;;; hmouse-tag.el --- Smart Key support of programming language constructs  -*- lexical-binding: t; -*-
;;
;; Author:       Bob Weiner
;;
;; Orig-Date:    24-Aug-91
;; Last-Mod:     28-Jan-24 at 18:36:34 by Bob Weiner
;;
;; SPDX-License-Identifier: GPL-3.0-or-later
;;
;; Copyright (C) 1991-2024  Free Software Foundation, Inc.
;; See the "HY-COPY" file for license information.
;;
;; This file is part of GNU Hyperbole.

;;; Commentary:

;;; Code:
;;; ************************************************************************
;;; Other required Elisp libraries
;;; ************************************************************************

(eval-and-compile
  (mapc #'require '(find-func hpath hui-select))
  (unless (or (featurep 'etags) (featurep 'tags))
    ;; Force use of .elc file here since otherwise the bin/etags
    ;; executable might be found in a user's load-path by the load
    ;; command.
    (load "etags.elc" t nil t)))

(require 'hsys-xref)

;;; ************************************************************************
;;; Public declarations
;;; ************************************************************************

(declare-function br-edit "ext:br")
(declare-function br-edit-feature "ext:br-ftr")
(declare-function python-import-file "ext:br-python-ft")
(declare-function python-to-definition "ext:br-python-ft")

(declare-function epc:manager-server-process "ext:epc")

(declare-function java-to-definition "ext:br-java-ft")

(declare-function jedi:-get-servers-in-use "ext:jedi-core")
(declare-function jedi:goto--line-column "ext:jedi-core")
(declare-function jedi:goto-definition "ext:jedi-core")

(declare-function objc-to-definition "ext:br-objc-ft")

(defvar br-env-spec)
(defvar br-lang-prefix)
(defvar buffer-tag-table)
(defvar jedi-mode)
(defvar jedi:find-file-function) ;; FIXME: RSW customization?
(defvar java-class-def-name-grpn)
(defvar java-class-def-regexp)

(defvar hkey-value)                     ; "hui-mouse.el"

(declare-function hsys-org-get-value "hsys-org")
(declare-function org-in-src-block-p "org")
(declare-function ibtype:def-symbol "hbut")

;;; ************************************************************************
;;; Public variables
;;; ************************************************************************

(defconst find-defact-regexp "^\\s-*(defact\\s-+%s\\s-"
  "The regexp used to search for a Hyperbole action type definition.
Note it must contain a ‘%s’ at the place where ‘format’
should insert the action type definition name.")

(defconst find-defal-regexp "^\\s-*(defal\\s-+%s\\s-"
  "The regexp used to search for a Hyperbole action link type definition.
Note it must contain a ‘%s’ at the place where ‘format’
should insert the action link type definition name.")

(defconst find-defib-regexp "^\\s-*(defib\\s-+%s\\s-"
  "The regexp used to search for a Hyperbole implicit button type definition.
Note it must contain a ‘%s’ at the place where ‘format’
should insert the implicit button type definition name.")

(defconst find-defil-regexp "^\\s-*(defil\\s-+%s\\s-"
  "The regexp used to search for a Hyperbole implicit link type definition.
Note it must contain a ‘%s’ at the place where ‘format’
should insert the implicit link type definition name.")

;; Change ert-deftest lookups to use this regexp rather than the
;; default, `xref-find-definitions', so is not dependent on TAGS
;; tables or the `default-directory' in the ERT results buffer.  When
;; a test is loaded, its symbol property, `ert--test', holds the
;; absolute path to its file, and find-function uses that when its
;; entry in `find-function-regexp-alist' is a regexp.
(defconst find-ert-test-regexp "^\\s-*(ert-deftest\\s-+%s\\s-"
  "The regexp used to search for an ert test definition.
Note it must contain a ‘%s’ at the place where ‘format’
should insert the implicit link type definition name.")

;; Add Hyperbole def types to `find-function-regexp-alist'.
(mapc (lambda (item)
	(setq find-function-regexp-alist
	      (assq-delete-all (car item) find-function-regexp-alist))
	(push item find-function-regexp-alist))
      '((defact    . find-defact-regexp)
	(defal     . find-defal-regexp)
	(defib     . find-defib-regexp)
	(defil     . find-defil-regexp)
	(ert--test . find-ert-test-regexp)))

(define-obsolete-variable-alias 'smart-asm-include-dirs
  'smart-asm-include-path "06.00")
(defcustom smart-asm-include-path nil
  "*Ordered list of directories to search for assembly language include files.
Each directory must end with a directory separator."
  :type '(repeat directory)
  :group 'hyperbole-commands)

(defconst smart-asm-include-regexp
  "[ \t*#|;]*\\(include\\|lib\\)[ \t]+\\([^ \t\n\r]+\\)"
  "Regexp to match to assembly language include file lines.
Include keyword matched is grouping 1.  File name is grouping 2 but may be
missing its suffix, so add \".ins\" or \".inc\" if need be.
Examples include:
       INCLUDE GLOBALS
         should jump to file \"globals.ins\"
       lib conditionals_equ.inc
         should include \"conditionals_equ.inc\"")

(define-obsolete-variable-alias 'smart-c-cpp-include-dirs
  'smart-c-cpp-include-path "06.00")
(defcustom smart-c-cpp-include-path '("/usr/include/")
  "*Ordered list of include directories by default searched by C/C++ preprocessor.
Each directory must end with a directory separator.  See also
`smart-c-include-path'."
  :type '(repeat directory)
  :group 'hyperbole-commands)

(define-obsolete-variable-alias 'smart-c-include-dirs
  'smart-c-include-path "06.00")
(defcustom smart-c-include-path nil
  "*Ordered list of directories to search for C/C++ include files.
Each directory must end with a directory separator.  Directories normally
searched by the C/C++ pre-processor should be set instead in
`smart-c-cpp-include-path'."
  :type '(repeat directory)
  :group 'hyperbole-commands)

(defcustom smart-c-use-lib-man nil
  "Non-nil means `smart-c' and `smart-c++' display man pages for library symbols.
When nil, the default, `smart-c' and `smart-c++' look up only symbols defined in
an etags TAGS file.

Create the file ~/.CLIBS-LIST and populate it with the full pathnames (one per
line) of all of the C/C++ libraries whose symbols you want to match against.
Your MANPATH environment variable must include paths for the man pages of
these libraries also.

Your smart-clib-sym executable script included with Hyperbole
must output a 1 if a symbol is from a C/C++ library listed in
~/.CLIBS-LIST or 0 if not!  Otherwise, don't set this variable to
t."
  :type 'boolean
  :group 'hyperbole-commands)

(defconst smart-c-include-regexp
  "[ \t/*]*#[ \t]*\\(include\\|import\\)[ \t]+\\([\"<]\\)\\([^\">]+\\)[\">]"
  "Regexp to match to C, C++, or Objective-C include file lines.
Include keyword matched is grouping 1.  Type of include, user-specified via
double quote, or system-related starting with `<' is given by grouping 2.
File name is grouping 3.")

(defcustom smart-java-package-path
  (and (fboundp 'getenv) (getenv "JAVA_HOME")
       (list (expand-file-name "src/" (file-name-as-directory (getenv "JAVA_HOME")))))
  "*Ordered list of directories to search for imported Java packages.
Each directory must end with a directory separator."
  :type '(repeat directory)
  :group 'hyperbole-commands)
(define-obsolete-variable-alias 'smart-java-include-dirs
  'smart-java-include-path "06.00")

(defconst smart-java-package-regexp
  "[ \t/*]*\\(package\\|import\\)[ \t]+\\([^; \t\n\r\f]+\\)"
  "Regexp to match to Java `package' and `import' lines.
Keyword matched is grouping 1.  Referent is grouping 2.")

(defcustom smart-emacs-tags-file nil
  "*Full path name of etags file for GNU Emacs source."
  :type '(file :must-match t)
  :group 'hyperbole-commands)

;;; ************************************************************************
;;; Public functions
;;; ************************************************************************

(defun smart-asm (&optional identifier next)
  "Jump to the definition of optional assembly IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching assembly tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If:
 (1) on an include statement, the include file is displayed;
     Look for include file in directory list `smart-asm-include-path';
 (2) on an identifier, the identifier definition is displayed,
     assuming the identifier is found within an `etags' generated tag file
     in the current directory or any of its ancestor directories."

  (interactive)
  (or (if identifier nil (smart-asm-include-file))
      (let ((tag (or identifier (smart-asm-at-tag-p t))))
	(message "Looking for `%s'..." tag)
	(condition-case ()
	    (progn
	      (smart-tags-display tag next)
	      (message "Found definition for `%s'" tag))
	  (error (message "`%s' definition not found in identifier lookup/tag tables" tag)
		 (beep))))))

;;;###autoload
(defun smart-asm-at-tag-p (&optional no-flash)
  "Return assembly tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "_.$a-zA-Z0-9")
	 (identifier (concat "[_.$a-zA-Z][" identifier-chars "]*")))
    (save-excursion
      (skip-chars-backward identifier-chars)
      (if (looking-at identifier)
	  (if no-flash
	      (buffer-substring-no-properties (point) (match-end 0))
	    (smart-flash-tag
	     (buffer-substring-no-properties (point) (match-end 0))
	     (point) (match-end 0)))))))

;;;###autoload
(defun smart-c++ (&optional identifier next)
  "Jump to the definition of optional C++ IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching C++ tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

See the documentation for `c++-to-definition' for the behavior of this
function when the OO-Browser has been loaded.
Otherwise:
 (1) on a `#include' statement, the include file is displayed;
     Look for include file in directory lists `smart-c-cpp-include-path'
     and `smart-c-include-path';
 (2) on a C++ identifier, the identifier definition is displayed,
     assuming the identifier is found within an `etags' generated tag file
     in the current directory or any of its ancestor directories;
 (3) if `smart-c-use-lib-man' is non-nil, the C++ identifier is
     recognized as a library symbol, and a man page is found for the
     identifier, then the man page is displayed."

  (interactive)
  (if (fboundp 'c++-to-definition)
      ;; Only fboundp if the OO-Browser has been loaded.
      (c++-to-definition t)
    (or (if identifier nil (smart-c-include-file))
	(smart-c++-tag identifier next))))

;;;###autoload
(defun smart-c++-tag (&optional identifier next)
  "Jump to the definition of optional C++ IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching C++ tag."
  (let ((tag (or identifier (smart-c++-at-tag-p))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag)
	  t)
      (error
       (if (or (not smart-c-use-lib-man)
	       (not (file-readable-p "~/.CLIBS-LIST")))
	   (progn (message "`%s' definition not found in identifier lookup/tag tables" tag)
		  (beep)
		  nil)
	 (message "Checking if `%s' is a C++ library function..." tag)
	 (if (smart-library-symbol tag)
	     (progn (message "Displaying C++ library man page for `%s'" tag)
		    (manual-entry tag)
		    t)
	   (message "`%s' definition not found in identifier lookup/tag tables or C++ libraries" tag)
	   (beep)
	   nil))))))

(defconst smart-c++-keywords
  '("_pragma" "alignas" "alignof" "and" "and_eq" "asm" "atomic_cancel"
    "atomic_commit " "atomic_noexcept" "auto" "bitand" "bitor" "bool"
    "break" "case" "catch" "char" "char16_t" "char32_t" "class" "compl"
    "concept" "const" "const_cast" "constexpr" "continue" "decltype"
    "default" "define" "defined" "delete" "do" "double" "dynamic_cast"
    "elif" "else" "else" "endif" "enum" "error" "explicit" "export"
    "extern" "false" "final" "float" "for" "friend" "goto" "if" "if"
    "ifdef" "ifndef" "import" "include" "inline" "int" "line" "long"
    "module" "mutable" "namespace" "new" "noexcept" "not" "not_eq"
    "nullptr" "operator" "or" "or_eq" "override" "posix" "pragma"
    "private" "protected" "public" "register" "reinterpret_cast"
    "requires" "return" "short" "signed" "sizeof" "static" "static_assert"
    "static_cast" "std" "struct" "switch" "synchronized" "template" "this"
    "thread_local" "throw" "transaction_safe" "transaction_safe_dynamic"
    "true" "try" "typedef" "typeid" "typename" "undef" "union" "unsigned"
    "using" "virtual" "void" "volatile" "wchar_t" "while" "xor" "xor_eq"))

(defun smart-c++-at-tag-p ()
  "Return C++ tag name that point is within, else nil."
  (let* ((identifier-chars "_:~<>a-zA-Z0-9")
	 (identifier-regexp
	  (concat "\\([_~:<a-zA-Z][" identifier-chars "]*\\)"
		  "\\([ \t]*[^]\) \t:;.,?~{}][^[\( \t:;.,~^!|?{}]?[=*]?\\)?"))
	 op-identifier identifier)
    (save-excursion
      (skip-chars-backward identifier-chars)
      (when (and (looking-at identifier-regexp)
		 (not (member (downcase (match-string 0)) smart-c++-keywords)))
	  ;; Don't flash button here since it was already flashed before
	  ;; this was called.
	(setq op-identifier (buffer-substring-no-properties (match-beginning 0) (match-end 0))
	      identifier (buffer-substring-no-properties (match-beginning 1) (match-end 1)))
	;; Have to allow for identifiers such as, `operator () (int, int)'
	;; yet not include the opening parenthesis in `min ()'.
	(if (string-match "\\<operator\\>" op-identifier)
	    op-identifier
	  identifier)))))

(defun smart-c (&optional identifier next list-of-tags-tables)
  "Jump to the definition of optional C IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching C tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If:
 (1) on a `#include' statement, the include file is displayed;
     Look for include file in directory lists `smart-c-cpp-include-path'
     and `smart-c-include-path';
 (2) on a C identifier, the identifier definition is displayed,
     assuming the identifier is found within an `etags' generated tag file
     in the current directory or any of its ancestor directories;
 (3) if `smart-c-use-lib-man' is non-nil, the C identifier is
     recognized as a library symbol, and a man page is found for the
     identifier, then the man page is displayed."

  (interactive)
  (or (if identifier nil (smart-c-include-file))
      (let ((tag (or identifier (smart-c-at-tag-p t))))
	(message "Looking for `%s'..." tag)
	(condition-case ()
	    (progn
	      (smart-tags-display tag next list-of-tags-tables)
	      (message "Found definition for `%s'" tag))
	  (error
	   (if (or (not smart-c-use-lib-man)
		   (not (file-readable-p "~/.CLIBS-LIST")))
	       (progn (message "`%s' definition not found in identifier lookup/tag tables" tag)
		      (beep))
	     (message "Checking if `%s' is a C library function..." tag)
	     (if (smart-library-symbol tag)
		 (progn (message "Displaying C library man page for `%s'" tag)
			(manual-entry tag))
	       (message "`%s' definition not found in identifier lookup/tag tables or C libraries" tag)
	       (beep))))))))

(defconst smart-c-keywords
  '("_generic" "_pragma" "alignas" "alignof" "asm" "atomic_bool"
    "atomic_char" "atomic_char16_t" "atomic_char32_t" "atomic_int"
    "atomic_int_fast16_t" "atomic_int_fast32_t" "atomic_int_fast64_t"
    "atomic_int_fast8_t" "atomic_int_least16_t" "atomic_int_least32_t"
    "atomic_int_least64_t" "atomic_int_least8_t" "atomic_intmax_t"
    "atomic_intptr_t" "atomic_llong" "atomic_long" "atomic_ptrdiff_t"
    "atomic_schar" "atomic_short" "atomic_size_t" "atomic_uchar"
    "atomic_uint" "atomic_uint_fast16_t" "atomic_uint_fast32_t"
    "atomic_uint_fast64_t" "atomic_uint_fast8_t" "atomic_uint_least16_t"
    "atomic_uint_least32_t" "atomic_uint_least64_t" "atomic_uint_least8_t"
    "atomic_uintmax_t" "atomic_uintptr_t" "atomic_ullong" "atomic_ulong"
    "atomic_ushort" "atomic_wchar_t" "auto" "bool" "break" "case" "char"
    "complex" "const" "continue" "default" "define" "defined" "do"
    "double" "elif" "else" "endif" "enum" "error" "extern" "float"
    "for" "fortran" "goto" "if" "ifdef" "ifndef" "imaginary"
    "include" "inline" "int" "line" "long" "noreturn" "pragma" "register"
    "restrict" "return" "short" "signed" "sizeof" "static" "static_assert"
    "struct" "switch" "thread_local" "typedef" "undef" "union" "unsigned"
    "void" "volatile" "while")
  "Sorted list of C keywords, all in lowercase.")

;;;###autoload
(defun smart-c-at-tag-p (&optional no-flash)
  "Return C tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "_a-zA-Z0-9")
	 (identifier (concat "[_a-zA-Z][" identifier-chars "]*")))
    (save-excursion
      (skip-chars-backward identifier-chars)
      (if (and (looking-at identifier)
	       (not (member (downcase (match-string 0)) smart-c++-keywords)))
	  (if no-flash
	      (buffer-substring-no-properties (point) (match-end 0))
	    (smart-flash-tag
	     (buffer-substring-no-properties (point) (match-end 0))
	     (point) (match-end 0)))))))

;;;###autoload
(defun smart-cc-mode-initialize ()
  "Load and initialize cc-mode if possible and always return nil."
  (ignore-errors (require 'cc-mode) (c-initialize-cc-mode))
  nil)

(defun smart-emacs-lisp-mode-p (&optional skip-identifier-flag)
  "Return non-nil if in a mode using Emacs Lisp symbols."
  ;; Beyond Lisp files, Emacs Lisp symbols appear frequently in Byte-Compiled
  ;; buffers, debugger buffers, program ChangeLog buffers, Help buffers,
  ;; *Warnings*, *Flymake log* and *Flymake diagnostics buffers.
  (or (apply #'derived-mode-p '(emacs-lisp-mode lisp-interaction-mode
				debugger-mode ert-results-mode))
      (string-match-p (concat "\\`\\*\\(Warnings\\|Flymake log\\|Compile-Log\\(-Show\\)?\\)\\*"
			      "\\|\\`\\*Flymake diagnostics")
		      (buffer-name))
      ;; Consider the following buffer types only if on an Emacs Lisp
      ;; symbol that can be looked up, e.g. in a TAGS file or via a
      ;; previous symbol load.
      (and (or (apply #'derived-mode-p '(help-mode change-log-mode))
	       (string-match-p "\\`\\*Help\\|Help\\*\\'" (buffer-name)))
	   (or skip-identifier-flag (smart-lisp-at-known-identifier-p)))))

(defun smart-fortran (&optional identifier next)
  "Jump to the definition of optional Fortran IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Fortran tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If on a Fortran identifier, the identifier definition is displayed,
assuming the identifier is found within an `etags' generated tag file
in the current directory or any of its ancestor directories."
  (interactive)
  (let ((tag (or identifier (smart-fortran-at-tag-p t))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag))
      (error
       (message "`%s' definition not found in identifier lookup/tag tables" tag)
       (beep)))))

(defconst smart-fortran-keywords
  '("abstract" "all" "allocatable" "allocate" "assign" "associate"
    "asynchronous" "backspace" "bind" "block" "block" "call" "case"
    "class" "close" "codimension" "common" "concurrent" "contains"
    "contiguous" "continue" "critical" "cycle" "data" "data" "deallocate"
    "deferred" "dimension" "do" "elemental" "else" "else" "elsewhere"
    "end" "endfile" "endif" "entry" "enum" "enumerator" "equivalence"
    "error" "exit" "extends" "external" "final" "flush" "forall" "format"
    "function" "generic" "goto" "if" "if" "images" "implicit" "import"
    "include" "inquire" "intent" "interface" "intrinsic" "lock" "memory"
    "module" "namelist" "non_overridable" "nopass" "nullify" "only" "open"
    "operator" "optional" "parameter" "pass" "pause" "pointer" "print"
    "private" "procedure" "program" "protected" "public" "pure" "read"
    "recursive" "result" "return" "rewind" "rewrite" "save" "select"
    "sequence" "stop" "stop" "submodule" "subroutine" "sync" "target"
    "then" "unlock" "use" "value" "volatile" "wait" "where" "while"
    "write")
  "Sorted list of Fortran keywords, all in lowercase.")

;;;###autoload
(defun smart-fortran-at-tag-p (&optional no-flash)
  "Return Fortran tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "_a-zA-Z0-9")
	 (identifier (concat "[_a-zA-Z][" identifier-chars "]*")))
    (save-excursion
      (skip-chars-backward identifier-chars)
      (if (looking-at identifier)
	  (if no-flash
	      (buffer-substring-no-properties (point) (match-end 0))
	    (smart-flash-tag
	     (buffer-substring-no-properties (point) (match-end 0))
	     (point) (match-end 0)))))))

;;;###autoload
(defun smart-java (&optional identifier next)
  "Jump to the definition of optional Java IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Java tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

See the documentation for `smart-java-oo-browser' for the behavior of this
function when the OO-Browser has been loaded.
Otherwise:
 (1) within a commented @see cross-reference, the referent is displayed;
 (2) on a `package' or `import' statement, the referent is displayed;
     Look for referent files in the directory list `smart-java-package-path';
 (3) on a Java identifier, the identifier definition is displayed,
     assuming the identifier is found within an `etags' generated tag file
     in the current directory or any of its ancestor directories."

  (interactive)
  (if (fboundp 'java-to-definition)
      ;; Only fboundp if the OO-Browser has been loaded.
      (smart-java-oo-browser)
    (or (if identifier nil (or (smart-java-cross-reference) (smart-java-packages)))
	(smart-java-tag identifier next))))

;;;###autoload
(defun smart-java-tag (&optional identifier next)
  "Jump to the definition of optional Java IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Java tag."
  (let ((tag (or identifier (smart-java-at-tag-p t))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag))
      (error (progn (message "`%s' definition not found in identifier lookup/tag tables" tag)
		    (beep))))))

;;; The following should be called only if the OO-Browser is available.
(defun smart-java-oo-browser (&optional _junk)
  "Jump to the definition of selected Java construct via OO-Browser support.
Optional JUNK is ignored.  Does nothing if the OO-Browser is not available.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If key is pressed:
 (1) within a commented @see cross-reference, the referent is displayed;
 (2) on a `package' or `import' statement, the referent is displayed;
     Look for referent files in the directory list `smart-java-package-path';
 (3) within a method declaration, its definition is displayed;
 (4) on a class name, the class definition is shown;
 (5) on a unique identifier reference, its definition is shown (when possible)."

  (interactive)
  (or (smart-java-cross-reference)
      (smart-java-packages)
      (java-to-definition t)))

(defconst smart-java-keywords
  '("abstract" "assert" "boolean" "break" "byte" "case" "catch" "char"
    "class" "const" "continue" "default" "do" "double" "else" "enum"
    "extends" "final" "finally" "float" "for" "goto" "if" "implements"
    "import" "instanceof" "int" "interface" "long" "native" "new"
    "package" "private" "protected" "public" "return" "short" "static"
    "strictfp" "super" "switch" "synchronized" "this" "throw" "throws"
    "transient" "try" "void" "volatile" "while")
  "Sorted list of Java keywords, all in lowercase.")

;;;###autoload
(defun smart-java-at-tag-p (&optional no-flash)
  "Return Java tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "_$.a-zA-Z0-9")
	 (identifier
	  (concat "[_$a-zA-Z][" identifier-chars "]*")))
    (save-excursion
      (skip-chars-backward identifier-chars)
      (if (and (/= (preceding-char) ?@) (looking-at identifier)
	       (not (member (downcase (match-string 0)) smart-java-keywords)))
	  (if no-flash
	      (buffer-substring-no-properties (point) (match-end 0))
	    (smart-flash-tag
	     (buffer-substring-no-properties (point) (match-end 0))
	     (point) (match-end 0)))))))

;;;###autoload
(defun smart-javascript (&optional identifier next)
  "Jump to the definition of optional JavaScript IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching JavaScript tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If on a JavaScript identifier, the identifier definition is displayed,
assuming the identifier is found within an `etags' generated tag file
in the current directory or any of its ancestor directories."
  (interactive)
  (let ((tag (or identifier (smart-javascript-at-tag-p t))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag))
      (error
       (message "`%s' definition not found in identifier lookup/tag tables" tag)
       (beep)))))

(defconst smart-javascript-keywords
  '("break" "case" "catch" "class" "const" "continue" "debugger"
    "default" "delete" "do" "else" "extends" "export" "false" "finally"
    "for" "function" "if" "in" "instanceof" "import" "let" "new" "null"
    "return" "super" "switch" "this" "throw" "true" "try" "typeof" "var"
    "void" "while" "with" "yield")
  "Sorted list of JavaScript keywords, all in lowercase.")

;;;###autoload
(defun smart-javascript-at-tag-p (&optional no-flash)
  "Return JavaScript tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (if (if (memq major-mode '(html-mode web-mode))
	  ;; Must be within a <script> tag or this predicate function
	  ;; fails (returns nil).
	  (save-excursion (if (re-search-backward "<\\(/?script\\)[\> \t\n]" nil t)
			      (string-equal (match-string 1) "script")))
	t)
      (let* ((identifier-chars "_$a-zA-Z0-9")
	     (identifier (concat "[_$a-zA-Z][" identifier-chars "]*")))
	(save-excursion
	  (skip-chars-backward identifier-chars)
	  (and (looking-at identifier)
	       (not (member (downcase (match-string 0)) smart-javascript-keywords))
	  (if no-flash
	      (buffer-substring-no-properties (point) (match-end 0))
	    (smart-flash-tag
	     (buffer-substring-no-properties (point) (match-end 0))
	     (point) (match-end 0))))))))

;;;###autoload
(defconst smart-lisp-identifier-first-char-regexp "[-<>*a-zA-Z]"
  "Regexp matching the first character of a Lisp identifier.")

;;;###autoload
(defconst smart-lisp-identifier-chars "-_:/*+=%$&?!<>a-zA-Z0-9~^@"
  "Regexp matching a valid char in a Lisp identifier except the first char.
Excludes character matching square brackets, so may be used with
skip-characters-forward/backward.")

;;;###autoload
(defconst smart-lisp-identifier (concat smart-lisp-identifier-first-char-regexp
					"[" smart-lisp-identifier-chars "]*")
  "Regexp matching a Lisp identifier.")

(defun smart-lisp (&optional show-doc)
  "Jump to the definition of any selected Lisp identifier or optionally SHOW-DOC.

Assume caller has checked that (smart-emacs-lisp-mode-p) is true.

If on an Emacs Lisp require, load, or autoload clause and the
`find-library' function from the \"load-library\" package has
been loaded, this jumps to the library source whenever possible.

Otherwise, if a definition for the identifier is found within a TAGS
file in the current directory or any of its ancestor directories, this
jumps to the definition.  Supports Hyperbole implicit button types and
action types.

With optional SHOW-DOC flag, show documentation for the tag at point
rather than displaying its source code definition.  In this case, tag
must be a bound or fbound symbol or it is ignored.

This command assumes that its caller has already checked that the key was
pressed in an appropriate buffer and has moved the cursor to the selected
buffer."

  (interactive)
  (unless (and (fboundp 'find-library)
	       ;; Handle Emacs Lisp `require', `load', and `autoload' clauses.
	       (let ((opoint (point))
		     type
		     name
		     lib)
		 (setq lib (and (search-backward "\(" nil t)
				(or
				 ;; load with a filename
				 (looking-at "(\\(load\\)[ \t]+\\(\\)\"\\([^][() \t\n\r`'\"]+\\)")
				 ;; autoload or require with a name and filename
				 (looking-at "(\\(autoload\\|require\\)[ \t]+'\\([^][() \t\n\r`'\"]+\\)[ \t\n\r]+\"\\([^][() \t\n\r`'\"]+\\)")
				 ;; require without a separate filename
				 (looking-at "(\\(require\\)\\(\\)[ \t]+'\\([^][() \t\n\r`'\"]+\\)"))))
		 (goto-char opoint)
		 (when lib
		   (setq type (match-string-no-properties 1)
			 name (match-string-no-properties 2)
			 lib (match-string-no-properties 3))
		   (hpath:display-buffer (current-buffer))
		   (find-library lib)
		   (goto-char (point-min))
		   (when (equal type "autoload")
		     ;; Ignore defgroup matches
		     (if (re-search-forward
			  (format "^[; \t]*(def.[^r][^ \t\n\r]*[ \t]+%s[ \t\n\r]" (regexp-quote name))
			  nil t)
			 (goto-char (match-beginning 0))
		       (error "(smart-lisp): Found autoload library but no definition for `%s'" name)))
		   t)))
    (smart-lisp-find-tag nil show-doc)))

(defun smart-lisp-find-tag (&optional tag show-doc)
  "Find the definition of optional Lisp TAG or show its documentation.
Use identifier at point when TAG is nil.  With optional prefix
arg SHOW-DOC non-nil, show its documentation.
Use `hpath:display-buffer' to show definition or documentation."
  (interactive
   (list (read-string (format "%s Lisp identifier: "
			      (if current-prefix-arg
				  "Show doc for" "Find")))
	 current-prefix-arg))
  (when (and tag (symbolp tag))
    (setq tag (symbol-name tag)))
  (unless (stringp tag)
    (setq tag (if (stringp hkey-value) hkey-value (smart-lisp-at-tag-p t))))
  (let* ((elisp-flag (smart-emacs-lisp-mode-p))
	 (tag-sym (intern-soft tag)))
    (cond ((and show-doc elisp-flag)
	   ;; Emacs Lisp function, variable and face documentation display.
	   (cond ((fboundp tag-sym) (describe-function tag-sym))
		 ((and tag-sym (boundp tag-sym)) (describe-variable tag-sym))
		 ((facep tag-sym) (describe-face tag-sym))
		 (tag-sym
		  ;; Handles ert test definitions, as one example.
		  (describe-symbol tag-sym))
		 ;; Ignore unbound symbols if displaying doc.
		 (t nil)))

	  ((and elisp-flag (fboundp 'find-function-noselect)
		(let ((result (smart-lisp-bound-symbol-def tag-sym)))
		  (when (and (cdr result)
			     (hpath:display-buffer (car result)))
		    (widen)
		    (goto-char (cdr result))
		    t))))

	  ;; If elisp-flag is true and tag-sym is a bound ert test
	  ;; symbol, then make xref use tags tables rather than its
	  ;; elisp backend since that does not support ert test
	  ;; symbols.  Otherwise, use standard xref backends for the
	  ;; current language.
	  (t (let ((etags-mode (and elisp-flag
				    (fboundp 'ert-test-boundp)
				    (ert-test-boundp tag-sym)
				    (boundp 'xref-etags-mode)
				    xref-etags-mode)))
	       (unwind-protect
		   (progn
		     (and (not etags-mode) elisp-flag (fboundp 'xref-etags-mode)
			  (xref-etags-mode 1))
		     (condition-case ()
			 ;; Tag of any language
			 (when (featurep 'etags)
			   (smart-tags-display tag show-doc))
		       (error (unless (and elisp-flag (stringp smart-emacs-tags-file)
					   (condition-case ()
					       (smart-tags-display
						tag show-doc (list smart-emacs-tags-file))
					     (error nil)))
				(error "(smart-lisp): No definition found for `%s'" tag)))))
		 (and (not etags-mode) elisp-flag (fboundp 'xref-etags-mode)
		      (xref-etags-mode 0))))))))

(defun smart-lisp-at-definition-p ()
  "Return non-nil if point is on the first line of a non-alias Lisp definition.
Apply only to non-help buffers and return nil in others."
    (unless (derived-mode-p 'help-mode)
      (save-excursion
	(beginning-of-line)
	;; Exclude any define- lines.
	(and (looking-at "\\(;*[ \t]*\\)?(\\(ert-\\)?def[[:alnum:]]+[[:space:]]")
	     ;; Ignore alias definitions since those typically have symbol tags to lookup.
	     (not (looking-at "\\(;*[ \t]*\\)?(def[^ \t\n\r]*alias"))
	     ;; Ignore lines that start with (default
	     (not (looking-at "\\(;*[ \t]*\\)?(default"))))))

(defun smart-lisp-at-load-expression-p ()
  "Return t if on the first line of a Lisp library load expression, else nil."
    (save-excursion
      (beginning-of-line)
      (looking-at "\\(;*[ \t]*\\)?(\\(autoload\\|load\\|require\\)\\s-")))

(defun smart-lisp-at-change-log-tag-p ()
  "When in change-log mode, match to bound Elisp identifiers only.
Also match to identifiers with a '-' in the middle.
These tight tests help eliminate undesired matches.
Return matching Elisp tag name that point is within, else nil."
  (when (derived-mode-p 'change-log-mode)
    (let ((identifier (smart-lisp-at-tag-p)))
      (and identifier (intern-soft identifier)
	   (string-match-p "[^-]-[^-]" identifier)
	   identifier))))

(defun smart-lisp-htype-tag (tag)
  "Given TAG at point, if a Hyperbole type, return the full symbol name, else TAG."
  (setq tag (cond ((and tag (string-match-p "::" tag))
		   tag)
		  ((and tag
			(save-excursion
			  (skip-chars-backward "^ \t\n\r\f")
			  (skip-chars-backward " \t\n\r\f")
			  (equal (smart-lisp-at-non-htype-tag-p t) "hact")))
		   ;; If tag is preceded by an 'hact' call, then treat as a Hyperbole actype.
		   (or (symtable:actype-p tag) tag))
		  (tag
		   (let ((tag-sym (intern-soft tag)))
		     ;; The partial names of htypes will be interned
		     ;; but not fboundp or boundp.
		     (if (and tag-sym (or (fboundp tag-sym) (boundp 'tag-sym)))
			 tag
		       (or (symtable:ibtype-p tag) (symtable:actype-p tag) tag))))))
  (cond ((or (null tag) (stringp tag))
	 tag)
	((symbolp tag)
	 (symbol-name tag))))

(defun smart-lisp-at-tag-p (&optional no-flash)
  "Return possibly non-existent Lisp tag name that point is within, else nil.
When optional NO-FLASH, do not flash.  Return nil when point is
on the first line of a non-alias Lisp definition.

Resolve Hyperbole implicit button type and action type references."
  (smart-lisp-htype-tag
   (smart-lisp-at-non-htype-tag-p no-flash)))

(defun smart-lisp-at-non-htype-tag-p (&optional no-flash)
  "Return possibly non-existent Lisp tag name that point is within, else nil.
When optional NO-FLASH, do not flash.  Return nil when point is
on the first line of a non-alias Lisp definition."
  (unless (smart-lisp-at-definition-p)
    (save-excursion
      (skip-chars-backward smart-lisp-identifier-chars)
      ;; Ignore double quoted strings and environment variables: $PATH, ${PATH}, $(PATH), {$PATH}, ($PATH)
      (unless (save-excursion
		(skip-chars-backward "[\"${(]")
		(looking-at "\"\\|\\$[{(]\\|[{]\\$]"))
	(when (and (looking-at smart-lisp-identifier)
		   ;; Ignore any punctuation matches.
		   (not (string-match-p "\\`[-<>*]+\\'" (match-string 0))))
	  ;; Ignore any leading '<' character from action buttons or
	  ;; other links, i.e. only when followed by an alphabetic character.
	  (let* ((action-button-prefix-flag
		  (and (eq (following-char) ?\<)
		       (memq (char-syntax (1+ (point))) '(?_ ?w))))
		 (suffix-flag
		  (or (eq (char-after (1- (match-end 0))) ?:)
		      (and action-button-prefix-flag
			   (eq (char-after (1- (match-end 0))) ?\>)))))
	    (when action-button-prefix-flag
	      (goto-char (1+ (point))))
	    (if no-flash
		(if suffix-flag
		    (buffer-substring-no-properties (point) (1- (match-end 0)))
		  (buffer-substring-no-properties (point) (match-end 0)))
	      (if suffix-flag
		  (smart-flash-tag
		   (buffer-substring-no-properties (point) (1- (match-end 0)))
		   (point) (1- (match-end 0)))
		(smart-flash-tag
		 (buffer-substring-no-properties (point) (match-end 0))
		 (point) (match-end 0))))))))))

;;;###autoload
(defun smart-lisp-mode-p ()
  "Return t if in a mode which use Lisp symbols."
  (or (smart-emacs-lisp-mode-p)
      (apply #'derived-mode-p '(lisp-mode scheme-mode))))

;;;###autoload
(defun smart-objc (&optional identifier next)
  "Jump to the definition of optional Objective-C IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Objective-C tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

See the documentation for `smart-objc-oo-browser' for the behavior of this
function when the OO-Browser has been loaded.
Otherwise:
 (1) on a `#include' statement, the include file is displayed;
     Look for include file in directory lists `objc-cpp-include-path' and
     `objc-include-path';
 (2) on an Objective-C identifier, the identifier definition is displayed,
     assuming the identifier is found within an `etags' generated tag file
     in the current directory or any of its ancestor directories;
 (3) if `smart-c-use-lib-man' is non-nil, the Objective-C identifier is
     recognized as a library symbol, and a man page is found for the
     identifier, then the man page is displayed."

  (interactive)
  
  (if (fboundp 'objc-to-definition)
      ;; Only fboundp if the OO-Browser has been loaded.
      (smart-objc-oo-browser)
    (or (if identifier nil (smart-c-include-file))
	(smart-objc-tag identifier next))))

;;;###autoload
(defun smart-objc-tag (&optional identifier next)
  (let ((tag (or identifier (smart-objc-at-tag-p t))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag))
      (error
       (if (or (not smart-c-use-lib-man)
	       (not (file-readable-p "~/.CLIBS-LIST")))
	   (progn (message "`%s' definition not found in identifier lookup/tag tables" tag)
		  (beep))
	 (message
	  "Checking if `%s' is an Objective-C library function..." tag)
	 (if (smart-library-symbol tag)
	     (progn
	       (message
		"Displaying Objective-C library man page for `%s'" tag)
	       (manual-entry tag))
	   (message "`%s' definition not found in identifier lookup/tag tables or Objective-C libraries"
		    tag)
	   (beep)))))))

;;; The following should be called only if the OO-Browser is available.
(defun smart-objc-oo-browser (&optional _junk)
  "Jump to the definition of selected Objective-C construct via OO-Browser support.
Optional JUNK is ignored.  Does nothing if the OO-Browser is not available.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If key is pressed:
 (1) on a `#include' statement, the include file is displayed;
     Look for include file in directory lists `smart-c-cpp-include-path'
     and `smart-c-include-path';
 (2) within a method declaration, its definition is displayed;
 (3) on a class name, the class definition is shown;
 (4) on a global variable or function identifier, its definition is shown.

 (2) and (3) require that an OO-Browser Environment has been loaded with
     the {\\`M-x' br-env-load RET} command."

  (interactive)
  (objc-to-definition t))

(defconst smart-objc-keywords
  (append '("bycopy" "byref" "id" "in" "inout" "oneway" "out" "self" "super")
	  smart-c-keywords)
  "Sorted list of Objective-C keywords, all in lowercase.")

(defun smart-objc-at-tag-p (&optional no-flash)
  "Return Objective-C tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "_a-zA-Z0-9")
	 (identifier
	  (concat "\\([-+][ \t]*\\)?\\([_a-zA-Z][" identifier-chars "]*\\)")))
    (save-excursion
      (skip-chars-backward identifier-chars)
      (if (and (/= (preceding-char) ?@) (looking-at identifier)
	       (not (member (downcase (match-string 0)) smart-objc-keywords)))
	  (if no-flash
	      (buffer-substring-no-properties (match-beginning 2) (match-end 2))
	    (smart-flash-tag
	     (buffer-substring-no-properties (match-beginning 2) (match-end 2))
	     (match-beginning 2) (match-end 2)))))))

(defun smart-jedi-find-file (file line column other-window)
  "Function that read a source FILE for jedi navigation.
It takes these arguments: (file-to-read other-window-flag
line_number column_number)."
  (hpath:display-buffer (find-file file) other-window)
  (jedi:goto--line-column line column))

(defun smart-python-jedi-to-definition-p ()
  "If Jedi Python identifier server is running, use it to jump to the definition.
See https://tkf.github.io/emacs-jedi/latest/."
  ;; Use functions from jedi-core.el only, not from jedi.el, since
  ;; company-jedi.el users will have loaded only jedi-core.el.
  (when (and (featurep 'jedi-core) jedi-mode)
    (let* ((servers (jedi:-get-servers-in-use))
	   (proc (epc:manager-server-process (car servers))))
      (and servers (processp proc)
	   (eq 'run (process-status (process-buffer proc)))
	   ;; The goto is performed asynchronously.
	   ;; It reports in the minibuffer when a definition is not found.
	   ;; !! TODO: Only works on tag at point, not the tagname passed in as jedi
	   ;; does not accept a tag parameter.
	   ;;
	   ;; jedi:find-file-function is an RSW custom
	   ;; modification that allows display-where to work;
	   ;; otherwise, will just display in another window.
	   (let ((jedi:find-file-function #'smart-jedi-find-file))
	     (jedi:goto-definition hpath:display-where)
	     ;; For use as a predicate, always return t if the Jedi server
	     ;; is running  so other lookup techniques are not tried.
	     t)))))

;;;###autoload
(defun smart-python (&optional identifier next)
  "Jump to the definition of optional Python IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Python tag.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

See the documentation for `smart-python-jedi-to-definition-p' for the
behavior when the Jedi python identifier server is in use.

See the documentation for `smart-python-oo-browser' for the behavior of this
function when the OO-Browser has been loaded.

Otherwise, on a Python identifier, the identifier definition is displayed,
assuming the identifier is found within an `etags' generated tag file
in the current directory or any of its ancestor directories."
  (interactive)
  (cond ((smart-python-jedi-to-definition-p))
	((fboundp 'python-to-definition)
	 ;; Only fboundp if the OO-Browser has been loaded.
	 (smart-python-oo-browser))
	(t
	 (smart-python-tag identifier next))))

;;;###autoload
(defun smart-python-tag (&optional identifier next)
  "Jump to the definition of optional Python IDENTIFIER or the one at point.
Optional second arg NEXT means jump to next matching Python tag."
  (let ((tag (or identifier (smart-python-at-tag-p t))))
    (message "Looking for `%s'..." tag)
    (condition-case ()
	(progn
	  (smart-tags-display tag next)
	  (message "Found definition for `%s'" tag))
      (error (progn (message "`%s' definition not found in identifier lookup/tag tables" tag)
		    (beep))))))

;;; The following should be called only if the OO-Browser is available.
(defun smart-python-oo-browser (&optional _junk)
  "Jump to the definition of selected Python construct via OO-Browser support.
Optional JUNK is ignored.  Does nothing if the OO-Browser is not available.

It assumes that its caller has already checked that the key was pressed in an
appropriate buffer and has moved the cursor to the selected buffer.

If key is pressed:
 (1) on an `import' line, the referent is displayed;
 (2) within a method declaration, its definition is displayed;
 (3) on a class name, the class definition is shown;
 (4) on a unique identifier reference, its definition is shown (when possible)."
  (interactive)
  (or (python-import-file t)
      (python-to-definition t)))

(defconst smart-python-keywords
  '("and" "as" "assert" "break" "class" "continue" "def" "del" "elif"
    "else" "except" "false" "finally" "for" "from" "global" "if"
    "import" "in" "is" "lambda" "none" "nonlocal" "not" "or" "pass"
    "raise" "return" "true" "try" "while" "with" "yield")
  "Sorted list of Python keywords, all in lowercase.")

;;;###autoload
(defun smart-python-at-tag-p (&optional no-flash)
  "Return Python tag name that point is within, else nil.
When optional NO-FLASH, do not flash."
  (let* ((identifier-chars "a-zA-Z0-9_")
	 (identifier-fragment (concat "[a-zA-Z_][" identifier-chars "]*"))
	 (identifier (concat identifier-fragment "\\(\\."
			     identifier-fragment "\\)*"))
	 start end tag)
    (save-excursion
      ;; Allow for name1.name2.module tags.
      (while (and (/= (skip-chars-backward identifier-chars) 0)
		  (/= (skip-chars-backward "\.") 0)))
      (when (= (following-char) ?.)
	(forward-char 1))
      (setq start (point))
      (while (and (/= (skip-chars-forward identifier-chars) 0)
		  (/= (skip-chars-forward "\.") 0)))
      (when (= (preceding-char) ?.)
	(backward-char 1))
      (setq end (point))
      (goto-char start)
      (setq tag (buffer-substring-no-properties start end))
      (if (and (looking-at identifier)
	       (not (member (downcase tag) smart-python-keywords)))
	  (if no-flash
	      tag
	    (smart-flash-tag tag start end))))))

;;; ************************************************************************
;;; Private functions
;;; ************************************************************************

(defun smart-ancestor-tag-files (&optional path name-of-tags-file)
  "Walk up PATH tree looking for NAME-OF-TAGS-FILE.
Return list from furthest to deepest (nearest)."
  (or path (setq path default-directory))
  (let ((tags-table-list)
	tags-file)
    (while (and
	    (stringp path)
	    (setq path (file-name-directory path))
	    (setq path (directory-file-name path))
	    ;; Not at root directory
	    (not (string-match
		  (concat (file-name-as-directory ":?") "\\'")
		  path)))
      (setq tags-file (expand-file-name (or name-of-tags-file "TAGS") path))
      (if (file-readable-p tags-file)
	  (setq tags-table-list (cons tags-file tags-table-list))))
    tags-table-list))

(defun smart-asm-include-file ()
  "If point is on an include file line, try to display file.
Returns non-nil iff on an include file line, even if file is not found.
Look for include file in `smart-asm-include-path' and add suffix \".ins\" or
\".inc\" to filename if it lacks a suffix."
  (let ((opoint (point)))
    ;; Some assemblers utilize the C preprocessor, so try that first.
    (cond ((smart-c-include-file))
	  ((progn (beginning-of-line)
		  (looking-at smart-asm-include-regexp))
	   (let ((file (buffer-substring-no-properties (match-beginning 2) (match-end 2)))
		 (path)
		 (dir-list smart-asm-include-path))
	     (goto-char opoint)
	     (setq dir-list (cons (file-name-directory buffer-file-name)
				  dir-list))
	     (if (string-match "\\." file)
		 (setq file (regexp-quote file))
	       (setq file (concat (regexp-quote file) "\\.in[sc]$")))
	     (while dir-list
	       (setq dir-list
		     (if (setq path (car (directory-files
					  (car dir-list) t file)))
			 nil
		       (cdr dir-list))))
	     ;;
	     ;; If path exists, display file
	     ;;
	     (if path
		 (unless (and (file-readable-p path)
			      (progn
				(hpath:find path)
				(or (require 'asm-mode nil t)
				    (progn (message "(smart-asm-include-file):  asm-mode undefined")
					   nil))))
		   (beep)
		   (message "(smart-asm-include-file):  `%s' unreadable" path))
	       (beep)
	       (message "(smart-asm-include-file):  `%s' not found" file))
	     path))
	  ;; not on an include file line
	  (t (goto-char opoint)
	     nil))))

(defun smart-c-include-file ()
  "If point is on an include file line, try to display file.
Returns non-nil iff on an include file line, even if file is not found.
Look for include file in `smart-c-cpp-include-path' and in directory list
`smart-c-include-path'."
  (let ((opoint (point)))
    (beginning-of-line)
    (if (looking-at smart-c-include-regexp)
	(let ((incl-type (string-to-char
			  (buffer-substring-no-properties (match-beginning 2)
							  (1+ (match-beginning 2)))))
	      (file (buffer-substring-no-properties (match-beginning 3) (match-end 3)))
	      (path)
	      (dir-list smart-c-include-path)
	      (found))
	  (goto-char opoint)
	  (setq dir-list (if (eq incl-type ?<)
			     (append dir-list smart-c-cpp-include-path)
			   (cons (file-name-directory buffer-file-name)
				 dir-list)))
	  (while dir-list
	    (setq path (expand-file-name file (car dir-list))
		  dir-list (if (setq found (file-exists-p path))
			       nil
			     (cdr dir-list))))
	  ;;
	  ;; If found, display file
	  ;;
	  (if found
	      (if (and (file-readable-p path)
		       (progn
			 (hpath:find path)
			 (or (require 'cc-mode nil t)
			     (progn (beep)
				    (message "(smart-c-include-file):  c-mode undefined")
				    nil))))
		  (smart-cc-mode-initialize)
		(beep)
		(message "(smart-c-include-file):  `%s' unreadable" path))
	    (beep)
	    (message "(smart-c-include-file):  `%s' not found" file))
	  path)
      (goto-char opoint)
      nil)))

(defun smart-flash-tag (tag start end)
  "Try to flash TAG at START to END in current buffer and return TAG.
This indicates that TAG is serving as a hyperlink button."
  ;; Button flashing code might not yet have been loaded if the whole
  ;; Hyperbole system has not been started.
  (when (and (fboundp 'hui:but-flash)
	     (fboundp 'ibut:label-set))
    (ibut:label-set tag start end)
    (hui:but-flash))
  tag)

(defun smart-lisp-at-known-identifier-p ()
  "Return identifier if point is within a known Lisp identifier, else nil.
The Lisp identifier is either listed in a tags table or is a
known Emacs Lisp identifier."
  (interactive)
  (unless (and (fboundp 'find-library)
	       ;; Handle Emacs Lisp `require', `load', and `autoload' clauses.
	       (let ((lib)
		     (opoint (point)))
		 (setq lib (and (re-search-backward "[()]" nil t)
				(looking-at (concat
					     "(\\(require\\|load\\|autoload\\)"
					     "[ \t]+.*['\"]"
					     "\\([^][() \t\n\r`'\"]+\\)"))))
		 (goto-char opoint)
		 (when lib
		   (ignore-errors (and (find-library-name lib) t)))))
    ;; Cache tag value
    (setq hkey-value (smart-lisp-at-tag-p t))
    (let* ((tag hkey-value)
	   (tag-sym (intern-soft tag)))
      (cond ((and (fboundp 'ert-test-boundp) (ert-test-boundp tag-sym))
	     tag)
	    ((when (and (fboundp 'find-function-noselect) tag-sym)
	       (let ((result (smart-lisp-bound-symbol-def tag-sym)))
		 (when (cdr result)
		   tag))))
	    ;; This part only works properly for Emacs Lisp, so is conditionalized.
	    ((and tag (smart-tags-find-p tag) tag))))))

(defun smart-lisp-bound-symbol-def (tag-sym)
  "Return a pair (buffer . point) where TAG-SYM is defined, else nil.
The buffer may be attached to a .elc file.  TAG-SYM may be a function,
variable or face."
  (save-excursion
    ;; Bound Emacs Lisp function, variable and face definition display.
    (ignore-errors (or (let ((func-lib (find-function-library tag-sym nil t))
			     tag-type ;; nil means regular Lisp function
			     tag-name)
			 (when func-lib
			   (setq tag-sym (car func-lib)
				 tag-name (symbol-name tag-sym))
			   (cond ((string-prefix-p "ibtypes::" tag-name)
				  (setq tag-type 'defib
					tag-sym (ibtype:def-symbol tag-sym)))
				 ((string-prefix-p "actypes::" tag-name)
				  (setq tag-type 'defact
					tag-sym (actype:def-symbol tag-sym))))
			   (find-function-search-for-symbol tag-sym tag-type (cdr func-lib))))
		       (find-variable-noselect tag-sym)
		       (find-definition-noselect tag-sym 'defface)))))

(defun smart-tags-find-p (tag)
  "Return non-nil if TAG is found within a tags table, else nil."
  (let* ((tags-table-list (smart-entire-tags-table-list))
	 (func (smart-tags-noselect-function))
	 (tags-file-name (if tags-table-list
			     nil
			   (and (boundp 'tags-file-name) tags-file-name)))
	 (tags-add-tables nil))
    (ignore-errors (and func (funcall func tag) t))))

(defun smart-java-cross-reference ()
  "If within a Java @see comment, edit the def and return non-nil, else nil.
Non-nil is returned even if the @see referent cannot be found.

Does nothing if the `oo-browser' command is undefined, since it requires that
package for class and feature lookups."
  ;;
  ;; Valid forms of @see cross-references are:
  ;;    * @see #getComponent                        - current class attribute
  ;;    * @see #waitForAll()                        - current class method, no arguments
  ;;    * @see #checkID(int, boolean)               - current class method, with arguments
  ;;    * @see java.awt.ColorModel#getRGBdefault    - library class method
  ;;    * @see Component#paintAll                   - class method
  ;;    * @see java.awt.GridBagLayout               - library class
  ;;    * @see Container                            - class
  ;;
  ;; For simplicity sake, this code ignores the library path given with any
  ;; class in favor of the OO-Browser's lookup tables.  It also ignores any
  ;; parameters associated with a method, and thus cannot distinguish between
  ;; methods with the same name within a single class, which we believe to be
  ;; fairly bad form anyway.
  ;;
  (let ((opoint (point)))
    (if (and (eq major-mode 'java-mode) buffer-file-name
	     (fboundp 'br-env-load)
	     (or (looking-at "@see[ \t]+")
		 (and (re-search-backward "[@\n\r\f]" nil t)
		      (looking-at "@see[ \t]+"))))
	(let ((class) (feature))
	  ;; Ignore any library path preceding a classname (grouping 1)
	  (cond
	   ((looking-at
	     "@see[ \t]+\\(#\\)?\\([^][(){} \t\n\r\f#]+[.]\\)?\\([^][(){} \t\n\r\f#.]+\\)[][(){} \t\n\r\f]")
	    (if (match-beginning 1)
		(setq class nil
		      feature (buffer-substring-no-properties (match-beginning 3)
							      (match-end 3)))
	      (setq class (buffer-substring-no-properties (match-beginning 3) (match-end 3))
		    feature nil)))
	   ((looking-at
	     "@see[ \t]+\\([^][(){} \t\n\r\f#]+[.]\\)?\\([^][(){} \t\n\r\f#.]+\\)#\\([^][(){} \t\n\r\f#.]+\\)")
	    (setq class (buffer-substring-no-properties (match-beginning 2)
							(match-end 2))
		  feature (buffer-substring-no-properties (match-beginning 3)
							  (match-end 3)))))
	  ;; Return to original point.
	  (goto-char opoint)
	  ;; Lookup class / feature.
	  (cond
	   ((and (null class) (null feature))
	    ;; Invalid or unrecognized @see format, so ignore.
	    (message "(smart-java-cross-reference): Invalid @see cross-reference format")
	    (beep)
	    t)
	   ;; Ensure that a Java OO-Browser environment has been loaded.
	   (t (if (or (and (boundp 'br-lang-prefix)
			   (equal br-lang-prefix "java-")
			   (boundp 'br-env-file) (stringp br-env-file)
			   (null br-env-spec))
		      ;; Load an existing Environment based on current
		      ;; buffer or prompt to build one.  This also
		      ;; loads the "br-java.el" library in which the
		      ;; `java-class-def-regexp' variable used below
		      ;; is defined.
		      (and (br-env-load
			    (car (nreverse
				  (smart-tags-file-list
				   nil
				   (if (boundp 'br-env-default-file)
				       br-env-default-file "OOBR")))))
			   (equal br-lang-prefix "java-")))
		  (cond ((null feature)
			 (br-edit nil class))
			(t
			 (if (null class)
			     (if (save-excursion
				   (or (re-search-backward java-class-def-regexp nil t)
				       (re-search-forward java-class-def-regexp nil t)))
				 (setq class (buffer-substring-no-properties
					      (match-beginning java-class-def-name-grpn)
					      (match-end java-class-def-name-grpn)))
			       (error "(smart-java-cross-reference): This @see must be in a class definition")))
			 (br-edit-feature class feature t)))
		(error "(smart-java-cross-reference): The OO-Browser failed to load a Java environment")))))
      ;; Return to original point.
      (goto-char opoint)
      nil)))

(defun smart-java-library-path (library-name)
  "Search up directory tree from current directory for a match to LIBRARY-NAME."
  (let ((path default-directory)
	(library-path)
	(library-regexp (if (string-match "\\.\\|'//" library-name)
			    (regexp-quote
			     (concat (file-name-as-directory "")
				     (substring library-name 0 (match-beginning 0))
				     (file-name-as-directory "")))))
	(start 0))
    ;; Return rightmost match to first part of library-name.
    (if library-regexp
	(while (string-match library-regexp path start)
	  (setq start (1+ (match-beginning 0))
		library-path (substring path 0 (match-beginning 0)))))
    library-path))

(defun smart-java-packages ()
  "If on a `package' or `import' line, try to display the associated referent.
Returns non-nil iff on such a line, even if the referent is not found.
Look for packages in `smart-java-package-path'."
  (let ((opoint (point)))
    (beginning-of-line)
    (if (looking-at smart-java-package-regexp)
	(let ((keyword-type (buffer-substring-no-properties
			     (match-beginning 1) (match-end 1)))
	      (referent (buffer-substring-no-properties (match-beginning 2) (match-end 2)))
	      (found)
	      (subpath)
	      dir-list path subfile)
	  (goto-char opoint)
	  (if (string-equal keyword-type "package")
	      (let ((library-path (smart-java-library-path referent)))
		(if library-path
		    (hpath:find (expand-file-name
				 (replace-regexp-in-string
				  "\\." (file-name-as-directory "") referent nil t)
				 library-path))
		  ;; Show the current directory, which should contain this package.
		  (hpath:find default-directory)))
	    ;; This is an `import' statement.  If it includes a *, show the
	    ;; associated library directory, otherwise, show the specific
	    ;; package.
	    (if (string-match "\\.\\*" referent)
		(setq subfile (substring referent 0 (match-beginning 0))
		      subfile (replace-regexp-in-string
			       "\\." (file-name-as-directory "") subfile nil t))
	      (setq subpath (replace-regexp-in-string
			     "\\." (file-name-as-directory "") referent nil t)
		    subfile (concat subpath ".java")))
	    ;;
	    ;; Try to find the path containing referent.
	    ;;
	    ;; Search up the current directory tree for a possible matching
	    ;; directory below which the referent library might live and add
	    ;; this to smart-java-package-path for searching.
	    (let ((library-path (smart-java-library-path referent)))
	      (if library-path
		  (setq dir-list (cons library-path smart-java-package-path))))

	    (while dir-list
	      (setq path (expand-file-name subfile (car dir-list))
		    dir-list (if (setq found (file-exists-p path))
				 nil
			       (cdr dir-list))))
	    (when (and (not found) subpath hyperb:microsoft-os-p)
		;; Try .jav suffix.
	      (setq subfile (concat subpath ".jav")
		    dir-list smart-java-package-path)
	      (while dir-list
		(setq path (expand-file-name subfile (car dir-list))
		      dir-list (if (setq found (file-exists-p path))
				   nil
				 (cdr dir-list)))))
	    ;;
	    ;; If found, display file
	    ;;
	    (if found
		(if (file-readable-p path)
		    (hpath:find path)
		  (beep)
		  (message "(smart-java-packages):  `%s' unreadable" path))
	      (beep)
	      (message "(smart-java-packages):  `%s' not found" referent))
	    path))
      (goto-char opoint)
      nil)))

(defun smart-library-symbol (tag)
  "Return non-nil if TAG is a library symbol listed in cache of such symbols.
See the \"${hyperb:dir}/smart-clib-sym\" script for more information."
  (let ((buf (get-buffer-create "*junk*"))
	(found))
    (with-current-buffer buf
      (setq buffer-read-only nil)
      (erase-buffer)
      (call-process (expand-file-name "smart-clib-sym" hyperb:dir)
		    nil buf nil tag)
      (setq found (string-equal (buffer-substring-no-properties 1 2) "1"))
      (set-buffer-modified-p nil)
      (kill-buffer buf)
      found)))

(defun smart-entire-tags-table-list ()
  "Return entire smart `tags-table-list' which includes `(smart-tags-file-list)."
  (or (and (boundp 'tags-table-list)
	   (not (smart-tags-org-src-block-p))
	   (progn (mapc (lambda (tags-table)
			  (add-to-list 'tags-table-list tags-table))
			(smart-tags-file-list))
		  tags-table-list))
      (smart-tags-file-list)))

(defun smart-tags-display (tag next &optional list-of-tags-tables)
  (when next (setq tag nil))
  (let* ((tags-table-list (or list-of-tags-tables
			      (smart-entire-tags-table-list)))
	 ;; Identifier searches should almost always be case-sensitive today
	 (tags-case-fold-search nil)
	 (func (smart-tags-noselect-function))
	 (tags-file-name (unless tags-table-list
			   (when (boundp 'tags-file-name) tags-file-name)))
	 find-tag-result
	 (tags-add-tables nil))
    (cond ((and func (or tags-table-list tags-file-name)
		(setq find-tag-result (funcall func tag)))
	   (cond ((or (eq (type-of find-tag-result) 'xref-item)
		      (vectorp find-tag-result))
		  (hpath:display-buffer (hsys-xref-item-buffer find-tag-result))
		  (goto-char (hsys-xref-item-position find-tag-result)))
		 (t
		  ;; Emacs with some unknown version of tags.
		  ;; Signals an error if tag is not found which is caught by
		  ;; many callers of this function.
		  ;; Find exact identifier matches only.
		  (with-no-warnings (xref-find-definitions tag)))))
	  ((or tags-table-list tags-file-name)
	   ;; Signals an error if tag is not found which is caught by
	   ;; many callers of this function.
	   ;; Find exact identifier matches only.
	   (with-no-warnings (xref-find-definitions tag)))
	  (t
	   (error "No existing tag tables in which to find `%s'" tag)))))

;;;###autoload
(defun smart-tags-file-path (file)
  "Expand relative FILE name by looking it up within appropriate tags files.
Return FILE unchanged if it exists relative to the current directory or
cannot be expanded via a tags file."
  (if (or (file-exists-p file) (file-name-absolute-p file))
      file
    (let ((tags-table-list (smart-tags-file-list))
	  (file-regexp
	   (concat "\^L\r?\n\\(.*/\\)?" (regexp-quote file) ",")))
      (save-excursion
	(while tags-table-list
	  (set-buffer (find-file-noselect (car tags-table-list)))
	  (goto-char (point-min))
	  (if (re-search-forward file-regexp nil t)
	      (setq file
		    (expand-file-name
		     (buffer-substring-no-properties (1- (match-end 0))
						     (progn (beginning-of-line)
							    (point))))
		    tags-table-list nil)
	    (setq tags-table-list (cdr tags-table-list)))))
      file)))

(defun smart-tags-org-src-block-p ()
  "Return non-nil if point is within an Org mode source block."
  (and (featurep 'hsys-org) (hsys-org-mode-p) (org-in-src-block-p t)))

;;;###autoload
(defun smart-tags-file-list (&optional curr-dir-or-filename name-of-tags-file)
  "Return tag files list for optional CURR-DIR-OR-FILENAME or `default-directory'.
Optional NAME-OF-TAGS-FILE is the literal filename (no directory) for which
to look.  If no tags file is found, an error is signaled."
  (let* ((path (or (and (smart-tags-org-src-block-p) (hsys-org-get-value :dir))
		   curr-dir-or-filename default-directory))
	 (tags-table-list (smart-ancestor-tag-files path name-of-tags-file)))
    ;; If no tags files were found and the current buffer may contain Emacs Lisp identifiers and
    ;; is in a 'load-path' directory, then use the default Emacs Lisp tag table.
    (if (and (not tags-table-list)
	     (stringp curr-dir-or-filename)
	     smart-emacs-tags-file
	     (smart-emacs-lisp-mode-p)
	     (let ((path (file-name-directory curr-dir-or-filename)))
	       (when path
		 (delq nil (mapcar
			    (lambda (p)
			      (when p
				(equal (file-name-as-directory p) path)))
			    load-path)))))
	(setq tags-table-list (list smart-emacs-tags-file)))
    ;; Return the appropriate tags file list.
    (cond (tags-table-list
	   ;; GNU Emacs when tags tables are found or provided by the user
	   (nreverse tags-table-list))
	  ((fboundp 'tags-table-check-computed-list)
	   ;; GNU Emacs in other cases
	   (tags-table-check-computed-list)
	   tags-table-computed-list)
	  ((when (boundp 'tags-file-name) tags-file-name)
	   (list tags-file-name))
	  (t (error "Needed tags file not found; see `man etags' for how to build one")))))

;;; ************************************************************************
;;; Private functions
;;; ************************************************************************

(defun smart-tags-noselect-function ()
  "Return the best available function for finding a tag definition.
The function does not select the tag definition."
  (car (delq nil (mapcar (lambda (func) (if (fboundp func) func))
			 '(hsys-xref-definition find-tag-noselect find-tag-internal)))))

(provide 'hmouse-tag)

;;; hmouse-tag.el ends here
