X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fghci.xml;h=d9295484c85e2f84ddf5ea1550b7604f6898e7a4;hb=aedb94f5f220b5e442b23ecc445fd38c8d9b6ba0;hp=299b1e5bb28477e8a59d4e3317b008ecacb1d3d3;hpb=087fc5a777f18ef6fa488d168cdf18ef8a22f374;p=ghc-hetmet.git diff --git a/docs/users_guide/ghci.xml b/docs/users_guide/ghci.xml index 299b1e5..d929548 100644 --- a/docs/users_guide/ghci.xml +++ b/docs/users_guide/ghci.xml @@ -302,12 +302,29 @@ Ok, modules loaded: A, B, C, D. confusion, because non-exported top-level definitions of a module are only available for use in expressions at the prompt when the module is interpreted (see ). For - this reason, if you ask GHCi to load a filename rather than a - module name (e.g. :load Main.hs rather than - :load Main) then any existing object file will - be ignored and the module will be interpreted rather than - compiled. Using -fobject-code disables this - behaviour (see ). + this reason, you might sometimes want to force GHCi to load a + module using the interpreter. This can be done by prefixing + a * to the module name or filename when + using :load, for example + + +Prelude> :load *A +Compiling A ( A.hs, interpreted ) +*A> + + +When the * is used, GHCi ignores any + pre-compiled object code and interprets the module. If you have + already loaded a number of modules as object code and decide that + you wanted to interpret one of them, instead of re-loading the whole + set you can use :add *M to specify that you want + M to be interpreted (note that this might cause + other modules to be interpreted too, because compiled modules cannot + depend on interpreted ones). + +To always compile everything to object code and never use the + interpreter, use the -fobject-code option (see + ). HINT: since GHCi will only use a compiled object file if it can be sure that the compiled version is up-to-date, a good technique @@ -552,9 +569,9 @@ Compiling Main ( Main.hs, interpreted ) NOTE: for technical reasons, GHCi can only support the *-form for modules that are interpreted. Compiled modules and package modules can only contribute their - exports to the current scope. This is why GHCi will always - interpret, not compile, a module if you specify its filename - rather than its module name to :load. + exports to the current scope. To ensure that GHCi loads the + interpreted version of a module, add the * + when loading the module, e.g. :load *M. The scope is manipulated using the :module command. For example, if the current @@ -650,13 +667,14 @@ Prelude IO> loaded”. - + Qualified names To make life slightly easier, the GHCi prompt also behaves as if there is an implicit import qualified declaration for every module in every - package, and every module currently loaded into GHCi. + package, and every module currently loaded into GHCi. This + behaviour can be disabled with the flag . @@ -1476,7 +1494,7 @@ a :: a *Main> :set -fbreak-on-exception *Main> :trace qsort ("abc" ++ undefined) -"Stopped at <exception thrown> +“Stopped at <exception thrown> _exception :: e [<exception thrown>] *Main> :hist -1 : qsort.hs:3:24-38 @@ -1761,13 +1779,16 @@ $ ghci -lm - :add module ... + :add *module ... :add Add module(s) to the current target set, and perform a - reload. + reload. Normally pre-compiled code for the module will be + loaded if available, or otherwise the module will be + compiled to byte-code. Using the * + prefix forces the module to be loaded as byte-code. @@ -2138,7 +2159,7 @@ Prelude> :. cmds.ghci - :load module ... + :load *module ... :load @@ -2155,6 +2176,11 @@ Prelude> :. cmds.ghci to unload all the currently loaded modules and bindings. + Normally pre-compiled code for a module will be loaded + if available, or otherwise the module will be compiled to + byte-code. Using the * prefix forces a + module to be loaded as byte-code. + After a :load command, the current context is set to: @@ -2360,7 +2386,9 @@ bar Inside prompt, the sequence %s is replaced by the names of the modules currently in scope, and %% is - replaced by %. + replaced by %. If prompt + starts with " then it is parsed as a Haskell String; + otherwise it is treated as a literal string.