vendor/structopt/examples/rename_all.rs

   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
  75 fn main() {
  76     let opt = Opt::from_args();
  77     println!("{:?}", opt);
  78 }