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+;;; mathtools.el --- Style hook for the LaTeX package `mathtools'.
+
+;; Copyright (C) 2011-2020 Free Software Foundation, Inc.
+
+;; Author: Mads Jensen <mje@inducks.org>
+;; Created: 2011-02-13
+;; Keywords: tex
+
+;; This file is part of AUCTeX.
+
+;; AUCTeX is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; AUCTeX 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 AUCTeX; see the file COPYING.  If not, write to the Free
+;; Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+;; 02110-1301, USA.
+
+;;; Commentary:
+
+;;  This file adds support for `mathtools.sty'
+
+;;; Comments:
+
+;;; This package serves as a wrapper for amsmath, adding more features
+;;; and fixing a few bugs in amsmath.  The mathstyle argument for many
+;;; of the macros is discussed at
+;;; <https://www.tug.org/TUGboat/Articles/tb22-4/tb72perlS.pdf>
+
+;;; Code:
+
+;; Needed for auto-parsing:
+(require 'tex)
+
+(eval-when-compile (require 'cl-lib))
+
+;; Silence the compiler:
+(declare-function font-latex-add-keywords
+		  "font-latex"
+		  (keywords class))
+
+(defvar LaTeX-amsmath-package-options)
+
+;; amsmath options which can be passed directly to mathtools are
+;; appended in the style hook below
+(defvar LaTeX-mathtools-package-options
+  '("fixamsmath" "donotfixamsmathbugs" "allowspaces" "disallowspaces"
+    ;; Update 2013: We now make \(\) and \[\] robust (can be disabled
+    ;; via nonrobust package option)
+    "nonrobust")
+  "Package options for the mathtools package.")
+(TeX-load-style "amsmath")
+(dolist (elt LaTeX-amsmath-package-options)
+  (add-to-list 'LaTeX-mathtools-package-options elt))
+
+(defvar LaTeX-mathtools-key-val-options
+  '(("showonlyrefs")
+    ("mathic" ("true" "false"))
+    ("showmanualtags" ("true" "false"))
+    ;; 3.4.1 Matrices
+    ("smallmatrix-align" ("c" "l" "r"))
+    ("smallmatrix-inner-space")
+    ;; 3.4.2 The multlined environment
+    ("firstline-afterskip")
+    ("lastline-preskip")
+    ("multlined-pos" ("c" "b" "t"))
+    ("multlined-width")
+    ;; 3.4.7 Centered \vdots
+    ("shortvdotsadjustabove")
+    ("shortvdotsadjustbelow")
+    ;; 3.5 Intertext and short intertext
+    ("original-intertext" ("true" "false"))
+    ("original-shortintertext" ("true" "false"))
+    ("above-intertext-sep")
+    ("below-intertext-sep")
+    ("above-shortintertext-sep")
+    ("below-shortintertext-sep")
+    ;; 3.7.2 Vertically centered colon
+    ("centercolon" ("true" "false"))
+    ;; 4.2 Left sub/superscripts
+    ("prescript-sub-format")
+    ("prescript-sup-format")
+    ("prescript-arg-format"))
+  "Options for the \\mathtoolsset command.")
+
+;; Setup for \newtagform
+(TeX-auto-add-type "mathtools-newtagform" "LaTeX")
+
+(defvar LaTeX-mathtools-newtagform-regexp
+  '("\\\\newtagform{\\([^}]+\\)}"
+    1 LaTeX-auto-mathtools-newtagform)
+  "Matches the first argument of \\newtagform from mathtools package.")
+
+;; Setup for \DeclarePairedDelimiter(X)?:
+(TeX-auto-add-type "mathtools-DeclarePairedDelimiter" "LaTeX")
+
+(defvar LaTeX-mathtools-DeclarePairedDelimiter-regexp
+  `(,(concat "\\\\DeclarePairedDelimiter\\(?:X\\|XPP\\)?"
+	     "{?"
+	     "\\\\\\([a-zA-Z]+\\)"
+	     "}?"
+	     "\\(?:\\[\\([0-9]+\\)\\]\\)?")
+    (1 2) LaTeX-auto-mathtools-DeclarePairedDelimiter)
+  "Match the arguments of \\DeclarePairedDelimiterX? from mathtools package.")
+
+;; Setup for \newgathered
+(TeX-auto-add-type "mathtools-newgathered" "LaTeX")
+
+(defvar LaTeX-mathtools-newgathered-regexp
+  '("\\\\newgathered{\\([^}]+\\)}"
+    1 LaTeX-auto-mathtools-newgathered)
+  "Matches the first argument of \\newgathered from mathtools package.")
+
+(defun LaTeX-mathtools-auto-prepare ()
+  "Clear various variables for mathtools package before parsing."
+  (setq LaTeX-auto-mathtools-newtagform             nil
+	LaTeX-auto-mathtools-DeclarePairedDelimiter nil
+	LaTeX-auto-mathtools-newgathered            nil))
+
+(defun LaTeX-mathtools-auto-cleanup ()
+  "Process the parsed elements for mathtools package."
+  (when (LaTeX-mathtools-DeclarePairedDelimiter-list)
+    (dolist (delim (LaTeX-mathtools-DeclarePairedDelimiter-list))
+      (let ((cmd (car delim))
+	    (arg (cadr delim)))
+	(TeX-add-symbols `(,cmd [ LaTeX-mathtools-arg-mathsize-completion ]
+				,(if (string= arg "")
+				     1
+				   (string-to-number arg)))
+			 `(,(concat cmd "*")
+			   ,(if (string= arg "")
+				1
+			      (string-to-number arg)))))))
+  (when (LaTeX-mathtools-newgathered-list)
+    (dolist (env (mapcar #'car (LaTeX-mathtools-newgathered-list)))
+      (LaTeX-add-environments env)
+      (add-to-list 'LaTeX-item-list
+		   `(,env . LaTeX-item-equation) t)
+      (add-to-list 'LaTeX-label-alist
+		   `(,env . LaTeX-amsmath-label) t)
+      (when (fboundp 'reftex-add-label-environments)
+	(reftex-add-label-environments `((,env ?e nil nil t)))))))
+
+(add-hook 'TeX-auto-prepare-hook #'LaTeX-mathtools-auto-prepare t)
+(add-hook 'TeX-auto-cleanup-hook #'LaTeX-mathtools-auto-cleanup t)
+(add-hook 'TeX-update-style-hook #'TeX-auto-parse t)
+
+(defun LaTeX-mathtools-arg-mathstyle-completion (optional)
+  "Query and insert mathstyle argument to various commands.
+If OPTIONAL, insert it as optional argument in brackets."
+  (TeX-argument-insert
+   (completing-read
+    (TeX-argument-prompt optional nil
+			 (concat "Math style: " TeX-esc) t)
+    '("displaystyle" "textstyle"
+      "scriptstyle"  "scriptscriptstyle"))
+   optional TeX-esc))
+
+(defun LaTeX-mathtools-arg-mathsize-completion (optional)
+  "Query and insert math size argument to various commands.
+If OPTIONAL, insert it as optional argument in brackets."
+  (TeX-argument-insert
+   (completing-read
+    (TeX-argument-prompt optional nil
+			 (concat "Size command: " TeX-esc) t)
+    '("big" "Big" "bigg" "Bigg"))
+   optional TeX-esc))
+
+(defun LaTeX-mathtools-arg-declarepaireddelimiter (optional &optional X)
+  "Query and insert various \\DeclarePairedDelimiter macros from mathtools package."
+  (let ((cmd (TeX-read-string (concat "Command: " TeX-esc)))
+	(arg (when X (TeX-read-string
+		      (TeX-argument-prompt t nil "Number of arguments")))))
+    (TeX-add-symbols `(,cmd [ LaTeX-mathtools-arg-mathsize-completion ]
+			    ,(if X
+				 ;; This is no precaution, arg has to be > 0
+				 (string-to-number arg)
+			       1))
+		     `(,(concat cmd "*")
+		       ,(if X
+			    (string-to-number arg)
+			  1)))
+    (LaTeX-add-mathtools-DeclarePairedDelimiters
+     `(,cmd ,(if X arg "")))
+    (TeX-argument-insert cmd optional TeX-esc)
+    (when arg
+      (insert (concat LaTeX-optop arg LaTeX-optcl)))))
+
+(defun LaTeX-mathtools-env-multlined (env)
+  "Query and insert two optional arguments for ENV multlined.
+If both arguments are given, insert them in brackets.  If only a
+width is given, insert it prefixed with a pair of empty
+brackets."
+  (let ((pos (TeX-read-string
+	      (TeX-argument-prompt t nil "Position (t, b or c (default))")))
+	(width (completing-read
+		(TeX-argument-prompt t nil "Width")
+		(mapcar
+		 (lambda (x) (concat TeX-esc (car x)))
+		 (LaTeX-length-list)))))
+    (LaTeX-insert-environment
+     env
+     (cond (;; both arguments
+	    (and pos   (not (string= pos ""))
+		 width (not (string= width "")))
+	    (format "[%s][%s]" pos width))
+	   (;; pos not empty, width empty
+	    (and pos (not (string= pos ""))
+		 (string= width ""))
+	    (format "[%s]" pos))
+	   (;; pos empty, width not
+	    (and (string= pos "")
+		 width (not (string= width "")))
+	    (format "[][%s]" width))
+	   (t nil)))))
+
+(defun LaTeX-mathtools-env-cases (env)
+  "Insert various cases ENVs incl. an ampersand from mathtools package."
+  (LaTeX-insert-environment env)
+  (save-excursion
+    (insert ?&)))
+
+(defun LaTeX-mathtools-item-cases ()
+  "Insert contents to terminate a line in multi-line cases environment.
+Put line break macro on the last line.  Next, insert an ampersand."
+  (end-of-line 0)
+  (just-one-space)
+  (TeX-insert-macro "\\")
+  (forward-line 1)
+  (save-excursion
+    (insert ?&)))
+
+;; Fontification
+(require 'texmathp)
+(cl-pushnew '("\\shortintertext" arg-off)
+	    texmathp-tex-commands-default :test #'equal)
+(texmathp-compile)
+
+(TeX-add-style-hook
+ "mathtools"
+ (lambda ()
+
+   ;; Add mathtools to parser
+   (TeX-auto-add-regexp LaTeX-mathtools-newtagform-regexp)
+   (TeX-auto-add-regexp LaTeX-mathtools-DeclarePairedDelimiter-regexp)
+   (TeX-auto-add-regexp LaTeX-mathtools-newgathered-regexp)
+
+   ;; "default" is pre-defined
+   (LaTeX-add-mathtools-newtagforms "default")
+
+   ;; mathtools requires amsmath, as some bugs in amsmath are fixed
+   (TeX-run-style-hooks "amsmath")
+
+   (LaTeX-add-environments
+    ;; 3.4.1 Matrices
+    '("matrix*"  [ "Vertical alignment (l, r or c (default))" ])
+    '("pmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("bmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("Bmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("vmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("Vmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("smallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("psmallmatrix")
+    '("psmallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("bsmallmatrix")
+    '("bsmallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("Bsmallmatrix")
+    '("Bsmallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("vsmallmatrix")
+    '("vsmallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    '("Vsmallmatrix")
+    '("Vsmallmatrix*" [ "Vertical alignment (l, r or c (default))" ])
+    ;; 3.4.2 The multlined environment
+    '("multlined" LaTeX-mathtools-env-multlined)
+    ;; 3.4.3 More cases -like environments
+    '("dcases"   LaTeX-mathtools-env-cases)
+    '("dcases*"  LaTeX-mathtools-env-cases)
+    '("rcases"   LaTeX-mathtools-env-cases)
+    '("rcases*"  LaTeX-mathtools-env-cases)
+    '("drcases"  LaTeX-mathtools-env-cases)
+    '("drcases*" LaTeX-mathtools-env-cases)
+    '("cases*"   LaTeX-mathtools-env-cases)
+    ;; 4.4 Spreading equations
+    '("spreadlines" "Spacing between lines")
+    ;; 4.5 Gathered environments
+    '("lgathered" ["Vertical position (t or b)"])
+    '("rgathered" ["Vertical position (t or b)"]))
+
+   (TeX-add-symbols
+    '("mathtoolsset" (TeX-arg-key-val LaTeX-mathtools-key-val-options))
+    ;; 3.1.1 A complement to \smash, \llap, and \rlap
+    '("mathllap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    '("mathrlap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    '("mathclap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    '("mathmakebox" [ (TeX-arg-length "Width") ] [ "Position" ] 1)
+    '("clap" 1)
+    '("mathmbox" 1)
+    ;; 3.1.2 Forcing a cramped style
+    '("cramped" [ LaTeX-mathtools-arg-mathstyle-completion ] 1)
+    '("crampedllap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    '("crampedrlap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    '("crampedclap" [ LaTeX-mathtools-arg-mathstyle-completion ] t)
+    ;; 3.1.3 Smashing an operator
+    '("smashoperator" [ "Position (l, r or lr (default)" ] 1)
+    ;; 3.1.4 Adjusting the limits of operators
+    '("adjustlimits" t (TeX-arg-literal "_") nil nil (TeX-arg-literal "_") nil)
+    ;; 3.1.5 Swapping space above AMS display math environments
+    '("SwapAboveDisplaySkip" 0)
+    ;; 3.2.1 The appearance of tags
+    '("newtagform"
+      (TeX-arg-eval
+       (lambda ()
+	 (let ((newtag (TeX-read-string
+			(TeX-argument-prompt nil nil "Name"))))
+	   (LaTeX-add-mathtools-newtagforms newtag)
+	   (format "%s" newtag))))
+       [ "Inner format" ] "Left" "Right")
+    '("renewtagform"
+      (TeX-arg-eval completing-read
+		    (TeX-argument-prompt nil nil "Name")
+		    (LaTeX-mathtools-newtagform-list))
+      [ "Inner format" ] "Left" "Right")
+    '("usetagform"
+      (TeX-arg-eval completing-read
+		    (TeX-argument-prompt nil nil "Name")
+		    (LaTeX-mathtools-newtagform-list)))
+    ;; 3.2.2 Showing only referenced tags
+    '("refeq" TeX-arg-ref)
+    '("noeqref" TeX-arg-ref)
+    ;; 3.3.1 Arrow-like symbols
+    '("xleftrightarrow" ["Below"] "Above")
+    '("xLeftarrow" ["Below"] "Above")
+    '("xRightarrow" ["Below"] "Above")
+    '("xLeftrightarrow" ["Below"] "Above")
+    '("xhookleftarrow" ["Below"] "Above")
+    '("xhookrightarrow" ["Below"] "Above")
+    '("xmapsto" ["Below"] "Above")
+    '("xrightharpoondown" ["Below"] "Above")
+    '("xrightharpoonup" ["Below"] "Above")
+    '("xleftharpoondown" ["Below"] "Above")
+    '("xleftharpoonup" ["Below"] "Above")
+    '("xrightleftharpoons" ["Below"] "Above")
+    '("xleftrightharpoons" ["Below"] "Above")
+    ;; 3.3.2 Braces and brackets
+    '("underbracket" [ (TeX-arg-length "Rule thickness") ]
+		     [ (TeX-arg-length "Bracket height") ] t)
+    '("overbracket"  [ (TeX-arg-length "Rule thickness") ]
+		     [ (TeX-arg-length "Bracket height") ] t)
+    '("underbrace" 1)
+    '("overbrace" 1)
+    '("LaTeXunderbrace" 1)
+    '("LaTeXoverbrace" 1)
+    ;; 3.4.2
+    '("shoveleft"  [ (TeX-arg-length "Dimension") ] 1)
+    '("shoveright" [ (TeX-arg-length "Dimension") ] 1)
+    ;; 3.4.4
+    '("MoveEqLeft" [ "Number" ])
+    ;; 3.4.5 Boxing a single line in an alignment
+    '("Aboxed" 1)
+    ;; 3.4.6 Adding arrows between lines in an alignment
+    '("ArrowBetweenLines" [ TeX-arg-macro ] )
+    '("ArrowBetweenLines*" [ TeX-arg-macro ] )
+    ;; 3.4.7 Centered \vdots
+    '("vdotswithin" "Symbol")
+    '("shortvdotswithin" "Symbol")
+    '("shortvdotswithin*" "Symbol")
+    '("MTFlushSpaceAbove")
+    '("MTFlushSpaceBelow")
+    ;; 3.5 Intertext and short intertext
+    ;; don't understand t, but intertext in amsmath.el uses it
+    '("shortintertext" t)
+    ;; 3.6 Paired delimiters
+    '("DeclarePairedDelimiter"
+      LaTeX-mathtools-arg-declarepaireddelimiter
+      "Left delimiter" "Right delimiter")
+    '("DeclarePairedDelimiterX"
+      (LaTeX-mathtools-arg-declarepaireddelimiter t)
+      "Left delimiter" "Right delimiter" t)
+    '("DeclarePairedDelimiterXPP"
+      (LaTeX-mathtools-arg-declarepaireddelimiter t)
+      "Pre-code" "Left delimiter" "Right delimiter" 2)
+    '("delimsize" 0)
+    ;; 3.6.1 Expert use
+    '("reDeclarePairedDelimiterInnerWrapper"
+      (TeX-arg-eval
+       (lambda ()
+	 (let ((cmd (completing-read
+		     (concat "Command: " TeX-esc)
+		     (mapcar #'car (LaTeX-mathtools-DeclarePairedDelimiter-list)))))
+	   (concat TeX-esc cmd))))
+      (TeX-arg-eval completing-read
+		    "star or nostar: "
+		    '("star" "nostar"))
+      t)
+    ;; 3.7.1 Left and right parentheses
+    '("lparen" TeX-arg-insert-right-brace-maybe)
+    '("rparen")
+    ;; 3.7.2 Vertically centered colon
+    "vcentcolon" "ordinarycolon" "coloneqq" "Coloneqq"
+    "coloneq" "Coloneq" "eqqcolon" "Eqqcolon" "eqcolon"
+    "Eqcolon" "colonapprox" "Colonapprox" "colonsim" "Colonsim"
+    "dblcolon"
+    ;; 3.7.3 A few missing symbols
+    "nuparrow" "ndownarrow" "bigtimes"
+    ;; 4.2 Left sub/superscripts
+    '("prescript" "Below" "Above" t)
+    ;; 4.3 Declaring math sizes
+    '("DeclareMathSizes" 4)
+    ;; 4.5 Gathered environments
+    '("newgathered"
+      (TeX-arg-eval
+       (lambda ()
+	 (let ((env (TeX-read-string
+		     (TeX-argument-prompt nil nil "Name"))))
+	   (LaTeX-add-environments env)
+	   (LaTeX-add-mathtools-newgathereds env)
+	   (add-to-list 'LaTeX-item-list
+			`(,env . LaTeX-item-equation) t)
+	   (add-to-list 'LaTeX-label-alist
+			`(,env . LaTeX-amsmath-label) t)
+	   (format "%s" env))))
+      3)
+    '("renewgathered"
+      (TeX-arg-eval completing-read
+		    (TeX-argument-prompt nil nil "Name")
+		    (LaTeX-mathtools-newgathered-list))
+      3)
+    ;; 4.6 Split fractions
+    '("splitfrac" 2)
+    '("splitdfrac" 2))
+
+   ;; Append delimiters to `TeX-braces-association'
+   ;; 3.7.1 Left and right parentheses
+   (make-local-variable 'TeX-braces-association)
+   (add-to-list 'TeX-braces-association '("\\lparen" . "\\rparen") t)
+
+   (setq LaTeX-item-list
+	 (append '(("multlined"   . LaTeX-item-equation)
+		   ("lgathered"   . LaTeX-item-equation)
+		   ("rgathered"   . LaTeX-item-equation)
+		   ("spreadlines" . LaTeX-item-equation)
+		   ("matrix*"     . LaTeX-item-equation)
+		   ("pmatrix*"    . LaTeX-item-equation)
+		   ("bmatrix*"    . LaTeX-item-equation)
+		   ("Bmatrix*"    . LaTeX-item-equation)
+		   ("vmatrix*"    . LaTeX-item-equation)
+		   ("Vmatrix*"    . LaTeX-item-equation)
+		   ("dcases"      . LaTeX-mathtools-item-cases)
+		   ("dcases*"     . LaTeX-mathtools-item-cases)
+		   ("rcases"      . LaTeX-mathtools-item-cases)
+		   ("rcases*"     . LaTeX-mathtools-item-cases)
+		   ("drcases"     . LaTeX-mathtools-item-cases)
+		   ("drcases*"    . LaTeX-mathtools-item-cases)
+		   ("cases*"      . LaTeX-mathtools-item-cases))
+		 LaTeX-item-list))
+
+   (setq LaTeX-label-alist
+	 (append '(("lgathered" . LaTeX-amsmath-label)
+		   ("rgathered" . LaTeX-amsmath-label)
+		   ("multlined" . LaTeX-amsmath-label))
+		 LaTeX-label-alist))
+
+   ;; RefTeX support: Add env's with `reftex-add-label-environments'
+   (when (fboundp 'reftex-add-label-environments)
+     (let ((envs '(("lgathered"  ?e nil nil t)
+		   ("rgathered"  ?e nil nil t)
+		   ("multlined"  ?e nil nil t))))
+       (dolist (env envs)
+	 (reftex-add-label-environments `(,env)))))
+
+   ;; Fontification
+   (when (and (featurep 'font-latex)
+	      (eq TeX-install-font-lock 'font-latex-setup))
+     (font-latex-add-keywords '(("mathtoolsset"  "{")
+				("newtagform"    "{[{{")
+				("renewtagform"  "{[{{")
+				("DeclarePairedDelimiter"     "|{\\{{")
+				("DeclarePairedDelimiterX"    "|{\\[{{{")
+				("DeclarePairedDelimiterXPP"  "|{\\[{{{{{")
+				("reDeclarePairedDelimiterInnerWrapper" "|{\\{{")
+				("DeclareMathSizes"           "{{{{")
+				("newgathered"                "{{{{")
+				("renewgathered"              "{{{{"))
+			      'function)
+     (font-latex-add-keywords '(("usetagform" "{"))
+			      'variable)
+     (font-latex-add-keywords '(("refeq"   "{")
+				("noeqref" "{"))
+			      'reference)))
+ LaTeX-dialect)
+
+;;; mathtools.el ends here