Implement ImportQualifiedPost

1 files changed, 32 insertions, 0 deletions

diff --git a/docs/users_guide/glasgow_exts.rst b/docs/users_guide/glasgow_exts.rst
index 6d09b44cb7..5fef204831 100644
--- a/docs/users_guide/glasgow_exts.rst
+++ b/docs/users_guide/glasgow_exts.rst
@@ -2109,6 +2109,38 @@ data constructor in an import or export list with the keyword
 ``pattern``, to allow the import or export of a data constructor without
 its parent type constructor (see :ref:`patsyn-impexp`).
 
+.. _importqualifiedpost:
+
+Writing qualified in postpositive position
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. extension:: ImportQualifiedPost
+    :shortdesc: ``ImportQualifiedPost`` allows the syntax ``import M qualified``
+
+    :since: 8.10.1
+
+    ``ImportQualifiedPost`` allows the syntax ``import M qualified``, that is, to annotate a module as qualified by writing ``qualified`` after the module name.
+
+To import a qualified module usually you must specify ``qualified`` in prepositive position : ``import qualified M``. This often leads to a "hanging indent" (which is automatically inserted by some autoformatters and common in many code bases. For example:
+
+.. code-block::  none
+
+ import qualified A
+ import           B
+ import           C
+
+The ``ImportQualifiedPost`` extension allows ``qualified`` to appear in postpositive position : ``import M qualified``. With this extension enabled, one can write:
+
+.. code-block:: none
+
+   import A qualified
+   import B
+   import C
+
+It is an error if ``qualified`` appears in both pre and postpositive positions.
+
+The warning ``-Wprepositive-qualified-syntax`` (off by default) reports on any occurrences of imports annotated ``qualified`` using prepositive syntax.
+
 .. _block-arguments:
 
 More liberal syntax for function arguments