Add var and find-var to lumo

Now that we have eval, we can easily provide var and find-var at the REPL.

src/cljs/snapshot/lumo/repl.clj

@@ -19,6 +19,15 @@
   [n]
   `(lumo.repl/source* '~n))
 
+(defmacro var
+  "Prints the source code for the given symbol, if it can find it.
+  This requires that the symbol resolve to a Var defined in a
+  namespace for which the source is available.
+
+  Example: (source filter)"
+  [n]
+  `(lumo.repl/eval '~n))
+
 (defmacro ^:private with-err-str
   "Evaluates exprs in a context in which *print-err-fn* is bound to .append
   on a fresh StringBuffer.  Returns the string created by any nested

src/cljs/snapshot/lumo/repl.cljs

@@ -1,5 +1,5 @@
 (ns lumo.repl
-  (:refer-clojure :exclude [load-file* eval])
+  (:refer-clojure :exclude [load-file* eval var])
   (:require-macros [cljs.env.macros :as env]
                    [cljs.analyzer.macros :refer [no-warn]]
                    [lumo.repl :refer [with-err-str]])
@@ -858,6 +858,12 @@
            (vreset! result value))))
      @result)))
 
+(defn find-var
+  "Returns the global var named by the namespace-qualified symbol, or
+  nil if no var with that name."
+  [sym]
+  (eval `(~'var ~sym)))
+
 (defn- intern
   ([ns name]
    (intern ns name nil))

src/js/cljs.js

@@ -544,7 +544,7 @@ async function startClojureScriptEngine(opts: CLIOptsType): Promise<mixed> {
       }
 
       execute(
-        "(require '[lumo.repl :refer [apropos find-doc] :refer-macros [dir doc source]])",
+        "(require '[lumo.repl :refer [apropos find-doc find-var] :refer-macros [dir doc source var]])",
         'text',
         true,
         false,

src/test/lumo/lumo/repl_tests.cljs

@@ -208,3 +208,8 @@ Special Form
     (is (= 3 (core/eval (list + 1 2))))
     (is (= 17 (core/eval '(let [a 10] (+ 3 4 a)))))
     (is (= 5 ((eval (eval '+)) 2 3)))))
+
+(when test-util/lumo-env?
+  (deftest test-find-var
+    (is (= #'cljs.core/map (lumo/find-var 'map)) "it should find function vars")
+    (is (= #'lumo.repl/*pprint-results* (lumo/find-var 'lumo.repl/*pprint-results*)) "it should find a var in another namespace")))