;;; clojure-mode.el -- Major mode for Clojure code

;; Copyright (C) 2008 Jeffrey Chu
;;
;; Author: Jeffrey Chu <jochu0@gmail.com>
;; 
;;   Originally by: Lennart Staflin <lenst@lysator.liu.se>
;;                  Copyright (C) 2007, 2008 Lennart Staflin
;;
;; This program 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.
;; 
;; This program 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 GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

(require 'cl)

(defgroup clojure-mode nil
  "A mode for Clojure"
  :prefix "clojure-mode-"
  :group 'applications)

(defcustom clojure-mode-font-lock-multiline-def t
  "Set to non-nil in order to enable font-lock of
multi-line (def...) forms. Changing this will require a
restart (ie. M-x clojure-mode) of existing clojure mode buffers."
  :type 'boolean
  :group 'clojure-mode)

(defcustom clojure-mode-font-lock-comment-sexp nil
  "Set to non-nil in order to enable font-lock of (comment...)
forms. This option is experimental. Changing this will require a
restart (ie. M-x clojure-mode) of existing clojure mode buffers."
  :type 'boolean
  :group 'clojure-mode)

(defcustom clojure-mode-load-command  "(clojure/load-file \"%s\")\n"
  "*Format-string for building a Clojure expression to load a file.
This format string should use `%s' to substitute a file name
and should result in a Clojure expression that will command the inferior Clojure
to load that file."
  :type 'string
  :group 'clojure-mode)

(defcustom clojure-mode-use-backtracking-indent nil
  "Set to non-nil to enable backtracking/context sensitive
indentation."
  :type 'boolean
  :group 'clojure-mode)

(defcustom clojure-max-backtracking 3
  "Maximum amount to backtrack up a list to check for context."
  :type 'integer
  :group 'clojure-mode)


(defvar clojure-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map lisp-mode-shared-map)
    (define-key map "\e\C-x" 'lisp-eval-defun)
    (define-key map "\C-x\C-e" 'lisp-eval-last-sexp)
    (define-key map "\C-c\C-e" 'lisp-eval-last-sexp)
    (define-key map "\C-c\C-l" 'clojure-load-file)
    (define-key map "\C-c\C-r" 'lisp-eval-region)
    (define-key map "\C-c\C-z" 'run-lisp)
    map)
  "Keymap for ordinary Clojure mode.
All commands in `lisp-mode-shared-map' are inherited by this map.")


(easy-menu-define clojure-menu clojure-mode-map "Menu used in `clojure-mode'."
  '("Clojure"
    ["Eval defun"         lisp-eval-defun         t]
    ["Eval defun and go"  lisp-eval-defun-and-go  t]
    ["Eval last sexp"     lisp-eval-last-sexp     t]
    ["Eval region"        lisp-eval-region        t]
    ["Eval region and go" lisp-eval-region-and-go t]
    ["Load file..."       clojure-load-file       t]
    ["Run Lisp"           run-lisp                t]))


(defvar clojure-mode-syntax-table
  (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
    (modify-syntax-entry ?~ "'   " table)
    (modify-syntax-entry ?, "    " table)
    (modify-syntax-entry ?\{ "(}" table)
    (modify-syntax-entry ?\} "){" table)
    (modify-syntax-entry ?\[ "(]" table)
    (modify-syntax-entry ?\] ")[" table)
    (modify-syntax-entry ?^ "'" table)
    (modify-syntax-entry ?= "'" table)
    table))


(defvar clojure-prev-l/c-dir/file nil
  "Record last directory and file used in loading or compiling.
This holds a cons cell of the form `(DIRECTORY . FILE)'
describing the last `clojure-load-file' or `clojure-compile-file' command.")


(defun clojure-mode ()
  "Major mode for editing Clojure code - similar to Lisp mode..
Commands:
Delete converts tabs to spaces as it moves back.
Blank lines separate paragraphs.  Semicolons start comments.
\\{clojure-mode-map}
Note that `run-lisp' may be used either to start an inferior Lisp job
or to switch back to an existing one.

Entry to this mode calls the value of `clojure-mode-hook'
if that value is non-nil."
  (interactive)
  (kill-all-local-variables)
  (use-local-map clojure-mode-map)
  (setq major-mode 'clojure-mode)
  (setq mode-name "Clojure")
  (lisp-mode-variables nil)
  (set-syntax-table clojure-mode-syntax-table)
  
  (set (make-local-variable 'comment-start-skip)
       "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\)\\(;+\\|#|\\) *")
  (set (make-local-variable 'lisp-indent-function)
       'clojure-indent-function)
  (set (make-local-variable 'font-lock-multiline) t)

  (if (and (not (boundp 'font-lock-extend-region-functions))
           (or clojure-mode-font-lock-multiline-def
               clojure-mode-font-lock-comment-sexp))
      (message "Clojure mode font lock extras are unavailable, please upgrade to atleast version 22 ")
    
   (when clojure-mode-font-lock-multiline-def
     (add-to-list 'font-lock-extend-region-functions 'clojure-font-lock-extend-region-def t))
   
   (when clojure-mode-font-lock-comment-sexp
     (add-to-list 'font-lock-extend-region-functions 'clojure-font-lock-extend-region-comment t)
     (make-local-variable 'clojure-font-lock-keywords)
     (add-to-list 'clojure-font-lock-keywords  'clojure-font-lock-mark-comment t)
     (set (make-local-variable 'open-paren-in-column-0-is-defun-start) nil)))

  (setq font-lock-defaults
	'(clojure-font-lock-keywords    ; keywords
	  nil nil
          (("+-*/.<>=!?$%_&~^:@" . "w")) ; syntax alist
          nil
	  (font-lock-mark-block-function . mark-defun)
	  (font-lock-syntactic-face-function . lisp-font-lock-syntactic-face-function)))
  
  (run-mode-hooks 'clojure-mode-hook))

(defun clojure-font-lock-def-at-point (point)
  "Find the position range between the top-most def* and the
fourth element afterwards. Note that this means there's no
gaurantee of proper font locking in def* forms that are not at
top-level."
  (goto-char point)
  (condition-case nil
      (beginning-of-defun)
    (error nil))
  
  (let ((beg-def (point)))
    (when (and (not (= point beg-def))
               (looking-at "(def"))
      (condition-case nil
       (progn
         ;; move forward as much as possible until failure (or success)
         (forward-char)
         (dotimes (i 4)
           (forward-sexp)))
       (error nil))
      (cons beg-def (point)))))

(defun clojure-font-lock-extend-region-def ()
  "Move fontification boundaries to always include the first four
elements of a def* forms."
  (let ((changed nil))
    (let ((def (clojure-font-lock-def-at-point font-lock-beg)))
      (when def
       (destructuring-bind (def-beg . def-end) def
         (when (and (< def-beg font-lock-beg)
                    (< font-lock-beg def-end))
           (setq font-lock-beg def-beg
                 changed t)))))

    (let ((def (clojure-font-lock-def-at-point font-lock-end)))
      (when def
       (destructuring-bind (def-beg . def-end) def
         (when (and (< def-beg font-lock-end)
                    (< font-lock-end def-end))
           (setq font-lock-end def-end
                 changed t)))))
    changed))

(defun clojure-font-lock-extend-region-comment ()
  "Move fontification boundaries to always contain
  entire (comment ..) sexp. Does not work if you have a
  white-space between ( and comment, but that is omitted to make
  this run faster."
  (let ((changed nil))
    (goto-char font-lock-beg)
    (condition-case nil (beginning-of-defun) (error nil))
    (let ((pos (re-search-forward "(comment\\>" font-lock-end t)))
      (when pos
        (forward-char -8)
        (when (< (point) font-lock-beg)
          (setq font-lock-beg (point)
                changed t))
        (condition-case nil (forward-sexp) (error nil))
        (when (> (point) font-lock-end)
          (setq font-lock-end (point)
                changed t))))
    changed))
        

(defun clojure-font-lock-mark-comment (limit)
  "Marks all (comment ..) forms with font-lock-comment-face."
  (let (pos)
    (while (and (< (point) limit)
                (setq pos (re-search-forward "(comment\\>" limit t)))
      (when pos
        (forward-char -8)
        (condition-case nil
            (add-text-properties (1+ (point)) (progn (forward-sexp) (1- (point)))
                                 '(face font-lock-comment-face multiline t))
          (error (forward-char 8))))))
  nil)

(defconst clojure-font-lock-keywords
  (eval-when-compile
    `( ;; Definitions.
      (,(concat "(\\(?:clojure/\\)?\\(def"
		;; Function declarations.
		"\\(n-?\\|multi\\|macro\\|method\\|"
		;; Variable declarations.
                "struct\\|once\\|"
		"\\)\\)\\>"
		;; Any whitespace
		"[ \r\n\t]*"
                ;; Possibly type or metadata
                "\\(?:#^\\(?:{[^}]*}\\|\\sw+\\)[ \r\n\t]*\\)?"
                
                "\\(\\sw+\\)?")
        (1 font-lock-keyword-face)
        (3 font-lock-function-name-face nil t))
      ;; Control structures
      (,(concat
         "(\\(?:clojure/\\)?" 
         (regexp-opt
          '("cond" "for" "loop" "let" "recur" "do" "binding" "with-meta"
            "when" "when-not" "when-let" "when-first" "if" "if-let"
            "delay" "lazy-cons" "." ".." "->" "and" "or" "locking"
            "dosync" "load"
            "sync" "doseq" "dotimes" "import" "unimport" "ns" "in-ns" "refer"
            "implement" "proxy" "time" "try" "catch" "finally" "throw"
            "doto" "with-open" "with-local-vars" "struct-map"
            "gen-class" "gen-and-load-class" "gen-and-save-class") t)
         "\\>")
        .  1)
      ;; (fn name? args ...)
      (,(concat "(\\(?:clojure/\\)?\\(fn\\)[ \t]+"
                ;; Possibly type
                "\\(?:#^\\sw+[ \t]*\\)?"
                ;; Possibly name
                "\\(\\sw+\\)?" )
        (1 font-lock-keyword-face)
        (2 font-lock-function-name-face nil t))
      ;; Constant values.
      ("\\<:\\sw+\\>" 0 font-lock-builtin-face)
      ;; Meta type annotation #^Type
      ("#^\\sw+" 0 font-lock-type-face)
      ))
  "Default expressions to highlight in Clojure mode.")


(defun clojure-load-file (file-name)
  "Load a Lisp file into the inferior Lisp process."
  (interactive (comint-get-source "Load Clojure file: " clojure-prev-l/c-dir/file
				  '(clojure-mode) t))
  (comint-check-source file-name) ; Check to see if buffer needs saved.
  (setq clojure-prev-l/c-dir/file (cons (file-name-directory file-name)
				     (file-name-nondirectory file-name)))
  (comint-send-string (inferior-lisp-proc)
		      (format clojure-mode-load-command file-name))
  (switch-to-lisp t))



(defun clojure-indent-function (indent-point state)
  "This function is the normal value of the variable `lisp-indent-function'.
It is used when indenting a line within a function call, to see if the
called function says anything special about how to indent the line.

INDENT-POINT is the position where the user typed TAB, or equivalent.
Point is located at the point to indent under (for default indentation);
STATE is the `parse-partial-sexp' state for that position.

If the current line is in a call to a Lisp function
which has a non-nil property `lisp-indent-function',
that specifies how to do the indentation.  The property value can be
* `defun', meaning indent `defun'-style;
* an integer N, meaning indent the first N arguments specially
  like ordinary function arguments and then indent any further
  arguments like a body;
* a function to call just as this function was called.
  If that function returns nil, that means it doesn't specify
  the indentation.

This function also returns nil meaning don't specify the indentation."
  (let ((normal-indent (current-column)))
    (goto-char (1+ (elt state 1)))
    (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
    (if (and (elt state 2)
             (not (looking-at "\\sw\\|\\s_")))
        ;; car of form doesn't seem to be a symbol
        (progn
          (if (not (> (save-excursion (forward-line 1) (point))
                      calculate-lisp-indent-last-sexp))
		(progn (goto-char calculate-lisp-indent-last-sexp)
		       (beginning-of-line)
		       (parse-partial-sexp (point)
					   calculate-lisp-indent-last-sexp 0 t)))
	    ;; Indent under the list or under the first sexp on the same
	    ;; line as calculate-lisp-indent-last-sexp.  Note that first
	    ;; thing on that line has to be complete sexp since we are
          ;; inside the innermost containing sexp.
          (backward-prefix-chars)
          (if (and (eq (char-after (point)) ?\[)
                   (eq (char-after (elt state 1)) ?\())
              (+ (current-column) 2) ;; this is probably inside a defn
            (current-column)))
      (let ((function (buffer-substring (point)
					(progn (forward-sexp 1) (point))))
            (open-paren (elt state 1))
	    method)
	(setq method (get (intern-soft function) 'clojure-indent-function))
        
	(cond ((member (char-after open-paren) '(?\[ ?\{))
	       (goto-char open-paren)
               (1+ (current-column)))
	      ((or (eq method 'defun)
		   (and (null method)
			(> (length function) 3)
			(string-match "\\`\\(?:clojure/\\)?def" function)))
	       (lisp-indent-defform state indent-point))
              
	      ((integerp method)
	       (lisp-indent-specform method state
				     indent-point normal-indent))
	      (method
		(funcall method indent-point state))
              (clojure-mode-use-backtracking-indent
               (clojure-backtracking-indent indent-point state normal-indent)))))))

(defun clojure-backtracking-indent (indent-point state normal-indent)
  "Experimental backtracking support. Will upwards in an sexp to
check for contextual indenting."
  (let (indent (path) (depth 0))
    (goto-char (elt state 1))
    (while (and (not indent)
                (< depth clojure-max-backtracking))
      (let ((containing-sexp (point)))
        (parse-partial-sexp (1+ containing-sexp) indent-point 1 t)
        (when (looking-at "\\sw\\|\\s_")
          (let* ((start (point))
                 (fn (buffer-substring start (progn (forward-sexp 1) (point))))
                 (meth (get (intern-soft fn) 'clojure-backtracking-indent)))
            (let ((n 0))
              (when (< (point) indent-point)
                (condition-case ()
                    (progn
                     (forward-sexp 1)
                     (while (< (point) indent-point)
                       (parse-partial-sexp (point) indent-point 1 t)
                       (incf n)
                       (forward-sexp 1)))
                  (error nil)))
              (push n path))
            (when meth
              (let ((def meth))
                (dolist (p path)
                  (if (and (listp def)
                           (< p (length def)))
                      (setq def (nth p def))
                    (if (listp def)
                        (setq def (car (last def)))
                      (setq def nil))))
                (goto-char (elt state 1))
                (when def
                  (setq indent (+ (current-column) def)))))))
        (goto-char containing-sexp)
        (condition-case ()
            (progn
              (backward-up-list 1)
              (incf depth))
          (error (setq depth clojure-max-backtracking)))))
    indent))

;; (defun clojure-indent-defn (indent-point state)
;;   "Indent by 2 if after a [] clause that's at the beginning of a
;; line"
;;   (if (not (eq (char-after (elt state 2)) ?\[))
;;       (lisp-indent-defform state indent-point)
;;     (goto-char (elt state 2))
;;     (beginning-of-line)
;;     (skip-syntax-forward " ")
;;     (if (= (point) (elt state 2))
;;         (+ (current-column) 2)
;;       (lisp-indent-defform state indent-point))))

;; (put 'defn 'clojure-indent-function 'clojure-indent-defn)
;; (put 'defmacro 'clojure-indent-function 'clojure-indent-defn)

;; clojure backtracking indent is experimental and the format for these

;; entries are subject to change
(put 'implement 'clojure-backtracking-indent '(4 (2)))
(put 'proxy 'clojure-backtracking-indent '(4 4 (2)))


(defun put-clojure-indent (sym indent)
  (put sym 'clojure-indent-function indent)
  (put (intern (format "clojure/%s" (symbol-name sym))) 'clojure-indent-function indent))

(defmacro define-clojure-indent (&rest kvs)
  `(progn
     ,@(mapcar (lambda (x) `(put-clojure-indent (quote ,(first x)) ,(second x))) kvs)))

(define-clojure-indent
  (catch 2)
  (defmuti 1)
  (do 0)
  (for 1)    ; FIXME (for seqs expr) and (for seqs filter expr)
  (if 1)
  (let 1)
  (loop 1)
  (struct-map 1)
  (assoc 1)

  (fn 'defun))

;; built-ins
(define-clojure-indent
  (ns 1)
  (binding 1)
  (comment 0)
  (defstruct 1)
  (doseq 1)
  (dotimes 1)
  (doto 1)
  (implement 1)
  (let 1)
  (when-let 1)
  (if-let 1)
  (locking 1)
  (proxy 2)
  (sync 1)
  (when 1)
  (when-first 1)
  (when-let 1)
  (when-not 1)
  (with-local-vars 1)
  (with-open 1)
  (with-precision 1))

;; macro indent (auto generated)

;; Things that just aren't right (manually removed)
; (put '-> 'clojure-indent-function 2)
; (put '.. 'clojure-indent-function 2)
; (put 'and 'clojure-indent-function 1)
; (put 'defmethod 'clojure-indent-function 2)
; (put 'defn- 'clojure-indent-function 1)
; (put 'memfn 'clojure-indent-function 1)
; (put 'or 'clojure-indent-function 1)
; (put 'lazy-cat 'clojure-indent-function 1)
; (put 'lazy-cons 'clojure-indent-function 1)

(provide 'clojure-mode)

;;; clojure-mode.el ends here