1 //! Example on how the `rename_all` parameter works.
2 //!
3 //! `rename_all` can be used to override the casing style used during argument
4 //! generation. By default the `kebab-case` style will be used but there are a wide
5 //! variety of other styles available.
6 //!
7 //! ## Supported styles overview:
8 //!
9 //! - **Camel Case**: Indicate word boundaries with uppercase letter, excluding
10 //!                   the first word.
11 //! - **Kebab Case**: Keep all letters lowercase and indicate word boundaries
12 //!                   with hyphens.
13 //! - **Pascal Case**: Indicate word boundaries with uppercase letter,
14 //!                    including the first word.
15 //! - **Screaming Snake Case**: Keep all letters uppercase and indicate word
16 //!                             boundaries with underscores.
17 //! - **Snake Case**: Keep all letters lowercase and indicate word boundaries
18 //!                   with underscores.
19 //! - **Verbatim**: Use the original attribute name defined in the code.
20 //!
21 //! - **Lower Case**: Keep all letters lowercase and remove word boundaries.
22 //!
23 //! - **Upper Case**: Keep all letters upperrcase and remove word boundaries.
24 
25 use structopt::StructOpt;
26 
27 #[derive(StructOpt, Debug)]
28 #[structopt(name = "rename_all", rename_all = "screaming_snake_case")]
29 enum Opt {
30     // This subcommand will be named `FIRST_COMMAND`. As the command doesn't
31     // override the initial casing style, ...
32     /// A screaming loud first command. Only use if necessary.
33     FirstCommand {
34         // this flag will be available as `--FOO` and `-F`.
35         /// This flag will even scream louder.
36         #[structopt(long, short)]
37         foo: bool,
38     },
39 
40     // As we override the casing style for this variant the related subcommand
41     // will be named `SecondCommand`.
42     /// Not nearly as loud as the first command.
43     #[structopt(rename_all = "pascal_case")]
44     SecondCommand {
45         // We can also override it again on a single field.
46         /// Nice quiet flag. No one is annoyed.
47         #[structopt(rename_all = "snake_case", long)]
48         bar_option: bool,
49 
50         // Renaming will not be propagated into subcommand flagged enums. If
51         // a non default casing style is required it must be defined on the
52         // enum itself.
53         #[structopt(subcommand)]
54         cmds: Subcommands,
55 
56         // or flattened structs.
57         #[structopt(flatten)]
58         options: BonusOptions,
59     },
60 }
61 
62 #[derive(StructOpt, Debug)]
63 enum Subcommands {
64     // This one will be available as `first-subcommand`.
65     FirstSubcommand,
66 }
67 
68 #[derive(StructOpt, Debug)]
69 struct BonusOptions {
70     // And this one will be available as `baz-option`.
71     #[structopt(long)]
72     baz_option: bool,
73 }
74 
main()75 fn main() {
76     let opt = Opt::from_args();
77     println!("{:?}", opt);
78 }
79