add function-from-example

Author: Case Nelson

README.md

@@ -2,7 +2,7 @@ A neovim port of [clj-refactor.el](https://github.com/clojure-emacs/clj-refactor
 
 # Usage 
 
-All commands are mapped under the `cr` prefix and use a two letter mnemonic shortcut. E.g. `crrs` for `:CRRenameSymbol`. The full list is below.
+All commands are mapped under the `cr` prefix and use a two letter mnemonic shortcut. E.g. `crrs` for `Clojure Refactor Rename Symbol`.The full list is below.
 
 # Installation
 
@@ -46,7 +46,7 @@ Using Vundle, add this to your vundle .config/nvim/init.vim section:
 - [ ] [add-project-dependency](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/add-project-dependency.gif)
 - [ ] [add-stubs](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/add-stubs.gif)
 - [x] `crcn` [clean-ns](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/clean-ns.gif)
-- [ ] [create-fn-from-example](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/create-fn-from-example.gif)
+- [x] `crfe` [create-fn-from-example](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/create-fn-from-example.gif)
 - [x] `crcc` [cycle-coll](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/cycle-coll.gif)
 - [x] `crci` [cycle-if](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/cycle-if.gif)
 - [x] `crcp` [cycle-privacy](https://github.com/clojure-emacs/clj-refactor.el/blob/master/examples/cycle-privacy.gif)

plugin/refactor.vim

@@ -5,6 +5,7 @@ noremap crci :CCycleIf<CR>
 noremap crcp :CCyclePrivacy<CR>
 noremap crct :CCycleThread<CR>
 noremap crel :CExpandLet<CR>
+noremap crfe :CFunctionFromExample<CR>
 noremap cril :CIntroduceLet 
 noremap crml :CMoveToLet 
 noremap crtf :CThreadFirstAll<CR>

rplugin/node/clj-refactor.js

@@ -77,6 +77,7 @@
      (.command js/plugin "CCyclePrivacy" #js {:eval "getpos('.')" :nargs 0} (partial run-transform transform/cycle-privacy))
      (.command js/plugin "CCycleThread" #js {:eval "getpos('.')" :nargs 0} (partial run-transform transform/cycle-thread))
      (.command js/plugin "CExpandLet" #js {:eval "getpos('.')" :nargs 0} (partial run-transform transform/expand-let))
+     (.command js/plugin "CFunctionFromExample" #js {:eval "getpos('.')" :nargs 0} (partial run-transform transform/function-from-example))
      (.command js/plugin "CIntroduceLet" #js {:eval "getpos('.')" :nargs 1} (partial run-transform transform/introduce-let))
      (.command js/plugin "CMoveToLet" #js {:eval "getpos('.')" :nargs 1} (partial run-transform transform/move-to-let))
      (.command js/plugin "CThread" #js {:eval "getpos('.')" :nargs 0} (partial run-transform transform/thread))

src/clj_refactor/main.cljs

@@ -250,3 +250,19 @@
 (defn cycle-privacy
   [zloc _]
   (cycle-op zloc 'defn 'defn-))
+
+(defn function-from-example
+  [zloc _]
+  (let [op-loc (edit/find-op zloc)
+        example-loc (z/up (edit/find-op zloc))
+        child-sexprs (n/child-sexprs (z/node example-loc))
+        fn-name (first child-sexprs)
+        args (for [[i arg] (map-indexed vector (rest child-sexprs))]
+               (if (symbol? arg)
+                 arg
+                 (symbol (str "arg" (inc i)))))]
+    (-> example-loc
+      (edit/exec-to z/up #(not (edit/top? %))) ; Go to top level form
+      (z/insert-left `(~'defn ~fn-name [~@args])) ; add declare
+      (z/insert-left (n/newline-node "\n\n"))))) ; add new line after location
+

src/clj_refactor/transform.cljs

@@ -11,16 +11,23 @@
       (z/find z/next #(= (z/sexpr %) goto))
       (f)))
 
+(defn apply-goto
+  [form goto f]
+  (zip-to form goto f))
+
 (defn apply-zip-to
   [form goto f]
-  (-> form
-      (zip-to goto f)
-      (z/sexpr)))
+  (z/sexpr (apply-goto form goto f)))
 
 (defn apply-zip
   [form goto f]
-  (-> form
-      (zip-to goto f)
+  (-> (apply-goto form goto f)
       (z/root-string)
       (r/read-string)))
 
+(defn apply-zip-root
+  [form goto f]
+  (r/read-string
+   (str "(do "
+        (z/root-string (apply-goto form goto f))
+        ")")))

test/clj_refactor/test_helper.cljs

@@ -4,7 +4,7 @@
               [clojure.string :as str]
               [clj-refactor.main :as m]
               [clj-refactor.transform :as t]
-              [clj-refactor.test-helper :refer [apply-zip apply-zip-to]]))
+              [clj-refactor.test-helper :refer [apply-zip apply-zip-to apply-zip-root]]))
 
 (deftest testing-introduce-let
   (are [i j] (= i j)
@@ -89,3 +89,11 @@
        '(defn a [b] (b c)) (apply-zip '(defn- a [b] (b c)) 'c t/cycle-privacy)
        '(defn- a [b] (b c)) (apply-zip '(defn a [b] (b c)) 'c t/cycle-privacy)
        '(a (b c)) (apply-zip '(a (b c)) 'b t/cycle-privacy)))
+
+(deftest testing-function-from-example
+  (are [i j] (= i j)
+       '(do (defn b [z]) (defn a [z] (b z)))
+       (apply-zip-root '(defn a [z] (b z)) 'b t/function-from-example)
+
+       '(do (defn b [arg1 z]) (defn a [z] (b (x y) z)))
+       (apply-zip-root '(defn a [z] (b (x y) z)) 'b t/function-from-example)))