Commit 14bced99 authored by xldenis's avatar xldenis Committed by Marge Bot

Put the docs for :instances in alphabetical position

parent 2bfabd22
......@@ -2483,6 +2483,39 @@ commonly used commands.
restriction (b), showing all instances that are in scope and mention
⟨name⟩ in their head.
.. ghci-cmd:: :instances; ⟨type⟩
Displays all the class instances available to the argument ⟨type⟩.
The command will match ⟨type⟩ with the first parameter of every
instance and then check that all constraints are satisfiable.
When combined with :extension:`PartialTypeSignatures`, a user can insert
wildcards into a query and learn the constraints required of each
wildcard for ⟨type⟩ match with an instance.
The output is a listing of all matching instances, simplified and
instantiated as much as possible.
For example:
.. code-block:: none
> :instances Maybe (Maybe Int)
instance Eq (Maybe (Maybe Int)) -- Defined in ‘GHC.Maybe’
instance Ord (Maybe (Maybe Int)) -- Defined in ‘GHC.Maybe’
instance Show (Maybe (Maybe Int)) -- Defined in ‘GHC.Show’
instance Read (Maybe (Maybe Int)) -- Defined in ‘GHC.Read’
> :set -XPartialTypeSignatures -fno-warn-partial-type-signatures
> :instances Maybe _
instance Eq _ => Eq (Maybe _) -- Defined in ‘GHC.Maybe’
instance Semigroup _ => Monoid (Maybe _) -- Defined in ‘GHC.Base’
instance Ord _ => Ord (Maybe _) -- Defined in ‘GHC.Maybe’
instance Semigroup _ => Semigroup (Maybe _) -- Defined in ‘GHC.Base’
instance Show _ => Show (Maybe _) -- Defined in ‘GHC.Show’
instance Read _ => Read (Maybe _) -- Defined in ‘GHC.Read’
.. ghci-cmd:: :issafe; [⟨module⟩]
Displays Safe Haskell information about the given module (or the
......@@ -2571,39 +2604,6 @@ commonly used commands.
The ``:loc-at`` command requires :ghci-cmd:`:set +c` to be set.
.. ghci-cmd:: :instances; ⟨type⟩
Displays all the class instances available to the argument ⟨type⟩.
The command will match ⟨type⟩ with the first parameter of every
instance and then check that all constraints are satisfiable.
When combined with :extension:`PartialTypeSignatures`, a user can insert
wildcards into a query and learn the constraints required of each
wildcard for ⟨type⟩ match with an instance.
The output is a listing of all matching instances, simplified and
instantiated as much as possible.
For example:
.. code-block:: none
> :instances Maybe (Maybe Int)
instance Eq (Maybe (Maybe Int)) -- Defined in ‘GHC.Maybe’
instance Ord (Maybe (Maybe Int)) -- Defined in ‘GHC.Maybe’
instance Show (Maybe (Maybe Int)) -- Defined in ‘GHC.Show’
instance Read (Maybe (Maybe Int)) -- Defined in ‘GHC.Read’
> :set -XPartialTypeSignatures -fno-warn-partial-type-signatures
> :instances Maybe _
instance Eq _ => Eq (Maybe _) -- Defined in ‘GHC.Maybe’
instance Semigroup _ => Monoid (Maybe _) -- Defined in ‘GHC.Base’
instance Ord _ => Ord (Maybe _) -- Defined in ‘GHC.Maybe’
instance Semigroup _ => Semigroup (Maybe _) -- Defined in ‘GHC.Base’
instance Show _ => Show (Maybe _) -- Defined in ‘GHC.Show’
instance Read _ => Read (Maybe _) -- Defined in ‘GHC.Read’
.. ghci-cmd:: :main; ⟨arg1⟩ ... ⟨argn⟩
When a program is compiled and executed, it can use the ``getArgs``
......
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