diff options
| -rw-r--r-- | compiler/ghci/Debugger.hs | 7 | ||||
| -rw-r--r-- | compiler/main/DynFlags.hs | 2 | ||||
| -rw-r--r-- | docs/users_guide/flags.xml | 6 | ||||
| -rw-r--r-- | docs/users_guide/ghci.xml | 9 |
4 files changed, 23 insertions, 1 deletions
diff --git a/compiler/ghci/Debugger.hs b/compiler/ghci/Debugger.hs index 179f68403b..5833e26d40 100644 --- a/compiler/ghci/Debugger.hs +++ b/compiler/ghci/Debugger.hs @@ -25,6 +25,7 @@ import Name import UniqSupply import TcType import GHC +import DynFlags import InteractiveEval import Outputable import Pretty ( Mode(..), showDocWith ) @@ -138,7 +139,11 @@ bindSuspensions cms@(Session ref) t = do -- A custom Term printer to enable the use of Show instances showTerm :: Session -> Term -> IO SDoc -showTerm cms@(Session ref) = cPprTerm (liftM2 (++) cPprShowable cPprTermBase) +showTerm cms@(Session ref) term = do + dflags <- GHC.getSessionDynFlags cms + if dopt Opt_PrintEvldWithShow dflags + then cPprTerm (liftM2 (++) cPprShowable cPprTermBase) term + else cPprTerm cPprTermBase term where cPprShowable _y = [\prec ty _ val tt -> if not (all isFullyEvaluatedTerm tt) diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs index 38591f02ac..c36a402ae1 100644 --- a/compiler/main/DynFlags.hs +++ b/compiler/main/DynFlags.hs @@ -266,6 +266,7 @@ data DynFlag | Opt_Hpc_No_Auto | Opt_BreakOnException | Opt_BreakOnError + | Opt_PrintEvldWithShow | Opt_GenManifest | Opt_EmbedManifest | Opt_RunCPSZ @@ -1192,6 +1193,7 @@ fFlags = [ ( "rewrite-rules", Opt_RewriteRules ), ( "break-on-exception", Opt_BreakOnException ), ( "break-on-error", Opt_BreakOnError ), + ( "print-evld-with-show", Opt_PrintEvldWithShow ), ( "run-cps", Opt_RunCPSZ ), ( "convert-to-zipper-and-back", Opt_ConvertToZipCfgAndBack), ( "vectorise", Opt_Vectorise ), diff --git a/docs/users_guide/flags.xml b/docs/users_guide/flags.xml index b417f7e52d..d706f11083 100644 --- a/docs/users_guide/flags.xml +++ b/docs/users_guide/flags.xml @@ -515,6 +515,12 @@ <entry><option>-fno-break-on-error</option></entry> </row> <row> + <entry><option>-fprint-evld-with-show</option></entry> + <entry><link linkend="breakpoints">Enable usage of Show instances in <literal>:print</literal></link></entry> + <entry>dynamic</entry> + <entry><option>-fno-print-evld-with-show</option></entry> + </row> + <row> <entry><option>-fno-print-bind-result</option></entry> <entry><link linkend="ghci-stmts">Turn off printing of binding results in GHCi</link></entry> <entry>dynamic</entry> diff --git a/docs/users_guide/ghci.xml b/docs/users_guide/ghci.xml index b1e36ec840..579cf23208 100644 --- a/docs/users_guide/ghci.xml +++ b/docs/users_guide/ghci.xml @@ -929,6 +929,7 @@ right :: [a] <literal>left</literal>:</para> <screen> +[qsort.hs:2:15-46] *Main> :set -fprint-evld-with-show [qsort.hs:2:15-46] *Main> :print left left = (_t1::[a]) </screen> @@ -948,6 +949,13 @@ left = (_t1::[a]) underscore, in this case <literal>_t1</literal>.</para> + <para>The flag <literal>-fprint-evld-with-show</literal> instructs + <literal>:print</literal> to reuse + available <literal>Show</literal> instances when possible. This happens + only when the contents of the variable being inspected + are completely evaluated.</para> + + <para>If we aren't concerned about preserving the evaluatedness of a variable, we can use <literal>:force</literal> instead of <literal>:print</literal>. The <literal>:force</literal> command @@ -1017,6 +1025,7 @@ right :: [a] <para>The execution continued at the point it previously stopped, and has now stopped at the breakpoint for a second time.</para> + <sect3 id="setting-breakpoints"> <title>Setting breakpoints</title> |