unless ,place
     (setf ,place ,val)))

(defun ein:eval-if-bound (symbol)
  (if (boundp symbol) (eval symbol)))

(defun ein:remove-by-index (list indices)
  "Remove elements from LIST if its index is in INDICES.
NOTE: This function creates new list."
  (loop for l in list
        for i from 0
        when (not (memq i indices))
        collect l))


;; utils.js compatible

(defun ein:utils-uuid ()
  "Return string with random (version 4) UUID.
Adapted from org-mode's `org-id-uuid'."
  (let ((rnd (md5 (format "%s%s%s%s%s%s%s"
			  (random t)
			  (current-time)
			  (user-uid)
			  (emacs-pid)
			  (user-full-name)
			  user-mail-address
			  (recent-keys)))))
    (format "%s-%s-4%s-%s%s-%s"
	    (substring rnd 0 8)
	    (substring rnd 8 12)
	    (substring rnd 13 16)
	    (format "%x"
		    (logior
		     #b10000000
		     (logand
		      #b10111111
		      (string-to-number
		       (substring rnd 16 18) 16))))
	    (substring rnd 18 20)
	    (substring rnd 20 32))))


(provide 'ein-utils)

;;; ein-utils.el ends here