From ba898aa8d8ef616bf36b0cf0b1c0ca6382ccf057 Mon Sep 17 00:00:00 2001
From: gilch <gilch@users.noreply.github.com>
Date: Mon, 18 Sep 2017 13:50:41 -0600
Subject: [PATCH] support (nonlocal) in `let`

---
 hy/contrib/walk.hy                   |  9 ++----
 tests/native_tests/contrib/walk.hy   | 36 +++++++++++++++--------
 tests/native_tests/py3_only_tests.hy | 43 ++++++++++++++++++++++------
 3 files changed, 61 insertions(+), 27 deletions(-)

diff --git a/hy/contrib/walk.hy b/hy/contrib/walk.hy
index 73e556c..2d2a202 100644
--- a/hy/contrib/walk.hy
+++ b/hy/contrib/walk.hy
@@ -161,7 +161,7 @@ as can nested let forms.
                ;; else expand if applicable
                (if (and (in form bound-symbols)
                         (not-in form protected-symbols))
-                   `(get ~g!let ~(name form))
+                   (HySymbol (+ g!let "::" form))
                    form))]
           ;; We have to treat special forms differently.
           ;; Quotation should suppress symbol expansion,
@@ -232,15 +232,10 @@ as can nested let forms.
           [True form]))
   (expand-symbols #{}
                    `(do
-                      (setv ~g!let {}
-                            ~@bindings)
+                      (setv ~@bindings)
                       ~@body)))
 
 #_[special cases for let
-   ;; this means we can't use a list for our let scope
-   ;; we're using a dict instead.
-   'del',
-
    ;; Symbols containing a dot should be converted to this form.
    ;; attrs should not get expanded,
    ;; but [] lookups should.
diff --git a/tests/native_tests/contrib/walk.hy b/tests/native_tests/contrib/walk.hy
index caf9151..1a7b4e3 100644
--- a/tests/native_tests/contrib/walk.hy
+++ b/tests/native_tests/contrib/walk.hy
@@ -135,8 +135,8 @@
          (do
            foo
            (assert False))
-         (except [ke LookupError]
-           (setv error ke)))
+         (except [ne NameError]
+           (setv error ne)))
        (setv foo 16)
        (assert (= foo 16))
        (setv [foo bar baz] [1 2 3])
@@ -153,6 +153,14 @@
          (if done (break))))
   (assert (= x 1)))
 
+(defn test-let-continue []
+  (let [foo []]
+       (for [x (range 10)]
+         (let [odd (odd? x)]
+              (if odd (continue))
+              (.append foo x)))
+       (assert (= foo [0 2 4 6 8]))))
+
 (defn test-let-yield []
   (defn grind []
     (yield 0)
@@ -231,16 +239,15 @@
         &rest 12]
        (defn foo [a b &rest xs]
          (-= a 1)
-         (-= c 1)
          (setv xs (list xs))
          (.append xs 42)
          (, &rest a b c xs))
        (assert (= xs 6))
        (assert (= a 88))
        (assert (= (foo 1 2 3 4)
-                  (, 12 0 2 63 [3 4 42])))
+                  (, 12 0 2 64 [3 4 42])))
        (assert (= xs 6))
-       (assert (= c 63))
+       (assert (= c 64))
        (assert (= a 88))))
 
 (defn test-let-kwargs []
@@ -275,12 +282,17 @@
                   (, 10 20 30)))
        (assert (= (, a b d)
                   (, 1 6 2)))))
-;; TODO
-;; test-let-continue
-;; test-let-closure
-;; test-let-global
+
+(defn test-let-closure []
+  (let [count [0]]
+       (defn +count [&optional [x 1]]
+         (+= (get count 0) x)
+         (get count 0)))
+  ;; let bindings can still exist outside of a let body
+  (assert (= 1 (+count)))
+  (assert (= 2 (+count)))
+  (assert (= 42 (+count 40))))
 
 ;; TODO
-;;; Python 3 only
-;; test-let-nonlocal
-;; test-let-kwonly
+;; test-let-global
+
diff --git a/tests/native_tests/py3_only_tests.hy b/tests/native_tests/py3_only_tests.hy
index 84b8053..90331fd 100644
--- a/tests/native_tests/py3_only_tests.hy
+++ b/tests/native_tests/py3_only_tests.hy
@@ -8,8 +8,8 @@
 
 (defn test-exception-cause []
   (try (raise ValueError :from NameError)
-  (except [e [ValueError]]
-    (assert (= (type (. e __cause__)) NameError)))))
+       (except [e [ValueError]]
+         (assert (= (type (. e __cause__)) NameError)))))
 
 
 (defn test-kwonly []
@@ -21,8 +21,8 @@
   ;; keyword-only without default ...
   (defn kwonly-foo-no-default [&kwonly foo] foo)
   (setv attempt-to-omit-default (try
-                                (kwonly-foo-no-default)
-                                (except [e [Exception]] e)))
+                                  (kwonly-foo-no-default)
+                                  (except [e [Exception]] e)))
   ;; works
   (assert (= (kwonly-foo-no-default :foo "quux") "quux"))
   ;; raises TypeError with appropriate message if not supplied
@@ -64,9 +64,36 @@
     (assert 0))
   (defn yield-from-test []
     (for* [i (range 3)]
-       (yield i))
+      (yield i))
     (try
-     (yield-from (yield-from-subgenerator-test))
-     (except [e AssertionError]
-       (yield 4))))
+      (yield-from (yield-from-subgenerator-test))
+      (except [e AssertionError]
+        (yield 4))))
   (assert (= (list (yield-from-test)) [0 1 2 1 2 3 4])))
+
+(require [hy.contrib.walk [let]])
+(defn test-let-nonlocal []
+  (let [a 88
+        c 64]
+       (defn foo [a b]
+         (nonlocal c)
+         (-= a 1)
+         (-= c 1)
+         (, a b c))
+       (assert (= a 88))
+       (assert (= (foo 1 2)
+                  (, 0 2 63)))
+       (assert (= c 63))
+       (assert (= a 88))))
+
+(defn test-let-optional []
+  (let [a 1
+        b 6
+        d 2]
+       (defn foo [&kwonly [a a] b [c d]]
+         (, a b c))
+       (assert (= (foo :b "b")
+                  (, 1 "b" 2)))
+       (assert (= (foo :b 20 :a 10 :c 30)
+                  (, 10 20 30)))))
+