diff options
Diffstat (limited to 'docs/users_guide/exts/existential_quantification.rst')
| -rw-r--r-- | docs/users_guide/exts/existential_quantification.rst | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/docs/users_guide/exts/existential_quantification.rst b/docs/users_guide/exts/existential_quantification.rst index e4c5a79149..c9cde919dd 100644 --- a/docs/users_guide/exts/existential_quantification.rst +++ b/docs/users_guide/exts/existential_quantification.rst @@ -116,7 +116,11 @@ example: :: } Here ``tag`` is a public field, with a well-typed selector function -``tag :: Counter a -> a``. The ``self`` type is hidden from the outside; +``tag :: Counter a -> a``. See :ref:`field-selectors-and-type-applications` +for a full description of how the types of top-level field selectors are +determined. + +The ``self`` type is hidden from the outside; any attempt to apply ``_this``, ``_inc`` or ``_display`` as functions will raise a compile-time error. In other words, *GHC defines a record selector function only for fields whose type does not mention the |