API to update repl-features

Author: dpsutton

README.md

@@ -243,22 +243,46 @@ configurable.
 You can see all the configuration options available using the command
 `M-x customize-group RET inf-clojure`.
 
+The supported repl-features are in an alist called
+`inc-clojure-repl-features` and it has the following shape:
+
+```emacs-lisp
+'((cljs . ((doc . "(cljs.repl/doc %s)")
+           (source . "(cljs.repl/source %s)")
+           (arglists . "(try (->> '%s cljs.core/resolve cljs.core/meta :arglists) (catch :default _ nil))")
+           (apropos . "(cljs.repl/apropos \"%s\")")
+           (ns-vars . "(cljs.repl/dir %s)")
+           (set-ns . "(in-ns '%s)")
+           (macroexpand . "(cljs.core/macroexpand '%s)")
+           (macroexpand-1 . "(cljs.core/macroexpand-1 '%s)"))))
+```
+
+If you want to add a new repl type, just `(add-to-list
+'inf-clojure-repl-features (cons new-repl-type '((doc
+. "(myrepl/doc-command %s") ...)))`
+
+If you want to update a specific form there is a function
+`inf-clojure-update-repl-feature` which can be used like so:
+
+```emacs-lisp
+(inf-clojure-update-feature 'clojure 'completion "(complete.core/completions \"%s\")")
+```
+
 #### REPL Type
 
-An `inf-clojure` REPL can be of different types: Clojure, ClojureScript, Lumo
-and Planck are all potentially valid options.
+An `inf-clojure` REPL can be of different types: Clojure,
+ClojureScript, Lumo and Planck are all potentially valid options.
 
-At the moment, the default Clojure REPL, the Lumo REPL, the Planck REPL and the
-Joker REPL are supported (standard ClojureScript is lacking mostly because some
-features require to access the compiler state,
-[cljs-tooling](https://github.com/clojure-emacs/cljs-tooling) is a good
-candidate for enabling support).
+At the moment, the default Clojure REPL, the Lumo REPL, the Planck
+REPL and the Joker REPL are supported.
 
-What does it mean that a REPL type is supported - well it means that `inf-clojure`
-would use the proper code internally to power commands like definition lookup and friends.
-Those differ from REPL to REPL and can't be implemented in a REPL-independent way. At
-boot type `inf-clojure` tries to detect the type of the REPL that was started and uses
-this type to dispatch the proper code for the respective REPL type.
+What does it mean that a REPL type is supported - well it means that
+`inf-clojure` would use the proper code internally to power commands
+like definition lookup and friends.  Those differ from REPL to REPL
+and can't be implemented in a REPL-independent way. At startup
+`inf-clojure` tries to detect the type of the REPL that was started
+and uses this type to dispatch the proper code for the respective REPL
+type.
 
 By default `inf-clojure` would start a standard Clojure REPL using
 `lein` or `boot` but you can easily change this.  To boot some other REPL just use the

inf-clojure.el

@@ -146,15 +146,40 @@
                 (macroexpand . "(clojure.core/macroexpand '%s)")
                 (macroexpand-1 . "(clojure.core/macroexpand-1 '%s)")))))
 
+(defun inf-clojure--get-feature (repl-type feature no-error)
+  "Get FEATURE for REPL-TYPE from repl-features.
+If no-error is truthy don't error if feature is not present."
+  (let ((feature-form (alist-get feature (alist-get repl-type inf-clojure-repl-features))))
+    (cond (feature-form feature-form)
+          (no-error nil)
+          (t (error "%s not configured for %s" feature repl-type)))))
+
 (defun inf-clojure-get-feature (proc feature &optional no-error)
   "Get FEATURE based on repl type for PROC."
   (let* ((repl-type (or (with-current-buffer (process-buffer proc)
                           inf-clojure-repl-type)
-                        (error "Repl type is not known")))
-         (feature-form (alist-get feature (alist-get repl-type inf-clojure-repl-features))))
-    (cond (feature-form feature-form)
-          (no-error nil)
-          (t (error "%s not configured for %s" feature repl-type)))))
+                        (error "Repl type is not known"))))
+    (inf-clojure--get-feature repl-type feature no-error)))
+
+(defun inf-clojure--update-feature (repl-type feature form)
+  "Return a copy of the datastructure containing the repl features.
+Given a REPL-TYPE ('clojure, 'lumo, ...) and a FEATURE ('doc,
+'apropos, ...) and a FORM this will return a new datastructure
+that can be set as `inf-clojure-repl-features'."
+  (let ((original (alist-get repl-type inf-clojure-repl-features)))
+    (if original
+        (cons (cons repl-type (cons (cons feature form) (assoc-delete-all feature original)))
+              (assoc-delete-all repl-type inf-clojure-repl-features))
+      (error "Attempted to update %s form of unknown repl type %s"
+             (symbol-name feature)
+             (symbol-name repl-type)))))
+
+(defun inf-clojure-update-feature (repl-type feature form)
+  "Mutate the repl features to the new FORM.
+Given a REPL-TYPE ('clojure, 'lumo, ...) and a FEATURE ('doc,
+'apropos, ...) and a FORM this will set
+`inf-clojure-repl-features' with these new values."
+  (setq inf-clojure-repl-features (inf-clojure--update-feature repl-type feature form)))
 
 (defun inf-clojure-proc (&optional no-error)
   "Return the current inferior Clojure process.

test/inf-clojure-tests.el

@@ -139,4 +139,14 @@
   (it "returns empty string when the command is empty"
      (expect (inf-clojure--sanitize-command "   ") :to-equal "")))
 
+(describe "inf-clojure--update-feature"
+  (it "updates new forms correctly"
+    (let ((inf-clojure-repl-features (inf-clojure--update-feature 'cljs 'doc "new doc")))
+      (expect (inf-clojure--get-feature 'cljs 'doc nil)
+              :to-equal "new doc")))
+  (describe "if the repl type is unknown"
+    (it "signals an error"
+      (expect (inf-clojure--update-feature 'not-found 'doc "new doc")
+              :to-throw))))
+
 ;;; inf-clojure-tests.el ends here