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| author | Ian Lynagh <igloo@earth.li> | 2008-09-26 20:38:32 +0000 |
|---|---|---|
| committer | Ian Lynagh <igloo@earth.li> | 2008-09-26 20:38:32 +0000 |
| commit | 0c12697ef809ab47dd10b6e292fe42140af72c3f (patch) | |
| tree | 9b4da47298b17a79ed46311f04e9fb863140e0bd /docs/users_guide/profiling.xml | |
| parent | 6790af558efad6467b9ec0fc40f7a2e43d437fc7 (diff) | |
| download | haskell-0c12697ef809ab47dd10b6e292fe42140af72c3f.tar.gz | |
Add an example of how to use SCCs to the user guide
Diffstat (limited to 'docs/users_guide/profiling.xml')
| -rw-r--r-- | docs/users_guide/profiling.xml | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/docs/users_guide/profiling.xml b/docs/users_guide/profiling.xml index 51ae6f71c3..f0d96ba98b 100644 --- a/docs/users_guide/profiling.xml +++ b/docs/users_guide/profiling.xml @@ -266,6 +266,22 @@ MAIN MAIN 0 0.0 0.0 100.0 100.0 far to the right as possible when parsing. (SCC stands for "Set Cost Centre").</para> + <para>Here is an example of a program with a couple of SCCs:</para> + +<programlisting> +main :: IO () +main = do let xs = {-# SCC "X" #-} [1..1000000] + let ys = {-# SCC "Y" #-} [1..2000000] + print $ last xs + print $ last $ init xs + print $ last ys + print $ last $ init ys +</programlisting> + + <para>which gives this heap profile when run:</para> + + <imagedata fileref="prof_scc.png"/> + </sect2> <sect2 id="prof-rules"> |