Merge branch 'jd/try' of git://github.com/jd/hy into pr-82

hy/compiler.py

@@ -176,7 +176,6 @@ class HyASTCompiler(object):
             tback=None)
 
     @builds("try")
-    @checkargs(min=1)
     def compile_try_expression(self, expr):
         expr.pop(0)  # try
 
@@ -186,11 +185,32 @@ class HyASTCompiler(object):
         else:
             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=self._code_branch(self.compile(expr.pop(0))),
-            handlers=[self.compile(s) for s in expr],
+            body=body,
+            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"),
@@ -116,12 +117,10 @@ def test_ast_bad_raise():
 
 def test_ast_good_try():
     "Make sure AST can compile valid try"
+    hy_compile(tokenize("(try)"))
     hy_compile(tokenize("(try 1)"))
-
-
-def test_ast_bad_try():
-    "Make sure AST can't compile invalid try"
-    cant_compile("(try)")
+    hy_compile(tokenize("(try 1 bla)"))
+    hy_compile(tokenize("(try 1 bla bla)"))
 
 
 def test_ast_good_catch():

tests/native_tests/language.hy

@@ -162,6 +162,15 @@
 
 (defn test-exceptions []
   "NATIVE: test Exceptions"
+
+  (try)
+
+  (try (pass))
+
+  (try (pass) (except))
+
+  (try (pass) (except [IOError]) (except))
+
   (try
     (raise (KeyError))
     (catch [[IOError]] (assert false))