build(ariadne): vendor clap

third_party/crates/clap-4.6.6/examples/escaped-positional.rs

@@ -0,0 +1,32 @@
+use clap::{ArgAction, arg, command, value_parser};
+
+fn main() {
+    let matches = command!() // requires `cargo` feature
+        .arg(arg!(eff: -f).action(ArgAction::SetTrue))
+        .arg(arg!(pea: -p <PEAR>).value_parser(value_parser!(String)))
+        .arg(
+            // Indicates that `slop` is only accessible after `--`.
+            arg!(slop: [SLOP])
+                .num_args(1..)
+                .last(true)
+                .value_parser(value_parser!(String)),
+        )
+        .get_matches();
+
+    // This is what will happen with `myprog -f -p=bob -- sloppy slop slop`...
+
+    // -f used: true
+    println!("-f used: {:?}", matches.get_flag("eff"));
+    // -p's value: Some("bob")
+    println!("-p's value: {:?}", matches.get_one::<String>("pea"));
+    // 'slops' values: Some(["sloppy", "slop", "slop"])
+    println!(
+        "'slops' values: {:?}",
+        matches
+            .get_many::<String>("slop")
+            .map(|vals| vals.collect::<Vec<_>>())
+            .unwrap_or_default()
+    );
+
+    // Continued program logic goes here...
+}