Add structopt dependency in version 0.3.7

This patch series replaces argparse with structopt in the argument
handling code. As a first step, we need structopt as a dependency.

Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d
Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296
Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7
Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1
Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2
Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de
Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad
Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca
Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a
Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3
Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2
Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3
Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393
Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7

1 files changed, 57 insertions, 0 deletions

diff --git a/clap/examples/08_subcommands.rs b/clap/examples/08_subcommands.rs
new file mode 100644
index 0000000..73bd098
--- /dev/null
+++ b/clap/examples/08_subcommands.rs
@@ -0,0 +1,57 @@
+extern crate clap;
+
+use clap::{App, Arg, SubCommand};
+
+fn main() {
+
+    // SubCommands function exactly like sub-Apps, because that's exactly what they are. Each
+    // instance of a SubCommand can have it's own version, author(s), Args, and even it's own
+    // subcommands.
+    //
+    // # Help and Version
+    // Just like Apps, each subcommand will get it's own "help" and "version" flags automatically
+    // generated. Also, like Apps, you can override "-V" or "-h" safely and still get "--help" and
+    // "--version" auto generated.
+    //
+    // NOTE: If you specify a subcommand for your App, clap will also autogenerate a "help"
+    // subcommand along with "-h" and "--help" (applies to sub-subcommands as well).
+    //
+    // Just like arg() and args(), subcommands can be specified one at a time via subcommand() or
+    // multiple ones at once with a Vec<SubCommand> provided to subcommands().
+    let matches = App::new("MyApp")
+                        // Normal App and Arg configuration goes here...
+
+                        // In the following example assume we wanted an application which
+                        // supported an "add" subcommand, this "add" subcommand also took
+                        // one positional argument of a file to add:
+                        .subcommand(SubCommand::with_name("add")                        // The name we call argument with
+                                                .about("Adds files to myapp")           // The message displayed in "myapp -h"
+                                                                                        // or "myapp help"
+                                                .version("0.1")                         // Subcommands can have independent version
+                                                .author("Kevin K.")                     // And authors
+                                                .arg(Arg::with_name("input")            // And their own arguments
+                                                            .help("the file to add")
+                                                            .index(1)
+                                                            .required(true)))
+                        .get_matches();
+
+    // You can check if a subcommand was used like normal
+    if matches.is_present("add") {
+        println!("'myapp add' was run.");
+    }
+
+    // You can get the independent subcommand matches (which function exactly like App matches)
+    if let Some(matches) = matches.subcommand_matches("add") {
+        // Safe to use unwrap() because of the required() option
+        println!("Adding file: {}", matches.value_of("input").unwrap());
+    }
+
+    // You can also match on a subcommand's name
+    match matches.subcommand_name() {
+        Some("add") => println!("'myapp add' was used"),
+        None        => println!("No subcommand was used"),
+        _           => println!("Some other subcommand was used"),
+    }
+
+    // Continued program logic goes here...
+}