diff options
| author | Owen Stephens <owen@owenstephens.co.uk> | 2014-04-10 17:44:11 +0100 |
|---|---|---|
| committer | Krzysztof Gogolewski <krz.gogolewski@gmail.com> | 2014-06-04 21:17:27 +0200 |
| commit | c63a465011b99eeafbb957074e54c2e6bbf751d9 (patch) | |
| tree | 8be21fc0af91e8826058f8f3e0a52f235fc590e5 /docs/users_guide | |
| parent | fe59334988fea384b119b7ef8372147b5c246bbf (diff) | |
| download | haskell-c63a465011b99eeafbb957074e54c2e6bbf751d9.tar.gz | |
Subsume NullaryTypeClasses by MultiParamTypeClasses (#8993)
MPTC now also handles the nullary case
Diffstat (limited to 'docs/users_guide')
| -rw-r--r-- | docs/users_guide/flags.xml | 1 | ||||
| -rw-r--r-- | docs/users_guide/glasgow_exts.xml | 4 |
2 files changed, 4 insertions, 1 deletions
diff --git a/docs/users_guide/flags.xml b/docs/users_guide/flags.xml index 063b573513..32701f49ca 100644 --- a/docs/users_guide/flags.xml +++ b/docs/users_guide/flags.xml @@ -1175,6 +1175,7 @@ </row> <row> <entry><option>-XNullaryTypeClasses</option></entry> + <entry>Deprecated, does nothing. <link linkend="nullary-type-classes">nullary (no parameter) type classes</link> are now enabled using <option>-XMultiParamTypeClasses</option>.</entry> <entry>Enable <link linkend="nullary-type-classes">nullary (no parameter) type classes</link>.</entry> <entry>dynamic</entry> <entry><option>-XNoNullaryTypeClasses</option></entry> diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml index 7872a88134..1622bc54c0 100644 --- a/docs/users_guide/glasgow_exts.xml +++ b/docs/users_guide/glasgow_exts.xml @@ -4317,7 +4317,9 @@ We use default signatures to simplify generic programming in GHC <sect3 id="nullary-type-classes"> <title>Nullary type classes</title> -Nullary (no parameter) type classes are enabled with <option>-XNullaryTypeClasses</option>. +Nullary (no parameter) type classes are enabled with +<option>-XMultiTypeClasses</option>; historically, they were enabled with the +(now deprecated) <option>-XNullaryTypeClasses</option>. Since there are no available parameters, there can be at most one instance of a nullary class. A nullary type class might be used to document some assumption in a type signature (such as reliance on the Riemann hypothesis) or add some |