diff options
| author | Simon Peyton Jones <simonpj@microsoft.com> | 2015-09-02 14:05:36 +0200 |
|---|---|---|
| committer | Ben Gamari <bgamari.foss@gmail.com> | 2015-09-02 09:11:51 -0400 |
| commit | 28ac9d31bcabeb44496c0e1750563f3091c62da9 (patch) | |
| tree | 427a29e1beca0ee3fee7a1bc825bb5fa2fa03dae /docs | |
| parent | c8f623e305ec0a51ac2406a1f754d244e05b96f5 (diff) | |
| download | haskell-28ac9d31bcabeb44496c0e1750563f3091c62da9.tar.gz | |
Improve the error messages for class instance errors
Summary: See Note [Displaying potential instances].
Reviewers: austin
Subscribers: KaneTW, thomie
Differential Revision: https://phabricator.haskell.org/D1176
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/users_guide/flags.xml | 6 | ||||
| -rw-r--r-- | docs/users_guide/using.xml | 10 |
2 files changed, 16 insertions, 0 deletions
diff --git a/docs/users_guide/flags.xml b/docs/users_guide/flags.xml index 0683752ee6..24917af252 100644 --- a/docs/users_guide/flags.xml +++ b/docs/users_guide/flags.xml @@ -36,6 +36,12 @@ <entry>-</entry> </row> <row> + <entry><option>-fprint-potential-instances</option></entry> + <entry>display all available instances in type error messages</entry> + <entry>dynamic</entry> + <entry>-fno-print-potential-instances</entry> + </row> + <row> <entry><option>-fprint-explicit-foralls</option></entry> <entry>Print explicit <literal>forall</literal> quantification in types. See also <option>-XExplicitForAll</option></entry> <entry>dynamic</entry> diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml index 502f7a3401..71d3467bbb 100644 --- a/docs/users_guide/using.xml +++ b/docs/users_guide/using.xml @@ -894,6 +894,16 @@ ghc -c Foo.hs </listitem> </varlistentry> + <varlistentry> + <term><option>--fprint-potential-instances</option> + <indexterm><primary><option>-fprint-potential-instances</option></primary></indexterm> + </term> + <listitem> + <para>When GHC can't find an instance for a class, it displays a short list of some + in the instances it knows about. With this flag it prints <emphasis>all</emphasis> + the instances it knows about. + </para></listitem> + </varlistentry> <varlistentry> <term><option>-fprint-explicit-foralls, -fprint-explicit-kinds, -fprint-unicode-syntax</option> |