Initial commit: Jolt — Clojure interpreter on Janet

- PEG-based Clojure reader (symbols, keywords, numbers, strings, lists,
  vectors, maps, sets, quote forms, reader macros, metadata)
- Tree-walking evaluator (quote, do, if, def, fn*, let*, loop*/recur,
  syntax-quote/unquote/unquote-splicing, macro system, ns/require/in-ns)
- 95+ clojure.core functions (predicates, math, collections, seq ops,
  higher-order, atoms, I/O)
- Public API (init, eval-string, eval-string*)
- REPL (jolt/main.janet)
- 7 test suites, all green
- MIT license

src/jolt/main.janet

@@ -0,0 +1,34 @@
+# Jolt REPL
+# Read-eval-print loop for Clojure expressions.
+
+(use ./api)
+(use ./types)
+
+(def ctx (init))
+
+(defn read-line [prompt]
+  (prin prompt)
+  (flush)
+  (let [line (file/read stdin :line)]
+    (if line (string/trim line) nil)))
+
+(defn print-value [v]
+  (if (nil? v)
+    (print "nil")
+    (if (and (table? v) (= :jolt/var (v :jolt/type)))
+      (printf "#'%s/%s" (ctx-current-ns ctx) ((var-name v) :name))
+      (print v))))
+
+(print "Jolt — Clojure on Janet")
+(print "Type (exit) to quit.\n")
+
+(var running true)
+(while running
+  (let [line (read-line (string (ctx-current-ns ctx) "=> "))]
+    (if (nil? line) (set running false)
+      (if (= line "(exit)") (set running false)
+        (if (not (= "" line))
+          (try
+            (print-value (eval-string ctx line))
+            ([err]
+             (eprint "Error: " err))))))))