This just modifies the code to support paths with spaces when compiling the dot files.

 ;;; graphviz-dot-mode.el --- Mode for the dot-language used
by graphviz (att). ;; Copyright (C) 2002 - 2005 Pieter Pareit
<pieter.pareit@scarlet.be>
  ;; 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 2 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 this program; if not, write to the Free
  ;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, ;; MA
  02111-1307 USA ;; Authors: Pieter Pareit
  <pieter.pareit@scarlet.be>
    ;; Rubens Ramos
    <rubensr AT users.sourceforge.net>
      ;; Victor Engmark
      <victor.engmark@gmail.com>
        ;; Maintainer: Pieter Pareit
        <pieter.pareit@planetinternet.be>
          ;; Homepage:
          http://users.skynet.be/ppareit/projects/graphviz-dot-mode/graphviz-dot-mode.html
          ;; This version homepage:
          https://paperless.blog/graphviz-dot-mode-for-emacs-patch/ ;; Created:
          28 Oct 2002 ;; Last modified: 5 Oct 2009 ;; Version: 0.3.4 ;;
          Keywords: mode dot dot-language dotlanguage graphviz graphs att ;;;
          Commentary: ;; Use this mode for editing files in the dot-language
          (www.graphviz.org and ;;
          http://www.research.att.com/sw/tools/graphviz/). ;; ;; To use
          graphviz-dot-mode, add ;; (load-file
          "PATH_TO_FILE/graphviz-dot-mode.el") ;; to your ~/.emacs(.el) or
          ~/.xemacs/init.el ;; ;; The graphviz-dot-mode will do font locking,
          indentation, preview of graphs ;; and eases compilation/error
          location. There is support for both GNU Emacs ;; and XEmacs. ;; ;;
          Font locking is automatic, indentation uses the same commands as ;;
          other modes, tab, M-j and C-M-q. Insertion of comments uses the ;;
          same commands as other modes, M-; . You can compile a file using ;;
          M-x compile or C-c c, after that M-x next-error will also work. ;;
          There is support for viewing an generated image with C-c p. ;;; Todo:
          ;; * cleanup the mess of graphviz-dot-compilation-parse-errors ;; *
          electric indentation is fundamentally broken, because ;; {...} are
          also used for record nodes. You could argue, I suppose, that ;; many
          diagrams don't need those, but it would be worth having a note (and ;;
          it makes sense that the default is now for electric indentation to be
          ;; off). ;;; History: ;; Version 0.3.5 bug fix ;; 2009-10-04: *
          compilation works with file paths which contain spaces ;; Version
          0.3.4 bug fixes ;; 24/02/2005: * fixed a bug in graphviz-dot-preview
          ;; Version 0.3.3 bug fixes ;; 13/02/2005: Reuben Thomas
          <rrt AT sc3d.org>
            ;; * add graphviz-dot-indent-width ;; Version 0.3.2 bug fixes ;;
            25/03/2004: Rubens Ramos
            <rubensr AT users.sourceforge.net>
              ;; * semi-colons and brackets are added when electric ;; behaviour
              is disabled. ;; * electric characters do not behave electrically
              inside ;; comments or strings. ;; * default for electric-braces is
              disabled now (makes more ;; sense I guess). ;; * using
              read-from-minibuffer instead of read-shell-command ;; for emacs.
              ;; * Fixed test for easymenu, so that it works on older ;;
              versions of XEmacs. ;; * Fixed indentation error when trying to
              indent last brace ;; of an empty graph. ;; * region-active-p does
              not exist in emacs (21.2 at least), ;; so removed from code ;; *
              Added uncomment menu option ;; Version 0.3.1 bug fixes ;;
              03/03/2004: * backward-word needs argument for older emacs ;;
              Version 0.3 added features and fixed bugs ;; 10/01/2004: fixed a
              bug in graphviz-dot-indent-graph ;; 08/01/2004: Rubens Ramos
              <rubensr AT users.sourceforge.net>
                ;; * added customization support ;; * Now it works on XEmacs and
                Emacs ;; * Added support to use an external Viewer ;; * Now
                things do not break when dot mode is entered ;; when there is no
                buffer name, but the side effect is ;; that in this case, the
                compilation command is not ;; correct. ;; * Preview works on
                XEmacs and emacs. ;; * Electric indentation on newline ;; *
                Minor changes to indentation ;; * Added keyword completion (but
                could be A LOT better) ;; * There are still a couple of ugly
                hacks. Look for 'RR'. ;; Version 0.2 added features ;;
                11/11/2002: added preview support. ;; 10/11/2002: indent a graph
                or subgraph at once with C-M-q. ;; 08/11/2002: relaxed rules for
                indentation, the may now be extra chars ;; after beginning of
                graph (comment's for example). ;; Version 0.1.2 bug fixes and
                naming issues ;; 06/11/2002: renamed dot-font-lock-defaults to
                dot-font-lock-keywords. ;; added some documentation to
                dot-colors. ;; provided a much better way to handle my
                max-specpdl-size ;; problem. ;; added an extra autoload cookie
                (hope this helps, as I don't ;; yet use autoload myself) ;;
                Version 0.1.1 bug fixes ;; 06/11/2002: added an missing
                attribute, for font-locking to work. ;; fixed the regex
                generating, so that it only recognizes ;; whole words ;;
                05/11/2002: there can now be extra white space chars after an
                '{'. ;; 04/11/2002: Why I use max-specpdl-size is now
                documented, and old value ;; gets restored. ;; Version 0.1
                initial release ;; 02/11/2002: implemented parser for
                *compilation* of a .dot file. ;; 01/11/2002: implemented
                compilation of an .dot file. ;; 31/10/2002: added syntax-table
                to the mode. ;; 30/10/2002: implemented indentation code. ;;
                29/10/2002: implemented all of font-lock. ;; 28/10/2002: derived
                graphviz-dot-mode from fundamental-mode, started ;; implementing
                font-lock. ;;; Code: (defconst graphviz-dot-mode-version "0.3.3"
                "Version of `graphviz-dot-mode.el'.") (defgroup graphviz nil
                "Major mode for editing Graphviz Dot files" :group 'tools)
                (defun graphviz-dot-customize () "Run \\[customize-group] for
                the `graphviz' group." (interactive) (customize-group
                'graphviz)) (defvar graphviz-dot-mode-abbrev-table nil "Abbrev
                table in use in Graphviz Dot mode buffers.")
                (define-abbrev-table 'graphviz-dot-mode-abbrev-table ())
                (defcustom graphviz-dot-dot-program "dot" "*Location of the dot
                program. This is used by `compile'." :type 'string :group
                'graphviz) (defcustom graphviz-dot-view-command "doted %s"
                "*External program to run on the buffer. You can use `%s' in
                this string, and it will be substituted by the buffer name."
                :type 'string :group 'graphviz) (defcustom
                graphviz-dot-view-edit-command nil "*Whether to allow the user
                to edit the command to run an external viewer." :type 'boolean
                :group 'graphviz) (defcustom graphviz-dot-save-before-view t
                "*If not nil, M-x graphviz-dot-view saves the current buffer
                before running the command." :type 'boolean :group 'graphviz)
                (defcustom graphviz-dot-auto-indent-on-newline t "*If not nil,
                `electric-graphviz-dot-terminate-line' is executed in a line is
                terminated." :type 'boolean :group 'graphviz) (defcustom
                graphviz-dot-indent-width default-tab-width "*Indentation width
                in Graphviz Dot mode buffers." :type 'integer :group 'graphviz)
                (defcustom graphviz-dot-auto-indent-on-braces nil "*If not nil,
                `electric-graphviz-dot-open-brace' and
                `electric-graphviz-dot-close-brace' are executed when { or } are
                typed" :type 'boolean :group 'graphviz) (defcustom
                graphviz-dot-auto-indent-on-semi t "*If not nil,
                `electric-graphviz-dot-semi' is executed when semicolon is
                typed" :type 'boolean :group 'graphviz) (defcustom
                graphviz-dot-preview-extension "png" "*The extension to use for
                the compilation and preview commands. The format for the
                compilation command is `dot -T<extension>
                  file.dot > file.<extension
                    >'." :type 'string :group 'graphviz) (defcustom
                    graphviz-dot-toggle-completions nil "*Non-nil means that
                    repeated use of \ \\<graphviz-dot-mode-map
                      >\\[graphviz-dot-complete-word] will toggle the possible
                      completions in the minibuffer. Normally, when there is
                      more than one possible completion, a buffer will display
                      all completions." :type 'boolean :group 'graphviz)
                      (defcustom graphviz-dot-delete-completions nil "*Non-nil
                      means that the completion buffer is automatically deleted
                      when a key is pressed." :type 'boolean :group 'graphviz)
                      (defcustom graphviz-dot-attr-keywords '("graph" "digraph"
                      "subgraph" "node" "edge" "strict" "rankdir" "size" "page"
                      "Damping" "Epsilon" "URL" "arrowhead" "arrowsize"
                      "arrowtail" "bb" "bgcolor" "bottomlabel" "center"
                      "clusterrank" "color" "comment" "compound" "concentrate"
                      "constraint" "decorate" "dim" "dir" "distortion"
                      "fillcolor" "fixedsize" "fontcolor" "fontname" "fontpath"
                      "fontsize" "group" "headURL" "headlabel" "headport"
                      "height" "label" "labelangle" "labeldistance" "labelfloat"
                      "labelfontcolor" "labelfontname" "labelfontsize"
                      "labeljust" "labelloc" "layer" "layers" "len" "lhead" "lp"
                      "ltail" "margin" "maxiter" "mclimit" "minlen" "model"
                      "nodesep" "normalize" "nslimit" "nslimit1" "ordering"
                      "orientation" "overlap" "pack" "pagedir" "pencolor"
                      "peripheries" "pin" "pos" "quantum" "rank" "ranksep"
                      "ratio" "rects" "regular" "remincross" "rotate" "samehead"
                      "sametail" "samplepoint" "searchsize" "sep" "shape"
                      "shapefile" "showboxes" "sides" "skew" "splines" "start"
                      "style" "stylesheet" "tailURL" "taillabel" "tailport"
                      "toplabel" "vertices" "voro_margin" "weight" "z")
                      "*Keywords for attribute names in a graph. This is used by
                      the auto completion code. The actual completion tables are
                      built when the mode is loaded, so changes to this are not
                      immediately visible." :type '(repeat (string :tag
                      "Keyword")) :group 'graphviz) (defcustom
                      graphviz-dot-value-keywords '("true" "false" "normal"
                      "inv" "dot" "invdot" "odot" "invodot" "none" "tee" "empty"
                      "invempty" "diamond" "odiamond" "box" "obox" "open" "crow"
                      "halfopen" "local" "global" "none" "forward" "back" "both"
                      "none" "BL" "BR" "TL" "TR" "RB" "RT" "LB" "LT" ":n" ":ne"
                      ":e" ":se" ":s" ":sw" ":w" ":nw" "same" "min" "source"
                      "max" "sink" "LR" "box" "polygon" "ellipse" "circle"
                      "point" "egg" "triangle" "plaintext" "diamond" "trapezium"
                      "parallelogram" "house" "hexagon" "octagon" "doublecircle"
                      "doubleoctagon" "tripleoctagon" "invtriangle"
                      "invtrapezium" "invhouse" "Mdiamond" "Msquare" "Mcircle"
                      "record" "Mrecord" "dashed" "dotted" "solid" "invis"
                      "bold" "filled" "diagonals" "rounded" ) "*Keywords for
                      attribute values. This is used by the auto completion
                      code. The actual completion tables are built when the mode
                      is loaded, so changes to this are not immediately
                      visible." :type '(repeat (string :tag "Keyword")) :group
                      'graphviz) ;;; Font-locking: (defvar
                      graphviz-dot-colors-list '(aliceblue antiquewhite
                      antiquewhite1 antiquewhite2 antiquewhite3 antiquewhite4
                      aquamarine aquamarine1 aquamarine2 aquamarine3 aquamarine4
                      azure azure1 azure2 azure3 azure4 beige bisque bisque1
                      bisque2 bisque3 bisque4 black blanchedalmond blue blue1
                      blue2 blue3 blue4 blueviolet brown brown1 brown2 brown3
                      brown4 burlywood burlywood1 burlywood2 burlywood3
                      burlywood4 cadetblue cadetblue1 cadetblue2 cadetblue3
                      cadetblue4 chartreuse chartreuse1 chartreuse2 chartreuse3
                      chartreuse4 chocolate chocolate1 chocolate2 chocolate3
                      chocolate4 coral coral1 coral2 coral3 coral4
                      cornflowerblue cornsilk cornsilk1 cornsilk2 cornsilk3
                      cornsilk4 crimson cyan cyan1 cyan2 cyan3 cyan4
                      darkgoldenrod darkgoldenrod1 darkgoldenrod2 darkgoldenrod3
                      darkgoldenrod4 darkgreen darkkhaki darkolivegreen
                      darkolivegreen1 darkolivegreen2 darkolivegreen3
                      darkolivegreen4 darkorange darkorange1 darkorange2
                      darkorange3 darkorange4 darkorchid darkorchid1 darkorchid2
                      darkorchid3 darkorchid4 darksalmon darkseagreen
                      darkseagreen1 darkseagreen2 darkseagreen3 darkseagreen4
                      darkslateblue darkslategray darkslategray1 darkslategray2
                      darkslategray3 darkslategray4 darkslategrey darkturquoise
                      darkviolet deeppink deeppink1 deeppink2 deeppink3
                      deeppink4 deepskyblue deepskyblue1 deepskyblue2
                      deepskyblue3 deepskyblue4 dimgray dimgrey dodgerblue
                      dodgerblue1 dodgerblue2 dodgerblue3 dodgerblue4 firebrick
                      firebrick1 firebrick2 firebrick3 firebrick4 floralwhite
                      forestgreen gainsboro ghostwhite gold gold1 gold2 gold3
                      gold4 goldenrod goldenrod1 goldenrod2 goldenrod3
                      goldenrod4 gray gray0 gray1 gray10 gray100 gray11 gray12
                      gray13 gray14 gray15 gray16 gray17 gray18 gray19 gray2
                      gray20 gray21 gray22 gray23 gray24 gray25 gray26 gray27
                      gray28 gray29 gray3 gray30 gray31 gray32 gray33 gray34
                      gray35 gray36 gray37 gray38 gray39 gray4 gray40 gray41
                      gray42 gray43 gray44 gray45 gray46 gray47 gray48 gray49
                      gray5 gray50 gray51 gray52 gray53 gray54 gray55 gray56
                      gray57 gray58 gray59 gray6 gray60 gray61 gray62 gray63
                      gray64 gray65 gray66 gray67 gray68 gray69 gray7 gray70
                      gray71 gray72 gray73 gray74 gray75 gray76 gray77 gray78
                      gray79 gray8 gray80 gray81 gray82 gray83 gray84 gray85
                      gray86 gray87 gray88 gray89 gray9 gray90 gray91 gray92
                      gray93 gray94 gray95 gray96 gray97 gray98 gray99 green
                      green1 green2 green3 green4 greenyellow grey grey0 grey1
                      grey10 grey100 grey11 grey12 grey13 grey14 grey15 grey16
                      grey17 grey18 grey19 grey2 grey20 grey21 grey22 grey23
                      grey24 grey25 grey26 grey27 grey28 grey29 grey3 grey30
                      grey31 grey32 grey33 grey34 grey35 grey36 grey37 grey38
                      grey39 grey4 grey40 grey41 grey42 grey43 grey44 grey45
                      grey46 grey47 grey48 grey49 grey5 grey50 grey51 grey52
                      grey53 grey54 grey55 grey56 grey57 grey58 grey59 grey6
                      grey60 grey61 grey62 grey63 grey64 grey65 grey66 grey67
                      grey68 grey69 grey7 grey70 grey71 grey72 grey73 grey74
                      grey75 grey76 grey77 grey78 grey79 grey8 grey80 grey81
                      grey82 grey83 grey84 grey85 grey86 grey87 grey88 grey89
                      grey9 grey90 grey91 grey92 grey93 grey94 grey95 grey96
                      grey97 grey98 grey99 honeydew honeydew1 honeydew2
                      honeydew3 honeydew4 hotpink hotpink1 hotpink2 hotpink3
                      hotpink4 indianred indianred1 indianred2 indianred3
                      indianred4 indigo ivory ivory1 ivory2 ivory3 ivory4 khaki
                      khaki1 khaki2 khaki3 khaki4 lavender lavenderblush
                      lavenderblush1 lavenderblush2 lavenderblush3
                      lavenderblush4 lawngreen lemonchiffon lemonchiffon1
                      lemonchiffon2 lemonchiffon3 lemonchiffon4 lightblue
                      lightblue1 lightblue2 lightblue3 lightblue4 lightcoral
                      lightcyan lightcyan1 lightcyan2 lightcyan3 lightcyan4
                      lightgoldenrod lightgoldenrod1 lightgoldenrod2
                      lightgoldenrod3 lightgoldenrod4 lightgoldenrodyellow
                      lightgray lightgrey lightpink lightpink1 lightpink2
                      lightpink3 lightpink4 lightsalmon lightsalmon1
                      lightsalmon2 lightsalmon3 lightsalmon4 lightseagreen
                      lightskyblue lightskyblue1 lightskyblue2 lightskyblue3
                      lightskyblue4 lightslateblue lightslategray lightslategrey
                      lightsteelblue lightsteelblue1 lightsteelblue2
                      lightsteelblue3 lightsteelblue4 lightyellow lightyellow1
                      lightyellow2 lightyellow3 lightyellow4 limegreen linen
                      magenta magenta1 magenta2 magenta3 magenta4 maroon maroon1
                      maroon2 maroon3 maroon4 mediumaquamarine mediumblue
                      mediumorchid mediumorchid1 mediumorchid2 mediumorchid3
                      mediumorchid4 mediumpurple mediumpurple1 mediumpurple2
                      mediumpurple3 mediumpurple4 mediumseagreen mediumslateblue
                      mediumspringgreen mediumturquoise mediumvioletred
                      midnightblue mintcream mistyrose mistyrose1 mistyrose2
                      mistyrose3 mistyrose4 moccasin navajowhite navajowhite1
                      navajowhite2 navajowhite3 navajowhite4 navy navyblue
                      oldlace olivedrab olivedrap olivedrab1 olivedrab2
                      olivedrap3 oragne palegoldenrod palegreen palegreen1
                      palegreen2 palegreen3 palegreen4 paleturquoise
                      paleturquoise1 paleturquoise2 paleturquoise3
                      paleturquoise4 palevioletred palevioletred1 palevioletred2
                      palevioletred3 palevioletred4 papayawhip peachpuff
                      peachpuff1 peachpuff2 peachpuff3 peachpuff4 peru pink
                      pink1 pink2 pink3 pink4 plum plum1 plum2 plum3 plum4
                      powderblue purple purple1 purple2 purple3 purple4 red red1
                      red2 red3 red4 rosybrown rosybrown1 rosybrown2 rosybrown3
                      rosybrown4 royalblue royalblue1 royalblue2 royalblue3
                      royalblue4 saddlebrown salmon salmon1 salmon2 salmon3
                      salmon4 sandybrown seagreen seagreen1 seagreen2 seagreen3
                      seagreen4 seashell seashell1 seashell2 seashell3 seashell4
                      sienna sienna1 sienna2 sienna3 sienna4 skyblue skyblue1
                      skyblue2 skyblue3 skyblue4 slateblue slateblue1 slateblue2
                      slateblue3 slateblue4 slategray slategray1 slategray2
                      slategray3 slategray4 slategrey snow snow1 snow2 snow3
                      snow4 springgreen springgreen1 springgreen2 springgreen3
                      springgreen4 steelblue steelblue1 steelblue2 steelblue3
                      steelblue4 tan tan1 tan2 tan3 tan4 thistle thistle1
                      thistle2 thistle3 thistle4 tomato tomato1 tomato2 tomato3
                      tomato4 transparent turquoise turquoise1 turquoise2
                      turquoise3 turquoise4 violet violetred violetred1
                      violetred2 violetred3 violetred4 wheat wheat1 wheat2
                      wheat3 wheat4 white whitesmoke yellow yellow1 yellow2
                      yellow3 yellow4 yellowgreen) "Possible color constants in
                      the dot language. The list of constant is available at
                      http://www.research.att.com/~erg/graphviz\
                      /info/colors.html") (defvar graphviz-dot-color-keywords
                      (mapcar 'symbol-name graphviz-dot-colors-list)) (defvar
                      graphviz-attr-keywords (mapcar '(lambda (elm) (cons elm
                      0)) graphviz-dot-attr-keywords)) (defvar
                      graphviz-value-keywords (mapcar '(lambda (elm) (cons elm
                      0)) graphviz-dot-value-keywords)) (defvar
                      graphviz-color-keywords (mapcar '(lambda (elm) (cons elm
                      0)) graphviz-dot-color-keywords)) ;;; Key map (defvar
                      graphviz-dot-mode-map () "Keymap used in Graphviz Dot
                      mode.") (if graphviz-dot-mode-map () (let ((map
                      (make-sparse-keymap))) (define-key map "\r"
                      'electric-graphviz-dot-terminate-line) (define-key map "{"
                      'electric-graphviz-dot-open-brace) (define-key map "}"
                      'electric-graphviz-dot-close-brace) (define-key map ";"
                      'electric-graphviz-dot-semi) (define-key map "\M-\t"
                      'graphviz-dot-complete-word) (define-key map "\C-\M-q"
                      'graphviz-dot-indent-graph) (define-key map "\C-cp"
                      'graphviz-dot-preview) (define-key map "\C-cc" 'compile)
                      (define-key map "\C-cv" 'graphviz-dot-view) (define-key
                      map "\C-c\C-c" 'comment-region) (define-key map "\C-c\C-u"
                      'graphviz-dot-uncomment-region) (setq
                      graphviz-dot-mode-map map) )) ;;; Syntax table (defvar
                      graphviz-dot-mode-syntax-table nil "Syntax table for
                      `graphviz-dot-mode'.") (if graphviz-dot-mode-syntax-table
                      () (let ((st (make-syntax-table))) (modify-syntax-entry ?/
                      ". 124b" st) (modify-syntax-entry ?* ". 23" st)
                      (modify-syntax-entry ?\n "> b" st) (modify-syntax-entry ?=
                      "." st) (modify-syntax-entry ?_ "_" st)
                      (modify-syntax-entry ?- "_" st) (modify-syntax-entry ?>
                      "." st) (modify-syntax-entry ?[ "(" st)
                      (modify-syntax-entry ?] ")" st) (modify-syntax-entry ?\"
                      "\"" st) (setq graphviz-dot-mode-syntax-table st) ))
                      (defvar graphviz-dot-font-lock-keywords
                      `(("\\(:?di\\|sub\\)?graph \\(\\sw+\\)" (2
                      font-lock-function-name-face)) (,(regexp-opt
                      graphviz-dot-value-keywords 'words) .
                      font-lock-reference-face) ;; to build the font-locking for
                      the colors, ;; we need more room for max-specpdl-size, ;;
                      after that we take the list of symbols, ;; convert them to
                      a list of strings, and make ;; an optimized regexp from
                      them (,(let ((max-specpdl-size (max max-specpdl-size
                      1200))) (regexp-opt graphviz-dot-color-keywords)) .
                      font-lock-string-face) (,(concat (regexp-opt
                      graphviz-dot-attr-keywords 'words) "[ \\t\\n]*=") ;; RR -
                      ugly, really, but I dont know why xemacs does not work ;;
                      if I change the next car to "1"... (0
                      font-lock-variable-name-face))) "Keyword highlighting
                      specification for `graphviz-dot-mode'.") ;;;###autoload
                      (defun graphviz-dot-mode () "Major mode for the dot
                      language. \\<graphviz-dot-mode-map>
                        TAB indents for graph lines.
                        \\[graphviz-dot-indent-graph]\t- Indentaion function.
                        \\[graphviz-dot-preview]\t- Previews graph in a buffer.
                        \\[graphviz-dot-view]\t- Views graph in an external
                        viewer. \\[graphviz-dot-indent-line]\t- Indents current
                        line of code. \\[graphviz-dot-complete-word]\t-
                        Completes the current word.
                        \\[electric-graphviz-dot-terminate-line]\t- Electric
                        newline. \\[electric-graphviz-dot-open-brace]\t-
                        Electric open braces.
                        \\[electric-graphviz-dot-close-brace]\t- Electric close
                        braces. \\[electric-graphviz-dot-semi]\t- Electric semi
                        colons. Variables specific to this mode:
                        graphviz-dot-dot-program (default `dot') Location of the
                        dot program. graphviz-dot-view-command (default `doted
                        %s') Command to run when `graphviz-dot-view' is
                        executed. graphviz-dot-view-edit-command (default nil)
                        If the user should be asked to edit the view command.
                        graphviz-dot-save-before-view (default t) Automatically
                        save current buffer berore `graphviz-dot-view'.
                        graphviz-dot-preview-extension (default `png') File type
                        to use for `graphviz-dot-preview'.
                        graphviz-dot-auto-indent-on-newline (default t) Whether
                        to run `electric-graphviz-dot-terminate-line' when
                        newline is entered. graphviz-dot-auto-indent-on-braces
                        (default t) Whether to run
                        `electric-graphviz-dot-open-brace' and
                        `electric-graphviz-dot-close-brace' when braces are
                        entered. graphviz-dot-auto-indent-on-semi (default t)
                        Whether to run `electric-graphviz-dot-semi' when semi
                        colon is typed. graphviz-dot-toggle-completions (default
                        nil) If completions should be displayed in the buffer
                        instead of a completion buffer when
                        \\[graphviz-dot-complete-word] is pressed repeatedly.
                        This mode can be customized by running
                        \\[graphviz-dot-customize]. Turning on Graphviz Dot mode
                        calls the value of the variable `graphviz-dot-mode-hook'
                        with no args, if that value is non-nil." (interactive)
                        (kill-all-local-variables) (use-local-map
                        graphviz-dot-mode-map) (setq major-mode
                        'graphviz-dot-mode) (setq mode-name "dot") (setq
                        local-abbrev-table graphviz-dot-mode-abbrev-table)
                        (set-syntax-table graphviz-dot-mode-syntax-table) (set
                        (make-local-variable 'indent-line-function)
                        'graphviz-dot-indent-line) (set (make-local-variable
                        'comment-start) "//") (set (make-local-variable
                        'comment-start-skip) "/\\*+ *\\|//+ *") (set
                        (make-local-variable 'font-lock-defaults)
                        '(graphviz-dot-font-lock-keywords)) ;; RR - If user is
                        running this in the scratch buffer, there is no ;;
                        buffer file name... (if (buffer-file-name) (set
                        (make-local-variable 'compile-command) (concat
                        graphviz-dot-dot-program " -T"
                        graphviz-dot-preview-extension " \"" buffer-file-name
                        "\" > \"" (file-name-sans-extension buffer-file-name)
                        "." graphviz-dot-preview-extension "\""))) (set
                        (make-local-variable 'compilation-parse-errors-function)
                        'graphviz-dot-compilation-parse-errors) (if dot-menu
                        (easy-menu-add dot-menu)) (run-hooks
                        'graphviz-dot-mode-hook) ) ;;;; Menu definitions (defvar
                        dot-menu nil "Menu for Graphviz Dot Mode. This menu will
                        get created automatically if you have the `easymenu'
                        package. Note that the latest X/Emacs releases contain
                        this package.") (and (condition-case nil (require
                        'easymenu) (error nil)) (easy-menu-define dot-menu
                        graphviz-dot-mode-map "Graphviz Mode menu" '("Graphviz"
                        ["Indent Graph" graphviz-dot-indent-graph t] ["Comment
                        Out Region" comment-region (mark)] ["Uncomment Region"
                        graphviz-dot-uncomment-region (mark)] "-" ["Compile"
                        compile t] ["Preview" graphviz-dot-preview (and
                        (buffer-file-name) (not (buffer-modified-p)))]
                        ["External Viewer" graphviz-dot-view (buffer-file-name)]
                        "-" ["Customize..." graphviz-dot-customize t] ))) ;;;;
                        Compilation ;; note on
                        graphviz-dot-compilation-parse-errors: ;; It would nicer
                        if we could just use compilation-error-regexp-alist ;;
                        to do that, 3 options: ;; - still write
                        dot-compilation-parse-errors, don't build ;; a return
                        list, but modify the *compilation* buffer ;; in a way
                        compilation-error-regexp-alist recognizes the ;; format.
                        ;; to do that, I should globally change
                        compilation-parse-function ;; to this function, and call
                        the old value of comp..-parse-fun.. ;; to provide the
                        return value. ;; two drawbacks are that, every
                        compilation would be run through ;; this function
                        (performance) and that in autoload there would ;; be a
                        chance that this function would not yet be known. ;; -
                        let the compilation run through a filter that would ;;
                        modify the output of dot or neato: ;; dot -Tpng
                        input.dot | filter ;; drawback: ugly, extra work for
                        user, extra decency ... ;; no-option ;; - modify dot and
                        neato !!! (PP:15/02/2005 seems to have happend, ;; so
                        version 0.4.0 should clean this mess up!) (defun
                        graphviz-dot-compilation-parse-errors (limit-search
                        find-at-least) "Parse the current buffer for dot errors.
                        See variable `compilation-parse-errors-functions' for
                        interface." (interactive) (save-excursion (set-buffer
                        "*compilation*") (goto-char (point-min)) (setq
                        compilation-error-list nil) (let (buffer-of-error)
                        (while (not (eobp)) (cond ((looking-at "^dot\\( -[^
                        ]+\\)* \\(.*\\)") (setq buffer-of-error
                        (find-file-noselect (buffer-substring-no-properties (nth
                        4 (match-data t)) (nth 5 (match-data t))))))
                        ((looking-at ".*:.*line \\([0-9]+\\)") (let
                        ((line-of-error (string-to-number
                        (buffer-substring-no-properties (nth 2 (match-data t))
                        (nth 3 (match-data t)))))) (setq compilation-error-list
                        (cons (cons (point-marker) (save-excursion (set-buffer
                        buffer-of-error) (goto-line line-of-error)
                        (beginning-of-line) (point-marker)))
                        compilation-error-list)))) (t t)) (forward-line 1)) )))
                        ;;;; ;;;; Indentation ;;;; (defun
                        graphviz-dot-uncomment-region (begin end) "Uncomments a
                        region of code." (interactive "r") (comment-region begin
                        end '(4))) (defun graphviz-dot-indent-line () "Indent
                        current line of dot code." (interactive) (if (bolp)
                        (graphviz-dot-real-indent-line) (save-excursion
                        (graphviz-dot-real-indent-line)))) (defun
                        graphviz-dot-real-indent-line () "Indent current line of
                        dot code." (beginning-of-line) (cond ((bobp) ;; simple
                        case, indent to 0 (indent-line-to 0)) ((looking-at "^[
                        \t]*}[ \t]*$") ;; block closing, deindent relative to
                        previous line (indent-line-to (save-excursion
                        (forward-line -1) (max 0 (- (current-indentation)
                        graphviz-dot-indent-width))))) ;; other cases need to
                        look at previous lines (t (indent-line-to
                        (save-excursion (forward-line -1) (cond ((looking-at
                        "\\(^.*{[^}]*$\\)") ;; previous line opened a block ;;
                        indent to that line (+ (current-indentation)
                        graphviz-dot-indent-width)) ((and (not (looking-at
                        ".*\\[.*\\].*")) (looking-at ".*\\[.*")) ; TODO:PP : can
                        be 1 regex ;; previous line started filling ;;
                        attributes, intend to that start (search-forward "[")
                        (current-column)) ((and (not (looking-at
                        ".*\\[.*\\].*")) (looking-at ".*\\].*")) ; TODO:PP : "
                        ;; previous line stopped filling ;; attributes, find the
                        line that started ;; filling them and indent to that
                        line (while (or (looking-at ".*\\[.*\\].*") (not
                        (looking-at ".*\\[.*"))) ; TODO:PP : " (forward-line
                        -1)) (current-indentation)) (t ;; default case, indent
                        the ;; same as previous line (current-indentation)) )))
                        ))) (defun graphviz-dot-indent-graph () "Indent the
                        graph/digraph/subgraph where point is at. This will
                        first teach the beginning of the graph were point is at,
                        and then indent this and each subgraph in it."
                        (interactive) (save-excursion ;; position point at start
                        of graph (while (not (or (looking-at "\\(^.*{[^}]*$\\)")
                        (bobp))) (forward-line -1)) ;; bracket { one +; bracket
                        } one - (let ((bracket-count 0)) (while (progn (cond ;;
                        update bracket-count ((looking-at "\\(^.*{[^}]*$\\)")
                        (setq bracket-count (+ bracket-count 1))) ;; update
                        bracket-count ((looking-at "^[ \t]*}[ \t]*$") (setq
                        bracket-count (- bracket-count 1)))) ;; indent this line
                        and move on (graphviz-dot-indent-line) (forward-line 1)
                        ;; as long as we are not completed or at end of buffer
                        (and (> bracket-count 0) (not (eobp)))))))) ;;;; ;;;;
                        Electric indentation ;;;; (defun
                        graphviz-dot-comment-or-string-p () (let ((state
                        (parse-partial-sexp (point-min) (point)))) (or (nth 4
                        state) (nth 3 state)))) (defun
                        graphviz-dot-newline-and-indent () (save-excursion
                        (beginning-of-line) (skip-chars-forward " \t")
                        (graphviz-dot-indent-line)) (delete-horizontal-space)
                        (newline) (graphviz-dot-indent-line)) (defun
                        electric-graphviz-dot-terminate-line () "Terminate line
                        and indent next line." (interactive) (if
                        graphviz-dot-auto-indent-on-newline
                        (graphviz-dot-newline-and-indent) (newline))) (defun
                        electric-graphviz-dot-open-brace () "Terminate line and
                        indent next line." (interactive) (insert "{") (if (and
                        graphviz-dot-auto-indent-on-braces (not
                        (graphviz-dot-comment-or-string-p)))
                        (graphviz-dot-newline-and-indent))) (defun
                        electric-graphviz-dot-close-brace () "Terminate line and
                        indent next line." (interactive) (insert "}") (if (and
                        graphviz-dot-auto-indent-on-braces (not
                        (graphviz-dot-comment-or-string-p))) (progn
                        (save-excursion (beginning-of-line) (skip-chars-forward
                        " \t") (graphviz-dot-indent-line)) (newline)
                        (graphviz-dot-indent-line)))) (defun
                        electric-graphviz-dot-semi () "Terminate line and indent
                        next line." (interactive) (insert ";") (if (and
                        graphviz-dot-auto-indent-on-semi (not
                        (graphviz-dot-comment-or-string-p)))
                        (graphviz-dot-newline-and-indent))) ;;;; ;;;; Preview
                        ;;;; (defun graphviz-dot-preview () "Shows an example of
                        the current dot file in an emacs buffer. This assumes
                        that we are running GNU Emacs or XEmacs under a
                        windowing system. See `image-file-name-extensions' for
                        customizing the files that can be loaded in GNU Emacs,
                        and `image-formats-alist' for XEmacs." (interactive) ;;
                        unsafe to compile ourself, ask it to the user (if
                        (buffer-modified-p) (message "Buffer needs to be
                        compiled.") (if (string-match "XEmacs" emacs-version) ;;
                        things are easier in XEmacs... (find-file-other-window
                        (concat (file-name-sans-extension buffer-file-name) "."
                        graphviz-dot-preview-extension)) ;; run through all the
                        extensions for images (let ((l
                        image-file-name-extensions)) (while (let ((f (concat
                        (file-name-sans-extension (buffer-file-name)) "." (car
                        l)))) ;; see if a file matches, might be best also to
                        check ;; if file is up to date TODO:PP (if
                        (file-exists-p f) (progn (auto-image-file-mode 1) ;; OK,
                        this is ugly, I would need to ;; know how I can reload a
                        file in an existing buffer (if (get-buffer "*preview*")
                        (kill-buffer "*preview*")) (set-buffer
                        (find-file-noselect f)) (rename-buffer "*preview*")
                        (display-buffer (get-buffer "*preview*")) ;; stop
                        iterating '()) ;; will stop iterating when l is nil
                        (setq l (cdr l))))) ;; each extension tested and nothing
                        found, let user know (when (eq l '()) (message "No image
                        found.")))))) ;;;; ;;;; View ;;;; (defun
                        graphviz-dot-view () "Runs an external viewer. This
                        creates an external process every time it is executed.
                        If `graphviz-dot-save-before-view' is set, the current
                        buffer is saved before the command is executed."
                        (interactive) (let ((cmd (if
                        graphviz-dot-view-edit-command (if (string-match
                        "XEmacs" emacs-version) (read-shell-command "View
                        command: " (format graphviz-dot-view-command
                        (buffer-file-name))) (read-from-minibuffer "View
                        command: " (format graphviz-dot-view-command
                        (buffer-file-name)))) (format graphviz-dot-view-command
                        (buffer-file-name))))) (if graphviz-dot-save-before-view
                        (save-buffer)) (setq novaproc
                        (start-process-shell-command (downcase mode-name) nil
                        cmd)) (message (format "Executing `%s'..." cmd)))) ;;;;
                        ;;;; Completion ;;;; (defvar graphviz-dot-str nil)
                        (defvar graphviz-dot-all nil) (defvar graphviz-dot-pred
                        nil) (defvar graphviz-dot-buffer-to-use nil) (defvar
                        graphviz-dot-flag nil) (defun graphviz-dot-get-state ()
                        "Returns the syntax state of the current point." (let
                        ((state (parse-partial-sexp (point-min) (point)))) (cond
                        ((nth 4 state) 'comment) ((nth 3 state) 'string) ((not
                        (nth 1 state)) 'out) (t (save-excursion
                        (skip-chars-backward "^[,=\\[]{};") (backward-char)
                        (cond ((looking-at "[\\[,]{};") 'attribute) ((looking-at
                        "=") (progn (backward-word 1) (if (looking-at
                        "[a-zA-Z]*color") 'color 'value))) (t 'other)))))))
                        (defun graphviz-dot-get-keywords () "Return possible
                        completions for a word" (let ((state
                        (graphviz-dot-get-state))) (cond ((equal state 'comment)
                        ()) ((equal state 'string) ()) ((equal state 'out)
                        graphviz-attr-keywords) ((equal state 'value)
                        graphviz-value-keywords) ((equal state 'color)
                        graphviz-color-keywords) ((equal state 'attribute)
                        graphviz-attr-keywords) (t graphviz-attr-keywords))))
                        (defvar graphviz-dot-last-word-numb 0) (defvar
                        graphviz-dot-last-word-shown nil) (defvar
                        graphviz-dot-last-completions nil) (defun
                        graphviz-dot-complete-word () "Complete word at current
                        point." (interactive) (let* ((b (save-excursion
                        (skip-chars-backward "a-zA-Z0-9_") (point))) (e
                        (save-excursion (skip-chars-forward "a-zA-Z0-9_")
                        (point))) (graphviz-dot-str (buffer-substring b e))
                        (allcomp (if (and graphviz-dot-toggle-completions
                        (string= graphviz-dot-last-word-shown graphviz-dot-str))
                        graphviz-dot-last-completions (all-completions
                        graphviz-dot-str (graphviz-dot-get-keywords)))) (match
                        (if graphviz-dot-toggle-completions "" (try-completion
                        graphviz-dot-str (mapcar '(lambda (elm) (cons elm 0))
                        allcomp))))) ;; Delete old string (delete-region b e) ;;
                        Toggle-completions inserts whole labels (if
                        graphviz-dot-toggle-completions (progn ;; Update entry
                        number in list (setq graphviz-dot-last-completions
                        allcomp graphviz-dot-last-word-numb (if (>=
                        graphviz-dot-last-word-numb (1- (length allcomp))) 0 (1+
                        graphviz-dot-last-word-numb))) (setq
                        graphviz-dot-last-word-shown (elt allcomp
                        graphviz-dot-last-word-numb)) ;; Display next match or
                        same string if no match was found (if (not (null
                        allcomp)) (insert "" graphviz-dot-last-word-shown)
                        (insert "" graphviz-dot-str) (message "(No match)"))) ;;
                        The other form of completion does not necessarily do
                        that. ;; Insert match if found, or the original string
                        if no match (if (or (null match) (equal match 't))
                        (progn (insert "" graphviz-dot-str) (message "(No
                        match)")) (insert "" match)) ;; Give message about
                        current status of completion (cond ((equal match 't) (if
                        (not (null (cdr allcomp))) (message "(Complete but not
                        unique)") (message "(Sole completion)"))) ;; Display
                        buffer if the current completion didn't help ;; on
                        completing the label. ((and (not (null (cdr allcomp)))
                        (= (length graphviz-dot-str) (length match)))
                        (with-output-to-temp-buffer "*Completions*"
                        (display-completion-list allcomp)) ;; Wait for a
                        keypress. Then delete *Completion* window
                        (momentary-string-display "" (point)) (if
                        graphviz-dot-delete-completions (delete-window
                        (get-buffer-window (get-buffer "*Completions*")))) )))))
                        ;;;###autoload (add-to-list 'auto-mode-alist
                        '("\\.dot\\'" . graphviz-dot-mode)) ;;;
                        graphviz-dot-mode.el ends here