Support PEP 328

Add support for proper relative imports

NEWS

@@ -27,6 +27,7 @@ Changes from 0.13.0
    * new `doc` macro and `#doc` tag macro
    * support for PEP 492 with `fn/a`, `defn/a`, `with/a` and `for/a`
    * remove `def`
+   * support for relative imports (PEP 328)
 
    [ Bug Fixes ]
    * Numeric literals are no longer parsed as symbols when followed by a dot

hy/compiler.py

@@ -1156,10 +1156,17 @@ class HyASTCompiler(object):
         def _compile_import(expr, module, names=None, importer=asty.Import):
             if not names:
                 names = [ast.alias(name=ast_str(module), asname=None)]
+
+            ast_module = ast_str(module)
+            module = ast_module.lstrip(".")
+            level = len(ast_module) - len(module)
+            if not module:
+                module = None
+
             ret = importer(expr,
-                           module=ast_str(module),
+                           module=module,
                            names=names,
-                           level=0)
+                           level=level)
             return Result() + ret
 
         expr.pop(0)  # index

tests/native_tests/__init__.py

@@ -0,0 +1,3 @@
+# Note that __init__.py is intentional so pytest (more specifically py.path)
+# will detect us as a Python package. There's logic there that involves looking
+# specifically for this file.

tests/native_tests/language.hy

@@ -1812,3 +1812,8 @@ macros()
   (defn f4 [[a b]] "not a docstring")
   (assert (none? (. f4 __doc__)))
   (assert (= (f4 [1 2]) "not a docstring")))
+
+(defn test-relative-import []
+  "Make sure relative imports work properly"
+  (import [..resources [tlib]]))
+  (assert (= (tlib.*secret-message* "Hello World")))

tests/resources/tlib.py

@@ -2,6 +2,9 @@ from hy.macros import macro
 from hy import HyList, HyInteger
 
 
+SECRET_MESSAGE = "Hello World"
+
+
 @macro("qplah")
 def tmac(ETname, *tree):
     return HyList((HyInteger(8), ) + tree)