Change the signature of (for) and (with).

(for) is restored to clojure-like flatness.
 (with) can be used without the nested list if you don't care about the
        name.

   Tests and examples updated.

NEWS

@@ -55,8 +55,6 @@ Changes from Hy 0.9.11
 
 
     [ Syntax Fixes ]
-    * for changed syntax from (for [] ...) -> (for [[]] ...)
-    * with changed syntax from (with [] ...) -> (with [[]] ...)
     * get allows multiple arguments
 
 

docs/language/api.rst

@@ -205,7 +205,8 @@ however is called only for every other value in the list.
     ;; assuming that (side-effect1) and (side-effect2) are functions and
     ;; collection is a list of numerical values
 
-    (for (x collection) (do
+    (for [x collection]
+      (do
         (side-effect1 x)
         (if (% x 2)
           (continue))
@@ -489,10 +490,10 @@ collection and calls side-effect to each element in the collection:
 .. code-block:: clj
 
     ;; assuming that (side-effect) is a function that takes a single parameter
-    (for [[element collection]] (side-effect element))
+    (for [element collection] (side-effect element))
 
     ;; for can have an optional else block
-    (for [[element collection]] (side-effect element)
+    (for [element collection] (side-effect element)
          (else (side-effect-2)))
 
 The optional `else` block is executed only if the `for` loop terminates
@@ -500,14 +501,14 @@ normally. If the execution is halted with `break`, the `else` does not execute.
 
 .. code-block:: clj
 
-    => (for [[element [1 2 3]]] (if (< element 3)
+    => (for [element [1 2 3]] (if (< element 3)
     ...                             (print element) 
     ...                             (break))
     ...    (else (print "loop finished")))
     1
     2
 
-    => (for [[element [1 2 3]]] (if (< element 4)
+    => (for [element [1 2 3]] (if (< element 4)
     ...                             (print element)
     ...                             (break))
     ...    (else (print "loop finished")))
@@ -680,7 +681,7 @@ function is defined and passed to another function for filtering output.
     ...             {:name "Dave" :age 5}])
 
     => (defn display-people [people filter]
-    ...  (for [[person people]] (if (filter person) (print (:name person)))))
+    ...  (for [person people] (if (filter person) (print (:name person)))))
 
     => (display-people people (fn [person] (< (:age person) 25)))
     Alice

eg/python3/futures/hello-world.hy

@@ -7,5 +7,5 @@
 
 (with-as (ThreadPoolExecutor 10) executor
   (setv jobs (list-comp (.submit executor task-to-do) (x (range 0 10))))
-  (for (future (as-completed jobs))
+  (for [future (as-completed jobs)]
     (.result future)))

hy/contrib/anaphoric.hy

@@ -31,14 +31,14 @@
 
 (defmacro ap-each [lst &rest body]
   "Evaluate the body form for each element in the list."
-  `(for [[it ~lst]] ~@body))
+  `(for [it ~lst] ~@body))
 
 
 (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)]]
-     (for [[it ~lst]]
+     (for [it ~lst]
        (if (p it)
          ~@body
          (break)))))
@@ -47,7 +47,7 @@
 (defmacro ap-map [form lst]
   "Yield elements evaluated in the form for each element in the list."
   `(let [[f (lambda [it] ~form)]]
-     (for [[v ~lst]]
+     (for [v ~lst]
        (yield (f v)))))
 
 
@@ -55,7 +55,7 @@
   "Yield elements evaluated for each element in the list when the
   predicate function returns True."
   `(let [[f (lambda [it] ~rep)]]
-     (for [[it ~lst]]
+     (for [it ~lst]
        (if (~predfn it)
          (yield (f it))
          (yield it)))))
@@ -64,7 +64,7 @@
 (defmacro ap-filter [form lst]
   "Yield elements returned when the predicate form evaluates to True."
   `(let [[pred (lambda [it] ~form)]]
-     (for [[val ~lst]]
+     (for [val ~lst]
        (if (pred val)
          (yield val)))))
 

hy/core/macros.hy

@@ -25,16 +25,29 @@
 ;;; These macros form the hy language
 ;;; They are automatically required in every module, except inside hy.core
 
+
+(import [hy.models.list [HyList]]
+        [hy.models.symbol [HySymbol]])
+
+
+
 (defmacro for [args &rest body]
   "shorthand for nested for loops:
-  (for [[x foo] [y bar]] baz) ->
+  (for [x foo
+        y bar]
+    baz) ->
   (for* [x foo]
     (for* [y bar]
       baz))"
+
+  (if (odd? (len args))
+    (macro-error args "`for' requires an even number of args."))
+
   (if (empty? body)
     (macro-error None "`for' requires a body to evaluate"))
   (if args
-    `(for* ~(.pop args 0) (for ~args ~@body))
+    `(for* [~(.pop args 0) ~(.pop args 0)]
+       (for ~args ~@body))
     `(do ~@body)))
 
 
@@ -44,8 +57,16 @@
   (with* [x foo]
     (with* [y bar]
       baz))"
-  (if args
-    `(with* ~(.pop args 0) (with ~args ~@body))
+
+  (if (not (empty? args))
+    (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.
+        `(with* [~@primary] (with ~args ~@body))
+        ;;; OK, let's just give it away. This may not be something we
+        ;;; can do, but that's really the programmer's problem.
+        `(with* [~primary] (with ~args ~@body))))
       `(do ~@body)))
 
 

tests/compilers/test_ast.py

@@ -313,7 +313,7 @@ def test_ast_valid_while():
 
 def test_ast_valid_for():
     "Make sure AST can compile valid for"
-    can_compile("(for [[a 2]] (print a))")
+    can_compile("(for [a 2] (print a))")
 
 
 def test_ast_invalid_for():
@@ -452,14 +452,14 @@ def test_for_compile_error():
         assert(False)
 
     try:
-        can_compile("(fn [] (for [[x]]))")
+        can_compile("(fn [] (for [x]))")
     except HyTypeError as e:
-        assert(e.message == "`for' requires a body to evaluate")
+        assert(e.message == "`for' requires an even number of args.")
     else:
         assert(False)
 
     try:
-        can_compile("(fn [] (for [[x xx]]))")
+        can_compile("(fn [] (for [x xx]))")
     except HyTypeError as e:
         assert(e.message == "`for' requires a body to evaluate")
     else:

tests/native_tests/language.hy

@@ -31,12 +31,12 @@
 (defn test-for-loop []
   "NATIVE: test for loops?"
   (setv count 0)
-  (for [[x [1 2 3 4 5]]]
+  (for [x [1 2 3 4 5]]
     (setv count (+ count x)))
   (assert (= count 15))
   (setv count 0)
-  (for [[x [1 2 3 4 5]]
-        [y [1 2 3 4 5]]]
+  (for [x [1 2 3 4 5]
+        y [1 2 3 4 5]]
     (setv count (+ count x y)))
   (assert (= count 150)))
 
@@ -404,9 +404,9 @@
 
 (defn test-yield []
   "NATIVE: test yielding"
-  (defn gen [] (for [[x [1 2 3 4]]] (yield x)))
+  (defn gen [] (for [x [1 2 3 4]] (yield x)))
   (setv ret 0)
-  (for [[y (gen)]] (setv ret (+ ret y)))
+  (for [y (gen)] (setv ret (+ ret y)))
   (assert (= ret 10)))
 
 
@@ -463,7 +463,7 @@
 (defn test-for-doodle []
   "NATIVE: test for-do"
   (do (do (do (do (do (do (do (do (do (setv (, x y) (, 0 0)))))))))))
-  (for [[- [1 2]]]
+  (for [- [1 2]]
     (do
      (setv x (+ x 1))
      (setv y (+ y 1))))
@@ -646,7 +646,7 @@
 
 (defn test-nested-if []
   "NATIVE: test nested if"
-  (for [[x (range 10)]]
+  (for [x (range 10)]
     (if (in "foo" "foobar")
       (do
        (if true true true))
@@ -810,14 +810,14 @@
 
 (defn test-break-breaking []
   "NATIVE: test checking if break actually breaks"
-  (defn holy-grail [] (for [[x (range 10)]] (if (= x 5) (break))) x)
+  (defn holy-grail [] (for [x (range 10)] (if (= x 5) (break))) x)
   (assert (= (holy-grail) 5)))
 
 
 (defn test-continue-continuation []
   "NATIVE: test checking if continue actually continues"
   (setv y [])
-  (for [[x (range 10)]] 
+  (for [x (range 10)] 
     (if (!= x 5) 
       (continue)) 
     (.append y x))