diff options
Diffstat (limited to 'docs/users_guide/ghci.rst')
| -rw-r--r-- | docs/users_guide/ghci.rst | 21 |
1 files changed, 8 insertions, 13 deletions
diff --git a/docs/users_guide/ghci.rst b/docs/users_guide/ghci.rst index fa8609d47b..d2bb33dd37 100644 --- a/docs/users_guide/ghci.rst +++ b/docs/users_guide/ghci.rst @@ -1023,13 +1023,8 @@ Type defaulting in GHCi single: Type defaulting; in GHCi single: Show class -.. ghc-flag:: -XExtendedDefaultRules - :shortdesc: Use GHCi's - :ref:`extended default rules <extended-default-rules>` in a normal - module. - :type: dynamic - :reverse: -XNoExtendedDefaultRules - :category: language +.. extension:: ExtendedDefaultRules + :shortdesc: Use GHCi's extended default rules in a normal module. :since: 6.8.1 @@ -1065,7 +1060,7 @@ and defaults the type variable if 3. At least one of the classes ``Ci`` is numeric. -At the GHCi prompt, or with GHC if the :ghc-flag:`-XExtendedDefaultRules` flag +At the GHCi prompt, or with GHC if the :extension:`ExtendedDefaultRules` flag is given, the types are instead resolved with the following method: Find all the unsolved constraints. Then: @@ -1118,7 +1113,7 @@ Interactive classes .. index:: single: Interactive classes -The interactive classes (only relevant when :ghc-flag:`-XExtendedDefaultRules` +The interactive classes (only relevant when :extension:`ExtendedDefaultRules` is in effect) are: any numeric class, ``Show``, ``Eq``, ``Ord``, ``Foldable`` or ``Traversable``. @@ -1132,7 +1127,7 @@ Extended rules around ``default`` declarations single: default declarations Since the rules for defaulting are relaxed under -:ghc-flag:`-XExtendedDefaultRules`, the rules for ``default`` declarations +:extension:`ExtendedDefaultRules`, the rules for ``default`` declarations are also relaxed. According to Section 4.3.4 of the Haskell 2010 Report, a ``default`` declaration looks like ``default (t1, ..., tn)`` where, for each ``ti``, ``Num ti`` must hold. This is relaxed to say that for each @@ -2781,7 +2776,7 @@ commonly used commands. Infers and prints the type of ⟨expression⟩, but without fiddling with type variables or class constraints. This is useful when you - are using :ghc-flag:`-XTypeApplications` and care about the distinction + are using :extension:`TypeApplications` and care about the distinction between specified type variables (available for type application) and inferred type variables (not available). This mode sometimes prints constraints (such as ``Show Int``) that could readily be solved, but @@ -2799,7 +2794,7 @@ commonly used commands. if possible. In this mode, if the inferred type is constrained by any interactive class (``Num``, ``Show``, ``Eq``, ``Ord``, ``Foldable``, or ``Traversable``), the constrained type variable(s) are defaulted - according to the rules described under :ghc-flag:`-XExtendedDefaultRules`. + according to the rules described under :extension:`ExtendedDefaultRules`. This mode is quite useful when the inferred type is quite general (such as for ``foldr``) and it may be helpful to see a more concrete instantiation. @@ -2994,7 +2989,7 @@ that option apply to loaded modules too. For example :seti -XMonoLocalBinds -It would be undesirable if :ghc-flag:`-XMonoLocalBinds` were to apply to loaded +It would be undesirable if :extension:`MonoLocalBinds` were to apply to loaded modules too: that might cause a compilation error, but more commonly it will cause extra recompilation, because GHC will think that it needs to recompile the module because the flags have changed. |