X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fusing.xml;h=06b9ccc315a6ad52eb4f500c3f18fcd2b9439e07;hb=58521c72cec262496dabf5fffb057d25ab17a0f7;hp=fad30ac245558c17c752a0e1622d10647e6c8238;hpb=46f02d59813499ba2aa44e7831e0b69ec6d8f25d;p=ghc-hetmet.git
diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml
index fad30ac..06b9ccc 100644
--- a/docs/users_guide/using.xml
+++ b/docs/users_guide/using.xml
@@ -844,7 +844,9 @@ ghc -c Foo.hs
,
,
,
- , and
+ ,
+ ,
+ , and
. The following
flags are
simple ways to select standard “packages” of warnings:
@@ -858,6 +860,7 @@ ghc -c Foo.hs
-W optionProvides the standard warnings plus
,
+ ,
,
,
, and
@@ -876,7 +879,8 @@ ghc -c Foo.hs
,
,
,
- , and
+ ,
+ , and
.
@@ -988,11 +992,25 @@ foreign import "&f" f :: FunPtr t
+ :
+
+
+
+ Causes a warning to be emitted when a datatype
+ T is exported
+ with all constructors, i.e. T(..), but is it
+ just a type synonym.
+ Also causes a warning to be emitted when a module is
+ re-exported, but that module exports nothing.
+
+
+
+ :
- Causes a warning to be emitted when a a datatype
+ Causes a warning to be emitted when a datatype
T is imported
with all constructors, i.e. T(..), but has been
exported abstractly, i.e. T.
@@ -1000,6 +1018,20 @@ foreign import "&f" f :: FunPtr t
+ :
+
+
+
+ Causes a warning to be emitted when an unlifted type
+ is bound in a way that looks lazy, e.g.
+ where (I# x) = .... Use
+ where !(I# x) = ... instead. This will be an
+ error, rather than a warning, in GHC 6.14.
+
+
+
+
+ :
@@ -1350,6 +1382,56 @@ f "2" = 2
+
+ :
+
+
+ unused do binding, warning
+ do binding, unused
+
+ Report expressions occuring in do and mdo blocks
+ that appear to silently throw information away.
+ For instance do { mapM popInt xs ; return 10 } would report
+ the first statement in the do block as suspicious,
+ as it has the type StackM [Int] and not StackM (), but that
+ [Int] value is not bound to anything. The warning is suppressed by
+ explicitly mentioning in the source code that your program is throwing something away:
+
+ do { _ <- mapM popInt xs ; return 10 }
+
+ Of course, in this particular situation you can do even better:
+
+ do { mapM_ popInt xs ; return 10 }
+
+
+
+
+
+
+ :
+
+
+ apparently erroneous do binding, warning
+ do binding, apparently erroneous
+
+ Report expressions occuring in do and mdo blocks
+ that appear to lack a binding.
+ For instance do { return (popInt 10) ; return 10 } would report
+ the first statement in the do block as suspicious,
+ as it has the type StackM (StackM Int) (which consists of two nested applications
+ of the same monad constructor), but which is not then "unpacked" by binding the result.
+ The warning is suppressed by explicitly mentioning in the source code that your program is throwing something away:
+
+ do { _ <- return (popInt 10) ; return 10 }
+
+ For almost all sensible programs this will indicate a bug, and you probably intended to write:
+
+ do { popInt 10 ; return 10 }
+
+
+
+
+
If you're feeling really paranoid, the
@@ -1728,7 +1810,9 @@ f "2" = 2
&phases;
-
+
+ &shared_libs;
+
Using Concurrent HaskellConcurrent Haskellusing