X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fmain%2FCmdLineOpts.lhs;h=e6fadc06012f5bbe98d1ae435bc9977e65570dca;hb=893a774d698f90cd2915cd5305b15bc02e1afb40;hp=69be7722e968dda87e889b321d500d78651bc7b7;hpb=671e6004c338712e79ccda55a4e7996db9174813;p=ghc-hetmet.git diff --git a/ghc/compiler/main/CmdLineOpts.lhs b/ghc/compiler/main/CmdLineOpts.lhs index 69be772..e6fadc0 100644 --- a/ghc/compiler/main/CmdLineOpts.lhs +++ b/ghc/compiler/main/CmdLineOpts.lhs @@ -1,4 +1,4 @@ -% + % (c) The University of Glasgow, 1996-2000 % \section[CmdLineOpts]{Things to do with command-line options} @@ -6,32 +6,50 @@ \begin{code} module CmdLineOpts ( - CoreToDo(..), - SimplifierSwitch(..), isAmongSimpl, - StgToDo(..), - SwitchResult(..), + CoreToDo(..), StgToDo(..), + SimplifierSwitch(..), + SimplifierMode(..), FloatOutSwitches(..), + HscLang(..), DynFlag(..), -- needed non-abstractly by DriverFlags DynFlags(..), v_Static_hsc_opts, - intSwitchSet, - switchIsOn, isStaticHscFlag, + -- Manipulating DynFlags + defaultDynFlags, -- DynFlags + dopt, -- DynFlag -> DynFlags -> Bool + dopt_set, dopt_unset, -- DynFlags -> DynFlag -> DynFlags + dopt_CoreToDo, -- DynFlags -> [CoreToDo] + dopt_StgToDo, -- DynFlags -> [StgToDo] + dopt_HscLang, -- DynFlags -> HscLang + dopt_OutName, -- DynFlags -> String + getOpts, -- (DynFlags -> [a]) -> IO [a] + setLang, + getVerbFlag, + + -- Manipulating the DynFlags state + getDynFlags, -- IO DynFlags + setDynFlags, -- DynFlags -> IO () + updDynFlags, -- (DynFlags -> DynFlags) -> IO () + dynFlag, -- (DynFlags -> a) -> IO a + setDynFlag, unSetDynFlag, -- DynFlag -> IO () + saveDynFlags, -- IO () + restoreDynFlags, -- IO DynFlags + + -- sets of warning opts + standardWarnings, + minusWOpts, + minusWallOpts, + + -- Output style options opt_PprStyle_NoPrags, + opt_PprStyle_RawTypes, opt_PprUserLength, opt_PprStyle_Debug, - dopt, - - -- other dynamic flags - dopt_CoreToDo, - dopt_StgToDo, - dopt_HscLang, - dopt_OutName, - -- profiling opts opt_AutoSccsOnAllToplevs, opt_AutoSccsOnExportedToplevs, @@ -48,8 +66,10 @@ module CmdLineOpts ( opt_NumbersStrict, opt_Parallel, opt_SMP, + opt_RuntimeTypes, -- optimisation opts + opt_NoMethodSharing, opt_DoSemiTagging, opt_FoldrBuildOn, opt_LiberateCaseThreshold, @@ -60,13 +80,11 @@ module CmdLineOpts ( opt_SimplNoPreInlining, opt_SimplDoEtaReduction, opt_SimplDoLambdaEtaExpansion, - opt_SimplCaseOfCase, opt_SimplCaseMerge, - opt_SimplPedanticBottoms, opt_SimplExcessPrecision, + opt_MaxWorkerArgs, -- Unfolding control - opt_UF_HiFileThreshold, opt_UF_CreationThreshold, opt_UF_UseThreshold, opt_UF_FunAppDiscount, @@ -85,33 +103,25 @@ module CmdLineOpts ( opt_IgnoreAsserts, opt_IgnoreIfacePragmas, opt_NoHiCheck, - opt_NoImplicitPrelude, opt_OmitBlackHoling, opt_OmitInterfacePragmas, opt_NoPruneTyDecls, opt_NoPruneDecls, opt_Static, opt_Unregisterised, - opt_Verbose + opt_EmitExternalCore ) where #include "HsVersions.h" -import Array ( array, (//) ) import GlaExts -import IOExts ( IORef, readIORef ) +import IOExts ( IORef, readIORef, writeIORef ) import Constants -- Default values for some flags import Util import FastTypes +import Config import Maybes ( firstJust ) -import Panic ( panic ) - -#if __GLASGOW_HASKELL__ < 301 -import ArrBase ( Array(..) ) -#else -import PrelArr ( Array(..) ) -#endif \end{code} %************************************************************************ @@ -154,54 +164,55 @@ main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop %************************************************************************ \begin{code} -data SwitchResult - = SwBool Bool -- on/off - | SwString FAST_STRING -- nothing or a String - | SwInt Int -- nothing or an Int -\end{code} - -\begin{code} data CoreToDo -- These are diff core-to-core passes, -- which may be invoked in any order, -- as many times as you like. = CoreDoSimplify -- The core-to-core simplifier. - (SimplifierSwitch -> SwitchResult) + SimplifierMode + [SimplifierSwitch] -- Each run of the simplifier can take a different -- set of simplifier-specific flags. | CoreDoFloatInwards - | CoreDoFloatOutwards Bool -- True <=> float lambdas to top level + | CoreDoFloatOutwards FloatOutSwitches | CoreLiberateCase | CoreDoPrintCore | CoreDoStaticArgs | CoreDoStrictness | CoreDoWorkerWrapper | CoreDoSpecialising + | CoreDoSpecConstr | CoreDoUSPInf | CoreDoCPResult | CoreDoGlomBinds | CoreCSE + | CoreDoRuleCheck Int{-CompilerPhase-} String -- Check for non-application of rules + -- matching this string | CoreDoNothing -- useful when building up lists of these things \end{code} \begin{code} data StgToDo - = StgDoStaticArgs - | StgDoLambdaLift - | StgDoMassageForProfiling -- should be (next to) last + = StgDoMassageForProfiling -- should be (next to) last -- There's also setStgVarInfo, but its absolute "lastness" -- is so critical that it is hardwired in (no flag). | D_stg_stats \end{code} \begin{code} +data SimplifierMode -- See comments in SimplMonad + = SimplGently + | SimplPhase Int + data SimplifierSwitch = MaxSimplifierIterations Int - | SimplInlinePhase Int - | DontApplyRules | NoCaseOfCase - | SimplLetToCase + +data FloatOutSwitches + = FloatOutSw Bool -- True <=> float lambdas to top level + Bool -- True <=> float constants to top level, + -- even if they do not escape a lambda \end{code} %************************************************************************ @@ -214,9 +225,7 @@ data SimplifierSwitch data DynFlag -- debugging flags - = Opt_D_dump_all - | Opt_D_dump_most - | Opt_D_dump_absC + = Opt_D_dump_absC | Opt_D_dump_asm | Opt_D_dump_cpranal | Opt_D_dump_deriv @@ -231,6 +240,7 @@ data DynFlag | Opt_D_dump_simpl | Opt_D_dump_simpl_iterations | Opt_D_dump_spec + | Opt_D_dump_prep | Opt_D_dump_stg | Opt_D_dump_stranal | Opt_D_dump_tc @@ -239,14 +249,16 @@ data DynFlag | Opt_D_dump_usagesp | Opt_D_dump_cse | Opt_D_dump_worker_wrapper - | Opt_D_show_passes | Opt_D_dump_rn_trace | Opt_D_dump_rn_stats | Opt_D_dump_stix | Opt_D_dump_simpl_stats + | Opt_D_dump_tc_trace + | Opt_D_dump_BCOs | Opt_D_source_stats | Opt_D_verbose_core2core | Opt_D_verbose_stg2stg + | Opt_D_dump_hi | Opt_D_dump_hi_diffs | Opt_D_dump_minimal_imports | Opt_DoCoreLinting @@ -267,25 +279,93 @@ data DynFlag | Opt_WarnUnusedImports | Opt_WarnUnusedMatches | Opt_WarnDeprecations + | Opt_WarnMisc -- language opts | Opt_AllowOverlappingInstances | Opt_AllowUndecidableInstances + | Opt_AllowIncoherentInstances + | Opt_NoMonomorphismRestriction | Opt_GlasgowExts | Opt_Generics + | Opt_NoImplicitPrelude - -- misc - | Opt_ReportCompile deriving (Eq) data DynFlags = DynFlags { - coreToDo :: [CoreToDo], - stgToDo :: [StgToDo], - hscLang :: HscLang, - hscOutName :: String, -- name of the file in which to place output - flags :: [DynFlag] + coreToDo :: [CoreToDo], + stgToDo :: [StgToDo], + hscLang :: HscLang, + hscOutName :: String, -- name of the output file + hscStubHOutName :: String, -- name of the .stub_h output file + hscStubCOutName :: String, -- name of the .stub_c output file + extCoreName :: String, -- name of the .core output file + verbosity :: Int, -- verbosity level + cppFlag :: Bool, -- preprocess with cpp? + ppFlag :: Bool, -- preprocess with a Haskell Pp? + stolen_x86_regs :: Int, + cmdlineHcIncludes :: [String], -- -#includes + + -- options for particular phases + opt_L :: [String], + opt_P :: [String], + opt_F :: [String], + opt_c :: [String], + opt_a :: [String], + opt_m :: [String], +#ifdef ILX + opt_I :: [String], + opt_i :: [String], +#endif + + -- hsc dynamic flags + flags :: [DynFlag] } +data HscLang + = HscC + | HscAsm + | HscJava + | HscILX + | HscInterpreted + | HscNothing + deriving (Eq, Show) + +defaultDynFlags = DynFlags { + coreToDo = [], stgToDo = [], + hscLang = HscC, + hscOutName = "", + hscStubHOutName = "", hscStubCOutName = "", + extCoreName = "", + verbosity = 0, + cppFlag = False, + ppFlag = False, + stolen_x86_regs = 4, + cmdlineHcIncludes = [], + opt_L = [], + opt_P = [], + opt_F = [], + opt_c = [], + opt_a = [], + opt_m = [], +#ifdef ILX + opt_I = [], + opt_i = [], +#endif + flags = standardWarnings, + } + +{- + Verbosity levels: + + 0 | print errors & warnings only + 1 | minimal verbosity: print "compiling M ... done." for each module. + 2 | equivalent to -dshow-passes + 3 | equivalent to existing "ghc -v" + 4 | "ghc -v -ddump-most" + 5 | "ghc -v -ddump-all" +-} + dopt :: DynFlag -> DynFlags -> Bool dopt f dflags = f `elem` (flags dflags) @@ -298,15 +378,108 @@ dopt_StgToDo = stgToDo dopt_OutName :: DynFlags -> String dopt_OutName = hscOutName -data HscLang - = HscC - | HscAsm - | HscJava - | HscInterpreted - deriving Eq - dopt_HscLang :: DynFlags -> HscLang dopt_HscLang = hscLang + +dopt_set :: DynFlags -> DynFlag -> DynFlags +dopt_set dfs f = dfs{ flags = f : flags dfs } + +dopt_unset :: DynFlags -> DynFlag -> DynFlags +dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) } + +getOpts :: (DynFlags -> [a]) -> IO [a] + -- We add to the options from the front, so we need to reverse the list +getOpts opts = dynFlag opts >>= return . reverse + +-- we can only switch between HscC, HscAsmm, and HscILX with dynamic flags +-- (-fvia-C, -fasm, -filx respectively). +setLang l = updDynFlags (\ dfs -> case hscLang dfs of + HscC -> dfs{ hscLang = l } + HscAsm -> dfs{ hscLang = l } + HscILX -> dfs{ hscLang = l } + _ -> dfs) + +getVerbFlag = do + verb <- dynFlag verbosity + if verb >= 3 then return "-v" else return "" +\end{code} + +----------------------------------------------------------------------------- +-- Mess about with the mutable variables holding the dynamic arguments + +-- v_InitDynFlags +-- is the "baseline" dynamic flags, initialised from +-- the defaults and command line options, and updated by the +-- ':s' command in GHCi. +-- +-- v_DynFlags +-- is the dynamic flags for the current compilation. It is reset +-- to the value of v_InitDynFlags before each compilation, then +-- updated by reading any OPTIONS pragma in the current module. + +\begin{code} +GLOBAL_VAR(v_InitDynFlags, defaultDynFlags, DynFlags) +GLOBAL_VAR(v_DynFlags, defaultDynFlags, DynFlags) + +setDynFlags :: DynFlags -> IO () +setDynFlags dfs = writeIORef v_DynFlags dfs + +saveDynFlags :: IO () +saveDynFlags = do dfs <- readIORef v_DynFlags + writeIORef v_InitDynFlags dfs + +restoreDynFlags :: IO DynFlags +restoreDynFlags = do dfs <- readIORef v_InitDynFlags + writeIORef v_DynFlags dfs + return dfs + +getDynFlags :: IO DynFlags +getDynFlags = readIORef v_DynFlags + +updDynFlags :: (DynFlags -> DynFlags) -> IO () +updDynFlags f = do dfs <- readIORef v_DynFlags + writeIORef v_DynFlags (f dfs) + +dynFlag :: (DynFlags -> a) -> IO a +dynFlag f = do dflags <- readIORef v_DynFlags; return (f dflags) + +setDynFlag, unSetDynFlag :: DynFlag -> IO () +setDynFlag f = updDynFlags (\dfs -> dopt_set dfs f) +unSetDynFlag f = updDynFlags (\dfs -> dopt_unset dfs f) +\end{code} + + +%************************************************************************ +%* * +\subsection{Warnings} +%* * +%************************************************************************ + +\begin{code} +standardWarnings + = [ Opt_WarnDeprecations, + Opt_WarnOverlappingPatterns, + Opt_WarnMissingFields, + Opt_WarnMissingMethods, + Opt_WarnDuplicateExports + ] + +minusWOpts + = standardWarnings ++ + [ Opt_WarnUnusedBinds, + Opt_WarnUnusedMatches, + Opt_WarnUnusedImports, + Opt_WarnIncompletePatterns, + Opt_WarnMisc + ] + +minusWallOpts + = minusWOpts ++ + [ Opt_WarnTypeDefaults, + Opt_WarnNameShadowing, + Opt_WarnMissingSigs, + Opt_WarnHiShadows + ] \end{code} %************************************************************************ @@ -341,10 +514,6 @@ lookup_def_int sw def = case (lookup_str sw) of Nothing -> def -- Use default Just xx -> read xx -lookup_def_char sw def = case (lookup_str sw) of - Just (xx:_) -> xx - _ -> def -- Use default - lookup_def_float sw def = case (lookup_str sw) of Nothing -> def -- Use default Just xx -> read xx @@ -377,6 +546,7 @@ unpacked_opts = -- debugging opts opt_PprStyle_NoPrags = lookUp SLIT("-dppr-noprags") opt_PprStyle_Debug = lookUp SLIT("-dppr-debug") +opt_PprStyle_RawTypes = lookUp SLIT("-dppr-rawtypes") opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name -- profiling opts @@ -397,18 +567,20 @@ opt_Parallel = lookUp SLIT("-fparallel") opt_SMP = lookUp SLIT("-fsmp") -- optimisation opts +opt_NoMethodSharing = lookUp SLIT("-fno-method-sharing") opt_DoSemiTagging = lookUp SLIT("-fsemi-tagging") opt_FoldrBuildOn = lookUp SLIT("-ffoldr-build-on") opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int) opt_StgDoLetNoEscapes = lookUp SLIT("-flet-no-escape") -opt_UnfoldCasms = lookUp SLIT("-funfold-casms-in-hi-file") +opt_UnfoldCasms = lookUp SLIT("-funfold-casms-in-hi-file") opt_UsageSPOn = lookUp SLIT("-fusagesp-on") opt_UnboxStrictFields = lookUp SLIT("-funbox-strict-fields") +opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int) {- The optional '-inpackage=P' flag tells what package we are compiling this module for. - The Prelude, for example is compiled with '-package prelude' + The Prelude, for example is compiled with '-inpackage std' -} opt_InPackage = case lookup_str "-inpackage=" of Just p -> _PK_ p @@ -417,28 +589,25 @@ opt_InPackage = case lookup_str "-inpackage=" of opt_EmitCExternDecls = lookUp SLIT("-femit-extern-decls") opt_EnsureSplittableC = lookUp SLIT("-fglobalise-toplev-names") opt_GranMacros = lookUp SLIT("-fgransim") -opt_HiVersion = lookup_def_int "-fhi-version=" 0 -- what version we're compiling. +opt_HiVersion = read cProjectVersionInt :: Int opt_HistorySize = lookup_def_int "-fhistory-size" 20 opt_IgnoreAsserts = lookUp SLIT("-fignore-asserts") opt_IgnoreIfacePragmas = lookUp SLIT("-fignore-interface-pragmas") opt_NoHiCheck = lookUp SLIT("-fno-hi-version-check") -opt_NoImplicitPrelude = lookUp SLIT("-fno-implicit-prelude") opt_OmitBlackHoling = lookUp SLIT("-dno-black-holing") opt_OmitInterfacePragmas = lookUp SLIT("-fomit-interface-pragmas") +opt_RuntimeTypes = lookUp SLIT("-fruntime-types") -- Simplifier switches -opt_SimplNoPreInlining = lookUp SLIT("-fno-pre-inlining") +opt_SimplNoPreInlining = lookUp SLIT("-fno-pre-inlining") -- NoPreInlining is there just to see how bad things -- get if you don't do it! -opt_SimplDoEtaReduction = lookUp SLIT("-fdo-eta-reduction") -opt_SimplDoLambdaEtaExpansion = lookUp SLIT("-fdo-lambda-eta-expansion") -opt_SimplCaseOfCase = lookUp SLIT("-fcase-of-case") -opt_SimplCaseMerge = lookUp SLIT("-fcase-merge") -opt_SimplPedanticBottoms = lookUp SLIT("-fpedantic-bottoms") -opt_SimplExcessPrecision = lookUp SLIT("-fexcess-precision") +opt_SimplDoEtaReduction = lookUp SLIT("-fdo-eta-reduction") +opt_SimplDoLambdaEtaExpansion = lookUp SLIT("-fdo-lambda-eta-expansion") +opt_SimplCaseMerge = lookUp SLIT("-fcase-merge") +opt_SimplExcessPrecision = lookUp SLIT("-fexcess-precision") -- Unfolding control -opt_UF_HiFileThreshold = lookup_def_int "-funfolding-interface-threshold" (45::Int) opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int) opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn @@ -448,11 +617,11 @@ opt_UF_UpdateInPlace = lookUp SLIT("-funfolding-update-in-place") opt_UF_CheapOp = ( 1 :: Int) -- Only one instruction; and the args are charged for opt_UF_DearOp = ( 4 :: Int) -opt_NoPruneDecls = lookUp SLIT("-fno-prune-decls") -opt_NoPruneTyDecls = lookUp SLIT("-fno-prune-tydecls") -opt_Static = lookUp SLIT("-static") -opt_Unregisterised = lookUp SLIT("-funregisterised") -opt_Verbose = lookUp SLIT("-v") +opt_NoPruneDecls = lookUp SLIT("-fno-prune-decls") +opt_NoPruneTyDecls = lookUp SLIT("-fno-prune-tydecls") +opt_Static = lookUp SLIT("-static") +opt_Unregisterised = lookUp SLIT("-funregisterised") +opt_EmitExternalCore = lookUp SLIT("-fext-core") \end{code} %************************************************************************ @@ -472,7 +641,6 @@ isStaticHscFlag f = "fticky-ticky", "fall-strict", "fdicts-strict", - "fgenerics", "firrefutable-tuples", "fnumbers-strict", "fparallel", @@ -489,29 +657,29 @@ isStaticHscFlag f = "fignore-asserts", "fignore-interface-pragmas", "fno-hi-version-check", - "fno-implicit-prelude", "dno-black-holing", + "fno-method-sharing", + "fno-monomorphism-restriction", "fomit-interface-pragmas", + "fruntime-types", "fno-pre-inlining", "fdo-eta-reduction", "fdo-lambda-eta-expansion", - "fcase-of-case", "fcase-merge", - "fpedantic-bottoms", "fexcess-precision", "funfolding-update-in-place", - "freport-compile", "fno-prune-decls", "fno-prune-tydecls", "static", "funregisterised", - "v" ] + "fext-core", + "frule-check" + ] || any (flip prefixMatch f) [ "fcontext-stack", "fliberate-case-threshold", - "fhi-version=", + "fmax-worker-args", "fhistory-size", - "funfolding-interface-threshold", "funfolding-creation-threshold", "funfolding-use-threshold", "funfolding-fun-discount", @@ -521,121 +689,11 @@ isStaticHscFlag f = %************************************************************************ %* * -\subsection{Switch ordering} -%* * -%************************************************************************ - -These things behave just like enumeration types. - -\begin{code} -instance Eq SimplifierSwitch where - a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b - -instance Ord SimplifierSwitch where - a < b = tagOf_SimplSwitch a <# tagOf_SimplSwitch b - a <= b = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b - - -tagOf_SimplSwitch (SimplInlinePhase _) = _ILIT(1) -tagOf_SimplSwitch (MaxSimplifierIterations _) = _ILIT(2) -tagOf_SimplSwitch DontApplyRules = _ILIT(3) -tagOf_SimplSwitch SimplLetToCase = _ILIT(4) -tagOf_SimplSwitch NoCaseOfCase = _ILIT(5) - --- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too! - -lAST_SIMPL_SWITCH_TAG = 5 -\end{code} - -%************************************************************************ -%* * -\subsection{Switch lookup} -%* * -%************************************************************************ - -\begin{code} -isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult -isAmongSimpl on_switches -- Switches mentioned later occur *earlier* - -- in the list; defaults right at the end. - = let - tidied_on_switches = foldl rm_dups [] on_switches - -- The fold*l* ensures that we keep the latest switches; - -- ie the ones that occur earliest in the list. - - sw_tbl :: Array Int SwitchResult - sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds... - all_undefined) - // defined_elems - - all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ] - - defined_elems = map mk_assoc_elem tidied_on_switches - in - -- (avoid some unboxing, bounds checking, and other horrible things:) -#if __GLASGOW_HASKELL__ < 405 - case sw_tbl of { Array bounds_who_needs_'em stuff -> -#else - case sw_tbl of { Array _ _ stuff -> -#endif - \ switch -> - case (indexArray# stuff (tagOf_SimplSwitch switch)) of -#if __GLASGOW_HASKELL__ < 400 - Lift v -> v -#elif __GLASGOW_HASKELL__ < 403 - (# _, v #) -> v -#else - (# v #) -> v -#endif - } - where - mk_assoc_elem k@(MaxSimplifierIterations lvl) - = (iBox (tagOf_SimplSwitch k), SwInt lvl) - mk_assoc_elem k@(SimplInlinePhase n) - = (iBox (tagOf_SimplSwitch k), SwInt n) - mk_assoc_elem k - = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom! - - -- cannot have duplicates if we are going to use the array thing - rm_dups switches_so_far switch - = if switch `is_elem` switches_so_far - then switches_so_far - else switch : switches_so_far - where - sw `is_elem` [] = False - sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s) - || sw `is_elem` ss -\end{code} - -Default settings for simplifier switches - -\begin{code} -defaultSimplSwitches = [MaxSimplifierIterations 1] -\end{code} - -%************************************************************************ -%* * \subsection{Misc functions for command-line options} %* * %************************************************************************ -\begin{code} -switchIsOn :: (switch -> SwitchResult) -> switch -> Bool - -switchIsOn lookup_fn switch - = case (lookup_fn switch) of - SwBool False -> False - _ -> True - -intSwitchSet :: (switch -> SwitchResult) - -> (Int -> switch) - -> Maybe Int - -intSwitchSet lookup_fn switch - = case (lookup_fn (switch (panic "intSwitchSet"))) of - SwInt int -> Just int - _ -> Nothing -\end{code} \begin{code} startsWith :: String -> String -> Maybe String