root/trunk/examples/util/config/CustomSyntax.d

/*******************************************************************************

    License:    Boost Software License, v. 1.0
                Academic Free License, v. 3.0
                BSD License

    Authors:    Marcin Kuszczak, www.zapytajmnie.com (author's christian site)
                This software is inspired and partially based on Boost C++
                library named 'program_options' and created by Vladimir Prus.

    Version:    0.9.1
    Date:       30-Apr-2008

    History:    0.9.0 (08-Oct-2007) -   initial public version

    Description:
                This example shows how to support custom options syntax.
                It's possible to install 'custom parser'. It will be invoked
                on all command line tokens and can return name/value pair, or
                nothing. If it returns nothing, usual processing will be done.

 ******************************************************************************/

import std.stdio;
import std.string;

import doost.util.config.ProgramOptions;
import doost.util.config.CommandLineStorage;

//------------------------------------------------------------------------------

/*******************************************************************************
    This custom option parse function recognize gcc-style
    option "-ffoo" / "-fno-foo".
 ******************************************************************************/
OptionPair reg_foo(char[] s) {
    OptionPair result;
    if (find(s, "-f") == 0) {
        if (s[2..5] == "no-") {
            result.name=s[5..$];
            result.value="false";
        }
        else {
            result.name=s[2..$];
            result.value="true";
        }
    }
    return result;
}

/*******************************************************************************
    Program entry point
 ******************************************************************************/
void main(char[][] args) {
    try {
        auto desc = new RegularOptions("Allowed options");
        desc.options()
            ("help", "produce a help message")
            ("foo", define!(char[]), "just an option")
        ;

        auto po =   (new ProgramOptions).next(
                        (new CommandLineStorage(args))
                            .options(desc)
                            .extraParser(delegate OptionPair (char[] s) { return reg_foo(s); })
                    );

        po.connect;

        if ("help" in po) {
            writefln(desc);
            writefln("In addition -ffoo and -fno-foo syntax are recognized.");
        }

        if ("foo" in po) {
            writefln("foo choosen with value: ", po["foo"]);
        }

        po.disconnect;
    }
    catch(ProgramOptionsException e) {
        writefln(e);
    }
}