chore(vendor): add anyhow crate

third_party/crates/clap-4.6.7/examples/git.rs

@@ -0,0 +1,187 @@
+use std::collections::HashMap;
+use std::ffi::OsString;
+use std::path::PathBuf;
+
+use clap::{ArgMatches, Command, arg};
+
+fn cli() -> Command {
+    Command::new("git")
+        .about("A fictional versioning CLI")
+        .subcommand_required(true)
+        .arg_required_else_help(true)
+        .allow_external_subcommands(true)
+        .subcommand(
+            Command::new("clone")
+                .about("Clones repos")
+                .arg(arg!(<REMOTE> "The remote to clone"))
+                .arg_required_else_help(true),
+        )
+        .subcommand(
+            Command::new("diff")
+                .about("Compare two commits")
+                .arg(arg!(base: [COMMIT]))
+                .arg(arg!(head: [COMMIT]))
+                .arg(arg!(path: [PATH]).last(true))
+                .arg(
+                    arg!(--color <WHEN>)
+                        .value_parser(["always", "auto", "never"])
+                        .num_args(0..=1)
+                        .require_equals(true)
+                        .default_value("auto")
+                        .default_missing_value("always"),
+                ),
+        )
+        .subcommand(
+            Command::new("push")
+                .about("pushes things")
+                .arg(arg!(<REMOTE> "The remote to target"))
+                .arg_required_else_help(true),
+        )
+        .subcommand(
+            Command::new("add")
+                .about("adds things")
+                .arg_required_else_help(true)
+                .arg(arg!(<PATH> ... "Stuff to add").value_parser(clap::value_parser!(PathBuf))),
+        )
+        .subcommand(
+            Command::new("stash")
+                .args_conflicts_with_subcommands(true)
+                .flatten_help(true)
+                .args(push_args())
+                .subcommand(Command::new("push").args(push_args()))
+                .subcommand(Command::new("pop").arg(arg!([STASH])))
+                .subcommand(Command::new("apply").arg(arg!([STASH]))),
+        )
+}
+
+fn push_args() -> Vec<clap::Arg> {
+    vec![arg!(-m --message <MESSAGE>)]
+}
+
+fn aliases() -> HashMap<&'static str, Vec<&'static str>> {
+    HashMap::from([
+        ("last", vec!["diff", "HEAD~", "HEAD", "--"]),
+        ("stage", vec!["add"]),
+    ])
+}
+
+fn parse_aliases() -> Result<ArgMatches, clap::Error> {
+    let matches = cli().try_get_matches()?;
+    expand_aliases(matches, Vec::new())
+}
+
+fn expand_aliases(
+    matches: ArgMatches,
+    mut expanded: Vec<String>,
+) -> Result<ArgMatches, clap::Error> {
+    let Some((name, sub_matches)) = matches.subcommand() else {
+        return Ok(matches);
+    };
+    if cli().find_subcommand(name).is_some() {
+        return Ok(matches);
+    }
+
+    let aliases = aliases();
+    let Some(alias) = aliases.get(name) else {
+        return Ok(matches);
+    };
+    let mut args = alias.iter().map(OsString::from).collect::<Vec<_>>();
+    args.extend(
+        sub_matches
+            .get_many::<OsString>("")
+            .into_iter()
+            .flatten()
+            .cloned(),
+    );
+    let matches = cli().no_binary_name(true).try_get_matches_from(args)?;
+    let new_name = matches.subcommand_name().expect("subcommand required");
+    expanded.push(name.to_owned());
+    if expanded.iter().any(|name| name == new_name) {
+        return Err(clap::Error::raw(
+            clap::error::ErrorKind::InvalidSubcommand,
+            format!("recursive alias `{}`", expanded[0]),
+        ));
+    }
+
+    expand_aliases(matches, expanded)
+}
+
+fn main() {
+    let matches = parse_aliases().unwrap_or_else(|error| error.exit());
+
+    match matches.subcommand() {
+        Some(("clone", sub_matches)) => {
+            println!(
+                "Cloning {}",
+                sub_matches.get_one::<String>("REMOTE").expect("required")
+            );
+        }
+        Some(("diff", sub_matches)) => {
+            let color = sub_matches
+                .get_one::<String>("color")
+                .map(|s| s.as_str())
+                .expect("defaulted in clap");
+
+            let mut base = sub_matches.get_one::<String>("base").map(|s| s.as_str());
+            let mut head = sub_matches.get_one::<String>("head").map(|s| s.as_str());
+            let mut path = sub_matches.get_one::<String>("path").map(|s| s.as_str());
+            if path.is_none() {
+                path = head;
+                head = None;
+                if path.is_none() {
+                    path = base;
+                    base = None;
+                }
+            }
+            let base = base.unwrap_or("stage");
+            let head = head.unwrap_or("worktree");
+            let path = path.unwrap_or("");
+            println!("Diffing {base}..{head} {path} (color={color})");
+        }
+        Some(("push", sub_matches)) => {
+            println!(
+                "Pushing to {}",
+                sub_matches.get_one::<String>("REMOTE").expect("required")
+            );
+        }
+        Some(("add", sub_matches)) => {
+            let paths = sub_matches
+                .get_many::<PathBuf>("PATH")
+                .into_iter()
+                .flatten()
+                .collect::<Vec<_>>();
+            println!("Adding {paths:?}");
+        }
+        Some(("stash", sub_matches)) => {
+            let stash_command = sub_matches.subcommand().unwrap_or(("push", sub_matches));
+            match stash_command {
+                ("apply", sub_matches) => {
+                    let stash = sub_matches.get_one::<String>("STASH");
+                    println!("Applying {stash:?}");
+                }
+                ("pop", sub_matches) => {
+                    let stash = sub_matches.get_one::<String>("STASH");
+                    println!("Popping {stash:?}");
+                }
+                ("push", sub_matches) => {
+                    let message = sub_matches.get_one::<String>("message");
+                    println!("Pushing {message:?}");
+                }
+                (name, _) => {
+                    unreachable!("Unsupported subcommand `{name}`")
+                }
+            }
+        }
+        Some((ext, sub_matches)) => {
+            let args = sub_matches
+                .get_many::<OsString>("")
+                .into_iter()
+                .flatten()
+                .collect::<Vec<_>>();
+            println!("Calling out to {ext:?} with {args:?}");
+        }
+        _ => unreachable!(), // If all subcommands are defined above, anything else is unreachable!()
+    }
+
+    // Continued program logic goes here...
+}