potential fix for #17

Author: jamdagni86

compiler/block.py

@@ -440,16 +440,29 @@ 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([a.arg for a in arg.elts])
+      else:
+        args.append(arg.arg)
     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):
+        self.add_vars(i, 'τ'.join(name), node)
+        for j, tuple_name in enumerate(name):
+          self.vars[tuple_name] = Var(tuple_name, Var.TYPE_LOCAL)
+      else:
+        self.add_vars(i, name, node)
+
+  def add_vars(self, i, name, node):
+    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)
 
   def visit_Yield(self, unused_node): # pylint: disable=unused-argument
     self.is_generator = True

compiler/expr_visitor.py

@@ -420,6 +420,19 @@ def visit_function_inline(self, node):
     # a separate pass so that we know whether to resolve a name as a local or a
     # global during the second pass.
     func_visitor = block.FunctionBlockVisitor(node)
+
+    for arg in reversed(node.args.args):
+      if isinstance(arg, ast.Tuple):
+        name = 'τ'.join(x.arg for x in arg.elts)
+        from copy import deepcopy
+        for j, elt in enumerate(reversed(arg.elts)):
+          index = ast.Index(value=ast.Num(n=len(arg.elts) - j - 1, loc=arg.loc), loc=arg.loc)
+          subscript = ast.Subscript(value=ast.Name(id=name, ctx=None, loc=arg.loc),
+                                    slice=index, ctx=arg.ctx, loc=arg.loc)
+          assign = ast.Assign(targets=[ast.Name(id=elt.arg, ctx=None, loc=arg.loc)],
+                              value=subscript, ctx=arg.ctx, loc=arg.loc)
+          node.body.insert(0, assign)
+
     for child in node.body:
       func_visitor.visit(child)
     func_block = block.FunctionBlock(self.block, node.name, func_visitor.vars,
@@ -443,9 +456,13 @@ 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(d) if d else expr.nil_expr as default:
+          if isinstance(a, ast.Tuple):
+            name = util.go_str('τ'.join(x.arg for x in 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')