Drop a set of brackets from let.

This changes let to use a flat list of symbol-value pairs instead of a
vector of vectors. One side effect is that (let [[a 1] z]) is not
expressible now, and one will explicitly need to set a nil value for z,
such as: (let [a 1 z nil]).

Closes #713.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

docs/language/api.rst

@@ -213,17 +213,17 @@ Examples of usage:
 
 .. code-block:: clj
 
-  =>(let [[collection {}]]
+  =>(let [collection {}]
   ... (assoc collection "Dog" "Bark")
   ... (print collection))
   {u'Dog': u'Bark'}
 
-  =>(let [[collection {}]]
+  =>(let [collection {}]
   ... (assoc collection "Dog" "Bark" "Cat" "Meow")
   ... (print collection))
   {u'Cat': u'Meow', u'Dog': u'Bark'}
 
-  =>(let [[collection [1 2 3 4]]]
+  =>(let [collection [1 2 3 4]]
   ... (assoc collection 2 None)
   ... (print collection))
   [1, 2, None, 4]
@@ -463,8 +463,8 @@ Parameters may have the following keywords in front of them:
     .. code-block:: clj
 
         => (defn zig-zag-sum [&rest numbers]
-             (let [[odd-numbers (list-comp x [x numbers] (odd? x))]
-	           [even-numbers (list-comp x [x numbers] (even? x))]]
+             (let [odd-numbers (list-comp x [x numbers] (odd? x))
+	           even-numbers (list-comp x [x numbers] (even? x))]
                (- (sum odd-numbers) (sum even-numbers))))
 
         => (zig-zag-sum)
@@ -486,7 +486,7 @@ Parameters may have the following keywords in front of them:
     .. code-block:: clj
 
         => (defn compare [a b &kwonly keyfn [reverse false]]
-        ...  (let [[result (keyfn a b)]]
+        ...  (let [result (keyfn a b)]
         ...    (if (not reverse)
         ...      result
         ...      (- result))))
@@ -786,8 +786,8 @@ list. Example usage:
 
 .. code-block:: clj
 
-   => (let [[animals {"dog" "bark" "cat" "meow"}]
-   ...      [numbers ["zero" "one" "two" "three"]]]
+   => (let [animals {"dog" "bark" "cat" "meow"}
+   ...      numbers ["zero" "one" "two" "three"]]
    ...  (print (get animals "dog"))
    ...  (print (get numbers 2)))
    bark
@@ -988,30 +988,24 @@ example showcases this behaviour:
 
 .. code-block:: clj
 
-    => (let [[x 5]] (print x)
-    ...  (let [[x 6]] (print x))
+    => (let [x 5] (print x)
+    ...  (let [x 6] (print x))
     ...  (print x))
     5
     6
     5
 
-The ``let`` macro takes two parameters: a vector defining *variables* and the
-*body* which gets executed. *variables* is a vector where each element is either
-a single variable or a vector defining a variable value pair. In the case of a
-single variable, it is assigned value ``None``; otherwise, the supplied value is
-used.
-
-.. code-block:: clj
-
-    => (let [x [y 5]] (print x y))
-    None 5
+The ``let`` macro takes two parameters: a vector defining *variables*
+and the *body* which gets executed. *variables* is a vector of
+variable and value pairs.
 
 Note that the variable assignments are executed one by one, from left to right.
 The following example takes advantage of this:
 
 .. code-block:: clj
 
-    => (let [[x 5] [y (+ x 1)]] (print x y))
+    => (let [x 5 
+             y (+ x 1)] (print x y))
     5 6
 
 
@@ -1050,15 +1044,15 @@ to modify variables through nested ``let`` or ``fn`` scopes:
 
 .. code-block:: clj
 
-    (let [[x 0]]
+    (let [x 0]
       (for [y (range 10)]
-        (let [[z (inc y)]]
+        (let [z (inc y)]
           (nonlocal x)  ; allow the setv to "jump scope" to resolve x
           (setv x (+ x y))))
       x)
 
     (defn some-function []
-      (let [[x 0]]
+      (let [x 0]
         (register-some-callback
           (fn [stuff]
             (nonlocal x)
@@ -1467,9 +1461,9 @@ expands to:
 
 .. code-block:: hy
 
-   (let [[a (gensym)
-         [b (gensym)
-         [c (gensym)]]
+   (let [a (gensym)
+         b (gensym)
+         c (gensym)]
      ...)
 
 .. seealso::

docs/language/core.rst

@@ -1103,7 +1103,7 @@ if *from-file* ends before a complete expression can be parsed.
    => (with [[f (open "example.hy")]]
    ...   (try
    ...     (while true
-   ...            (let [[exp (read f)]]
+   ...            (let [exp (read f)]
    ...              (do
    ...                (print "OHY" exp)
    ...                (eval exp))))

docs/language/internals.rst

@@ -381,7 +381,7 @@ A first pass might be something like:
 .. code-block:: hy
 
    (defmacro nif [expr pos-form zero-form neg-form]
-     `(let [[obscure-name ~expr]]
+     `(let [obscure-name ~expr]
        (cond [(pos? obscure-name) ~pos-form]
              [(zero? obscure-name) ~zero-form]
              [(neg? obscure-name) ~neg-form])))
@@ -396,8 +396,8 @@ such an occasion. A much better version of ``nif`` would be:
 .. code-block:: hy
 
    (defmacro nif [expr pos-form zero-form neg-form]
-     (let [[g (gensym)]]
-       `(let [[~g ~expr]]
+     (let [g (gensym)]
+       `(let [~g ~expr]
           (cond [(pos? ~g) ~pos-form]
                 [(zero? ~g) ~zero-form]
                 [(neg? ~g) ~neg-form]))))
@@ -415,9 +415,9 @@ expands to:
 
 .. code-block:: hy
 
-   (let [[a (gensym)
-         [b (gensym)
-         [c (gensym)]]
+   (let [a (gensym)
+         b (gensym)
+         c (gensym)]
      ...)
 
 so our re-written ``nif`` would look like:
@@ -426,7 +426,7 @@ so our re-written ``nif`` would look like:
 
    (defmacro nif [expr pos-form zero-form neg-form]
      (with-gensyms [g]
-       `(let [[~g ~expr]]
+       `(let [~g ~expr]
           (cond [(pos? ~g) ~pos-form]
                 [(zero? ~g) ~zero-form]
                 [(neg? ~g) ~neg-form]))))
@@ -440,7 +440,7 @@ Our final version of ``nif``, built with ``defmacro/g!`` becomes:
 .. code-block:: hy
 
    (defmacro/g! nif [expr pos-form zero-form neg-form]
-     `(let [[~g!res ~expr]]
+     `(let [~g!res ~expr]
         (cond [(pos? ~g!res) ~pos-form]
               [(zero? ~g!res) ~zero-form]
               [(neg? ~g!res) ~neg-form]))))

docs/style-guide.rst

@@ -105,8 +105,8 @@ Layout & Indentation
 
   .. code-block:: clj
 
-     (let [[foo (bar)]
-           [qux (baz)]]
+     (let [foo (bar)]
+           qux (baz)]
         (foo qux))
 
 

eg/twisted/get-page.hy

@@ -27,7 +27,7 @@
   (reactor.stop))
 
 (defn get-page [url]
-  (let [[d (getPage url)]]
+  (let [d (getPage url)]
     (d.addCallback get-page-size)
     (d.addErrback log-error)
     (d.addCallback finish)))

hy/contrib/alias.hy

@@ -30,8 +30,8 @@
 
 (defmacro defn-alias [names lambda-list &rest body]
   "define one function with several names"
-  (let [[main (first names)]
-        [aliases (rest names)]]
+  (let [main (first names)
+        aliases (rest names)]
     (setv ret `(do (defn ~main ~lambda-list ~@body)))
     (for* [name aliases]
       (.append ret

hy/contrib/anaphoric.hy

@@ -26,7 +26,7 @@
 
 
 (defmacro ap-if (test-form &rest args)
-  `(let [[it ~test-form]] (if it ~@args)))
+  `(let [it ~test-form] (if it ~@args)))
 
 
 (defmacro ap-each [lst &rest body]
@@ -37,7 +37,7 @@
 (defmacro ap-each-while [lst form &rest body]
   "Evalutate the body form for each element in the list while the
   predicate form evaluates to True."
-  `(let [[p (lambda [it] ~form)]]
+  `(let [p (lambda [it] ~form)]
      (for [it ~lst]
        (if (p it)
          ~@body
@@ -46,8 +46,9 @@
 
 (defmacro ap-map [form lst]
   "Yield elements evaluated in the form for each element in the list."
-  (let [[v (gensym 'v)] [f (gensym 'f)]]
-    `(let [[~f (lambda [it] ~form)]]
+  (let [v (gensym 'v)
+        f (gensym 'f)]
+    `(let [~f (lambda [it] ~form)]
        (for [~v ~lst]
          (yield (~f ~v))))))
 
@@ -55,7 +56,7 @@
 (defmacro ap-map-when [predfn rep lst]
   "Yield elements evaluated for each element in the list when the
   predicate function returns True."
-  `(let [[f (lambda [it] ~rep)]]
+  `(let [f (lambda [it] ~rep)]
      (for [it ~lst]
        (if (~predfn it)
          (yield (f it))
@@ -64,7 +65,7 @@
 
 (defmacro ap-filter [form lst]
   "Yield elements returned when the predicate form evaluates to True."
-  `(let [[pred (lambda [it] ~form)]]
+  `(let [pred (lambda [it] ~form)]
      (for [val ~lst]
        (if (pred val)
          (yield val)))))
@@ -85,7 +86,7 @@
 (defmacro ap-first [predfn lst]
   "Yield the first element that passes `predfn`"
   (with-gensyms [n]
-    `(let [[~n None]]
+    `(let [~n None]
        (ap-each ~lst (when ~predfn (setv ~n it) (break)))
        ~n)))
 
@@ -93,7 +94,7 @@
 (defmacro ap-last [predfn lst]
   "Yield the last element that passes `predfn`"
   (with-gensyms [n]
-    `(let [[~n None]]
+    `(let [~n None]
        (ap-each ~lst (none? ~n)
                 (when ~predfn
                   (setv ~n it)))
@@ -103,10 +104,10 @@
 (defmacro ap-reduce [form lst &optional [initial-value None]]
   "Anaphoric form of reduce, `acc' and `it' can be used for a form"
   (if (none? initial-value)
-    `(let [[acc (car ~lst)]]
+    `(let [acc (car ~lst)]
        (ap-each (cdr ~lst) (setv acc ~form))
        acc)
-    `(let [[acc ~initial-value]]
+    `(let [acc ~initial-value]
        (ap-each ~lst (setv acc ~form))
        acc)))
 
@@ -115,7 +116,7 @@
   "Pushes a value through several forms.
   (Anaphoric version of -> and ->>)"
   (if (empty? forms) var
-      `(ap-pipe (let [[it ~var]] ~(first forms)) ~@(rest forms))))
+      `(ap-pipe (let [it ~var] ~(first forms)) ~@(rest forms))))
 
 
 (defmacro ap-compose [&rest forms]

hy/contrib/botsbuildbots.hy

@@ -26,8 +26,8 @@
     (do
      (import [requests])
 
-     (let [[r (requests.get
-               "https://raw.githubusercontent.com/hylang/hy/master/AUTHORS")]]
+     (let [r (requests.get
+              "https://raw.githubusercontent.com/hylang/hy/master/AUTHORS")]
        (repeat r.text)))
     (except [e ImportError]
       (repeat "Botsbuildbots requires `requests' to function."))))

hy/contrib/curry.hy

@@ -2,8 +2,8 @@
 
 
 (defn curry [func]
-  (let [[sig (.getargspec inspect func)]
-        [count (len sig.args)]]
+  (let [sig (.getargspec inspect func)
+        count (len sig.args)]
 
     (fn [&rest args]
       (if (< (len args) count)

hy/contrib/loop.hy

@@ -58,7 +58,7 @@
 
 
 (defmacro/g! fnr [signature &rest body]
-  (let [[new-body (recursive-replace 'recur g!recur-fn body)]]
+  (let [new-body (recursive-replace 'recur g!recur-fn body)]
     `(do
       (import [hy.contrib.loop [--trampoline--]])
       (with-decorator
@@ -85,7 +85,7 @@
   ;; If recur is used in a non-tail-call position, None is returned, which
   ;; causes chaos. Fixing this to detect if recur is in a tail-call position
   ;; and erroring if not is a giant TODO.
-  (let [[fnargs (map (fn [x] (first x)) bindings)]
-        [initargs (map second bindings)]]
+  (let [fnargs (map (fn [x] (first x)) bindings)
+        initargs (map second bindings)]
     `(do (defnr ~g!recur-fn [~@fnargs] ~@body)
          (~g!recur-fn ~@initargs))))

hy/contrib/meth.hy

@@ -3,8 +3,8 @@
 
 (defmacro route-with-methods [name path methods params &rest code]
   "Same as route but with an extra methods array to specify HTTP methods"
-  `(let [[deco (apply app.route [~path]
-                                    {"methods" ~methods})]]
+  `(let [deco (apply app.route [~path]
+                     {"methods" ~methods})]
      (with-decorator deco
        (defn ~name ~params
          (do ~@code)))))

hy/core/bootstrap.hy

@@ -42,22 +42,14 @@
 
 (defmacro let [variables &rest body]
   "Execute `body` in the lexical context of `variables`"
-  (setv macroed_variables [])
   (if (not (isinstance variables HyList))
     (macro-error variables "let lexical context must be a list"))
-  (for* [variable variables]
-    (if (isinstance variable HyList)
-      (do
-       (if (!= (len variable) 2)
-         (macro-error variable "let variable assignments must contain two items"))
-       (.append macroed-variables `(setv ~(get variable 0) ~(get variable 1))))
-      (if (isinstance variable HySymbol)
-        (.append macroed-variables `(setv ~variable None))
-        (macro-error variable "let lexical context element must be a list or symbol"))))
+  (if (= (len variables) 0)
     `((fn []
-     ~@macroed-variables
-     ~@body)))
-
+        ~@body))
+    `((fn []
+        (setv ~@variables)
+        ~@body))))
 
 (defmacro if-python2 [python2-form python3-form]
   "If running on python2, execute python2-form, else, execute python3-form"

hy/core/language.hy

@@ -84,7 +84,8 @@
 (defn distinct [coll]
   "Return a generator from the original collection with duplicates
    removed"
-  (let [[seen (set)] [citer (iter coll)]]
+  (let [seen (set)
+        citer (iter coll)]
   (for* [val citer]
     (if (not_in val seen)
       (do
@@ -158,7 +159,7 @@
 
 (defn drop-last [n coll]
   "Return a sequence of all but the last n elements in coll."
-  (let [[iters (tee coll)]]
+  (let [iters (tee coll)]
     (map first (apply zip [(get iters 0)
                            (drop n (get iters 1))]))))
 
@@ -210,7 +211,7 @@
 (setv _gensym_lock (Lock))
 
 (defn gensym [&optional [g "G"]]
-  (let [[new_symbol None]]
+  (let [new_symbol None]
     (global _gensym_counter)
     (global _gensym_lock)
     (.acquire _gensym_lock)
@@ -310,14 +311,15 @@
    from the latter (left-to-right) will be combined with the mapping in
    the result by calling (f val-in-result val-in-latter)."
   (if (any maps)
-    (let [[merge-entry (fn [m e]
-			 (let [[k (get e 0)] [v (get e 1)]]
+    (let [merge-entry (fn [m e]
+                        (let [k (get e 0)
+                              v (get e 1)]
                         (if (in k m)
                           (assoc m k (f (get m k) v))
                           (assoc m k v)))
-			 m)]
-	  [merge2 (fn [m1 m2]
-		    (reduce merge-entry (.items m2) (or m1 {})))]]
+          m)
+      merge2 (fn [m1 m2]
+               (reduce merge-entry (.items m2) (or m1 {})))]
     (reduce merge2 maps))))
 
 (defn neg? [n]
@@ -402,7 +404,8 @@
   "Return every nth member of coll
      raises ValueError for (not (pos? n))"
   (if (pos? n)
-    (let [[citer (iter coll)] [skip (dec n)]]
+    (let [citer (iter coll)
+          skip (dec n)]
     (for* [val citer]
       (yield val)
       (for* [_ (range skip)]

hy/core/macros.hy

@@ -39,7 +39,7 @@
       baz))"
 
   (if (not (empty? args))
-    (let [[primary (.pop args 0)]]
+    (let [primary (.pop args 0)]
       (if (isinstance primary HyList)
         ;;; OK. if we have a list, we can go ahead and unpack that
         ;;; as the argument to with.
@@ -115,7 +115,7 @@
    [(empty? args) `(do ~@body ~@belse)]
    [(= (len args) 2) `(for* [~@args] (do ~@body) ~@belse)]
    [true
-    (let [[alist (cut args 0 nil 2)]]
+    (let [alist (cut args 0 nil 2)]
       `(for* [(, ~@alist) (genexpr (, ~@alist) [~@args])] (do ~@body) ~@belse))]))
 
 
@@ -138,7 +138,7 @@
     (if (isinstance expression HyExpression)
       `(~(first expression) ~f ~@(rest expression))
       `(~expression ~f)))
-  `(let [[~f ~form]]
+  `(let [~f ~form]
      ~@(map build-form expressions)
      ~f))
 
@@ -180,13 +180,24 @@
 
 
 (defmacro with-gensyms [args &rest body]
-  `(let ~(HyList (map (fn [x] `[~x (gensym '~x)]) args))
+  (setv syms [])
+  (for* [arg args]
+    (.extend syms `[~arg (gensym '~arg)]))
+  `(let ~syms
      ~@body))
 
 (defmacro defmacro/g! [name args &rest body]
-  (let [[syms (list (distinct (filter (fn [x] (and (hasattr x "startswith") (.startswith x "g!"))) (flatten body))))]]
+  (let [syms (list
+              (distinct
+               (filter (fn [x]
+                         (and (hasattr x "startswith")
+                              (.startswith x "g!")))
+                       (flatten body))))
+        gensyms []]
+    (for* [sym syms]
+      (.extend gensyms `[~sym (gensym (cut '~sym 2))]))
     `(defmacro ~name [~@args]
-       (let ~(HyList (map (fn [x] `[~x (gensym (cut '~x 2))]) syms))
+       (let ~gensyms
          ~@body))))
 
 
@@ -211,9 +222,9 @@
 
 (defmacro defmain [args &rest body]
   "Write a function named \"main\" and do the if __main__ dance"
-  (let [[retval (gensym)]
-        [mainfn `(fn [~@args]
-                   ~@body)]]
+  (let [retval (gensym)
+        mainfn `(fn [~@args]
+                  ~@body)]
     `(when (= --name-- "__main__")
        (import sys)
        (setv ~retval (apply ~mainfn sys.argv))
@@ -222,6 +233,6 @@
 
 
 (defreader @ [expr]
-  (let [[decorators (cut expr nil -1)]
-        [fndef (get expr -1)]]
+  (let [decorators (cut expr nil -1)
+        fndef (get expr -1)]
     `(with-decorator ~@decorators ~fndef)))

hy/core/shadow.hy

@@ -26,7 +26,7 @@
 
 (defn + [&rest args]
   "Shadow + operator for when we need to import / map it against something"
-  (let [[count (len args)]]
+  (let [count (len args)]
     (if (zero? count)
       (raise (TypeError "Need at least 1 argument to add/concatenate"))
       (if (= count 1)
@@ -36,7 +36,7 @@
 
 (defn - [&rest args]
   "Shadow - operator for when we need to import / map it against something"
-  (let [[count (len args)]]
+  (let [count (len args)]
     (if (= count 0)
       (raise (TypeError "Need at least 1 argument to subtract"))
       (if (= count 1)
@@ -53,7 +53,7 @@
 
 (defn / [&rest args]
   "Shadow / operator for when we need to import / map it against something"
-  (let [[count (len args)]]
+  (let [count (len args)]
     (if (= count 0)
       (raise (TypeError "Need at least 1 argument to divide"))
       (if (= count 1)

scripts/reformat-changelog

@@ -8,18 +8,18 @@
       " -- Alexander Artemenko <svetlyak.40wt@gmail.com>  Thu, 30 Sep 2014 13:06:09 +0400")
 
 (defn read-lines-from-file [filename]
-  (let [[f (codecs.open filename "r" "utf-8")]]
-       (fn [] (let [[line (.readline f) ]]
+  (let [f (codecs.open filename "r" "utf-8")]
+    (fn [] (let [line (.readline f) ]
              line))))
 
 
 (defn get-version-number [line]
-  (let [[match (re.search r"Changes from.*(\d+\.\d+\.\d+)$" line)]]
+  (let [match (re.search r"Changes from.*(\d+\.\d+\.\d+)$" line)]
     (if match
-           (let [[version (.group match (int 1))]
-                 [numbered (list (map int (.split version "."))) ]
-                 [explicit-mapping {"0.9.12" "0.10.0"
-                                    "0.8.2" "0.9.0"}]]
+      (let [version (.group match (int 1))
+            numbered (list (map int (.split version ".")))
+            explicit-mapping {"0.9.12" "0.10.0"
+                                        "0.8.2" "0.9.0"}]
         (assoc numbered 2 (+ (get numbered 2) 1))
         (.get explicit-mapping
               version
@@ -36,14 +36,14 @@
 
 
 (defn read-versions-from-file [filename]
-  (let [[reader (read-lines-from-file filename)]]
+  (let [reader (read-lines-from-file filename)]
     (read-versions-rec (reader)
                        reader)))
 
 (defn read-versions-rec [line reader]
   (if line 
-      (let [[version (get-version-number line)]
-        [[content next-line] (read-version-content reader)]]
+      (let [version (get-version-number line)
+            [content next-line] (read-version-content reader)]
 
         (+ [{"from" version
              "content" content}]
@@ -61,6 +61,6 @@
 
 
 (defmain [&rest args]
-  (let ((versions (read-versions-from-file "NEWS")))
+  (let [versions (read-versions-from-file "NEWS")]
     (for [version versions]
       (print (.encode (format-deb-version version) "utf-8")))))

tests/compilers/test_ast.py

@@ -321,20 +321,18 @@ def test_ast_invalid_for():
 
 def test_ast_valid_let():
     "Make sure AST can compile valid let"
-    can_compile("(let [])")
     can_compile("(let [a b])")
-    can_compile("(let [[a 1]])")
-    can_compile("(let [[a 1] b])")
+    can_compile("(let [a 1])")
+    can_compile("(let [a 1 b nil])")
 
 
 def test_ast_invalid_let():
     "Make sure AST can't compile invalid let"
     cant_compile("(let 1)")
     cant_compile("(let [1])")
-    cant_compile("(let [[a 1 2]])")
-    cant_compile("(let [[]])")
-    cant_compile("(let [[a]])")
-    cant_compile("(let [[1]])")
+    cant_compile("(let [a 1 2])")
+    cant_compile("(let [a])")
+    cant_compile("(let [1])")
 
 
 def test_ast_expression_basics():

tests/native_tests/contrib/anaphoric.hy

@@ -55,7 +55,7 @@
                 [3 6 9])
   (assert-equal (list (ap-map (* it 3) []))
                 [])
-  (assert-equal (let [[v 1] [f 1]] (list (ap-map (it v f) [(fn [a b] (+ a b))])))
+  (assert-equal (let [v 1 f 1] (list (ap-map (it v f) [(fn [a b] (+ a b))])))
                 [2]))
 
 (defn test-ap-map-when []
@@ -79,9 +79,9 @@
 
 (defn test-ap-dotimes []
   "NATIVE: testing anaphoric dotimes"
-  (assert-equal (let [[n []]] (ap-dotimes 3 (.append n 3)) n)
+  (assert-equal (let [n []] (ap-dotimes 3 (.append n 3)) n)
 		[3 3 3])
-  (assert-equal (let [[n []]] (ap-dotimes 3 (.append n it)) n)
+  (assert-equal (let [n []] (ap-dotimes 3 (.append n it)) n)
 		[0 1 2]))
 
 (defn test-ap-first []

tests/native_tests/contrib/meth.hy

@@ -9,44 +9,44 @@
       f)))
 
 (defn test_route []
-  (let [[app (FakeMeth)]]
+  (let [app (FakeMeth)]
     (route get-index "/" []  (str "Hy world!"))
     (setv app-rules (getattr app "rules"))
     (assert (in "/" app-rules))
-    (let [[(, rule-fun rule-opt) (get app-rules "/")]]
+    (let [(, rule-fun rule-opt) (get app-rules "/")]
       (assert (not (empty? rule-opt)))
       (assert (in "GET" (get rule-opt "methods")))
       (assert (= (getattr rule-fun "__name__") "get_index"))
       (assert (= "Hy world!" (rule-fun))))))
 
 (defn test_post_route []
-  (let [[app (FakeMeth)]]
+  (let [app (FakeMeth)]
     (post-route get-index "/" []  (str "Hy world!"))
     (setv app-rules (getattr app "rules"))
     (assert (in "/" app-rules))
-    (let [[(, rule-fun rule-opt) (get app-rules "/")]]
+    (let [(, rule-fun rule-opt) (get app-rules "/")]
       (assert (not (empty? rule-opt)))
       (assert (in "POST" (get rule-opt "methods")))
       (assert (= (getattr rule-fun "__name__") "get_index"))
       (assert (= "Hy world!" (rule-fun))))))
 
 (defn test_put_route []
-  (let [[app (FakeMeth)]]
+  (let [app (FakeMeth)]
     (put-route get-index "/" []  (str "Hy world!"))
     (setv app-rules (getattr app "rules"))
     (assert (in "/" app-rules))
-    (let [[(, rule-fun rule-opt) (get app-rules "/")]]
+    (let [(, rule-fun rule-opt) (get app-rules "/")]
       (assert (not (empty? rule-opt)))
       (assert (in "PUT" (get rule-opt "methods")))
       (assert (= (getattr rule-fun "__name__") "get_index"))
       (assert (= "Hy world!" (rule-fun))))))
 
 (defn test_delete_route []
-  (let [[app (FakeMeth)]]
+  (let [app (FakeMeth)]
     (delete-route get-index "/" []  (str "Hy world!"))
     (setv app-rules (getattr app "rules"))
     (assert (in "/" app-rules))
-    (let [[(, rule-fun rule-opt) (get app-rules "/")]]
+    (let [(, rule-fun rule-opt) (get app-rules "/")]
       (assert (not (empty? rule-opt)))
       (assert (in "DELETE" (get rule-opt "methods")))
       (assert (= (getattr rule-fun "__name__") "get_index"))

tests/native_tests/contrib/walk.hy

@@ -15,17 +15,17 @@
              walk-form)))
 
 (defn test-walk []
-  (let [[acc '()]]
+  (let [acc '()]
     (assert (= (walk (partial collector acc) identity walk-form)
                [nil nil]))
     (assert (= acc walk-form)))
-  (let [[acc []]]
+  (let [acc []]
     (assert (= (walk identity (partial collector acc) walk-form)
                nil))
     (assert (= acc [walk-form]))))
 
 (defn test-walk-iterators []
-  (let [[acc []]]
+  (let [acc []]
     (assert (= (walk (fn [x] (* 2 x)) (fn [x] x)
                      (drop 1 [1 [2 [3 [4]]]]))
                [[2 [3 [4]] 2 [3 [4]]]]))))

tests/native_tests/core.hy

@@ -592,7 +592,7 @@
   (setv res (list (take-nth 3 [1 2 3 None 5 6])))
   (assert-equal res [1 None])
   ;; using 0 should raise ValueError
-  (let [[passed false]]
+  (let [passed false]
     (try
      (setv res (list (take-nth 0 [1 2 3 4 5 6 7])))
      (except [ValueError] (setv passed true)))

tests/native_tests/defclass.hy

@@ -36,7 +36,7 @@
          (+ self.x value))])
   (assert (= B.x 42))
   (assert (= (.y (B) 5) 47))
-  (let [[b (B)]]
+  (let [b (B)]
     (setv B.x 0)
     (assert (= (.y b 1) 1))))
 

tests/native_tests/language.hy

@@ -355,7 +355,7 @@
   (try (do) (except [IOError]) (except))
 
   ;; Test correct (raise)
-  (let [[passed false]]
+  (let [passed false]
     (try
      (try
       (raise IndexError)
@@ -365,7 +365,7 @@
     (assert passed))
 
   ;; Test incorrect (raise)
-  (let [[passed false]]
+  (let [passed false]
     (try
      (raise)
      ;; Python 2 raises TypeError
@@ -374,16 +374,15 @@
        (setv passed true)))
     (assert passed))
 
-
   ;; Test (finally)
-  (let [[passed false]]
+  (let [passed false]
     (try
      (do)
      (finally (setv passed true)))
     (assert passed))
 
   ;; Test (finally) + (raise)
-  (let [[passed false]]
+  (let [passed false]
     (try
      (raise Exception)
      (except)
@@ -392,8 +391,8 @@
 
 
   ;; Test (finally) + (raise) + (else)
-  (let [[passed false]
-        [not-elsed true]]
+  (let [passed false
+        not-elsed true]
     (try
      (raise Exception)
      (except)
@@ -460,13 +459,13 @@
      (setv foobar42ofthebaz 42)
      (assert (= foobar42ofthebaz 42))))
 
-  (let [[passed false]]
+  (let [passed false]
     (try
      (try (do) (except) (else (bla)))
      (except [NameError] (setv passed true)))
     (assert passed))
 
-  (let [[x 0]]
+  (let [x 0]
     (try
      (raise IOError)
      (except [IOError]
@@ -474,7 +473,7 @@
      (else (setv x 44)))
     (assert (= x 45)))
 
-  (let [[x 0]]
+  (let [x 0]
     (try
      (raise KeyError)
      (except []
@@ -482,7 +481,7 @@
      (else (setv x 44)))
     (assert (= x 45)))
 
-  (let [[x 0]]
+  (let [x 0]
     (try
      (try
       (raise KeyError)
@@ -561,7 +560,7 @@
 (defn test-yield-in-try []
   "NATIVE: test yield in try"
   (defn gen []
-    (let [[x 1]]
+    (let [x 1]
     (try (yield x)
          (finally (print x)))))
   (setv output (list (gen)))
@@ -631,13 +630,13 @@
 
 (defn test-for-else []
   "NATIVE: test for else"
-  (let [[x 0]]
+  (let [x 0]
     (for* [a [1 2]]
       (setv x (+ x a))
       (else (setv x (+ x 50))))
     (assert (= x 53)))
 
-  (let [[x 0]]
+  (let [x 0]
     (for* [a [1 2]]
       (setv x (+ x a))
       (else))
@@ -751,28 +750,28 @@
 (defn test-let []
   "NATIVE: test let works rightish"
   ;; TODO: test sad paths for let
-  (assert (= (let [[x 1] [y 2] [z 3]] (+ x y z)) 6))
-  (assert (= (let [[x 1] a [y 2] b] (if a 1 2)) 2))
-  (assert (= (let [x] x) nil))
-  (assert (= (let [[x "x not bound"]] (setv x "x bound by setv") x)
+  (assert (= (let [x 1 y 2 z 3] (+ x y z)) 6))
+  (assert (= (let [x 1 a nil y 2 b nil] (if a 1 2)) 2))
+  (assert (= (let [x nil] x) nil))
+  (assert (= (let [x "x not bound"] (setv x "x bound by setv") x)
              "x bound by setv"))
-  (assert (= (let [[x "let nests scope correctly"]]
-               (let [y] x))
+  (assert (= (let [x "let nests scope correctly"]
+               (let [y nil] x))
              "let nests scope correctly"))
-  (assert (= (let [[x 999999]]
-               (let [[x "x being rebound"]] x))
+  (assert (= (let [x 999999]
+               (let [x "x being rebound"] x))
              "x being rebound"))
-  (assert (= (let [[x "x not being rebound"]]
-               (let [[x 2]] nil)
+  (assert (= (let [x "x not being rebound"]
+               (let [x 2] nil)
                x)
              "x not being rebound"))
-  (assert (= (let [[x (set [3 2 1 3 2])] [y x] [z y]] z) (set [1 2 3])))
+  (assert (= (let [x (set [3 2 1 3 2]) y x z y] z) (set [1 2 3])))
   (import math)
-  (let [[cos math.cos]
-        [foo-cos (fn [x] (cos x))]]
+  (let [cos math.cos
+        foo-cos (fn [x] (cos x))]
     (assert (= (cos math.pi) -1.0))
     (assert (= (foo-cos (- math.pi)) -1.0))
-    (let [[cos (fn [_] "cos has been locally rebound")]]
+    (let [cos (fn [_] "cos has been locally rebound")]
       (assert (= (cos cos) "cos has been locally rebound"))
       (assert (= (-> math.pi (/ 3) foo-cos (round 2)) 0.5)))
     (setv cos (fn [_] "cos has been rebound by setv"))
@@ -792,9 +791,9 @@
 (defn test-let-scope []
   "NATIVE: test let works rightish"
   (setv y 123)
-  (assert (= (let [[x 1]
-                   [y 2]
-                   [z 3]]
+  (assert (= (let [x 1
+                   y 2
+                   z 3]
                (+ x y z))
              6))
   (try
@@ -805,31 +804,31 @@
 
 (defn test-symbol-utf-8 []
   "NATIVE: test symbol encoded"
-  (let [[♥ "love"]
-        [⚘ "flower"]]
+  (let [♥ "love"
+        ⚘ "flower"]
     (assert (= (+ ⚘ ♥) "flowerlove"))))
 
 
 (defn test-symbol-dash []
   "NATIVE: test symbol encoded"
-  (let [[♥-♥ "doublelove"]
-        [-_- "what?"]]
+  (let [♥-♥ "doublelove"
+        -_- "what?"]
     (assert (= ♥-♥ "doublelove"))
     (assert (= -_- "what?"))))
 
 
 (defn test-symbol-question-mark []
   "NATIVE: test foo? -> is_foo behavior"
-  (let [[foo? "nachos"]]
+  (let [foo? "nachos"]
     (assert (= is_foo "nachos"))))
 
 
 (defn test-and []
   "NATIVE: test the and function"
-  (let [[and123 (and 1 2 3)]
-        [and-false (and 1 False 3)]
-        [and-true (and)]
-        [and-single (and 1)]]
+  (let [and123 (and 1 2 3)
+        and-false (and 1 False 3)
+        and-true (and)
+        and-single (and 1)]
     (assert (= and123 3))
     (assert (= and-false False))
     (assert (= and-true True))
@@ -842,11 +841,11 @@
 
 (defn test-or []
   "NATIVE: test the or function"
-  (let [[or-all-true (or 1 2 3 True "string")]
-        [or-some-true (or False "hello")]
-        [or-none-true (or False False)]
-        [or-false (or)]
-        [or-single (or 1)]]
+  (let [or-all-true (or 1 2 3 True "string")
+        or-some-true (or False "hello")
+        or-none-true (or False False)
+        or-false (or)
+        or-single (or 1)]
     (assert (= or-all-true 1))
     (assert (= or-some-true "hello"))
     (assert (= or-none-true False))
@@ -861,12 +860,12 @@
 (defn test-if-return-branching []
   "NATIVE: test the if return branching"
                                 ; thanks, algernon
-  (assert (= 1 (let [[x 1]
-                     [y 2]]
+  (assert (= 1 (let [x 1
+                     y 2]
                  (if true
                    2)
                  1)))
-  (assert (= 1 (let [[x 1] [y 2]]
+  (assert (= 1 (let [x 1 y 2]
                  (do)
                  (do)
                  ((fn [] 1))))))
@@ -915,9 +914,9 @@
 (defn test-eval-globals []
   "NATIVE: test eval with explicit global dict"
   (assert (= 'bar (eval (quote foo) {'foo 'bar})))
-  (assert (= 1 (let [[d {}]] (eval '(setv x 1) d) (eval (quote x) d))))
-  (let [[d1 {}]
-        [d2 {}]]
+  (assert (= 1 (let [d {}] (eval '(setv x 1) d) (eval (quote x) d))))
+  (let [d1 {}
+        d2 {}]
     (eval '(setv x 1) d1)
     (try
       (do
@@ -998,7 +997,7 @@
 
 (defn test-if-let-mixing []
   "NATIVE: test that we can now mix if and let"
-  (assert (= 0 (if true (let [[x 0]] x) 42))))
+  (assert (= 0 (if true (let [x 0] x) 42))))
 
 (defn test-if-in-if []
   "NATIVE: test that we can use if in if"

tests/native_tests/mathematics.hy

@@ -69,73 +69,73 @@
 
 (defn test-augassign-add []
   "NATIVE: test augassign add"
-  (let [[x 1]]
+  (let [x 1]
     (+= x 41)
     (assert (= x 42))))
 
 (defn test-augassign-sub []
   "NATIVE: test augassign sub"
-  (let [[x 1]]
+  (let [x 1]
     (-= x 41)
     (assert (= x -40))))
 
 (defn test-augassign-mult []
   "NATIVE: test augassign mult"
-  (let [[x 1]]
+  (let [x 1]
     (*= x 41)
     (assert (= x 41))))
 
 (defn test-augassign-div []
   "NATIVE: test augassign div"
-  (let [[x 42]]
+  (let [x 42]
     (/= x 2)
     (assert (= x 21))))
 
 (defn test-augassign-floordiv []
   "NATIVE: test augassign floordiv"
-  (let [[x 42]]
+  (let [x 42]
     (//= x 2)
     (assert (= x 21))))
 
 (defn test-augassign-mod []
   "NATIVE: test augassign mod"
-  (let [[x 42]]
+  (let [x 42]
     (%= x 2)
     (assert (= x 0))))
 
 (defn test-augassign-pow []
   "NATIVE: test augassign pow"
-  (let [[x 2]]
+  (let [x 2]
     (**= x 3)
     (assert (= x 8))))
 
 (defn test-augassign-lshift []
   "NATIVE: test augassign lshift"
-  (let [[x 2]]
+  (let [x 2]
     (<<= x 2)
     (assert (= x 8))))
 
 (defn test-augassign-rshift []
   "NATIVE: test augassign rshift"
-  (let [[x 8]]
+  (let [x 8]
     (>>= x 1)
     (assert (= x 4))))
 
 (defn test-augassign-bitand []
   "NATIVE: test augassign bitand"
-  (let [[x 8]]
+  (let [x 8]
     (&= x 1)
     (assert (= x 0))))
 
 (defn test-augassign-bitor []
   "NATIVE: test augassign bitand"
-  (let [[x 0]]
+  (let [x 0]
     (|= x 2)
     (assert (= x 2))))
 
 (defn test-augassign-bitxor []
   "NATIVE: test augassign bitand"
-  (let [[x 1]]
+  (let [x 1]
     (^= x 1)
     (assert (= x 0))))
 
@@ -147,13 +147,13 @@
 (defclass HyTestMatrix [list]
   [--matmul--
    (fn [self other]
-     (let [[n (len self)]
-           [m (len (. other [0]))]
-           [result []]]
+     (let [n (len self)
+           m (len (. other [0]))
+           result []]
        (for [i (range m)]
-         (let [[result-row []]]
+         (let [result-row []]
            (for [j (range n)]
-             (let [[dot-product 0]]
+             (let [dot-product 0]
                (for [k (range (len (. self [0])))]
                  (+= dot-product (* (. self [i] [k])
                                     (. other [k] [j]))))
@@ -179,15 +179,15 @@
     (assert (= (@ first-test-matrix second-test-matrix)
                product-of-test-matrices))
     ;; Python <= 3.4
-    (let [[matmul-attempt (try (@ first-test-matrix second-test-matrix)
-                               (except [e [Exception]] e))]]
+    (let [matmul-attempt (try (@ first-test-matrix second-test-matrix)
+                              (except [e [Exception]] e))]
       (assert (isinstance matmul-attempt NameError)))))
 
 (defn test-augassign-matmul []
   "NATIVE: test augmented-assignment matrix multiplication"
-  (let [[matrix first-test-matrix]
-        [matmul-attempt (try (@= matrix second-test-matrix)
-                              (except [e [Exception]] e))]]
+  (let [matrix first-test-matrix
+        matmul-attempt (try (@= matrix second-test-matrix)
+                              (except [e [Exception]] e))]
     (if PY35
       (assert (= product-of-test-matrices matrix))
       (assert (isinstance matmul-attempt NameError)))))

tests/native_tests/native_macros.hy

@@ -107,8 +107,8 @@
   (import [astor.codegen [to_source]])
   (import [hy.importer [import_buffer_to_ast]])
   (setv macro1 "(defmacro nif [expr pos zero neg]
-      (let [[g (gensym)]]
-        `(let [[~g ~expr]]
+      (let [g (gensym)]
+        `(let [~g ~expr]
            (cond [(pos? ~g) ~pos]
                  [(zero? ~g) ~zero]
                  [(neg? ~g) ~neg]))))
@@ -133,7 +133,7 @@
   (import [hy.importer [import_buffer_to_ast]])
   (setv macro1 "(defmacro nif [expr pos zero neg]
       (with-gensyms [a]
-        `(let [[~a ~expr]]
+        `(let [~a ~expr]
            (cond [(pos? ~a) ~pos]
                  [(zero? ~a) ~zero]
                  [(neg? ~a) ~neg]))))
@@ -155,7 +155,7 @@
   (import [astor.codegen [to_source]])
   (import [hy.importer [import_buffer_to_ast]])
   (setv macro1 "(defmacro/g! nif [expr pos zero neg]
-        `(let [[~g!res ~expr]]
+        `(let [~g!res ~expr]
            (cond [(pos? ~g!res) ~pos]
                  [(zero? ~g!res) ~zero]
                  [(neg? ~g!res) ~neg])))

tests/native_tests/py3_only_tests.hy

@@ -15,14 +15,14 @@
 (defn test-kwonly []
   "NATIVE: test keyword-only arguments"
   ;; keyword-only with default works
-  (let [[kwonly-foo-default-false (fn [&kwonly [foo false]] foo)]]
+  (let [kwonly-foo-default-false (fn [&kwonly [foo false]] foo)]
     (assert (= (apply kwonly-foo-default-false) false))
     (assert (= (apply kwonly-foo-default-false [] {"foo" true}) true)))
   ;; keyword-only without default ...
-  (let [[kwonly-foo-no-default (fn [&kwonly foo] foo)]
-        [attempt-to-omit-default (try
+  (let [kwonly-foo-no-default (fn [&kwonly foo] foo)
+        attempt-to-omit-default (try
                                  (kwonly-foo-no-default)
-                                  (except [e [Exception]] e))]]
+                                 (except [e [Exception]] e))]
     ;; works
     (assert (= (apply kwonly-foo-no-default [] {"foo" "quux"}) "quux"))
     ;; raises TypeError with appropriate message if not supplied
@@ -30,9 +30,9 @@
     (assert (in "missing 1 required keyword-only argument: 'foo'"
                 (. attempt-to-omit-default args [0]))))
   ;; keyword-only with other arg types works
-  (let [[function-of-various-args
+  (let [function-of-various-args
         (fn [a b &rest args &kwonly foo &kwargs kwargs]
-           (, a b args foo kwargs))]]
+          (, a b args foo kwargs))]
     (assert (= (apply function-of-various-args
                       [1 2 3 4] {"foo" 5 "bar" 6 "quux" 7})
                (, 1 2 (, 3 4)  5 {"bar" 6 "quux" 7})))))

tests/native_tests/shadow.hy

@@ -1,6 +1,6 @@
 (defn test-shadow-addition []
   "NATIVE: test shadow addition"
-  (let [[x +]]
+  (let [x +]
     (assert (try
              (x)
              (except [TypeError] True)
@@ -21,7 +21,7 @@
 
 (defn test-shadow-subtraction []
   "NATIVE: test shadow subtraction"
-  (let [[x -]]
+  (let [x -]
     (assert (try
              (x)
              (except [TypeError] True)
@@ -33,7 +33,7 @@
 
 (defn test-shadow-multiplication []
   "NATIVE: test shadow multiplication"
-  (let [[x *]]
+  (let [x *]
     (assert (= (x) 1))
     (assert (= (x 3) 3))
     (assert (= (x 3 3) 9))))
@@ -41,7 +41,7 @@
 
 (defn test-shadow-division []
   "NATIVE: test shadow division"
-  (let [[x /]]
+  (let [x /]
     (assert (try
              (x)
              (except [TypeError] True)
@@ -71,12 +71,12 @@
                 [1 1]
                 [2 2]]]
       (assert (= (apply x args) (not (apply y args))))))
-  (let [[s-lt <]
-        [s-gt >]
-        [s-le <=]
-        [s-ge >=]
-        [s-eq =]
-        [s-ne !=]]
+  (let [s-lt <
+        s-gt >
+        s-le <=
+        s-ge >=
+        s-eq =
+        s-ne !=]
     (assert (apply s-lt [1 2 3]))
     (assert (not (apply s-lt [3 2 1])))
     (assert (apply s-gt [3 2 1]))