report more option errors

src/QuickBench.hs

@@ -54,14 +54,15 @@ Options:
 -- quickbench.cabal
 -- README.md
 -- quickbench.1.md
--- any Just assumptions below, if changing [default] annotations.
+-- unknown option checking below
+-- Just assumptions below, if changing [default] annotations.
 -- Try to avoid writing the same thing different ways in all of these places.
 
 defaultFile :: FilePath
 defaultFile = "bench.sh"
 
 data Opts = Opts {
---  docopts :: Arguments,
+ docopts :: Arguments,
  file :: Maybe FilePath
  ,executables :: [String]
  ,iterations :: Int
@@ -90,7 +91,7 @@ getOpts = do
  precision' <- readint $ fromJust $ option "precision"
  let
  opts = Opts {
---  docopts = dopts,
+ docopts = dopts,
  file = option "file"
  ,executables = maybe [] (splitOn ",") $ option "with"
  ,iterations = iterations'
@@ -104,10 +105,24 @@ getOpts = do
  }
  when (debug opts || "--debug" `elem` lateflags) $ err $ ppShow opts ++ "\n"
  when (help opts) $ putStrLn (usage docoptpatterns) >> exitSuccess
- unless (null lateflags) $
- fail $ printf "option %s should appear before argument %s"
- (show $ head lateflags)
- (show $ head args) -- safe, we don't see lateflags without some regular args
+ -- try to report some errors docopts misses
+ case (lateflags, args) of
+ -- unknown option
+ -- quickbench a -fk user error (unknown option: "fk")
+ -- (f:_,[]) | not $ elem f [
+ -- "file","f"
+ -- ,"with","w"
+ -- ,"iterations","n"
+ -- ,"cycles","N"
+ -- ,"precision","p"
+ -- ,"verbose","v"
+ -- ,"more-verbose","V"
+ -- ] -> fail $ printf "unknown option: %s" (show f)
+ -- option value missing
+ (f:_,[]) -> fail $ printf "option %s needs a value or is unknown" (show f)
+ -- option following arguments
+ (f:_,a:_) -> fail $ printf "option %s should appear before argument %s or is unknown" (show f) (show a)
+ _ -> return ()
  return opts
 
 -- | Run the quickbench program, returning an error message if there was a problem.