Sophie

Sophie

distrib > Mandriva > 2010.0 > i586 > media > contrib-release > by-pkgid > 1f2b142b9d2ef4849a6f5316fa1c5b12 > files > 1415

ghc-6.10.4-1mdv2010.0.i586.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!--Rendered using the Haskell Html Library v0.2-->
<HTML
><HEAD
><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8"
><TITLE
>System.Console.GetOpt</TITLE
><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css"
><SCRIPT SRC="haddock-util.js" TYPE="text/javascript"
></SCRIPT
><SCRIPT TYPE="text/javascript"
>window.onload = function () {setSynopsis("mini_System-Console-GetOpt.html")};</SCRIPT
></HEAD
><BODY
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="topbar"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD
><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" "
></TD
><TD CLASS="title"
>base-4.1.0.0: Basic libraries</TD
><TD CLASS="topbut"
><A HREF="index.html"
>Contents</A
></TD
><TD CLASS="topbut"
><A HREF="doc-index.html"
>Index</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="modulebar"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD
><FONT SIZE="6"
>System.Console.GetOpt</FONT
></TD
><TD ALIGN="right"
><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="infohead"
>Portability</TD
><TD CLASS="infoval"
>portable</TD
></TR
><TR
><TD CLASS="infohead"
>Stability</TD
><TD CLASS="infoval"
>experimental</TD
></TR
><TR
><TD CLASS="infohead"
>Maintainer</TD
><TD CLASS="infoval"
>libraries@haskell.org</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="section4"
><B
>Contents</B
></TD
></TR
><TR
><TD
><DL
><DT
><A HREF="#1"
>GetOpt
</A
></DT
><DT
><A HREF="#2"
>Examples
</A
></DT
><DD
><DL
><DT
><A HREF="#3"
>Interpreting flags as concrete values
</A
></DT
><DT
><A HREF="#4"
>Interpreting flags as transformations of an options record
</A
></DT
></DL
></DD
></DL
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Description</TD
></TR
><TR
><TD CLASS="doc"
>This library provides facilities for parsing the command-line options
 in a standalone program.  It is essentially a Haskell port of the GNU 
 <TT
>getopt</TT
> library.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Synopsis</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><A HREF="#v%3AgetOpt"
>getOpt</A
> ::  <A HREF="System-Console-GetOpt.html#t%3AArgOrder"
>ArgOrder</A
> a -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; [<A HREF="Data-Char.html#t%3AString"
>String</A
>] -&gt; ([a], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>])</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AgetOpt%27"
>getOpt'</A
> ::  <A HREF="System-Console-GetOpt.html#t%3AArgOrder"
>ArgOrder</A
> a -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; [<A HREF="Data-Char.html#t%3AString"
>String</A
>] -&gt; ([a], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>])</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AusageInfo"
>usageInfo</A
> ::  <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3AArgOrder"
>ArgOrder</A
> a </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
>= <A HREF="#v%3ARequireOrder"
>RequireOrder</A
></TD
></TR
><TR
><TD CLASS="decl"
>| <A HREF="#v%3APermute"
>Permute</A
></TD
></TR
><TR
><TD CLASS="decl"
>| <A HREF="#v%3AReturnInOrder"
>ReturnInOrder</A
> (<A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a)</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3AOptDescr"
>OptDescr</A
> a = <A HREF="#v%3AOption"
>Option</A
> [<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
>] [<A HREF="Data-Char.html#t%3AString"
>String</A
>] (<A HREF="System-Console-GetOpt.html#t%3AArgDescr"
>ArgDescr</A
> a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3AArgDescr"
>ArgDescr</A
> a </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
>= <A HREF="#v%3ANoArg"
>NoArg</A
> a</TD
></TR
><TR
><TD CLASS="decl"
>| <A HREF="#v%3AReqArg"
>ReqArg</A
> (<A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="decl"
>| <A HREF="#v%3AOptArg"
>OptArg</A
> (<A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="1"
><A NAME="1"
>GetOpt
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:getOpt"
><A NAME="v%3AgetOpt"
></A
></A
><B
>getOpt</B
> ::  <A HREF="System-Console-GetOpt.html#t%3AArgOrder"
>ArgOrder</A
> a -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; [<A HREF="Data-Char.html#t%3AString"
>String</A
>] -&gt; ([a], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>])</TD
></TR
><TR
><TD CLASS="doc"
><P
>Process the command-line, and return the list of values that matched
(and those that didn't). The arguments are:
</P
><UL
><LI
> The order requirements (see <TT
><A HREF="System-Console-GetOpt.html#t%3AArgOrder"
>ArgOrder</A
></TT
>)
</LI
><LI
> The option descriptions (see <TT
><A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
></TT
>)
</LI
><LI
> The actual command line arguments (presumably got from 
  System.Environment.getArgs).
</LI
></UL
><P
><TT
><A HREF="System-Console-GetOpt.html#v%3AgetOpt"
>getOpt</A
></TT
> returns a triple consisting of the option arguments, a list
of non-options, and a list of error messages.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:getOpt'"
><A NAME="v%3AgetOpt%27"
></A
></A
><B
>getOpt'</B
> ::  <A HREF="System-Console-GetOpt.html#t%3AArgOrder"
>ArgOrder</A
> a -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; [<A HREF="Data-Char.html#t%3AString"
>String</A
>] -&gt; ([a], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>], [<A HREF="Data-Char.html#t%3AString"
>String</A
>])</TD
></TR
><TR
><TD CLASS="doc"
>This is almost the same as <TT
><A HREF="System-Console-GetOpt.html#v%3AgetOpt"
>getOpt</A
></TT
>, but returns a quadruple
consisting of the option arguments, a list of non-options, a list of
unrecognized options, and a list of error messages.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:usageInfo"
><A NAME="v%3AusageInfo"
></A
></A
><B
>usageInfo</B
> ::  <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; [<A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
> a] -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="doc"
>Return a string describing the usage of a command, derived from
 the header (first argument) and the options described by the 
 second argument.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:ArgOrder"
><A NAME="t%3AArgOrder"
></A
></A
><B
>ArgOrder</B
> a </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="ndoc"
>What to do with options following non-options
</TD
></TR
><TR
><TD CLASS="section4"
>Constructors</TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:RequireOrder"
><A NAME="v%3ARequireOrder"
></A
></A
><B
>RequireOrder</B
></TD
><TD CLASS="rdoc"
>no option processing after first non-option
</TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:Permute"
><A NAME="v%3APermute"
></A
></A
><B
>Permute</B
></TD
><TD CLASS="rdoc"
>freely intersperse options and non-options
</TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:ReturnInOrder"
><A NAME="v%3AReturnInOrder"
></A
></A
><B
>ReturnInOrder</B
> (<A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a)</TD
><TD CLASS="rdoc"
>wrap non-options into options
</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:OptDescr"
><A NAME="t%3AOptDescr"
></A
></A
><B
>OptDescr</B
> a </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="ndoc"
><P
>Each <TT
><A HREF="System-Console-GetOpt.html#t%3AOptDescr"
>OptDescr</A
></TT
> describes a single option.
</P
><P
>The arguments to <TT
><A HREF="System-Console-GetOpt.html#v%3AOption"
>Option</A
></TT
> are:
</P
><UL
><LI
> list of short option characters
</LI
><LI
> list of long option strings (without &quot;--&quot;)
</LI
><LI
> argument descriptor
</LI
><LI
> explanation of option for user
</LI
></UL
></TD
></TR
><TR
><TD CLASS="section4"
>Constructors</TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:Option"
><A NAME="v%3AOption"
></A
></A
><B
>Option</B
> [<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
>] [<A HREF="Data-Char.html#t%3AString"
>String</A
>] (<A HREF="System-Console-GetOpt.html#t%3AArgDescr"
>ArgDescr</A
> a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
><TD CLASS="rdoc"
></TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:ArgDescr"
><A NAME="t%3AArgDescr"
></A
></A
><B
>ArgDescr</B
> a </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="ndoc"
>Describes whether an option takes an argument or not, and if so
 how the argument is injected into a value of type <TT
>a</TT
>.
</TD
></TR
><TR
><TD CLASS="section4"
>Constructors</TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:NoArg"
><A NAME="v%3ANoArg"
></A
></A
><B
>NoArg</B
> a</TD
><TD CLASS="rdoc"
>no argument expected
</TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:ReqArg"
><A NAME="v%3AReqArg"
></A
></A
><B
>ReqArg</B
> (<A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
><TD CLASS="rdoc"
>option requires argument
</TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:OptArg"
><A NAME="v%3AOptArg"
></A
></A
><B
>OptArg</B
> (<A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; a) <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
><TD CLASS="rdoc"
>optional argument
</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="2"
><A NAME="2"
>Examples
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="doc"
>To hopefully illuminate the role of the different data structures,
 here are the command-line options for a (very simple) compiler,
 done in two different ways.
 The difference arises because the type of <TT
><A HREF="System-Console-GetOpt.html#v%3AgetOpt"
>getOpt</A
></TT
> is
 parameterized by the type of values derived from flags.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="3"
><A NAME="3"
>Interpreting flags as concrete values
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="doc"
><P
>A simple choice for the type associated with flags is to define a type
<TT
>Flag</TT
> as an algebraic type representing the possible flags and their
arguments:
</P
><PRE
>    module Opts1 where
    
    import System.Console.GetOpt
    import Data.Maybe ( fromMaybe )
    
    data Flag 
     = Verbose  | Version 
     | Input String | Output String | LibDir String
       deriving Show
    
    options :: [OptDescr Flag]
    options =
     [ Option ['v']     [&quot;verbose&quot;] (NoArg Verbose)       &quot;chatty output on stderr&quot;
     , Option ['V','?'] [&quot;version&quot;] (NoArg Version)       &quot;show version number&quot;
     , Option ['o']     [&quot;output&quot;]  (OptArg outp &quot;FILE&quot;)  &quot;output FILE&quot;
     , Option ['c']     []          (OptArg inp  &quot;FILE&quot;)  &quot;input FILE&quot;
     , Option ['L']     [&quot;libdir&quot;]  (ReqArg LibDir &quot;DIR&quot;) &quot;library directory&quot;
     ]
    
    inp,outp :: Maybe String -&gt; Flag
    outp = Output . fromMaybe &quot;stdout&quot;
    inp  = Input  . fromMaybe &quot;stdin&quot;
    
    compilerOpts :: [String] -&gt; IO ([Flag], [String])
    compilerOpts argv = 
       case getOpt Permute options argv of
          (o,n,[]  ) -&gt; return (o,n)
          (_,_,errs) -&gt; ioError (userError (concat errs ++ usageInfo header options))
      where header = &quot;Usage: ic [OPTION...] files...&quot;
</PRE
><P
>Then the rest of the program will use the constructed list of flags
to determine it's behaviour.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="4"
><A NAME="4"
>Interpreting flags as transformations of an options record
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="doc"
><P
>A different approach is to group the option values in a record of type
<TT
>Options</TT
>, and have each flag yield a function of type
<TT
>Options -&gt; Options</TT
> transforming this record.
</P
><PRE
>    module Opts2 where

    import System.Console.GetOpt
    import Data.Maybe ( fromMaybe )

    data Options = Options
     { optVerbose     :: Bool
     , optShowVersion :: Bool
     , optOutput      :: Maybe FilePath
     , optInput       :: Maybe FilePath
     , optLibDirs     :: [FilePath]
     } deriving Show

    defaultOptions    = Options
     { optVerbose     = False
     , optShowVersion = False
     , optOutput      = Nothing
     , optInput       = Nothing
     , optLibDirs     = []
     }

    options :: [OptDescr (Options -&gt; Options)]
    options =
     [ Option ['v']     [&quot;verbose&quot;]
         (NoArg (\ opts -&gt; opts { optVerbose = True }))
         &quot;chatty output on stderr&quot;
     , Option ['V','?'] [&quot;version&quot;]
         (NoArg (\ opts -&gt; opts { optShowVersion = True }))
         &quot;show version number&quot;
     , Option ['o']     [&quot;output&quot;]
         (OptArg ((\ f opts -&gt; opts { optOutput = Just f }) . fromMaybe &quot;output&quot;)
                 &quot;FILE&quot;)
         &quot;output FILE&quot;
     , Option ['c']     []
         (OptArg ((\ f opts -&gt; opts { optInput = Just f }) . fromMaybe &quot;input&quot;)
                 &quot;FILE&quot;)
         &quot;input FILE&quot;
     , Option ['L']     [&quot;libdir&quot;]
         (ReqArg (\ d opts -&gt; opts { optLibDirs = optLibDirs opts ++ [d] }) &quot;DIR&quot;)
         &quot;library directory&quot;
     ]

    compilerOpts :: [String] -&gt; IO (Options, [String])
    compilerOpts argv =
       case getOpt Permute options argv of
          (o,n,[]  ) -&gt; return (foldl (flip id) defaultOptions o, n)
          (_,_,errs) -&gt; ioError (userError (concat errs ++ usageInfo header options))
      where header = &quot;Usage: ic [OPTION...] files...&quot;
</PRE
><P
>Similarly, each flag could yield a monadic function transforming a record,
of type <TT
>Options -&gt; IO Options</TT
> (or any other monad), allowing option
processing to perform actions of the chosen monad, e.g. printing help or
version messages, checking that file arguments exist, etc.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="botbar"
>Produced by <A HREF="http://www.haskell.org/haddock/"
>Haddock</A
> version 2.4.2</TD
></TR
></TABLE
></BODY
></HTML
>

Perl :: Catalyst :: PostgreSQL :: RPM Valid HTML 4.01 Transitional