feature/lookup: reduce coupling w/ lookup backends

You can now control exactly what lookup backends are used for the
various lookup commands (definition, references, online and file).

This allows you to disable (or add) backends by manipulating the default
value for these lists with add-hook or remove-hook:

* +lookup-definition-functions
* +lookup-references-functions
* +lookup-documentation-functions
* +lookup-file-functions

modules/feature/lookup/autoload/lookup.el

@@ -114,16 +114,92 @@ properties:
                (+helm-file-search nil :query query)
                t))))))
 
-;;;###autoload
+
-(defun +lookup-xref-definitions (identifier)
+;;
+;; Lookup backends
+
+(defun +lookup-xref-definitions-backend (identifier)
   "Non-interactive wrapper for `xref-find-definitions'"
   (xref-find-definitions identifier))
 
-;;;###autoload
+(defun +lookup-xref-references-backend (identifier)
-(defun +lookup-xref-references (identifier)
   "Non-interactive wrapper for `xref-find-references'"
   (xref-find-references identifier))
 
+(defun +lookup-dumb-jump-backend (_identifier)
+  "Look up the symbol at point (or selection) with `dumb-jump', which conducts a
+project search with ag, rg, pt, or git-grep, combined with extra heuristics to
+reduce false positives.
+
+This backend prefers \"just working\" over accuracy."
+  (when (require 'dumb-jump nil t)
+    ;; dumb-jump doesn't tell us if it succeeded or not
+    (let (successful)
+      (cl-letf* ((old-fn (symbol-function 'dumb-jump-get-results))
+                 ((symbol-function 'dumb-jump-get-results)
+                  (lambda (&optional prompt)
+                    (let* ((plist (funcall old-fn prompt))
+                           (results (plist-get plist :results)))
+                      (when (and results (> (length results) 0))
+                        (setq successful t))
+                      plist))))
+        (if other-window
+            (dumb-jump-go-other-window)
+          (dumb-jump-go))
+        successful))))
+
+(defun +lookup-project-search-backend (identifier)
+  "Conducts a simple project text search for IDENTIFIER.
+
+Uses and requires `+ivy-file-search' or `+helm-file-search'. Will return nil if
+neither is available. These search backends will use ag, rg, or pt (in an order
+dictated by `+ivy-project-search-engines' or `+helm-project-search-engines',
+falling back to git-grep)."
+  (unless identifier
+    (let ((query (rxt-quote-pcre identifier)))
+      (ignore-errors
+        (cond ((featurep! :completion ivy)
+               (+ivy-file-search nil :query query)
+               t)
+              ((featurep! :completion helm)
+               (+helm-file-search nil :query query)
+               t))))))
+
+(defun +lookup-evil-goto-definition-backend (identifier)
+  "Uses `evil-goto-definition' to conduct a text search for IDENTIFIER in the
+current buffer."
+  (and (featurep 'evil)
+       evil-mode
+       (ignore-errors
+         (cl-destructuring-bind (beg . end)
+             (bounds-of-thing-at-point 'symbol)
+           (evil-goto-definition)
+           (let ((pt (point)))
+             (not (and (>= pt beg)
+                       (<  pt end))))))))
+
+(defun +lookup-dash-docsets-backend (identifier)
+  "Looks up IDENTIFIER in available Dash docsets, if any are installed.
+
+Docsets must be installed with `+lookup/install-docset'. These can also be
+accessed via `+lookup/in-docsets'."
+  (and (featurep! +docsets)
+       (or (require 'counsel-dash nil t)
+           (require 'helm-dash nil t))
+       (let ((docsets (+lookup-docsets-for-buffer)))
+         (when (cl-some #'+lookup-docset-installed-p docsets)
+           (+lookup/in-docsets identifier docsets)
+           t))))
+
+(defun +lookup-online-backend (identifier)
+  "Opens the browser and searches for IDENTIFIER online.
+
+Will prompt for which search engine to use the first time (or if the universal
+argument is non-nil)."
+  (+lookup/online
+   identifier
+   (+lookup--online-provider (not current-prefix-arg))))
+
 
 ;;
 ;; Main commands
@@ -146,35 +222,7 @@ evil-mode is active."
         ((and +lookup-definition-functions
               (+lookup--jump-to :definition identifier)))
 
-        ((and (require 'dumb-jump nil t)
+        ((error "Couldn't find the definition of '%s'" identifier))))
-              ;; dumb-jump doesn't tell us if it succeeded or not
-              (let (successful)
-                (cl-letf* ((old-fn (symbol-function 'dumb-jump-get-results))
-                           ((symbol-function 'dumb-jump-get-results)
-                            (lambda (&optional prompt)
-                              (let* ((plist (funcall old-fn prompt))
-                                     (results (plist-get plist :results)))
-                                (when (and results (> (length results) 0))
-                                  (setq successful t))
-                                plist))))
-                  (if other-window
-                      (dumb-jump-go-other-window)
-                    (dumb-jump-go))
-                  successful))))
-
-        ((+lookup--file-search identifier))
-
-        ((and (featurep 'evil)
-              evil-mode
-              (ignore-errors
-                (cl-destructuring-bind (beg . end)
-                    (bounds-of-thing-at-point 'symbol)
-                  (evil-goto-definition)
-                  (let ((pt (point)))
-                    (not (and (>= pt beg)
-                              (<  pt end))))))))
-
-        ((error "Couldn't find '%s'" identifier))))
 
 ;;;###autoload
 (defun +lookup/references (identifier)
@@ -190,9 +238,7 @@ search otherwise."
         ((and +lookup-references-functions
               (+lookup--jump-to :references identifier)))
 
-        ((+lookup--file-search identifier))
+        ((error "Couldn't find references of '%s'" identifier))))
-
-        ((error "Couldn't find '%s'" identifier))))
 
 ;;;###autoload
 (defun +lookup/documentation (identifier)
@@ -210,17 +256,7 @@ Goes down a list of possible backends:
         ((and +lookup-documentation-functions
               (+lookup--jump-to :documentation identifier)))
 
-        ((and (featurep! +docsets)
+        ((user-error "Couldn't find documentation for '%s'" identifier))))
-              (or (require 'counsel-dash nil t)
-                  (require 'helm-dash nil t))
-              (let ((docsets (+lookup-docsets-for-buffer)))
-                (when (cl-some #'+lookup-docset-installed-p docsets)
-                  (+lookup/in-docsets identifier docsets)
-                  t))))
-
-        ((+lookup/online
-          identifier
-          (+lookup--online-provider (not current-prefix-arg))))))
 
 (defvar ffap-file-finder)
 ;;;###autoload
@@ -276,7 +312,10 @@ Otherwise, falls back on `find-file-at-point'."
 (defvar helm-dash-docsets)
 ;;;###autoload
 (defun +lookup/in-docsets (&optional query docsets)
-  "TODO"
+  "Looks up QUERY (a string) in available Dash docsets for the current buffer.
+
+DOCSETS is a list of docset strings. Docsets can be installed with
+`+lookup/install-docset'."
   (interactive)
   (let* ((counsel-dash-docsets
           (unless (eq docsets 'blank)

modules/feature/lookup/config.el

@@ -29,7 +29,11 @@ produces an url. Used by `+lookup/online'.")
 (defvar +lookup-open-url-fn #'browse-url
   "Function to use to open search urls.")
 
-(defvar +lookup-definition-functions '(+lookup-xref-definitions)
+(defvar +lookup-definition-functions
+  '(+lookup-xref-definitions-backend
+    +lookup-dumb-jump-backend
+    +lookup-project-search-backend
+    +lookup-evil-goto-definition-backend)
   "Functions for `+lookup/definition' to try, before resorting to `dumb-jump'.
 Stops at the first function to return non-nil or change the current
 window/point.
@@ -38,7 +42,9 @@ If the argument is interactive (satisfies `commandp'), it is called with
 `call-interactively' (with no arguments). Otherwise, it is called with one
 argument: the identifier at point.")
 
-(defvar +lookup-references-functions '(+lookup-xref-references)
+(defvar +lookup-references-functions
+  '(+lookup-xref-references-backend
+    +lookup-project-search-backend)
   "Functions for `+lookup/references' to try, before resorting to `dumb-jump'.
 Stops at the first function to return non-nil or change the current
 window/point.
@@ -47,7 +53,9 @@ If the argument is interactive (satisfies `commandp'), it is called with
 `call-interactively' (with no arguments). Otherwise, it is called with one
 argument: the identifier at point.")
 
-(defvar +lookup-documentation-functions ()
+(defvar +lookup-documentation-functions
+  '(+lookup-dash-docsets-backend
+    +lookup-online-backend)
   "Functions for `+lookup/documentation' to try, before resorting to
 `dumb-jump'. Stops at the first function to return non-nil or change the current
 window/point.