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| author | Richard Eisenberg <eir@cis.upenn.edu> | 2015-09-19 16:44:29 -0400 |
|---|---|---|
| committer | Richard Eisenberg <eir@cis.upenn.edu> | 2015-09-20 21:39:16 -0400 |
| commit | 27f9186d8e35387c3f48f848ff3b2c8e967a9c97 (patch) | |
| tree | 5db851877abac7e2669828aa937aecdfe90c4b1c /docs | |
| parent | 1292c17e61400dfa0c27eddff4bea6a935006657 (diff) | |
| download | haskell-27f9186d8e35387c3f48f848ff3b2c8e967a9c97.tar.gz | |
Clarify parsing infelicity.
This fixes #10855.
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/users_guide/bugs.xml | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/docs/users_guide/bugs.xml b/docs/users_guide/bugs.xml index 1b4d5c93a2..bff2bcf056 100644 --- a/docs/users_guide/bugs.xml +++ b/docs/users_guide/bugs.xml @@ -101,13 +101,25 @@ main = do args <- getArgs <programlisting> (let x = 42 in x == 42 == True)</programlisting></para> </listitem> + + <listitem> + <para>The Haskell Report allows you to put a unary + <literal>-</literal> preceding certain expressions headed by + keywords, allowing constructs like <literal>- case x of + ...</literal> or <literal>- do { ... }</literal>. GHC does + not allow this. Instead, unary <literal>-</literal> is + allowed before only expressions that could potentially + be applied as a function. + </para> + </listitem> + </itemizedlist> </sect3> <sect3 id="infelicities-exprs-pats"> <title>Expressions and patterns</title> - <para>In its default mode, GHC makes some programs slightly more defined + <para>In its default mode, GHC makes some programs slightly more defined than they should be. For example, consider <programlisting> f :: [a] -> b -> b |