fix for #17

compiler/block.py

@@ -249,6 +249,8 @@ def resolve_name(self, writer, name):
         if var:
           if var.type == Var.TYPE_GLOBAL:
             return self._resolve_global(writer, name)
+          if var.type == Var.TYPE_TUPLE_PARAM:
+            return expr.GeneratedLocalVar(name)
           writer.write_checked_call1('πg.CheckLocal(πF, {}, {})',
                                      util.adjust_local_name(name),
                                      util.go_str(name))
@@ -263,6 +265,7 @@ class Var(object):
   TYPE_LOCAL = 0
   TYPE_PARAM = 1
   TYPE_GLOBAL = 2
+  TYPE_TUPLE_PARAM = 3
 
   def __init__(self, name, var_type, arg_index=None):
     self.name = name
@@ -273,6 +276,9 @@ def __init__(self, name, var_type, arg_index=None):
     elif var_type == Var.TYPE_PARAM:
       assert arg_index is not None
       self.init_expr = 'πArgs[{}]'.format(arg_index)
+    elif var_type == Var.TYPE_TUPLE_PARAM:
+      assert arg_index is None
+      self.init_expr = 'nil'
     else:
       assert arg_index is None
       self.init_expr = None
@@ -364,16 +370,40 @@ def __init__(self, node):
     BlockVisitor.__init__(self)
     self.is_generator = False
     node_args = node.args
-    args = [a.arg for a in node_args.args]
+    args = []
+    for arg in node_args.args:
+      if isinstance(arg, ast.Tuple):
+        args.append(arg.elts)
+      else:
+        args.append(arg.arg)
+     # args = [a.arg for a in node_args.args]
+
     if node_args.vararg:
       args.append(node_args.vararg.arg)
     if node_args.kwarg:
       args.append(node_args.kwarg.arg)
     for i, name in enumerate(args):
-      if name in self.vars:
-        msg = "duplicate argument '{}' in function definition".format(name)
-        raise util.ParseError(node, msg)
-      self.vars[name] = Var(name, Var.TYPE_PARAM, arg_index=i)
+      if isinstance(name, list):
+        arg_name = 'τ{}'.format(id(name))
+        for el in name:
+          self._parse_tuple(el, node)
+        self.vars[arg_name] = Var(arg_name, Var.TYPE_PARAM, i)
+      else:
+        self._check_duplicate_args(name, node)
+        self.vars[name] = Var(name, Var.TYPE_PARAM, arg_index=i)
+
+  def _parse_tuple(self, el, node):
+    if isinstance(el, ast.Tuple):
+      for x in el.elts:
+        self._parse_tuple(x, node)
+    else:
+      self._check_duplicate_args(el.arg, node)
+      self.vars[el.arg] = Var(el.arg, Var.TYPE_TUPLE_PARAM)
+
+  def _check_duplicate_args(self, name, node):
+    if name in self.vars:
+      msg = "duplicate argument '{}' in function definition".format(name)
+      raise util.ParseError(node, msg)
 
   def visit_Yield(self, unused_node): # pylint: disable=unused-argument
     self.is_generator = True

compiler/block_test.py

@@ -26,6 +26,7 @@
 from grumpy.compiler import util
 from grumpy import pythonparser
 
+
 class PackageTest(unittest.TestCase):
 
   def testCreate(self):
@@ -224,6 +225,13 @@ def testYieldExpr(self):
     self.assertEqual(sorted(visitor.vars.keys()), ['foo'])
     self.assertRegexpMatches(visitor.vars['foo'].init_expr, r'UnboundLocal')
 
+  def testTupleArgs(self):
+    func = _ParseStmt('def foo((bar, baz)): pass')
+    visitor = block.FunctionBlockVisitor(func)
+    self.assertEqual(len(visitor.vars), 3)
+    self.assertEqual(len([v for v in visitor.vars if visitor.vars[v].type == block.Var.TYPE_TUPLE_PARAM]), 2)
+    self.assertIn('bar', visitor.vars)
+    self.assertIn('baz', visitor.vars)
 
 def _MakeModuleBlock():
   importer = imputil.Importer(None, '__main__', '/tmp/foo.py', False)

compiler/stmt.py

@@ -504,6 +504,13 @@ def visit_function_inline(self, node):
     func_block = block.FunctionBlock(self.block, node.name, func_visitor.vars,
                                      func_visitor.is_generator)
     visitor = StatementVisitor(func_block, self.future_node)
+
+    for arg in node.args.args:
+      if isinstance(arg, ast.Tuple):
+        arg_name = 'τ{}'.format(id(arg.elts))
+        with visitor.writer.indent_block():
+          visitor._tie_target(arg, util.adjust_local_name(arg_name))  # pylint: disable=protected-access
+
     # Indent so that the function body is aligned with the goto labels.
     with visitor.writer.indent_block():
       visitor._visit_each(node.body)  # pylint: disable=protected-access
@@ -519,9 +526,13 @@ def visit_function_inline(self, node):
       defaults = [None] * (argc - len(args.defaults)) + args.defaults
       for i, (a, d) in enumerate(zip(args.args, defaults)):
         with self.visit_expr(d) if d else expr.nil_expr as default:
+          if isinstance(a, ast.Tuple):
+            name = util.go_str('τ{}'.format(id(a.elts)))
+          else:
+            name = util.go_str(a.arg)
           tmpl = '$args[$i] = πg.Param{Name: $name, Def: $default}'
           self.writer.write_tmpl(tmpl, args=func_args.expr, i=i,
-                                 name=util.go_str(a.arg), default=default.expr)
+                                 name=name, default=default.expr)
       flags = []
       if args.vararg:
         flags.append('πg.CodeFlagVarArg')
@@ -583,6 +594,8 @@ def visit_function_inline(self, node):
   def _assign_target(self, target, value):
     if isinstance(target, ast.Name):
       self.block.bind_var(self.writer, target.id, value)
+    elif isinstance(target, ast.arg):
+      self.block.bind_var(self.writer, target.arg, value)
     elif isinstance(target, ast.Attribute):
       with self.visit_expr(target.value) as obj:
         self.writer.write_checked_call1(

compiler/stmt_test.py

@@ -243,6 +243,30 @@ def foo(a, b):
           print a, b
         foo('bar', 'baz')""")))
 
+  def testFunctionDefWithTupleArgs(self):
+    self.assertEqual((0, "('bar', 'baz')\n"), _GrumpRun(textwrap.dedent("""\
+        def foo((a, b)):
+          print(a, b)
+        foo(('bar', 'baz'))""")))
+
+  def testFunctionDefWithNestedTupleArgs(self):
+    self.assertEqual((0, "('bar', 'baz', 'qux')\n"), _GrumpRun(textwrap.dedent("""\
+        def foo(((a, b), c)):
+          print(a, b, c)
+        foo((('bar', 'baz'), 'qux'))""")))
+
+  def testFunctionDefWithMultipleTupleArgs(self):
+    self.assertEqual((0, "('bar', 'baz')\n"), _GrumpRun(textwrap.dedent("""\
+        def foo(((a, ), (b, ))):
+          print(a, b)
+        foo((('bar',), ('baz', )))""")))
+
+  def testFunctionDefTupleArgsInLambda(self):
+    self.assertEqual((0, "[(3, 2), (4, 3), (12, 1)]\n"), _GrumpRun(textwrap.dedent("""\
+        c = {12: 1, 3: 2, 4: 3}
+        top = sorted(c.items(), key=lambda (k,v): v)
+        print (top)""")))
+
   def testFunctionDefGenerator(self):
     self.assertEqual((0, "['foo', 'bar']\n"), _GrumpRun(textwrap.dedent("""\
         def gen():