Better document :stepover and its limitations

[ghc-hetmet.git] / docs / users_guide / ghci.xml

diff --git a/docs/users_guide/ghci.xml b/docs/users_guide/ghci.xml
index 82ee330..a8ebbd7 100644 (file)
--- a/docs/users_guide/ghci.xml
+++ b/docs/users_guide/ghci.xml
@@ -1125,48 +1125,9 @@ _result :: IO ()
         <replaceable>expr</replaceable> is ommitted, then it single-steps from
         the current breakpoint. <literal>:stepover</literal> 
         works similarly.</para>
- 
-      <para>In the current version of the debugger, <literal>:stepover</literal>
-       is limited to work locally in the lexical sense, that is in the context
-       of the current expression body.
-       When you run to the end of the expression, <literal>:stepover</literal>
-       stops working and switches to behave like regular <literal>:step</literal>. 
-       This means 
-       that it will fail to step over the last function application. As a result,
-       currently <literal>:stepover</literal> works great for monadic code, but 
-       interacts less perfectly with pure code. For example, if stopped at the 
-       line 2, on the entire expression 
-       <literal>qsort left ++ [a] ++ qsort right</literal>:</para>
-<screen>
-... [qsort2.hs:2:15-46] *Main> :step
-Stopped at qsort2.hs:2:15-46
-
-... [qsort2.hs:2:15-46] *Main> :list
-2  qsort (a:as) = qsort left ++ [a] ++ qsort right
-</screen>
-       
-      <para> The first <literal>:stepover</literal> will step over the first
-           <literal>qsort</literal> recursive call, as expected. The second one 
-           will step over the evaluation of <literal>[a]</literal>, again as
-           expected. However, the third one has lexically <quote>run out</quote>
-           of the current expression, and will behave like regular 
-           <literal>:step</literal>, performing one step of lazy evaluation and
-           stopping at the next breakpoint. In this case it is indeed the second
-           recursive application of <literal>qsort</literal>.</para>
-<screen>
-[qsort2.hs:2:36-46] *Main> :stepover
-Warning: no more breakpoints in this function body, switching to :step
-Stopped at qsort2.hs:(1,0)-(3,55)
-
-[qsort2.hs:2:36-46] *Main> :list
-_result :: [a]
-1  qsort [] = []
-2  qsort (a:as) = qsort left ++ [a] ++ qsort right
-3    where (left,right) = (filter (&lt;=a) as, filter (>a) as)
-</screen>
+
       <para>The <literal>:list</literal> command is particularly useful when
-        single-stepping, to see where you currently are, as just shown
-       in the above example.</para>
+        single-stepping, to see where you currently are:</para>
 
 <screen>
 [qsort.hs:5:7-47] *Main> :list
@@ -1528,10 +1489,6 @@ Just 20
             CAF (e.g. main), stop at a breakpoint, and ask for the value of the
             CAF at the prompt again.</para>
         </listitem>
-       <listitem> <literal>:stepover</literal> only works lexically locally, in the
-         body of the current expression. As a result, it can be rather impredictable
-         when used in pure functional code, as opposed to monadic code.
-       </listitem>
        <listitem><para>
          Implicit parameters (see <xref linkend="implicit-parameters"/>) are only available 
          at the scope of a breakpoint if there is an explicit type signature.