(c-offsets-alist): Fix typo.

[bpt/emacs.git] / lisp / progmodes / fortran.el

;;; fortran.el --- Fortran mode for GNU Emacs

;; Copyright (c) 1986, 93, 94, 95, 97, 98, 99, 2000, 2001
;;   Free Software Foundation, Inc.

;; Author: Michael D. Prange <prange@erl.mit.edu>
;; Maintainer: Glenn Morris <gmorris@ast.cam.ac.uk>
;; Keywords: languages

;; This file is part of GNU Emacs.

;; GNU Emacs 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 2, or (at your option)
;; any later version.

;; GNU Emacs 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., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; This mode is documented in the Emacs manual.
;;
;; Note that it is for editing Fortran77 or Fortran90 fixed source
;; form.  For editing Fortran 90 free format source, use `f90-mode'
;; (f90.el).  It is meant to support the GNU Fortran language
;; implemented by g77 (its extensions to Fortran77 and
;; interpretations, e.g. of blackslash in strings).

;;; History:

;; Fortran mode was upgraded by Stephen A. Wood (saw@cebaf.gov).

;; We acknowledge many contributions and valuable suggestions by
;; Lawrence R. Dodd, Ralf Fassel, Ralph Finch, Stephen Gildea,
;; Dr. Anil Gokhale, Ulrich Mueller, Mark Neale, Eric Prestemon,
;; Gary Sabot and Richard Stallman.

;;; Code:

;; Todo:

;; * Tidy it all up (more)!
;; * Implement insertion and removal of statement continuations in
;;   mixed f77/f90 style, with the first `&' past column 72 and the
;;   second in column 6.
;; * Support any other extensions to f77 grokked by GNU Fortran I've missed.

(defgroup fortran nil
  "Fortran mode for Emacs"
  :link '(custom-manual "(emacs)Fortran")
  :group 'languages)

(defgroup fortran-indent nil
  "Indentation variables in Fortran mode"
  :prefix "fortran-"
  :group 'fortran)

(defgroup fortran-comment nil
  "Comment-handling variables in Fortran mode"
  :prefix "fortran-"
  :group 'fortran)


;;;###autoload
(defcustom fortran-tab-mode-default nil
  "*Default tabbing/carriage control style for empty files in Fortran mode.
A value of t specifies tab-digit style of continuation control.
A value of nil specifies that continuation lines are marked
with a character in column 6."
  :type 'boolean
  :group 'fortran-indent)

;; Buffer local, used to display mode line.
(defcustom fortran-tab-mode-string nil
  "String to appear in mode line when TAB format mode is on."
  :type '(choice (const nil) string)
  :group 'fortran-indent)
(make-variable-buffer-local 'fortran-tab-mode-string)

(defcustom fortran-do-indent 3
  "*Extra indentation applied to DO blocks."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-if-indent 3
  "*Extra indentation applied to IF blocks."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-structure-indent 3
  "*Extra indentation applied to STRUCTURE, UNION, MAP and INTERFACE blocks."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-continuation-indent 5
  "*Extra indentation applied to Fortran continuation lines."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-comment-indent-style 'fixed
  "*How to indent comments.
nil forces comment lines not to be touched,
`fixed' makes fixed comment indentation to `fortran-comment-line-extra-indent'
  columns beyond `fortran-minimum-statement-indent-fixed' (for
  `indent-tabs-mode' of nil) or `fortran-minimum-statement-indent-tab' (for
  `indent-tabs-mode' of t), and
`relative' indents to current Fortran indentation plus
  `fortran-comment-line-extra-indent'."
  :type '(radio (const :tag "Untouched" nil) (const fixed) (const relative))
  :group 'fortran-indent)

(defcustom fortran-comment-line-extra-indent 0
  "*Amount of extra indentation for text within full-line comments."
  :type 'integer
  :group 'fortran-indent
  :group 'fortran-comment)

(defcustom fortran-comment-line-start "C"
  "*Delimiter inserted to start new full-line comment.
You might want to change this to \"*\", for instance."
  :version "21.1"
  :type 'string
  :group 'fortran-comment)

;; This used to match preprocessor lines too, but that messes up
;; filling and doesn't seem to be necessary.
(defcustom fortran-comment-line-start-skip
  "^[CcDd*!]\\(\\([^ \t\n]\\)\\2+\\)?[ \t]*"
  "*Regexp to match the start of a full-line comment."
  :version "21.1"
  :type 'regexp
  :group 'fortran-comment)

(defcustom fortran-directive-re
  "^[ \t]*#.*"
  "*Regexp to match a directive line.
The matching text will be fontified with `font-lock-keyword-face'.
The matching line will be given zero indentation."
  :version "21.4"
  :type 'regexp
  :group 'fortran-indent)

(defcustom fortran-minimum-statement-indent-fixed 6
  "*Minimum statement indentation for fixed format continuation style."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-minimum-statement-indent-tab (max tab-width 6)
  "*Minimum statement indentation for TAB format continuation style."
  :type 'integer
  :group 'fortran-indent)

;; Note that this is documented in the v18 manuals as being a string
;; of length one rather than a single character.
;; The code in this file accepts either format for compatibility.
(defcustom fortran-comment-indent-char " "
  "*Single-character string inserted for Fortran comment indentation.
Normally a space."
  :type 'string
  :group 'fortran-comment)

(defcustom fortran-line-number-indent 1
  "*Maximum indentation for Fortran line numbers.
5 means right-justify them within their five-column field."
  :type 'integer
  :group 'fortran-indent)

(defcustom fortran-check-all-num-for-matching-do nil
  "*Non-nil causes all numbered lines to be treated as possible DO loop ends."
  :type 'boolean
  :group 'fortran)

(defcustom fortran-blink-matching-if nil
  "*Non-nil causes \\[fortran-indent-line] on ENDIF statement to blink on matching IF.
Also, from an ENDDO statement blink on matching DO [WHILE] statement."
  :type 'boolean
  :group 'fortran)

(defcustom fortran-continuation-string "$"
  "*Single-character string used for Fortran continuation lines.
In fixed format continuation style, this character is inserted in
column 6 by \\[fortran-split-line] to begin a continuation line.
Also, if \\[fortran-indent-line] finds this at the beginning of a line, it will
convert the line into a continuation line of the appropriate style.
Normally $."
  :type 'string
  :group 'fortran)

(defcustom fortran-comment-region "c$$$"
  "*String inserted by \\[fortran-comment-region] at start of each \
line in region."
  :type 'string
  :group 'fortran-comment)

(defcustom fortran-electric-line-number t
  "*Non-nil causes line number digits to be moved to the correct \
column as typed."
  :type 'boolean
  :group 'fortran)

(defvar fortran-column-ruler-fixed
  "0   4 6  10        20        30        40        5\
0        60        70\n\
\[   ]|{   |    |    |    |    |    |    |    |    \
\|    |    |    |    |}\n"
  "String displayed above current line by \\[fortran-column-ruler].
This variable used in fixed format mode.")

(defvar fortran-column-ruler-tab
  "0       810        20        30        40        5\
0        60        70\n\
\[   ]|  { |    |    |    |    |    |    |    |    \
\|    |    |    |    |}\n"
  "String displayed above current line by \\[fortran-column-ruler].
This variable used in TAB format mode.")

(defvar fortran-analyze-depth 100
  "Number of lines to scan to determine whether to use fixed or TAB \
format style.")

(defcustom fortran-break-before-delimiters t
  "*Non-nil causes filling to break lines before delimiters."
  :type 'boolean
  :group 'fortran)

(defvar fortran-mode-syntax-table
  (let ((table (make-syntax-table)))
    ;; We might like `;' to be punctuation (g77 multi-statement
    ;; lines), but that screws abbrevs.
    (modify-syntax-entry ?\; "w" table)
    (modify-syntax-entry ?\r " " 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)
    ;; Consistent with GNU Fortran -- see the manual.
    (modify-syntax-entry ?\\ "\\" table)
    ;; This might be better as punctuation, as for C, but this way you
    ;; can treat floating-point numbers as symbols.
    (modify-syntax-entry ?. "_" table)  ; e.g. `a.ne.b'
    (modify-syntax-entry ?_ "_" table)
    (modify-syntax-entry ?$ "_" table)  ; esp. VMSisms
    (modify-syntax-entry ?\! "<" table)
    (modify-syntax-entry ?\n ">" table)
    table)
  "Syntax table in use in Fortran mode buffers.")

;; Comments are real pain in Fortran because there is no way to
;; represent the standard comment syntax in an Emacs syntax table.
;; (We can do so for F90-style).  Therefore an unmatched quote in a
;; standard comment will throw fontification off on the wrong track.
;; So we do syntactic fontification with regexps.

(defvar fortran-font-lock-keywords-1 nil
  "Subdued level highlighting for Fortran mode.")

(defvar fortran-font-lock-keywords-2 nil
  "Medium level highlighting for Fortran mode.")

(defvar fortran-font-lock-keywords-3 nil
  "Gaudy level highlighting for Fortran mode.")

(defvar fortran-font-lock-syntactic-keywords nil
  "`font-lock-syntactic-keywords' for Fortran.
These get fixed-format comments fontified.")

(let ((comment-chars "cd\\*")           ; `d' for `debugging' comments
      (fortran-type-types
       (eval-when-compile
         (let ((re (regexp-opt
                    (let ((simple-types
                           '("character" "byte" "integer" "logical"
                             "none" "real" "complex"
                             "double precision" "double complex"))
                          (structured-types '("structure" "union" "map"))
                          (other-types '("record" "dimension"
                                         "parameter" "common" "save"
                                         "external" "intrinsic" "data"
                                         "equivalence")))
                      (append
                       (mapcar (lambda (x) (concat "implicit " x))
                               simple-types)
                       simple-types
                       (mapcar (lambda (x) (concat "end " x))
                               structured-types)
                       structured-types
                       other-types)))))
           ;; In the optimized regexp above, replace spaces by a
           ;; regexp for optional whitespace; regexp-opt would have
           ;; escaped that.
           (mapconcat #'identity (split-string re) "[ \t]*"))))
      (fortran-keywords
       (eval-when-compile
         (regexp-opt '("continue" "format" "end" "enddo" "if" "then"
                       "else" "endif" "elseif" "while" "inquire" "stop"
                       "return" "include" "open" "close" "read" "write"
                       "format" "print" "select" "case" "cycle" "exit"
                       "rewind" "backspace"))))
      (fortran-logicals
       (eval-when-compile
         (regexp-opt '("and" "or" "not" "lt" "le" "eq" "ge" "gt" "ne"
                       "true" "false")))))
  (setq fortran-font-lock-syntactic-keywords
        ;; Fixed format comments.  (!-style handled normally.)
        (list
         (list (concat "^[" comment-chars "]") 0 '(11))
         (list (concat "^[^" comment-chars "\t\n]" ".\\{71\\}"
                       "\\([^\n]+\\)")
               1 '(11))))
  (setq fortran-font-lock-keywords-1
        (list
         ;; Program, subroutine and function declarations, plus calls.
         (list (concat "\\<\\(block[ \t]*data\\|call\\|entry\\|function\\|"
                       "program\\|subroutine\\)\\>[ \t]*\\(\\sw+\\)?")
               '(1 font-lock-keyword-face)
               '(2 font-lock-function-name-face nil t))))
  (setq fortran-font-lock-keywords-2
        (append fortran-font-lock-keywords-1
                (list
                 ;; Fontify all type specifiers (must be first; see below).
                 (cons (concat "\\<\\(" fortran-type-types "\\)\\>")
                       'font-lock-type-face)
                 ;; Fontify all builtin keywords (except logical, do
                 ;; and goto; see below).
                 (concat "\\<\\(" fortran-keywords "\\)\\>")
                 ;; Fontify all builtin operators.
                 (concat "\\.\\(" fortran-logicals "\\)\\.")
                 ;; Fontify do/goto keywords and targets, and goto tags.
                 (list "\\<\\(do\\|go *to\\)\\>[ \t]*\\([0-9]+\\)?"
                       '(1 font-lock-keyword-face)
                       '(2 font-lock-constant-face nil t))
                 (cons "^ *\\([0-9]+\\)" 'font-lock-constant-face))))
  (setq fortran-font-lock-keywords-3
        (append
         ;; The list `fortran-font-lock-keywords-1'.
         fortran-font-lock-keywords-1
         ;; Fontify all type specifiers plus their declared items.
         (list
          (list (concat "\\<\\(" fortran-type-types "\\)\\>[ \t(/]*\\(*\\)?")
                ;; Fontify the type specifier.
                '(1 font-lock-type-face)
                ;; Fontify each declaration item (or just the /.../ block name).
                `(font-lock-match-c-style-declaration-item-and-skip-to-next
                  ;; Start after any *(...) expression.
                  (condition-case nil
                      (and (and (match-beginning ,(+ 2 (regexp-opt-depth
                                                        fortran-type-types)))
                                (forward-sexp))
                           (forward-sexp))
                    (error nil))
                  ;; No need to clean up.
                  nil
                  ;; Fontify as a variable name, functions are
                  ;; fontified elsewhere.
                  (1 font-lock-variable-name-face nil t))))
         ;; Things extra to `fortran-font-lock-keywords-3'
         ;; (must be done first).
         (list
          ;; Fontify goto-like `err=label'/`end=label' in read/write
          ;; statements.
          '(", *\\(e\\(nd\\|rr\\)\\)\\> *\\(= *\\([0-9]+\\)\\)?"
            (1 font-lock-keyword-face) (4 font-lock-constant-face nil t))
          ;; Highlight standard continuation character and in a
          ;; TAB-formatted line.
          '("^     \\([^ 0]\\)" 1 font-lock-string-face)
          '("^\t\\([1-9]\\)" 1 font-lock-string-face))
         (list
          ;; cpp stuff (ugh)
;;;       '("^# *[a-z]+" . font-lock-keyword-face))
          `(,fortran-directive-re (0 font-lock-keyword-face t)))
         ;; The list `fortran-font-lock-keywords-2' less that for types
         ;; (see above).
         (cdr (nthcdr (length fortran-font-lock-keywords-1)
                      fortran-font-lock-keywords-2)))))

(defvar fortran-font-lock-keywords fortran-font-lock-keywords-1
  "Default expressions to highlight in Fortran mode.")
\f
(defvar fortran-imenu-generic-expression
  ;; These patterns could be confused by sequence nos. in cols 72+ and
  ;; don't allow continuations everywhere.
  (list
   (list
    nil
    ;; [This will be fooled by `end function' allowed by G77.  Also,
    ;; it assumes sensible whitespace is employed.]
    (concat
     ;; leading whitespace:
     "^\\s-+\\("
     ;; function declaration with optional type, e.g. `real',
     ;; `real*4', character(*), `double precision':
     "\\(\\sw\\|\\s-\\|[*()+]\\)*"
     "\\<function\\|subroutine\\|entry\\|block\\s-*data\\|program\\)"
     ;; Possible statement continuation:
     "[ \t" fortran-continuation-string "]+"
     ;; Variable to index:
     "\\(\\sw+\\)")
    3)
   ;; Un-named block data
   (list nil "^\\s-+\\(block\\s-*data\\)\\s-*$" 1))
  "Imenu generic expression for `imenu-default-create-index-function'.")

(defvar fortran-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map ";" 'fortran-abbrev-start)
    (define-key map "\C-c;" 'fortran-comment-region)
    (define-key map "\M-;" 'fortran-indent-comment)
    (define-key map "\M-\n" 'fortran-split-line)
    (define-key map "\M-\C-q" 'fortran-indent-subprogram)
    (define-key map "\C-c\C-w" 'fortran-window-create-momentarily)
    (define-key map "\C-c\C-r" 'fortran-column-ruler)
    (define-key map "\C-c\C-p" 'fortran-previous-statement)
    (define-key map "\C-c\C-n" 'fortran-next-statement)
    (define-key map "\C-c\C-d" 'fortran-join-line) ; like f90
    (define-key map "\M-^" 'fortran-join-line) ; subvert delete-indentation
    (define-key map "0" 'fortran-electric-line-number)
    (define-key map "1" 'fortran-electric-line-number)
    (define-key map "2" 'fortran-electric-line-number)
    (define-key map "3" 'fortran-electric-line-number)
    (define-key map "4" 'fortran-electric-line-number)
    (define-key map "5" 'fortran-electric-line-number)
    (define-key map "6" 'fortran-electric-line-number)
    (define-key map "7" 'fortran-electric-line-number)
    (define-key map "8" 'fortran-electric-line-number)
    (define-key map "9" 'fortran-electric-line-number)

    ;; Menu
    (easy-menu-define
     fortran-mode-menu map ""
     `("Fortran"
       ["Manual" (info "(emacs)Fortran")]
       ("Customization"
        ,(custom-menu-create 'fortran)
        ["Set" Custom-set t]
        ["Save" Custom-save t]
        ["Reset to Current" Custom-reset-current t]
        ["Reset to Saved" Custom-reset-saved t]
        ["Reset to Standard Settings" Custom-reset-standard t])
       "----"
       ["Toggle Auto-fill" auto-fill-mode :style toggle
        :selected auto-fill-function]
       ["Toggle abbrev-mode" abbrev-mode :style toggle :selected abbrev-mode]
       "----"
       ["Comment-out Region" fortran-comment-region mark-active]
       ["Uncomment-out region"
        (fortran-comment-region (region-beginning) (region-end) 1)
        mark-active]
       ["Indent Region" indent-region mark-active]
       ["Indent Subprogram" fortran-indent-subprogram t]
       "----"
       ["Beginning of Subprogram" fortran-beginning-of-subprogram t]
       ["End of Subprogram" fortran-end-of-subprogram t]
       ("Mark"
        ["Subprogram" mark-defun t]
        ["IF Block" fortran-mark-if t]
        ["DO Block" fortran-mark-do t])
       ["Narrow to Subprogram" narrow-to-defun t]
       ["Widen" widen t]
       "----"
       ["Temporary column ruler" fortran-column-ruler t]
       ["72-column window" fortran-window-create t]
       ["Full Width Window"
        (enlarge-window-horizontally (- (frame-width) (window-width)))
        (< (window-width) (frame-width))]
       ["Momentary 72-column window" fortran-window-create-momentarily t]
       "----"
       ["Break Line at Point" fortran-split-line t]
       ["Join Line" fortran-join-line t]
       ["Fill Statement/Comment" fill-paragraph  t]
       "----"
       ["Add imenu menu"
        imenu-add-menubar-index (not (and (boundp 'imenu--index-alist)
                                          imenu--index-alist))]))
    map)
  "Keymap used in Fortran mode.")
\f
(defvar fortran-mode-abbrev-table
  (let (abbrevs-changed)
    (define-abbrev-table 'fortran-mode-abbrev-table nil)
    ;; Use the 6th arg (SYSTEM-FLAG) of define-abbrev if possible.
    ;; Only use `apply' to quieten the byte-compiler.
    (mapcar
     (function (lambda (element)
                 (condition-case nil
                     (apply 'define-abbrev fortran-mode-abbrev-table
                            (append element '(nil 0 t)))
                   (wrong-number-of-arguments
                    (apply 'define-abbrev fortran-mode-abbrev-table
                           (append element '(nil 0)))))))
     '((";au"   "automatic"         )
       (";b"    "byte"              )
       (";bd"   "block data"        )
       (";ch"   "character"         )
       (";cl"   "close"             )
       (";c"    "continue"          )
       (";cm"   "common"            )
       (";cx"   "complex"           )
       (";df"   "define"            )
       (";di"   "dimension"         )
       (";do"   "double"            )
       (";dc"   "double complex"    )
       (";dp"   "double precision"  )
       (";dw"   "do while"          )
       (";e"    "else"              )
       (";ed"   "enddo"             )
       (";el"   "elseif"            )
       (";en"   "endif"             )
       (";eq"   "equivalence"       )
       (";ew"   "endwhere"          )
       (";ex"   "external"          )
       (";ey"   "entry"             )
       (";f"    "format"            )
       (";fa"   ".false."           )
       (";fu"   "function"          )
       (";g"    "goto"              )
       (";im"   "implicit"          )
       (";ib"   "implicit byte"     )
       (";ic"   "implicit complex"  )
       (";ich"  "implicit character")
       (";ii"   "implicit integer"  )
       (";il"   "implicit logical"  )
       (";ir"   "implicit real"     )
       (";inc"  "include"           )
       (";in"   "integer"           )
       (";intr" "intrinsic"         )
       (";l"    "logical"           )
       (";n"    "namelist"          )
       (";o"    "open"              )   ; was ;op
       (";pa"   "parameter"         )
       (";pr"   "program"           )
       (";ps"   "pause"             )
       (";p"    "print"             )
       (";rc"   "record"            )
       (";re"   "real"              )
       (";r"    "read"              )
       (";rt"   "return"            )
       (";rw"   "rewind"            )
       (";s"    "stop"              )
       (";sa"   "save"              )
       (";st"   "structure"         )
       (";sc"   "static"            )
       (";su"   "subroutine"        )
       (";tr"   ".true."            )
       (";ty"   "type"              )
       (";vo"   "volatile"          )
       (";w"    "write"             )
       (";wh"   "where"             )))
    fortran-mode-abbrev-table))
\f
(eval-when-compile                      ; silence compiler
  (defvar imenu-case-fold-search)
  (defvar imenu-syntax-alist))

(defcustom fortran-mode-hook nil
  "Hook run by Fortran mode."
  :type 'hook
  :group 'fortran)

;;;###autoload
(defun fortran-mode ()
  "Major mode for editing Fortran code.
\\[fortran-indent-line] indents the current Fortran line correctly.
DO statements must not share a common CONTINUE.

Type ;? or ;\\[help-command] to display a list of built-in abbrevs for
Fortran keywords.

Key definitions:
\\{fortran-mode-map}

Variables controlling indentation style and extra features:

 `comment-start'
    If you want to use comments starting with `!',
    set this to the string \"!\".
 `fortran-do-indent'
    Extra indentation within do blocks.  (default 3)
 `fortran-if-indent'
    Extra indentation within if blocks.  (default 3)
 `fortran-structure-indent'
    Extra indentation within structure, union, map and interface blocks.
    (default 3)
 `fortran-continuation-indent'
    Extra indentation applied to continuation statements.  (default 5)
 `fortran-comment-line-extra-indent'
    Amount of extra indentation for text within full-line comments.  (default 0)
 `fortran-comment-indent-style'
    nil    means don't change indentation of text in full-line comments,
    fixed  means indent that text at `fortran-comment-line-extra-indent' beyond
           the value of `fortran-minimum-statement-indent-fixed' (for fixed
           format continuation style) or `fortran-minimum-statement-indent-tab'
           (for TAB format continuation style).
    relative  means indent at `fortran-comment-line-extra-indent' beyond the
              indentation for a line of code.
    (default 'fixed)
 `fortran-comment-indent-char'
    Single-character string to be inserted instead of space for
    full-line comment indentation.  (default \" \")
 `fortran-minimum-statement-indent-fixed'
    Minimum indentation for Fortran statements in fixed format mode.  (def.6)
 `fortran-minimum-statement-indent-tab'
    Minimum indentation for Fortran statements in TAB format mode.  (default 9)
 `fortran-line-number-indent'
    Maximum indentation for line numbers.  A line number will get
    less than this much indentation if necessary to avoid reaching
    column 5.  (default 1)
 `fortran-check-all-num-for-matching-do'
    Non-nil causes all numbered lines to be treated as possible \"continue\"
    statements.  (default nil)
 `fortran-blink-matching-if'
    Non-nil causes \\[fortran-indent-line] on an ENDIF statement to blink on
    matching IF.  Also, from an ENDDO statement, blink on matching DO [WHILE]
    statement.  (default nil)
 `fortran-continuation-string'
    Single-character string to be inserted in column 5 of a continuation
    line.  (default \"$\")
 `fortran-comment-region'
    String inserted by \\[fortran-comment-region] at start of each line in
    region.  (default \"c$$$\")
 `fortran-electric-line-number'
    Non-nil causes line number digits to be moved to the correct column
    as typed.  (default t)
 `fortran-break-before-delimiters'
    Non-nil causes lines to be broken before delimiters.
    (default t)

Turning on Fortran mode calls the value of the variable `fortran-mode-hook'
with no args, if that value is non-nil."
  (interactive)
  (kill-all-local-variables)
  (setq local-abbrev-table fortran-mode-abbrev-table)
  (set-syntax-table fortran-mode-syntax-table)
  ;; Font Lock mode support.
  (make-local-variable 'font-lock-defaults)
  (setq font-lock-defaults '((fortran-font-lock-keywords
                              fortran-font-lock-keywords-1
                              fortran-font-lock-keywords-2
                              fortran-font-lock-keywords-3)
                             nil t ((?/ . "$/") ("_$" . "w"))
                             fortran-beginning-of-subprogram))
  (set (make-local-variable 'font-lock-syntactic-keywords)
       fortran-font-lock-syntactic-keywords)
  (make-local-variable 'fortran-break-before-delimiters)
  (setq fortran-break-before-delimiters t)
  (make-local-variable 'indent-line-function)
  (setq indent-line-function 'fortran-indent-line)
  (make-local-variable 'comment-indent-function)
  (setq comment-indent-function 'fortran-comment-indent)
  (set (make-local-variable 'comment-start-skip)
       ;; We can't reuse `fortran-comment-line-start-skip' directly because
       ;; it contains backrefs whereas we need submatch-1 to end at the
       ;; beginning of the comment delimiter.
       ;; (concat "\\(\\)\\(![ \t]*\\|" fortran-comment-line-start-skip "\\)")
       "\\(\\)\\(?:^[CcDd*]\\|!\\)\\(?:\\([^ \t\n]\\)\\2+\\)?[ \t]*")
  (set (make-local-variable 'comment-padding) "$$$")
  (make-local-variable 'comment-start)
  (setq comment-start fortran-comment-line-start)
  (make-local-variable 'require-final-newline)
  (setq require-final-newline t)
  (make-local-variable 'abbrev-all-caps)
  (setq abbrev-all-caps t)
  (make-local-variable 'indent-tabs-mode)
  (setq indent-tabs-mode nil)
;;;(setq abbrev-mode t) ; ?? (abbrev-mode 1) instead??
  (set (make-local-variable 'fill-column) 72)
  (use-local-map fortran-mode-map)
  (setq mode-name "Fortran")
  (setq major-mode 'fortran-mode)
  (make-local-variable 'fortran-comment-line-extra-indent)
  (make-local-variable 'fortran-minimum-statement-indent-fixed)
  (make-local-variable 'fortran-minimum-statement-indent-tab)
  (make-local-variable 'fortran-column-ruler-fixed)
  (make-local-variable 'fortran-column-ruler-tab)
  (setq fortran-tab-mode-string " TAB-format")
  (setq indent-tabs-mode (fortran-analyze-file-format))
  (setq imenu-case-fold-search t)
  (setq imenu-generic-expression fortran-imenu-generic-expression)
  (setq imenu-syntax-alist '(("_$" . "w")))
  (set (make-local-variable 'fill-paragraph-function) 'fortran-fill-paragraph)
  (set (make-local-variable 'normal-auto-fill-function) 'fortran-auto-fill)
  (set (make-local-variable 'indent-line-function) 'fortran-indent-line)
  (set (make-local-variable 'indent-region-function)
       (lambda (start end)
         (let (fortran-blink-matching-if ; avoid blinking delay
               indent-region-function)
           (indent-region start end nil))))
  (set (make-local-variable 'beginning-of-defun-function)
       #'fortran-beginning-of-subprogram)
  (set (make-local-variable 'end-of-defun-function)
       #'fortran-end-of-subprogram)
  (set (make-local-variable 'add-log-current-defun-function)
       #'fortran-current-defun)
  (set (make-local-variable 'dabbrev-case-fold-search) 'case-fold-search)
  (run-hooks 'fortran-mode-hook))
\f
(defsubst fortran-comment-indent ()
  (save-excursion
    (if (looking-at fortran-comment-line-start-skip) 0
      (skip-chars-backward " \t")
      (max (+ 1 (current-column))
           comment-column))))

(defun fortran-indent-comment ()
  "Align or create comment on current line.
Existing comments of all types are recognized and aligned.
If the line has no comment, a side-by-side comment is inserted and aligned
if the value of `comment-start' is not nil and allows such comments.
Otherwise, a separate-line comment is inserted, on this line
or on a new line inserted before this line if this line is not blank."
  (interactive)
  (beginning-of-line)
  ;; Recognize existing comments of either kind.
  (cond ((fortran-find-comment-start-skip 'all)
         (goto-char (match-beginning 0))
         (if (bolp)
             (fortran-indent-line)
           (if (not (= (current-column)
                       (fortran-comment-indent)))
               (progn (delete-horizontal-space)
                      (indent-to (fortran-comment-indent))))))
        ;; No existing comment.
        ;; If side-by-side comments are defined, insert one,
        ;; unless line is now blank.
        ((and comment-start (not (looking-at "[ \t]*$"))
              (string-match comment-start-skip (concat " " comment-start)))
         (end-of-line)
         (delete-horizontal-space)
         (indent-to (fortran-comment-indent))
         (insert comment-start))
        ;; Else insert separate-line comment, making a new line if nec.
        (t
         (if (looking-at "^[ \t]*$")
             (delete-horizontal-space)
           (beginning-of-line)
           (insert ?\n)
           (forward-char -1))
         (insert fortran-comment-line-start)
         (insert-char (if (stringp fortran-comment-indent-char)
                          (aref fortran-comment-indent-char 0)
                        fortran-comment-indent-char)
                      (- (fortran-calculate-indent) (current-column))))))

(defun fortran-comment-region (beg-region end-region arg)
  "Comments every line in the region.
Puts `fortran-comment-region' at the beginning of every line in the region.
BEG-REGION and END-REGION are args which specify the region boundaries.
With non-nil ARG, uncomments the region."
  (interactive "*r\nP")
  (let ((end-region-mark (copy-marker end-region))
        (save-point (point-marker)))
    (goto-char beg-region)
    (beginning-of-line)
    (if (not arg)                       ;comment the region
        (progn (insert fortran-comment-region)
               (while (and  (= (forward-line 1) 0)
                            (< (point) end-region-mark))
                 (insert fortran-comment-region)))
      (let ((com (regexp-quote fortran-comment-region))) ;uncomment the region
        (if (looking-at com)
            (delete-region (point) (match-end 0)))
        (while (and  (= (forward-line 1) 0)
                     (< (point) end-region-mark))
          (if (looking-at com)
              (delete-region (point) (match-end 0))))))
    (goto-char save-point)
    (set-marker end-region-mark nil)
    (set-marker save-point nil)))
\f
(defun fortran-abbrev-start ()
  "Typing ;\\[help-command] or ;? lists all the Fortran abbrevs.
Any other key combination is executed normally."
  (interactive)
  (let (c)
    (insert last-command-char)
    (if (or (eq (setq c (read-event)) ??)    ;insert char if not equal to `?'
            (eq c help-char))
        (fortran-abbrev-help)
      (setq unread-command-events (list c)))))

(defun fortran-abbrev-help ()
  "List the currently defined abbrevs in Fortran mode."
  (interactive)
  (message "Listing abbrev table...")
  (display-buffer (fortran-prepare-abbrev-list-buffer))
  (message "Listing abbrev table...done"))

(defun fortran-prepare-abbrev-list-buffer ()
  (save-excursion
    (set-buffer (get-buffer-create "*Abbrevs*"))
    (erase-buffer)
    (insert-abbrev-table-description 'fortran-mode-abbrev-table t)
    (goto-char (point-min))
    (set-buffer-modified-p nil)
    (edit-abbrevs-mode))
  (get-buffer-create "*Abbrevs*"))

(defun fortran-column-ruler ()
  "Insert a column ruler momentarily above current line, till next keystroke.
The ruler is defined by the value of `fortran-column-ruler-fixed' when in fixed
format mode, and `fortran-column-ruler-tab' when in TAB format mode.
The key typed is executed unless it is SPC."
  (interactive)
  (momentary-string-display
   (if indent-tabs-mode
       fortran-column-ruler-tab
     fortran-column-ruler-fixed)
   (save-excursion
     (beginning-of-line)
     (if (eq (window-start (selected-window))
             (window-point (selected-window)))
         (line-beginning-position 2)
       (point)))
   nil "Type SPC or any command to erase ruler."))

(defun fortran-window-create ()
  "Make the window 72 columns wide.
See also `fortran-window-create-momentarily'."
  (interactive)
  (let ((window-min-width 2))
    (if (< (window-width) (frame-width))
        (enlarge-window-horizontally (- (frame-width)
                                        (window-width) 1)))
    (let* ((window-edges (window-edges))
           (scroll-bar-width (- (nth 2 window-edges)
                                (car window-edges)
                                (window-width))))
      (split-window-horizontally (+ 72 scroll-bar-width)))
    (other-window 1)
    (switch-to-buffer " fortran-window-extra" t)
    (select-window (previous-window))))

(defun fortran-window-create-momentarily (&optional arg)
  "Momentarily make the window 72 columns wide.
Optional ARG non-nil and non-unity disables the momentary feature.
See also `fortran-window-create'."
  (interactive "p")
  (if (or (not arg)
          (= arg 1))
      (save-window-excursion
        (progn
          (condition-case nil
              (fortran-window-create)
            (error (error "No room for Fortran window")))
          (message "Type SPC to continue editing.")
          (let ((char (read-event)))
            (or (equal char (string-to-char " "))
                (setq unread-command-events (list char))))))
    (fortran-window-create)))

(defun fortran-split-line ()
  "Break line at point and insert continuation marker and alignment."
  (interactive)
  (delete-horizontal-space)
  (if (save-excursion
        (let ((pos (point)))
          (beginning-of-line)
          (and (fortran-find-comment-start-skip 'all)
               (< (match-beginning 0) pos))))
      (insert ?\n (match-string 0))
    (if indent-tabs-mode
        (insert ?\n ?\t (fortran-numerical-continuation-char))
      (insert "\n " fortran-continuation-string))) ; Space after \n important
  (fortran-indent-line))                ; when the cont string is C, c or *.

(defun fortran-remove-continuation ()
  (if (looking-at "\\(     [^ 0\n]\\|\t[1-9]\\|&\\)")
      (progn (replace-match "")
             (delete-indentation)
             t)))

(defun fortran-join-line (arg)
  "Join current line to the previous one and re-indent.
With a prefix argument, repeat this operation that many times.
If the prefix argument ARG is negative, join the next -ARG lines.
Continuation lines are correctly handled."
  (interactive "*p")
  (save-excursion
    (when (> 0 arg)
      (setq arg (- arg))
      (forward-line arg))
    (while (not (zerop arg))
      (beginning-of-line)
      (or (fortran-remove-continuation)
          (delete-indentation))
      (setq arg (1- arg)))
    (fortran-indent-line)))

(defun fortran-numerical-continuation-char ()
  "Return a digit for tab-digit style of continuation lines.
If, previous line is a tab-digit continuation line, returns that digit
plus one.  Otherwise return 1.  Zero not allowed."
  (save-excursion
    (forward-line -1)
    (if (looking-at "\t[1-9]")
        (+ ?1 (% (- (char-after (+ (point) 1)) ?0) 9))
      ?1)))

(put 'fortran-electric-line-number 'delete-selection t)
(defun fortran-electric-line-number (arg)
  "Self insert, but if part of a Fortran line number indent it automatically.
Auto-indent does not happen if a numeric ARG is used."
  (interactive "P")
  (if (or arg (not fortran-electric-line-number))
      (if arg
          (self-insert-command (prefix-numeric-value arg))
        (self-insert-command 1))
    (if (or (and (= 5 (current-column))
                 (save-excursion
                   (beginning-of-line)
                   (looking-at " \\{5\\}"))) ;In col 5 with only spaces to left.
            (and (= (if indent-tabs-mode
                        fortran-minimum-statement-indent-tab
                      fortran-minimum-statement-indent-fixed) (current-column))
                 (eq ?\t (char-after (line-beginning-position))) ;In col 8
                                        ; with a single tab to the left.
                 (not (or (eq last-command 'fortran-indent-line)
                          (eq last-command
                              'fortran-indent-new-line))))
            (save-excursion
              (re-search-backward "[^ \t0-9]"
                                  (line-beginning-position)
                                  t))   ;not a line number
            (looking-at "[0-9]"))       ;within a line number
        (self-insert-command (prefix-numeric-value arg))
      (skip-chars-backward " \t")
      (insert last-command-char)
      (fortran-indent-line))))
\f
(defvar fortran-end-prog-re1
  "end\
\\([ \t]*\\(program\\|subroutine\\|function\\|block[ \t]*data\\)\\>\
\\([ \t]*\\(\\sw\\|\\s_\\)+\\)?\\)?")
(defvar fortran-end-prog-re
  (concat "^[ \t0-9]*" fortran-end-prog-re1)
  "Regexp possibly marking subprogram end.")

(defun fortran-check-end-prog-re ()
  "Check a preliminary match against `fortran-end-prog-re'."
  ;; Having got a possible match for the subprogram end, we need a
  ;; match of whitespace, avoiding possible column 73+ stuff.
  (save-match-data
    (string-match "^\\s-*\\(\\'\\|\\s<\\)"
                  (buffer-substring (match-end 0)
                                    (min (line-end-position)
                                         (+ 72 (line-beginning-position)))))))

;; Note that you can't just check backwards for `subroutine' &c in
;; case of un-marked main programs not at the start of the file.
(defun fortran-beginning-of-subprogram ()
  "Move point to the beginning of the current Fortran subprogram."
  (interactive)
  (save-match-data
    (let ((case-fold-search t))
      (beginning-of-line -1)
      (if (catch 'ok
            (while (re-search-backward fortran-end-prog-re nil 'move)
              (if (fortran-check-end-prog-re)
                  (throw 'ok t))))
          (forward-line)))))

(defun fortran-end-of-subprogram ()
  "Move point to the end of the current Fortran subprogram."
  (interactive)
  (save-match-data
    (let ((case-fold-search t))
      (if (save-excursion               ; on END
            (beginning-of-line)
            (and (looking-at fortran-end-prog-re)
                 (fortran-check-end-prog-re)))
          (forward-line)
        (beginning-of-line 2)
        (catch 'ok
          (while (re-search-forward fortran-end-prog-re nil 'move)
            (if (fortran-check-end-prog-re)
                (throw 'ok t))))
        (goto-char (match-beginning 0))
        (forward-line)))))

(defun fortran-previous-statement ()
  "Move point to beginning of the previous Fortran statement.
Returns 'first-statement if that statement is the first
non-comment Fortran statement in the file, and nil otherwise.
Directive lines are treated as comments."
  (interactive)
  (let (not-first-statement continue-test)
    (beginning-of-line)
    (setq continue-test
          (and
           (not (looking-at fortran-comment-line-start-skip))
           (not (looking-at fortran-directive-re))
           (or (looking-at
                (concat "[ \t]*"
                        (regexp-quote fortran-continuation-string)))
               (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]"))))
    (while (and (setq not-first-statement (= (forward-line -1) 0))
                (or (looking-at fortran-comment-line-start-skip)
                    (looking-at fortran-directive-re)
                    (looking-at "[ \t]*$\\| \\{5\\}[^ 0\n]\\|\t[1-9]")
                    (looking-at (concat "[ \t]*" comment-start-skip)))))
    (cond ((and continue-test
                (not not-first-statement))
           (message "Incomplete continuation statement."))
          (continue-test
           (fortran-previous-statement))
          ((not not-first-statement)
           'first-statement))))

(defun fortran-next-statement ()
  "Move point to beginning of the next Fortran statement.
Returns 'last-statement if that statement is the last
non-comment Fortran statement in the file, and nil otherwise.
Directive lines are treated as comments."
  (interactive)
  (let (not-last-statement)
    (beginning-of-line)
    (while (and (setq not-last-statement
                      (and (= (forward-line 1) 0)
                           (not (eobp))))
                (or (looking-at fortran-comment-line-start-skip)
                    (looking-at fortran-directive-re)
                    (looking-at "[ \t]*$\\|     [^ 0\n]\\|\t[1-9]")
                    (looking-at (concat "[ \t]*" comment-start-skip)))))
    (if (not not-last-statement)
        'last-statement)))
\f
(defun fortran-blink-match (regex keyword find-begin)
  "From a line matching REGEX, blink matching KEYWORD statement line.
Use function FIND-BEGIN to match it."
  (let ((top-of-window (window-start))
        (end-point (point))
        (case-fold-search t)
        matching
        message)
    (if (save-excursion
          (beginning-of-line)
          (skip-chars-forward " \t0-9")
          (looking-at regex))
        (progn
          (if (not (setq matching (funcall find-begin)))
              (setq message (concat "No matching " keyword "."))
            (if (< matching top-of-window)
                (save-excursion
                  (goto-char matching)
                  (beginning-of-line)
                  (setq message
                        (concat "Matches "
                                (buffer-substring (point)
                                                  (line-end-position)))))))
          (if message
              (message "%s" message)
            (goto-char matching)
            (sit-for 1)
            (goto-char end-point))))))

(defun fortran-blink-matching-if ()
  "From an ENDIF or ELSE statement, blink the matching IF statement."
  (fortran-blink-match "e\\(nd[ \t]*if\\|lse\\([ \t]*if\\)?\\)\\b"
                       "if" #'fortran-beginning-if))

(defun fortran-blink-matching-do ()
  "From an ENDDO statement, blink the matching DO or DO WHILE statement."
  (fortran-blink-match "end[ \t]*do\\b" "do" #'fortran-beginning-do))

(defun fortran-mark-do ()
  "Put mark at end of Fortran DO [WHILE]-ENDDO construct, point at beginning.
The marks are pushed."
  (interactive)
  (let (enddo-point do-point)
    (if (setq enddo-point (fortran-end-do))
        (if (not (setq do-point (fortran-beginning-do)))
            (message "No matching do.")
          (goto-char enddo-point)
          (push-mark)
          (goto-char do-point)))))

(defun fortran-end-do ()
  "Search forward for first unmatched ENDDO.
Return point or nil."
  (let ((case-fold-search t))
    (if (save-excursion (beginning-of-line)
                        (skip-chars-forward " \t0-9")
                        (looking-at "end[ \t]*do\\b"))
        ;; Sitting on one.
        (match-beginning 0)
      ;; Search for one.
      (save-excursion
        (let ((count 1))
          (while (and (not (= count 0))
                      (not (eq (fortran-next-statement) 'last-statement))
                      ;; Keep local to subprogram
                      (not (and (looking-at fortran-end-prog-re)
                                (fortran-check-end-prog-re))))
            (skip-chars-forward " \t0-9")
            (cond ((looking-at "end[ \t]*do\\b")
                   (setq count (1- count)))
                  ((looking-at
                    "\\(\\(\\sw\\|\\s_\\)+:[ \t]*\\)?do[ \t]+[^0-9]")
                   (setq count (+ count 1)))))
          (and (= count 0)
               ;; All pairs accounted for.
               (point)))))))

(defun fortran-beginning-do ()
  "Search backwards for first unmatched DO [WHILE].
Return point or nil.  Ignores labelled DO loops (ie DO 10 ... 10 CONTINUE)."
  (let ((case-fold-search t)
        (dostart-re "\\(\\(\\sw\\|\\s_\\)+:[ \t]*\\)?do[ \t]+[^0-9]"))
    (if (save-excursion
          (beginning-of-line)
          (skip-chars-forward " \t0-9")
          (looking-at dostart-re))
        ;; Sitting on one.
        (match-beginning 0)
      ;; Search for one.
      (save-excursion
        (let ((count 1))
          (while (and (not (= count 0))
                      (not (eq (fortran-previous-statement) 'first-statement))
                      ;; Keep local to subprogram
                      (not (and (looking-at fortran-end-prog-re)
                                (fortran-check-end-prog-re))))
            (skip-chars-forward " \t0-9")
            (cond ((looking-at dostart-re)
                   (setq count (1- count)))
                  ;; Note labelled loop ends not considered.
                  ((looking-at "end[ \t]*do\\b")
                   (setq count (1+ count)))))
          (and (= count 0)
               ;; All pairs accounted for.
               (point)))))))

(defun fortran-mark-if ()
  "Put mark at end of Fortran IF-ENDIF construct, point at beginning.
The marks are pushed."
  (interactive)
  (let (endif-point if-point)
    (if (setq endif-point (fortran-end-if))
        (if (not (setq if-point (fortran-beginning-if)))
            (message "No matching if.")
          ;; Set mark, move point.
          (goto-char endif-point)
          (push-mark)
          (goto-char if-point)))))

(defvar fortran-if-start-re "\\(\\(\\sw\\|\\s_\\)+:[ \t]*\\)?if[ \t]*(")

(defun fortran-end-if ()
  "Search forwards for first unmatched ENDIF.
Return point or nil."
  (let ((case-fold-search t))
    (if (save-excursion (beginning-of-line)
                        (skip-chars-forward " \t0-9")
                        (looking-at "end[ \t]*if\\b"))
        ;; Sitting on one.
        (match-beginning 0)
      ;; Search for one.  The point has been already been moved to first
      ;; letter on line but this should not cause troubles.
      (save-excursion
        (let ((count 1))
          (while (and (not (= count 0))
                      (not (eq (fortran-next-statement) 'last-statement))
                      ;; Keep local to subprogram.
                      (not (and (looking-at fortran-end-prog-re)
                                (fortran-check-end-prog-re))))
            (skip-chars-forward " \t0-9")
            (cond ((looking-at "end[ \t]*if\\b")
                   (setq count (- count 1)))
                  ((looking-at fortran-if-start-re)
                   (save-excursion
                     (if (or
                          (looking-at ".*)[ \t]*then\\b[ \t]*[^ \t(=a-z0-9]")
                          (let (then-test) ; Multi-line if-then.
                            (while
                                (and
                                 (= (forward-line 1) 0)
                                 ;; Search forward for then.
                                 (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]")
                                 (not
                                  (setq then-test
                                        (looking-at
                                         ".*then\\b[ \t]*[^ \t(=a-z0-9]")))))
                            then-test))
                         (setq count (+ count 1)))))))
          (and (= count 0)
               ;; All pairs accounted for.
               (point)))))))

(defun fortran-beginning-if ()
  "Search backwards for first unmatched IF-THEN.
Return point or nil."
  (let ((case-fold-search t))
    (if (save-excursion
          ;; May be sitting on multi-line if-then statement, first
          ;; move to beginning of current statement.  Note:
          ;; `fortran-previous-statement' moves to previous statement
          ;; *unless* current statement is first one.  Only move
          ;; forward if not first-statement.
          (if (not (eq (fortran-previous-statement) 'first-statement))
              (fortran-next-statement))
          (skip-chars-forward " \t0-9")
          (and
           (looking-at fortran-if-start-re)
           (save-match-data
             (or (looking-at ".*)[ \t]*then\\b[ \t]*[^ \t(=a-z0-9]")
                 ;; Multi-line if-then.
                 (let (then-test)
                   (while
                     (and (= (forward-line 1) 0)
                            ;; Search forward for then.
                            (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]")
                            (not
                             (setq then-test
                                   (looking-at
                                    ".*then\\b[ \t]*[^ \t(=a-z0-9]")))))
                   then-test)))))
        ;; Sitting on one.
        (match-beginning 0)
      ;; Search for one.
      (save-excursion
        (let ((count 1))
          (while (and (not (= count 0))
                      (not (eq (fortran-previous-statement) 'first-statement))
                      ;; Keep local to subprogram.
                      (not (and (looking-at fortran-end-prog-re)
                                (fortran-check-end-prog-re))))
            (skip-chars-forward " \t0-9")
            (cond ((looking-at fortran-if-start-re)
                   (save-excursion
                     (if (or
                          (looking-at ".*)[ \t]*then\\b[ \t]*[^ \t(=a-z0-9]")
                          (let (then-test) ; Multi-line if-then.
                            (while
                                (and
                                 (= (forward-line 1) 0)
                                 ;; Search forward for then.
                                 (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]")
                                 (not
                                  (setq then-test
                                        (looking-at
                                         (concat ".*then\\b[ \t]*"
                                                 "[^ \t(=a-z0-9]"))))))
                            then-test))
                         (setq count (- count 1)))))
                  ((looking-at "end[ \t]*if\\b")
                   (setq count (+ count 1)))))
          (and (= count 0)
               ;; All pairs accounted for.
               (point)))))))
\f
(defun fortran-indent-line ()
  "Indent current Fortran line based on its contents and on previous lines."
  (interactive)
  (let ((cfi (fortran-calculate-indent)))
    (save-excursion
      (beginning-of-line)
      (if (or (not (= cfi (fortran-current-line-indentation)))
              (and (re-search-forward "^[ \t]*[0-9]+" (+ (point) 4) t)
                   (not (fortran-line-number-indented-correctly-p))))
          (fortran-indent-to-column cfi)
        (beginning-of-line)
        (if (fortran-find-comment-start-skip)
            (fortran-indent-comment))))
    ;; Never leave point in left margin.
    (if (< (current-column) cfi)
        (move-to-column cfi))
    (if (and auto-fill-function
             (> (save-excursion (end-of-line) (current-column))
                fill-column))
        (save-excursion
          (end-of-line)
          (fortran-fill)))
    (if fortran-blink-matching-if
        (progn
          (fortran-blink-matching-if)
          (fortran-blink-matching-do)))))

(defun fortran-auto-fill ()
  (if (> (current-column) (current-fill-column))
      (let ((cfi (fortran-calculate-indent)))
        (save-excursion
          (beginning-of-line)
          (if (or (not (= cfi (fortran-current-line-indentation)))
                  (and (re-search-forward "^[ \t]*[0-9]+"
                                          (+ (point) 4) t)
                       (not (fortran-line-number-indented-correctly-p))))
              (fortran-indent-to-column cfi)
            (beginning-of-line)
            (if (fortran-find-comment-start-skip)
                (fortran-indent-comment))))
        (fortran-fill)
        ;; Never leave point in left margin.
        (if (< (current-column) cfi)
            (move-to-column cfi)))))

;; Historically this was a separate function which advertised itself
;; as reindenting but only did so where `most likely to be necessary'.
(defalias 'fortran-indent-new-line 'reindent-then-newline-and-indent)

(defun fortran-indent-subprogram ()
  "Properly indent the Fortran subprogram which contains point."
  (interactive)
  (save-excursion
    (mark-defun)
    (message "Indenting subprogram...")
    (indent-region (point) (mark) nil))
  (message "Indenting subprogram...done."))

(defun fortran-calculate-indent ()
  "Calculates the Fortran indent column based on previous lines."
  (let (icol first-statement (case-fold-search t)
             (fortran-minimum-statement-indent
              (if indent-tabs-mode
                  fortran-minimum-statement-indent-tab
                fortran-minimum-statement-indent-fixed)))
    (save-excursion
      (setq first-statement (fortran-previous-statement))
      (if first-statement
          (setq icol fortran-minimum-statement-indent)
        (progn
          (if (= (point) (point-min))
              (setq icol fortran-minimum-statement-indent)
            (setq icol (fortran-current-line-indentation)))
          (skip-chars-forward " \t0-9")
          (cond ((looking-at "\\(\\(\\sw\\|\\s_\\)+:[ \t]*\\)?if[ \t]*(")
                 (if (or (looking-at ".*)[ \t]*then\\b[ \t]*[^ \t_$(=a-z0-9]")
                         (let (then-test)       ;multi-line if-then
                           (while (and (= (forward-line 1) 0)
                                       ;;search forward for then
                                       (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]")
                                       (not (setq then-test
                                                  (looking-at
                                                   ".*then\\b[ \t]\
*[^ \t_$(=a-z0-9]")))))
                           then-test))
                     (setq icol (+ icol fortran-if-indent))))
                ((looking-at "else\\(if\\)?\\b")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "select[ \t]*case[ \t](.*)")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "case[ \t]*(.*)")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "case[ \t]*default\\b")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "\\(otherwise\\|else[ \t]*where\\)\\b")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "where[ \t]*(.*)[ \t]*\n")
                 (setq icol (+ icol fortran-if-indent)))
                ((looking-at "do\\b")
                 (setq icol (+ icol fortran-do-indent)))
                ((looking-at
                  "\\(structure\\|union\\|map\\|interface\\)\
\\b[ \t]*[^ \t=(a-z]")
                 (setq icol (+ icol fortran-structure-indent)))
                ((and (looking-at fortran-end-prog-re1)
                      (fortran-check-end-prog-re))
                 ;; Previous END resets indent to minimum
                 (setq icol fortran-minimum-statement-indent))))))
    (save-excursion
      (beginning-of-line)
      (cond ((looking-at "[ \t]*$"))
            ;; Check for directive before comment, so as not to indent.
            ((looking-at fortran-directive-re)
             (setq fortran-minimum-statement-indent 0 icol 0))
            ((looking-at fortran-comment-line-start-skip)
             (cond ((eq fortran-comment-indent-style 'relative)
                    (setq icol (+ icol fortran-comment-line-extra-indent)))
                   ((eq fortran-comment-indent-style 'fixed)
                    (setq icol (+ fortran-minimum-statement-indent
                                  fortran-comment-line-extra-indent))))
             (setq fortran-minimum-statement-indent 0))
            ((or (looking-at (concat "[ \t]*"
                                     (regexp-quote
                                      fortran-continuation-string)))
                 (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]"))
             (setq icol (+ icol fortran-continuation-indent)))
            (first-statement)
            ((and fortran-check-all-num-for-matching-do
                  (looking-at "[ \t]*[0-9]+")
                  (fortran-check-for-matching-do))
             (setq icol (- icol fortran-do-indent)))
            (t
             (skip-chars-forward " \t0-9")
             (cond ((looking-at "end[ \t]*\\(if\\|select\\|where\\)\\b")
                    (setq icol (- icol fortran-if-indent)))
                   ((looking-at "else\\(if\\)?\\b")
                    (setq icol (- icol fortran-if-indent)))
                   ((looking-at "case[ \t]*\\((.*)\\|default\\>\\)")
                    (setq icol (- icol fortran-if-indent)))
                   ((looking-at "\\(otherwise\\|else[ \t]*where\\)\\b")
                    (setq icol (- icol fortran-if-indent)))
                   ((and (looking-at "continue\\b")
                         (fortran-check-for-matching-do))
                    (setq icol (- icol fortran-do-indent)))
                   ((looking-at "end[ \t]*do\\b")
                    (setq icol (- icol fortran-do-indent)))
                   ((looking-at "end[ \t]*\
\\(structure\\|union\\|map\\|interface\\)\\b[ \t]*[^ \t=(a-z]")
                    (setq icol (- icol fortran-structure-indent)))
                   ((and (looking-at fortran-end-prog-re1)
                         (fortran-check-end-prog-re)
                         (not (= icol fortran-minimum-statement-indent)))
                    (message "Warning: `end' not in column %d.  Probably\
 an unclosed block." fortran-minimum-statement-indent))))))
    (max fortran-minimum-statement-indent icol)))
\f
(defun fortran-current-line-indentation ()
  "Indentation of current line, ignoring Fortran line number or continuation.
This is the column position of the first non-whitespace character
aside from the line number and/or column 5/8 line-continuation character.
For comment lines, returns indentation of the first
non-indentation text within the comment."
  (save-excursion
    (beginning-of-line)
    (cond ((looking-at fortran-comment-line-start-skip)
           (goto-char (match-end 0))
           (skip-chars-forward
            (if (stringp fortran-comment-indent-char)
                fortran-comment-indent-char
              (char-to-string fortran-comment-indent-char))))
          ((or (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]"))
           (goto-char (match-end 0)))
          (t
           ;; Move past line number.
           (skip-chars-forward "[ \t0-9]")))
    ;; Move past whitespace.
    (skip-chars-forward " \t")
    (current-column)))

(defun fortran-indent-to-column (col)
  "Indent current line with spaces to column COL.
notes: 1) A non-zero/non-blank character in column 5 indicates a continuation
          line, and this continuation character is retained on indentation;
       2) If `fortran-continuation-string' is the first non-whitespace
          character, this is a continuation line;
       3) A non-continuation line which has a number as the first
          non-whitespace character is a numbered line.
       4) A TAB followed by a digit indicates a continuation line."
  (save-excursion
    (beginning-of-line)
    (if (looking-at fortran-comment-line-start-skip)
        (if fortran-comment-indent-style
            (let* ((char (if (stringp fortran-comment-indent-char)
                             (aref fortran-comment-indent-char 0)
                           fortran-comment-indent-char))
                   (chars (string ?  ?\t char)))
              (goto-char (match-end 0))
              (skip-chars-backward chars)
              (delete-region (point) (progn (skip-chars-forward chars)
                                            (point)))
              (insert-char char (- col (current-column)))))
      (if (looking-at "\t[1-9]")
          (if indent-tabs-mode
              (goto-char (match-end 0))
            (delete-char 2)
            (insert-char ?  5)
            (insert fortran-continuation-string))
        (if (looking-at " \\{5\\}[^ 0\n]")
            (if indent-tabs-mode
                (progn (delete-char 6)
                       (insert ?\t (fortran-numerical-continuation-char) 1))
              (forward-char 6))
          (delete-horizontal-space)
          ;; Put line number in columns 0-4
          ;; or put continuation character in column 5.
          (cond ((eobp))
                ((looking-at (regexp-quote fortran-continuation-string))
                 (if indent-tabs-mode
                     (progn
                       (indent-to
                        (if indent-tabs-mode
                            fortran-minimum-statement-indent-tab
                          fortran-minimum-statement-indent-fixed))
                       (delete-char 1)
                       (insert-char (fortran-numerical-continuation-char) 1))
                   (indent-to 5)
                   (forward-char 1)))
                ((looking-at "[0-9]+")
                 (let ((extra-space (- 5 (- (match-end 0) (point)))))
                   (if (< extra-space 0)
                       (message "Warning: line number exceeds 5-digit limit.")
                     (indent-to (min fortran-line-number-indent extra-space))))
                 (skip-chars-forward "0-9")))))
      ;; Point is now after any continuation character or line number.
      ;; Put body of statement where specified.
      (delete-horizontal-space)
      (indent-to col)
      ;; Indent any comment following code on the same line.
      (if (fortran-find-comment-start-skip)
          (progn (goto-char (match-beginning 0))
                 (if (not (= (current-column) (fortran-comment-indent)))
                     (progn (delete-horizontal-space)
                            (indent-to (fortran-comment-indent)))))))))

(defun fortran-line-number-indented-correctly-p ()
  "Return t if current line's line number is correctly indented.
Do not call if there is no line number."
  (save-excursion
    (beginning-of-line)
    (skip-chars-forward " \t")
    (and (<= (current-column) fortran-line-number-indent)
         (or (= (current-column) fortran-line-number-indent)
             (progn (skip-chars-forward "0-9")
                    (= (current-column) 5))))))

(defun fortran-check-for-matching-do ()
  "When called from a numbered statement, return t if matching DO is found.
Otherwise return nil."
  (let ((case-fold-search t)
        charnum)
    (save-excursion
      (beginning-of-line)
      (if (looking-at "[ \t]*[0-9]+")
          (progn
            (skip-chars-forward " \t")
            (skip-chars-forward "0")    ;skip past leading zeros
            (setq charnum
                  (buffer-substring (point) (progn
                                              (skip-chars-forward "0-9")
                                              (point))))
            (beginning-of-line)
            (save-restriction
              (save-excursion
                (narrow-to-defun)
                (and (re-search-backward
                      (concat
                       "\\(^[ \t0-9]*do[ \t]*0*"
                       charnum "\\b\\)\\|" "\\(^[ \t]*0*"
                       charnum "\\b\\)")
                      nil t)
                     (looking-at
                      (concat "^[ \t0-9]*do[ \t]*0*"
                              charnum))))))))))

(defun fortran-find-comment-start-skip (&optional all)
  "Move to past `comment-start-skip' found on current line.
Return non-nil if `comment-start-skip' found, nil if not.
If ALL is nil, only match comments that start in column > 0."
  (interactive)
  ;; Hopefully at some point we can just use the line below!  -stef
  ;; (comment-search-forward (line-end-position) t))
  (when (or all comment-start-skip)
    (let ((pos (point))
          (css (if comment-start-skip
                   (concat fortran-comment-line-start-skip
                           "\\|" comment-start-skip)
                 fortran-comment-line-start-skip)))
      (when (re-search-forward css (line-end-position) t)
        (if (and (or all (> (match-beginning 0) (line-beginning-position)))
                 (or (save-match-data
                       (not (fortran-is-in-string-p (match-beginning 0))))
                     ;; Recurse for rest of line.
                     (fortran-find-comment-start-skip all)))
            (point)
          (goto-char pos)
          nil)))))

;;From: ralf@up3aud1.gwdg.de (Ralf Fassel)
;; Test if TAB format continuation lines work.
(defun fortran-is-in-string-p (where)
  "Return non-nil iff WHERE (a buffer position) is inside a Fortran string."
  (save-excursion
    (goto-char where)
    (cond
     ((bolp) nil)                       ; bol is never inside a string
     ((save-excursion                   ; comment lines too
        (beginning-of-line)
        (looking-at fortran-comment-line-start-skip)) nil)
     (t (let (;; ok, serious now. Init some local vars:
              (parse-state '(0 nil nil nil nil nil 0))
              (quoted-comment-start (if comment-start
                                        (regexp-quote comment-start)))
              (not-done t)
              parse-limit end-of-line)
          ;; move to start of current statement
          (fortran-next-statement)
          (fortran-previous-statement)
          ;; now parse up to WHERE
          (while not-done
            (if (or ;; skip to next line if:
                 ;; - comment line?
                 (looking-at fortran-comment-line-start-skip)
                 ;; - at end of line?
                 (eolp)
                 ;; - not in a string and after comment-start?
                 (and (not (nth 3 parse-state))
                      comment-start
                      (equal comment-start
                             (char-to-string (preceding-char)))))
                (if (> (forward-line) 0)
                    (setq not-done nil))
              ;; else:
              ;; if we are at beginning of code line, skip any
              ;; whitespace, labels and tab continuation markers.
              (if (bolp) (skip-chars-forward " \t0-9"))
              ;; if we are in column <= 5 now, check for continuation char
              (cond ((= 5 (current-column)) (forward-char 1))
                    ((and (< (current-column) 5)
                          (equal fortran-continuation-string
                                 (char-to-string (following-char)))
                          (forward-char 1))))
              ;; find out parse-limit from here
              (setq end-of-line (line-end-position))
              (setq parse-limit (min where end-of-line))
              ;; parse max up to comment-start, if non-nil and in current line
              (if comment-start
                  (save-excursion
                    (if (re-search-forward quoted-comment-start end-of-line t)
                        (setq parse-limit (min (point) parse-limit)))))
              ;; now parse if still in limits
              (if (< (point) where)
                  (setq parse-state (parse-partial-sexp
                                     (point) parse-limit nil nil parse-state))
                (setq not-done nil))))
          ;; result is
          (nth 3 parse-state))))))

;; From old version.
(defalias 'fortran-auto-fill-mode 'auto-fill-mode)

(defun fortran-fill ()
  (let* ((auto-fill-function #'fortran-auto-fill)
         (opoint (point))
         (bol (line-beginning-position))
         (eol (line-end-position))
         (bos (min eol (+ bol (fortran-current-line-indentation))))
         (quote
          (save-excursion
            (goto-char bol)
            (if (looking-at fortran-comment-line-start-skip)
                nil                     ; OK to break quotes on comment lines.
              (move-to-column fill-column)
              (if (fortran-is-in-string-p (point))
                  (save-excursion (re-search-backward "\\S\"\\s\"\\S\"" bol t)
                                  (if fortran-break-before-delimiters
                                      (point)
                                    (1+ (point))))))))
         ;; decide where to split the line. If a position for a quoted
         ;; string was found above then use that, else break the line
         ;; before the last delimiter.
         ;; Delimiters are whitespace, commas, and operators.
         ;; Will break before a pair of *'s.
         (fill-point
          (or quote
              (save-excursion
                (move-to-column (1+ fill-column))
                (skip-chars-backward "^ \t\n,'+-/*=)"
;;;              (if fortran-break-before-delimiters
;;;                  "^ \t\n,'+-/*=" "^ \t\n,'+-/*=)")
                 )
                (if (<= (point) (1+ bos))
                    (progn
                      (move-to-column (1+ fill-column))
                      ;;what is this doing???
                      (if (not (re-search-forward "[\t\n,'+-/*)=]" eol t))
                          (goto-char bol))))
                (if (bolp)
                    (re-search-forward "[ \t]" opoint t)
                  (backward-char)
                  (if (looking-at "\\s\"")
                      (forward-char)
                    (skip-chars-backward " \t\*")))
                (if fortran-break-before-delimiters
                    (point)
                  (1+ (point)))))))
    ;; if we are in an in-line comment, don't break unless the
    ;; line of code is longer than it should be. Otherwise
    ;; break the line at the column computed above.
    ;;
    ;; Need to use fortran-find-comment-start-skip to make sure that quoted !'s
    ;; don't prevent a break.
    (when (and (save-excursion
                 (beginning-of-line)
                 (when (fortran-find-comment-start-skip)
                   (goto-char (match-beginning 0))
                   (>= (point) fill-point)))
               (save-excursion
                 (goto-char fill-point)
                 (not (bolp)))
               (> (save-excursion
                    (goto-char opoint)
                    (current-column))
                  (min (1+ fill-column)
                       (+ (fortran-calculate-indent)
                          fortran-continuation-indent))))
      (goto-char fill-point)
      (fortran-break-line)
      (end-of-line))))

(defun fortran-break-line ()
  (let ((opoint (point))
        (bol (line-beginning-position))
        (comment-string
         (save-excursion
           (if (fortran-find-comment-start-skip)
               (delete-and-extract-region
                (match-beginning 0) (line-end-position))))))
    ;; Forward line 1 really needs to go to next non white line
    (if (save-excursion (forward-line)
                        (looking-at " \\{5\\}[^ 0\n]\\|\t[1-9]"))
        (progn
          (end-of-line)
          (delete-region (point) (match-end 0))
          (delete-horizontal-space)
          (fortran-fill))
      (fortran-split-line))
    (if comment-string
        (save-excursion
          (goto-char bol)
          (end-of-line)
          (delete-horizontal-space)
          (indent-to (fortran-comment-indent))
          (insert comment-string)))))

(defun fortran-analyze-file-format ()
  "Return nil if fixed format is used, t if TAB formatting is used.
Use `fortran-tab-mode-default' if no non-comment statements are found in the
file before the end or the first `fortran-analyze-depth' lines."
  (let ((i 0))
    (save-excursion
      (goto-char (point-min))
      (setq i 0)
      (while (not (or
                   (eobp)
                   (eq (char-after) ?\t)
                   (looking-at " \\{6\\}")
                   (> i fortran-analyze-depth)))
        (forward-line)
        (setq i (1+ i)))
      (cond
       ((eq (char-after) ?\t) t)
       ((looking-at " \\{6\\}") nil)
       (fortran-tab-mode-default t)
       (t nil)))))

(or (assq 'fortran-tab-mode-string minor-mode-alist)
    (setq minor-mode-alist (cons
                            '(fortran-tab-mode-string
                              (indent-tabs-mode fortran-tab-mode-string))
                            minor-mode-alist)))

(defun fortran-fill-paragraph (&optional justify)
  "Fill surrounding comment block as paragraphs, else fill statement.
Intended as the value of `fill-paragraph-function'."
  (interactive "P")
  (save-excursion
    (beginning-of-line)
    (if (not (looking-at fortran-comment-line-start-skip))
        (fortran-fill-statement)
        ;; We're in a comment block.  Find the start and end of a
        ;; paragraph, delimited either by non-comment lines or empty
        ;; comments.  (Get positions as markers, since the
        ;; `indent-region' below can shift the block's end).
        (let* ((non-empty-comment
                (concat fortran-comment-line-start-skip "[^ \t\n]"))
               (start (save-excursion
                        ;; Find (start of) first line.
                        (while (and (zerop (forward-line -1))
                                    (looking-at non-empty-comment)))
                        (or (looking-at non-empty-comment)
                            (forward-line)) ; overshot
                        (point-marker)))
               (end (save-excursion
                      ;; Find start of first line past region to fill.
                      (while (progn
                               (forward-line)
                               (looking-at non-empty-comment)))
                      (point-marker))))
          ;; Indent the block, find the string comprising the effective
          ;; comment start skip and use that as a fill-prefix for
          ;; filling the region.
          (indent-region start end nil)
          (let ((paragraph-ignore-fill-prefix nil)
                (fill-prefix (progn
                               (beginning-of-line)
                               (looking-at fortran-comment-line-start-skip)
                               (match-string 0))))
            (let (fill-paragraph-function)
              (fill-region start end justify))) ; with normal `fill-paragraph'
          (set-marker start nil)
          (set-marker end nil))))
  t)

(defun fortran-fill-statement ()
  "Fill a fortran statement up to `fill-column'."
  (interactive)
  (let ((auto-fill-function #'fortran-auto-fill))
    (if (not (save-excursion
               (beginning-of-line)
               (or (looking-at "[ \t]*$")
                   (looking-at fortran-comment-line-start-skip)
                   (and comment-start-skip
                        (looking-at (concat "[ \t]*" comment-start-skip))))))
        (save-excursion
          ;; Find beginning of statement.
          (fortran-next-statement)
          (fortran-previous-statement)
          ;; Re-indent initially.
          (fortran-indent-line)
          ;; Replace newline plus continuation field plus indentation with
          ;; single space.
          (while (progn
                   (forward-line)
                   (fortran-remove-continuation)))
          (fortran-previous-statement)))
    (fortran-indent-line)))

(defun fortran-strip-sequence-nos (&optional do-space)
  "Delete all text in column 72 and up (assumed to be sequence numbers).
Normally also deletes trailing whitespace after stripping such text.
Supplying prefix arg DO-SPACE prevents stripping the whitespace."
  (interactive "p")
  (save-excursion
    (goto-char (point-min))
    (while (re-search-forward "^.\\{72\\}\\(.*\\)" nil t)
      (replace-match "" nil nil nil 1)
      (unless do-space (delete-horizontal-space)))))

;; This code used to live in add-log.el, but this is a better place
;; for it.
(defun fortran-current-defun ()
  "Function to use for `add-log-current-defun-function' in Fortran mode."
  (save-excursion
    ;; We must be inside function body for this to work.
    (fortran-beginning-of-subprogram)
    (let ((case-fold-search t))         ; case-insensitive
      ;; search for fortran subprogram start
      (if (re-search-forward
           (concat "^[ \t]*\\(program\\|subroutine\\|function"
                   "\\|[ \ta-z0-9*()]*[ \t]+function\\|"
                   "\\(block[ \t]*data\\)\\)")
           (save-excursion (fortran-end-of-subprogram)
                           (point))
           t)
          (or (match-string-no-properties 2)
              (progn
                ;; move to EOL or before first left paren
                (if (re-search-forward "[(\n]" nil t)
                    (progn (backward-char)
                           (skip-chars-backward " \t"))
                  (end-of-line))
                ;; Use the name preceding that.
                (buffer-substring-no-properties (point) (progn (backward-sexp)
                                                               (point)))))
        "main"))))

(provide 'fortran)

;;; fortran.el ends here