1 files changed, 83 insertions, 0 deletions
diff --git a/examples/completion-derive.rs b/examples/completion-derive.rs
new file mode 100644
index 0000000..9f1a55d
--- /dev/null
+++ b/examples/completion-derive.rs
@@ -0,0 +1,83 @@
+//! How to use value hints and generate shell completions.
+//!
+//! Usage with zsh:
+//! ```console
+//! $ cargo run --example completion-derive -- --generate=zsh > /usr/local/share/zsh/site-functions/_completion_derive
+//! $ compinit
+//! $ ./target/debug/examples/completion_derive --<TAB>
+//! ```
+//! fish:
+//! ```console
+//! $ cargo run --example completion-derive -- --generate=fish > completion_derive.fish
+//! $ . ./completion_derive.fish
+//! $ ./target/debug/examples/completion_derive --<TAB>
+//! ```
+use clap::{Args, Command, CommandFactory, Parser, Subcommand, ValueHint};
+use clap_complete::{generate, Generator, Shell};
+use std::ffi::OsString;
+use std::io;
+use std::path::PathBuf;
+
+#[derive(Parser, Debug, PartialEq)]
+#[command(name = "completion-derive")]
+struct Opt {
+    // If provided, outputs the completion file for given shell
+    #[arg(long = "generate", value_enum)]
+    generator: Option<Shell>,
+    #[command(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand, Debug, PartialEq)]
+enum Commands {
+    #[command(visible_alias = "hint")]
+    ValueHint(ValueHintOpt),
+}
+
+#[derive(Args, Debug, PartialEq)]
+struct ValueHintOpt {
+    // Showcasing all possible ValueHints:
+    #[arg(long, value_hint = ValueHint::Unknown)]
+    unknown: Option<String>,
+    #[arg(long, value_hint = ValueHint::Other)]
+    other: Option<String>,
+    #[arg(short, long, value_hint = ValueHint::AnyPath)]
+    path: Option<PathBuf>,
+    #[arg(short, long, value_hint = ValueHint::FilePath)]
+    file: Option<PathBuf>,
+    #[arg(short, long, value_hint = ValueHint::DirPath)]
+    dir: Option<PathBuf>,
+    #[arg(short, long, value_hint = ValueHint::ExecutablePath)]
+    exe: Option<PathBuf>,
+    #[arg(long, value_hint = ValueHint::CommandName)]
+    cmd_name: Option<OsString>,
+    #[arg(short, long, value_hint = ValueHint::CommandString)]
+    cmd: Option<String>,
+    // Command::trailing_var_ar is required to use ValueHint::CommandWithArguments
+    #[arg(trailing_var_arg = true, value_hint = ValueHint::CommandWithArguments)]
+    command_with_args: Vec<String>,
+    #[arg(short, long, value_hint = ValueHint::Username)]
+    user: Option<String>,
+    #[arg(long, value_hint = ValueHint::Hostname)]
+    host: Option<String>,
+    #[arg(long, value_hint = ValueHint::Url)]
+    url: Option<String>,
+    #[arg(long, value_hint = ValueHint::EmailAddress)]
+    email: Option<String>,
+}
+
+fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
+    generate(gen, cmd, cmd.get_name().to_string(), &mut io::stdout());
+}
+
+fn main() {
+    let opt = Opt::parse();
+
+    if let Some(generator) = opt.generator {
+        let mut cmd = Opt::command();
+        eprintln!("Generating completion file for {generator:?}...");
+        print_completions(generator, &mut cmd);
+    } else {
+        println!("{opt:#?}");
+    }
+}