diff --git a/.gitignore b/.gitignore
index c4ea3ce..ab9afee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,3 +32,4 @@ target/repl-port
 .repl-buffer
 .repl-buffer.janet
 .env
+janet/jpm_tree
diff --git a/janet/judge b/janet/judge
new file mode 120000
index 0000000..1ececd9
--- /dev/null
+++ b/janet/judge
@@ -0,0 +1 @@
+./jpm_tree/bin/judge
\ No newline at end of file
diff --git a/janet/judgy.fish b/janet/judgy.fish
new file mode 100755
index 0000000..4f7b069
--- /dev/null
+++ b/janet/judgy.fish
@@ -0,0 +1,9 @@
+#!/opt/homebrew/bin/fish
+
+set FILE $argv[1]
+set TESTFILE (string join "" $FILE ".tested")
+judge $FILE
+if test -e $TESTFILE
+    cp $TESTFILE $FILE
+    rm $TESTFILE
+end
diff --git a/janet/language.test.janet b/janet/language.test.janet
new file mode 100644
index 0000000..b375ac2
--- /dev/null
+++ b/janet/language.test.janet
@@ -0,0 +1,371 @@
+# testing Ludus langauge constructs
+(try (os/cd "janet") ([_] nil)) # for REPL
+(import /scanner :as s)
+(import /parser :as p)
+(import /validate :as v)
+(import /interpreter :as i)
+(import /errors :as e)
+(import /base :as b)
+
+(use judge)
+
+(defn run [source]
+ (def ctx @{})
+ (def scanned (s/scan source :test))
+ (when (any? (scanned :errors))
+  (e/scan-error (scanned :errors)) (error "scanning errors"))
+ (def parsed (p/parse scanned))
+ (when (any? (parsed :errors))
+  (e/parse-error (parsed :errors)) (error "parsing errors"))
+ (def valid (v/valid parsed ctx))
+ (when (any? (valid :errors)) (each err (valid :errors)
+  (e/validation-error err)) (error "validation errors"))
+ (i/interpret (parsed :ast) ctx))
+
+(deftest "returns bare values from single-line scripts"
+ (test (run "true") true)
+ (test (run "false") false)
+ (test (run "nil") :^nil)
+ (test (run "12.34") 12.34)
+ (test (run "-32") -32)
+ (test (run "0") 0)
+ (test (run ":foo") :foo)
+ (test (run ":bar") :bar)
+ (test (run `"a string, a text, a language"`) "a string, a text, a language"))
+
+(deftest "returns empty collections from single-line scripts"
+ (test (run "()") [])
+ (test (run "#{}") @{})
+ (test (run "${}") @{:^type :set})
+ (test (run "[]") @[]))
+
+(deftest "returns populated collections from single-line scripts"
+ (test (run "(1, 2, 3)") [1 2 3])
+ (test (run "[:a, :b, :c]") @[:a :b :c])
+ (test (run "${1, 2, 3, 3}") @{1 true 2 true 3 true :^type :set})
+ (test (run "#{:a 1, :b 2}") @{:a 1 :b 2}))
+
+(deftest "returns nested collections from single-line scripts"
+ (test (run "((), (1, 2), [:a, (:b)], #{:foo true, :bar false})")
+   [[]
+    [1 2]
+    @[:a [:b]]
+    @{:bar false :foo true}])
+ (test (run `#{:foo #{:bar "thing", :baz (1, :foo, nil)}}`) @{:foo @{:bar "thing" :baz [1 :foo :^nil]}}))
+
+(deftest "binds names in let bindings with various patterns"
+ (test (run `let foo = :bar; foo`) :bar)
+ (test (run `let 42 = 42`) 42)
+ (test (run `let foo = :bar; let quux = 42; (foo, quux)`) [:bar 42])
+ (test (run `let (:ok, value) = (:ok, 42); value`) 42)
+ (test (run `let #{:a x, ...} = #{:a 1, :b 2}; x`) 1))
+
+(deftest "executes if/then/else properly"
+ (test (run `if nil then :foo else :bar`) :bar)
+ (test (run `if false then :foo else :bar`) :bar)
+ (test (run `if true then :foo else :bar`) :foo)
+ (test (run `if 42 then :foo else panic! "oops"`) :foo))
+
+(deftest "panics"
+ (test-error (run `panic! "oops"`)
+   {:msg "oops"
+    :node {:data {:data "oops"
+                  :token {:input :test
+                          :lexeme "\"oops\""
+                          :line 1
+                          :literal "oops"
+                          :source "panic! \"oops\""
+                          :start 7
+                          :type :string}
+                  :type :string}
+           :token {:input :test
+                   :lexeme "panic!"
+                   :line 1
+                   :literal :none
+                   :source "panic! \"oops\""
+                   :start 0
+                   :type :panic}
+           :type :panic}})
+)
+
+(deftest "no match in let panics"
+ (test-error (run "let :foo = :bar")
+   {:msg "no match: let binding"
+    :node {:data @[{:data :foo
+                    :token {:input :test
+                            :lexeme ":foo"
+                            :line 1
+                            :literal :foo
+                            :source "let :foo = :bar"
+                            :start 4
+                            :type :keyword}
+                    :type :keyword}
+                   {:data :bar
+                    :token {:input :test
+                            :lexeme ":bar"
+                            :line 1
+                            :literal :bar
+                            :source "let :foo = :bar"
+                            :start 11
+                            :type :keyword}
+                    :type :keyword}]
+           :token {:input :test
+                   :lexeme "let"
+                   :line 1
+                   :literal :none
+                   :source "let :foo = :bar"
+                   :start 0
+                   :type :let}
+           :type :let}
+    :value :bar})
+)
+
+(deftest "blocks execute code and work"
+ (test (run `
+ let bar = 12
+ let foo = {
+  let bar = 42
+  let baz = :quux
+  :foo
+ }
+ (foo, bar)
+ `)
+   [:foo 12])
+ (test (run `
+ let foo = {
+  let bar = 12
+  {
+   let bar = 15
+   bar
+  }
+ }
+ `)
+   15))
+
+(deftest "unbound name panics"
+ (test-error (run `foo`) "validation errors"))
+
+(deftest "rebinding name panics"
+ (test-error (run `let foo = 42; let foo = 23`) "validation errors"))
+
+(deftest "when forms work as expected"
+ (test (run `
+  when {
+   false -> :nope
+   nil -> :nope
+   12 -> :yes
+  }
+ `)
+   :yes)
+ (test-error (run `
+  when {
+   false -> :nope
+   nil -> :nope
+  }
+ `)
+   {:msg "no match: when form"
+    :node {:data @[[{:data false
+                     :token {:input :test
+                             :lexeme "false"
+                             :line 2
+                             :literal false
+                             :source "  when {\n   false -> :nope\n   nil -> :nope\n  }\n "
+                             :start 12
+                             :type :false}
+                     :type :bool}
+                    {:data :nope
+                     :token {:input :test
+                             :lexeme ":nope"
+                             :line 2
+                             :literal :nope
+                             :source "  when {\n   false -> :nope\n   nil -> :nope\n  }\n "
+                             :start 21
+                             :type :keyword}
+                     :type :keyword}]
+                   [{:token {:input :test
+                             :lexeme "nil"
+                             :line 3
+                             :literal :none
+                             :source "  when {\n   false -> :nope\n   nil -> :nope\n  }\n "
+                             :start 30
+                             :type :nil}
+                     :type :nil}
+                    {:data :nope
+                     :token {:input :test
+                             :lexeme ":nope"
+                             :line 3
+                             :literal :nope
+                             :source "  when {\n   false -> :nope\n   nil -> :nope\n  }\n "
+                             :start 37
+                             :type :keyword}
+                     :type :keyword}]]
+           :token {:input :test
+                   :lexeme "when"
+                   :line 1
+                   :literal :none
+                   :source "  when {\n   false -> :nope\n   nil -> :nope\n  }\n "
+                   :start 2
+                   :type :when}
+           :type :when}})
+)
+
+(deftest "match forms work as expected"
+ (test (run `
+  match :foo with {
+   :bar -> :nope
+   :baz -> :nope
+   x -> x
+  }
+ `)
+   :foo)
+ (test (run `
+  let foo = 42
+  match (:ok, foo) with {
+   (:err, _) -> :nope
+   (:ok, :foo) -> :nope
+   (:ok, _) -> :yes
+  }
+ `)
+   :yes)
+ (test-error (run `
+  let foo = "foo"
+  match foo with {
+   "bar" -> :nope
+   "baz" -> :nope
+   12.34 -> :nope 
+  }
+ `)
+   {:msg "no match: match form"
+    :node @{:data [{:data "foo"
+                    :token {:input :test
+                            :lexeme "foo"
+                            :line 2
+                            :literal :none
+                            :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                            :start 26
+                            :type :word}
+                    :type :word}
+                   @[[{:data "bar"
+                       :token {:input :test
+                               :lexeme "\"bar\""
+                               :line 3
+                               :literal "bar"
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 40
+                               :type :string}
+                       :type :string}
+                      nil
+                      {:data :nope
+                       :token {:input :test
+                               :lexeme ":nope"
+                               :line 3
+                               :literal :nope
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 49
+                               :type :keyword}
+                       :type :keyword}]
+                     [{:data "baz"
+                       :token {:input :test
+                               :lexeme "\"baz\""
+                               :line 4
+                               :literal "baz"
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 58
+                               :type :string}
+                       :type :string}
+                      nil
+                      {:data :nope
+                       :token {:input :test
+                               :lexeme ":nope"
+                               :line 4
+                               :literal :nope
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 67
+                               :type :keyword}
+                       :type :keyword}]
+                     [{:data 12.34
+                       :token {:input :test
+                               :lexeme "12.34"
+                               :line 5
+                               :literal 12.34
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 76
+                               :type :number}
+                       :type :number}
+                      nil
+                      {:data :nope
+                       :token {:input :test
+                               :lexeme ":nope"
+                               :line 5
+                               :literal :nope
+                               :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                               :start 85
+                               :type :keyword}
+                       :type :keyword}]]]
+            :match @match-fn
+            :token {:input :test
+                    :lexeme "match"
+                    :line 2
+                    :literal :none
+                    :source "  let foo = \"foo\"\n  match foo with {\n   \"bar\" -> :nope\n   \"baz\" -> :nope\n   12.34 -> :nope \n  }\n "
+                    :start 20
+                    :type :match}
+            :type :match}
+    :value "foo"})
+)
+
+(deftest "string patterns work as expected"
+ (test (run `let "I {verb} the {noun}" = "I am the walrus"; (verb, noun)`) ["am" "walrus"])
+ (test (run `let "a {b} c {d}" = "a because I love you c yourself out the door"; (b, d)`)
+   ["because I love you"
+    "yourself out the door"])
+)
+
+(deftest "lambdas may be defined and called"
+ (test (run `
+  let foo = fn () -> :foo
+  foo ()
+ `)
+   :foo)
+ (test (run `
+  let pair = fn (x, y) -> (x, y)
+  pair (:foo, :bar)
+ `)
+   [:foo :bar])
+ (test-error (run `
+  let foo = fn () -> :foo
+  foo (:bar)
+ `)
+   {:called @{:^type :fn
+              :body [[{:data @[]
+                       :token {:input :test
+                               :lexeme "("
+                               :line 1
+                               :source "  let foo = fn () -> :foo\n  foo (:bar)\n "
+                               :start 15
+                               :type :lparen}
+                       :type :tuple}
+                      nil
+                      {:data :foo
+                       :token {:input :test
+                               :lexeme ":foo"
+                               :line 1
+                               :literal :foo
+                               :source "  let foo = fn () -> :foo\n  foo (:bar)\n "
+                               :start 21
+                               :type :keyword}
+                       :type :keyword}]]
+              :ctx @{}
+              :match @match-fn}
+    :msg "no match: function call"
+    :node {:data "foo"
+           :token {:input :test
+                   :lexeme "foo"
+                   :line 2
+                   :literal :none
+                   :source "  let foo = fn () -> :foo\n  foo (:bar)\n "
+                   :start 28
+                   :type :word}
+           :type :word}
+    :value [:bar]})
+)
diff --git a/janet/prelude.test.janet b/janet/prelude.test.janet
new file mode 100644
index 0000000..6be9933
--- /dev/null
+++ b/janet/prelude.test.janet
@@ -0,0 +1,34 @@
+# testing the prelude
+(try (os/cd "janet") ([_] nil))
+(import /scanner :as s)
+(import /parser :as p)
+(import /validate :as v)
+(import /interpreter :as i)
+(import /errors :as e)
+(import /base :as b)
+(import /load-prelude :as pre)
+(use judge)
+
+(defn run [source]
+ (when (= :error pre/pkg) (error "could not load prelude"))
+ (def ctx @{:^parent pre/ctx})
+ (def scanned (s/scan source :test))
+ (when (any? (scanned :errors))
+  (e/scan-error (scanned :errors)) (error "scanning errors"))
+ (def parsed (p/parse scanned))
+ (when (any? (parsed :errors))
+  (e/parse-error (parsed :errors)) (error "parsing errors"))
+ (def valid (v/valid parsed ctx))
+ (when (any? (valid :errors)) (each err (valid :errors)
+  (e/validation-error err)) (error "validation errors"))
+ (i/interpret (parsed :ast) ctx))
+
+(deftest "debug add_msg"
+ (test (run `
+  let msgs = [1, :foo, nil]
+  let msg =	do msgs > map (string, _)
+  msg
+ `)
+   @["1" ":foo" ":^nil"])
+ # (test (run `print! ("foo", "bar")`) :ok)
+)
diff --git a/janet/project.janet b/janet/project.janet
new file mode 100644
index 0000000..a43aa16
--- /dev/null
+++ b/janet/project.janet
@@ -0,0 +1,5 @@
+(declare-project
+  :dependencies [
+    {:url "https://github.com/ianthehenry/judge.git"
+     :tag "v2.8.1"}
+  ])
diff --git a/janet/test.janet b/janet/test.janet
deleted file mode 100644
index 4057c58..0000000
--- a/janet/test.janet
+++ /dev/null
@@ -1,7 +0,0 @@
-(def myodd? nil)
-
-(defn myeven? [x] (if (= 0 x) true (myodd? (dec x))))
-
-(defn myodd? [x] (if (= 0 x) false (myeven? (dec x))))
-
-(myeven? 2)
diff --git a/janet/watchy.fish b/janet/watchy.fish
new file mode 100755
index 0000000..f9b1e76
--- /dev/null
+++ b/janet/watchy.fish
@@ -0,0 +1,5 @@
+#!/opt/homebrew/bin/fish
+
+set FILE $argv[1]
+
+fd $FILE | entr ./judgy.fish /_