[project @ 2003-03-11 18:41:43 by panne]

[ghc-base.git] / System / Console / GetOpt.hs

diff --git a/System/Console/GetOpt.hs b/System/Console/GetOpt.hs
index 0b564e5..0062b02 100644 (file)
--- a/System/Console/GetOpt.hs
+++ b/System/Console/GetOpt.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  System.Console.GetOpt
--- Copyright   :  (c) Sven Panne Oct. 1996 (small changes Dec. 1997)
+-- Copyright   :  (c) Sven Panne Oct. 1996 (small changes Feb. 2003)
 -- License     :  BSD-style (see the file libraries/base/LICENSE)
 -- 
 -- Maintainer  :  libraries@haskell.org
@@ -24,13 +24,17 @@ it...) and the recognition of long options with a single dash
 (e.g. '-help' is recognised as '--help', as long as there is no short
 option 'h').
 
-Other differences between GNU's getopt and this implementation: * To
-enforce a coherent description of options and arguments, there are
-explanation fields in the option/argument descriptor.  * Error
-messages are now more informative, but no longer POSIX
-compliant... :-( And a final Haskell advertisement: The GNU C
-implementation uses well over 1100 lines, we need only 195 here,
-including a 46 line example! :-)
+Other differences between GNU's getopt and this implementation:
+
+* To enforce a coherent description of options and arguments, there
+  are explanation fields in the option/argument descriptor.
+
+* Error messages are now more informative, but no longer POSIX
+  compliant... :-(
+
+And a final Haskell advertisement: The GNU C implementation uses well
+over 1100 lines, we need only 195 here, including a 46 line example! 
+:-)
 -}
 
 module System.Console.GetOpt (
@@ -62,7 +66,7 @@ The arguments to 'Option' are:
 
 * list of short option characters
 
-* list of long option strings (without "--")
+* list of long option strings (without \"--\")
 
 * argument descriptor
 
@@ -127,7 +131,7 @@ Process the command-line, and return the list of values that matched
 * The option descriptions (see 'OptDescr')
 
 * The actual command line arguments (presumably got from 
-  'System.Console.Environment.getArgs').
+  'System.Environment.getArgs').
 
 'getOpt' returns a triple, consisting of the argument values, a list
 of options that didn\'t match, and a list of error messages.
@@ -161,7 +165,9 @@ getNext a            rest _        = (NonOpt a,rest)
 longOpt :: String -> [String] -> [OptDescr a] -> (OptKind a,[String])
 longOpt ls rs optDescr = long ads arg rs
    where (opt,arg) = break (=='=') ls
-         options   = [ o  | o@(Option _ ls _ _) <- optDescr, l <- ls, opt `isPrefixOf` l ]
+         getWith p = [ o  | o@(Option _ ls _ _) <- optDescr, l <- ls, opt `p` l ]
+         exact     = getWith (==)
+         options   = if null exact then getWith isPrefixOf else exact
          ads       = [ ad | Option _ _ ad _ <- options ]
          optStr    = ("--"++opt)
 
@@ -256,14 +262,14 @@ test order cmdline = case getOpt order options cmdline of
 
 {- $example
 
-To hopefully illuminate the role of the different "GetOpt" data
+To hopefully illuminate the role of the different data
 structures, here\'s the command-line options for a (very simple)
 compiler:
 
 >    module Opts where
 >    
->    import GetOpt
->    import Maybe ( fromMaybe )
+>    import System.Console.GetOpt
+>    import Data.Maybe ( fromMaybe )
 >    
 >    data Flag 
 >     = Verbose  | Version 
@@ -287,7 +293,7 @@ compiler:
 >    compilerOpts argv = 
 >      case (getOpt Permute options argv) of
 >         (o,n,[]  ) -> return (o,n)
->         (_,_,errs) -> failIO (concat errs ++ usageInfo header options)
+>         (_,_,errs) -> ioError (userError (concat errs ++ usageInfo header options))
 >      where header = "Usage: ic [OPTION...] files..."
 
 -}