\\{emacs-lisp-mode-map}"
:group 'lisp
- (defvar xref-find-function)
- (defvar xref-identifier-completion-table-function)
+ (defvar xref-backend-functions)
(defvar project-library-roots-function)
(lisp-mode-variables nil nil 'elisp)
(add-hook 'after-load-functions #'elisp--font-lock-flush-elisp-buffers)
(setq imenu-case-fold-search nil)
(add-function :before-until (local 'eldoc-documentation-function)
#'elisp-eldoc-documentation-function)
- (setq-local xref-find-function #'elisp-xref-find)
- (setq-local xref-identifier-completion-table-function
- #'elisp--xref-identifier-completion-table)
+ (add-hook 'xref-backend-functions #'elisp--xref-backend nil t)
(setq-local project-library-roots-function #'elisp-library-roots)
(add-hook 'completion-at-point-functions
#'elisp-completion-at-point nil 'local))
(declare-function xref-make "xref" (summary location))
(declare-function xref-collect-references "xref" (symbol dir))
-(defun elisp-xref-find (action id)
- (require 'find-func)
- ;; FIXME: use information in source near point to filter results:
- ;; (dvc-log-edit ...) - exclude 'feature
- ;; (require 'dvc-log-edit) - only 'feature
- ;; Semantic may provide additional information
- (pcase action
- (`definitions
- (let ((sym (intern-soft id)))
- (when sym
- (elisp--xref-find-definitions sym))))
- (`references
- (elisp--xref-find-references id))
- (`apropos
- (elisp--xref-find-apropos id))))
+(defun elisp--xref-backend () 'elisp)
;; WORKAROUND: This is nominally a constant, but the text properties
;; are not preserved thru dump if use defconst. See bug#21237.
non-nil result supercedes the xrefs produced by
`elisp--xref-find-definitions'.")
-;; FIXME: name should be singular; match xref-find-definition
+(cl-defmethod xref-backend-definitions ((_backend (eql elisp)) identifier)
+ (require 'find-func)
+ ;; FIXME: use information in source near point to filter results:
+ ;; (dvc-log-edit ...) - exclude 'feature
+ ;; (require 'dvc-log-edit) - only 'feature
+ ;; Semantic may provide additional information
+ ;;
+ (let ((sym (intern-soft identifier)))
+ (when sym
+ (elisp--xref-find-definitions sym))))
+
(defun elisp--xref-find-definitions (symbol)
;; The file name is not known when `symbol' is defined via interactive eval.
(let (xrefs)
(declare-function project-roots "project")
(declare-function project-current "project")
-(defun elisp--xref-find-references (symbol)
+(cl-defmethod xref-backend-references ((_backend (eql elisp)) symbol)
"Find all references to SYMBOL (a string) in the current project."
(cl-mapcan
(lambda (dir)
(project-roots pr)
(project-library-roots pr)))))
-(defun elisp--xref-find-apropos (regexp)
+(cl-defmethod xref-backend-apropos ((_backend (eql elisp)) regexp)
(apply #'nconc
(let (lst)
(dolist (sym (apropos-internal regexp))
(facep sym)))
'strict))
-(defun elisp--xref-identifier-completion-table ()
+(cl-defmethod xref-backend-identifier-completion-table ((_backend (eql elisp)))
elisp--xref-identifier-completion-table)
(cl-defstruct (xref-elisp-location
;; referencing commands, in particular "find-definition".
;;
;; Some part of the functionality must be implemented in a language
-;; dependent way and that's done by defining `xref-find-function',
-;; `xref-identifier-at-point-function' and
-;; `xref-identifier-completion-table-function', which see.
+;; dependent way and that's done by defining an xref backend.
;;
-;; A major mode should make these variables buffer-local first.
+;; That consists of a constructor function, which should return a
+;; backend value, and a set of implementations for the generic
+;; functions:
;;
-;; `xref-find-function' can be called in several ways, see its
-;; description. It has to operate with "xref" and "location" values.
+;; `xref-backend-identifier-at-point',
+;; `xref-backend-identifier-completion-table',
+;; `xref-backend-definitions', `xref-backend-references',
+;; `xref-backend-apropos', which see.
+;;
+;; A major mode would normally use `add-hook' to add the backend
+;; constructor to `xref-backend-functions'.
+;;
+;; The last three methods operate with "xref" and "location" values.
;;
;; One would usually call `make-xref' and `xref-make-file-location',
;; `xref-make-buffer-location' or `xref-make-bogus-location' to create
;; Each identifier must be represented as a string. Implementers can
;; use string properties to store additional information about the
;; identifier, but they should keep in mind that values returned from
-;; `xref-identifier-completion-table-function' should still be
+;; `xref-backend-identifier-completion-table' should still be
;; distinct, because the user can't see the properties when making the
;; choice.
;;
-;; See the functions `etags-xref-find' and `elisp-xref-find' for full
-;; examples.
+;; See the etags and elisp-mode implementations for full examples.
;;; Code:
\f
;;; API
-(declare-function etags-xref-find "etags" (action id))
-(declare-function tags-lazy-completion-table "etags" ())
+;; We make the etags backend the default for now, until something
+;; better comes along.
+(defvar xref-backend-functions (list #'xref--etags-backend)
+ "Special hook to find the xref backend for the current context.
+Each functions on this hook is called in turn with no arguments
+and should return either nil to mean that it is not applicable,
+or an xref backend, which is a value to be used to dispatch the
+generic functions.")
-;; For now, make the etags backend the default.
-(defvar xref-find-function #'etags-xref-find
- "Function to look for cross-references.
-It can be called in several ways:
+(defun xref-find-backend ()
+ (run-hook-with-args-until-success 'xref-backend-functions))
- (definitions IDENTIFIER): Find definitions of IDENTIFIER. The
-result must be a list of xref objects. If IDENTIFIER contains
-sufficient information to determine a unique definition, returns
-only that definition. If there are multiple possible definitions,
-return all of them. If no definitions can be found, return nil.
+(defun xref--etags-backend () 'etags)
- (references IDENTIFIER): Find references of IDENTIFIER. The
-result must be a list of xref objects. If no references can be
-found, return nil.
+(cl-defgeneric xref-backend-definitions (backend identifier)
+ "Find definitions of IDENTIFIER.
- (apropos PATTERN): Find all symbols that match PATTERN. PATTERN
-is a regexp.
+The result must be a list of xref objects. If IDENTIFIER
+contains sufficient information to determine a unique definition,
+return only that definition. If there are multiple possible
+definitions, return all of them. If no definitions can be found,
+return nil.
IDENTIFIER can be any string returned by
-`xref-identifier-at-point-function', or from the table returned
-by `xref-identifier-completion-table-function'.
+`xref-backend-identifier-at-point', or from the table returned by
+`xref-backend-identifier-completion-table'.
To create an xref object, call `xref-make'.")
-(defvar xref-identifier-at-point-function #'xref-default-identifier-at-point
- "Function to get the relevant identifier at point.
+(cl-defgeneric xref-backend-references (backend identifier)
+ "Find references of IDENTIFIER.
+The result must be a list of xref objects. If no references can
+be found, return nil.")
+
+(cl-defgeneric xref-backend-apropos (backend pattern)
+ "Find all symbols that match PATTERN.
+PATTERN is a regexp")
+
+(cl-defgeneric xref-backend-identifier-at-point (_backend)
+ "Return the relevant identifier at point.
The return value must be a string or nil. nil means no
identifier at point found.
If it's hard to determine the identifier precisely (e.g., because
it's a method call on unknown type), the implementation can
return a simple string (such as symbol at point) marked with a
-special text property which `xref-find-function' would recognize
-and then delegate the work to an external process.")
-
-(defvar xref-identifier-completion-table-function #'tags-lazy-completion-table
- "Function that returns the completion table for identifiers.")
-
-(defun xref-default-identifier-at-point ()
+special text property which e.g. `xref-backend-definitions' would
+recognize and then delegate the work to an external process."
(let ((thing (thing-at-point 'symbol)))
(and thing (substring-no-properties thing))))
+(cl-defgeneric xref-backend-identifier-completion-table (backend)
+ "Returns the completion table for identifiers.")
+
\f
;;; misc utilities
(defun xref--alistify (list key test)
(defun xref--read-identifier (prompt)
"Return the identifier at point or read it from the minibuffer."
- (let ((id (funcall xref-identifier-at-point-function)))
+ (let* ((backend (xref-find-backend))
+ (id (xref-backend-identifier-at-point backend)))
(cond ((or current-prefix-arg
(not id)
(xref--prompt-p this-command))
"[ :]+\\'" prompt))
id)
prompt)
- (funcall xref-identifier-completion-table-function)
+ (xref-backend-identifier-completion-table backend)
nil nil nil
'xref--read-identifier-history id))
(t id))))
;;; Commands
(defun xref--find-xrefs (input kind arg window)
- (let ((xrefs (funcall xref-find-function kind arg)))
+ (let ((xrefs (funcall (intern (format "xref-backend-%s" kind))
+ (xref-find-backend)
+ arg)))
(unless xrefs
(user-error "No %s found for: %s" (symbol-name kind) input))
(xref--show-xrefs xrefs window)))
(cl-mapcan (lambda (hit) (xref--collect-matches
hit (format "\\_<%s\\_>" (regexp-quote symbol))))
hits)
+ ;; TODO: Implement "lightweight" buffer visiting, so that we
+ ;; don't have to kill them.
(mapc #'kill-buffer
(cl-set-difference (buffer-list) orig-buffers)))))
(unwind-protect
(cl-mapcan (lambda (hit) (xref--collect-matches hit regexp))
(nreverse hits))
+ ;; TODO: Same as above.
(mapc #'kill-buffer
(cl-set-difference (buffer-list) orig-buffers)))))
projects / emacs.git / commitdiff