try: accept a simpler form

Signed-off-by: Julien Danjou <julien@danjou.info>

hy/compiler.py

@@ -186,16 +186,31 @@ class HyASTCompiler(object):
             Try = ast.TryExcept
 
         if len(expr) == 0:
+            # (try)
             body = [ast.Pass(lineno=expr.start_line,
                              col_offset=expr.start_column)]
         else:
+            # (try something…)
             body = self._code_branch(self.compile(expr.pop(0)))
 
+        if len(expr) == 0:
+            # (try) or (try body)
+            handlers = [ast.ExceptHandler(
+                lineno=expr.start_line,
+                col_offset=expr.start_column,
+                type=None,
+                name=None,
+                body=[ast.Pass(lineno=expr.start_line,
+                               col_offset=expr.start_column)])]
+        else:
+            # (try body except except…)
+            handlers = [self.compile(s) for s in expr]
+
         return Try(
             lineno=expr.start_line,
             col_offset=expr.start_column,
             body=body,
-            handlers=[self.compile(s) for s in expr],
+            handlers=handlers,
             finalbody=[],
             orelse=[])
 

tests/compilers/test_ast.py

@@ -1,4 +1,5 @@
 # Copyright (c) 2013 Paul Tagliamonte <paultag@debian.org>
+# Copyright (c) 2013 Julien Danjou <julien@danjou.info>
 #
 # Permission is hereby granted, free of charge, to any person obtaining a
 # copy of this software and associated documentation files (the "Software"),
@@ -118,6 +119,8 @@ def test_ast_good_try():
     "Make sure AST can compile valid try"
     hy_compile(tokenize("(try)"))
     hy_compile(tokenize("(try 1)"))
+    hy_compile(tokenize("(try 1 bla)"))
+    hy_compile(tokenize("(try 1 bla bla)"))
 
 
 def test_ast_good_catch():

tests/native_tests/language.hy

@@ -165,6 +165,12 @@
 
   (try)
 
+  (try (pass))
+
+  (try (pass) (except))
+
+  (try (pass) (except [IOError]) (except))
+
   (try
     (raise (KeyError))
     (catch [[IOError]] (assert false))