X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fghci.xml;h=69078d5093ebb2e0489bf0d06d74a7f16594cdc1;hb=d62101efb9e263173b69fb89c07f03dcf805e81f;hp=82ee33054d6bdbeda1f1b04cc26730a7abfac83f;hpb=8fcfc8d6e42ea5bf49422024bc71d3728ee97db9;p=ghc-hetmet.git diff --git a/docs/users_guide/ghci.xml b/docs/users_guide/ghci.xml index 82ee330..69078d5 100644 --- a/docs/users_guide/ghci.xml +++ b/docs/users_guide/ghci.xml @@ -1109,8 +1109,10 @@ right :: [a] bug. GHCi offers two variants of stepping. Use :step to enable all the breakpoints in the program, and execute until the next breakpoint is - reached. Use :stepover to step over function - applications, which of course are executed all the same. + reached. Use :steplocal to limit the set + of enabled breakpoints to those in the current top level function. + Similarly, use :stepmodule to single step only on + breakpoints contained in the current module. For example: @@ -1125,48 +1127,9 @@ _result :: IO () expr is ommitted, then it single-steps from the current breakpoint. :stepover works similarly. - - In the current version of the debugger, :stepover - 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, :stepover - stops working and switches to behave like regular :step. - This means - that it will fail to step over the last function application. As a result, - currently :stepover works great for monadic code, but - interacts less perfectly with pure code. For example, if stopped at the - line 2, on the entire expression - qsort left ++ [a] ++ qsort right: - -... [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 - - - The first :stepover will step over the first - qsort recursive call, as expected. The second one - will step over the evaluation of [a], again as - expected. However, the third one has lexically run out - of the current expression, and will behave like regular - :step, performing one step of lazy evaluation and - stopping at the next breakpoint. In this case it is indeed the second - recursive application of qsort. - -[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 (<=a) as, filter (>a) as) - + The :list command is particularly useful when - single-stepping, to see where you currently are, as just shown - in the above example. + single-stepping, to see where you currently are: [qsort.hs:5:7-47] *Main> :list @@ -1528,10 +1491,6 @@ Just 20 CAF (e.g. main), stop at a breakpoint, and ask for the value of the CAF at the prompt again. - :stepover 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. - Implicit parameters (see ) are only available at the scope of a breakpoint if there is an explicit type signature.