Avoid cyclic dependency by merging callers.py into hooks.py

docs/api_reference.rst

@@ -9,8 +9,8 @@ Api Reference
     :show-inheritance:
 
 
-.. automethod:: pluggy.callers._Result.get_result
+.. automethod:: pluggy._result._Result.get_result
 
-.. automethod:: pluggy.callers._Result.force_result
+.. automethod:: pluggy._result._Result.force_result
 
 .. automethod:: pluggy.hooks._HookCaller.call_extra

docs/index.rst

@@ -360,11 +360,11 @@ be implemented as generator function with a single ``yield`` in its body:
         if config.use_defaults:
             outcome.force_result(defaults)
 
-The generator is `sent`_ a :py:class:`pluggy.callers._Result` object which can
+The generator is `sent`_ a :py:class:`pluggy._result._Result` object which can
 be assigned in the ``yield`` expression and used to override or inspect
 the final result(s) returned back to the caller using the
-:py:meth:`~pluggy.callers._Result.force_result` or
-:py:meth:`~pluggy.callers._Result.get_result` methods.
+:py:meth:`~pluggy._result._Result.force_result` or
+:py:meth:`~pluggy._result._Result.get_result` methods.
 
 .. note::
     Hook wrappers can **not** return results (as per generator function

src/pluggy/__init__.py

@@ -14,5 +14,4 @@
 ]
 
 from .manager import PluginManager, PluginValidationError
-from .callers import HookCallError
-from .hooks import HookspecMarker, HookimplMarker
+from .hooks import HookspecMarker, HookimplMarker, HookCallError

src/pluggy/_result.py

@@ -0,0 +1,64 @@
+import sys
+import warnings
+
+
+if sys.version_info < (3,):
+    exec(
+        """
+def _reraise(cls, val, tb):
+    raise cls, val, tb
+"""
+    )
+
+
+class _Result(object):
+    def __init__(self, result, excinfo):
+        self._result = result
+        self._excinfo = excinfo
+
+    @property
+    def excinfo(self):
+        return self._excinfo
+
+    @property
+    def result(self):
+        """Get the result(s) for this hook call (DEPRECATED in favor of ``get_result()``)."""
+        msg = "Use get_result() which forces correct exception handling"
+        warnings.warn(DeprecationWarning(msg), stacklevel=2)
+        return self._result
+
+    @classmethod
+    def from_call(cls, func):
+        __tracebackhide__ = True
+        result = excinfo = None
+        try:
+            result = func()
+        except BaseException:
+            excinfo = sys.exc_info()
+
+        return cls(result, excinfo)
+
+    def force_result(self, result):
+        """Force the result(s) to ``result``.
+
+        If the hook was marked as a ``firstresult`` a single value should
+        be set otherwise set a (modified) list of results. Any exceptions
+        found during invocation will be deleted.
+        """
+        self._result = result
+        self._excinfo = None
+
+    def get_result(self):
+        """Get the result(s) for this hook call.
+
+        If the hook was marked as a ``firstresult`` only a single value
+        will be returned otherwise a list of results.
+        """
+        __tracebackhide__ = True
+        if self._excinfo is None:
+            return self._result
+        else:
+            ex = self._excinfo
+            if sys.version_info >= (3,):
+                raise ex[1].with_traceback(ex[2])
+            _reraise(*ex)  # noqa

src/pluggy/_tracing.py

@@ -1,7 +1,7 @@
 """
 Tracing utils
 """
-from .callers import _Result
+from ._result import _Result
 
 
 class TagTracer(object):