getopt improvements by Igor Lesik

Below is a paste of the page at The code should be added to std.getopt, perhaps as an overload of the current function. Thanks Igor! I will add your name to the authors list when I make the change. getoptex One way to extend Phobos library std.getopt.getopt function is make a wrapper around it that could be feeded with usage information about every option and let it automatically gather all usage strings into one usage/help message block, similarly to Boost program_options library Links: Below is an example how getoptEx could be used: import getoptex; import std.stdio; void main(string[] args) { string inputFile, outputFile; bool helpPrinted = getoptEx( "Test program to demonstrate getoptEx\n"~ "written by Igor Lesik on Feb 2010\n"~ "Usage: test1 { --switch }\n", args, std.getopt.config.caseInsensitive, "input", "\tinput file name,\n"~ "\tmust be html file", &inputFile, "output", "\toutput file name", &outputFile, "author", "\tprint name of\n"~ "\tthe author", delegate() {writeln("Igor Lesik");} ); if (helpPrinted) return; writeln("Input file name:", inputFile); writeln("Output file name:", outputFile); } If you call the program with --help option, then output is: >test1.exe --help Test program to demonstrate getoptEx written by Igor Lesik on Feb 2010 Usage: test1 { --switch } --input input file name, must be html file --output output file name --author print name of the author --help produce help message getopEx implementation: module getoptex; import std.stdio; import std.getopt; private import std.contracts; private import std.typetuple; private import std.conv; bool getoptEx(T...)(string helphdr, ref string[] args, T opts) { enforce(args.length, "Invalid arguments string passed: program name missing"); string helpMsg = GetoptHelp(opts); // extract all help strings bool helpPrinted = false; // state tells if called with "--help" void printHelp() { writeln("\n", helphdr, "\n", helpMsg, "--help", "\n\tproduce help message"); helpPrinted = true; } getopt(args, GetoptEx!(opts), "help", &printHelp); return helpPrinted; } private template GetoptEx(TList...) { static if (TList.length) { static if (is(typeof(TList[0]) : config)) { // it's a configuration flag, lets move on alias TypeTuple!(TList[0],GetoptEx!(TList[1 .. $])) GetoptEx; } else { // it's an option string, eat help string alias TypeTuple!(TList[0],TList[2],GetoptEx!(TList[3 .. $])) GetoptEx; } } else { alias TList GetoptEx; } } private string GetoptHelp(T...)(T opts) { static if (opts.length) { static if (is(typeof(opts[0]) : config)) { // it's a configuration flag, skip it return GetoptHelp(opts[1 .. $]); } else { // it's an option string string option = to!(string)(opts[0]); string help = to!(string)(opts[1]); return( "--"~option~"\n"~help~"\n"~GetoptHelp(opts[3 .. $]) ); } } else { return to!(string)("\n"); } } Page generated by Ddoc.