1 files changed, 189 insertions, 0 deletions
diff --git a/third_party/rust/clap/src/mkeymap.rs b/third_party/rust/clap/src/mkeymap.rs
new file mode 100644
index 0000000000..8ba3dcb306
--- /dev/null
+++ b/third_party/rust/clap/src/mkeymap.rs
@@ -0,0 +1,189 @@
+use crate::{build::Arg, util::Id, INTERNAL_ERROR_MSG};
+
+use std::{ffi::OsStr, ffi::OsString, iter::Iterator, ops::Index};
+
+#[derive(PartialEq, Eq, Debug, Clone)]
+pub(crate) struct Key {
+    key: KeyType,
+    index: usize,
+}
+
+#[derive(Default, PartialEq, Eq, Debug, Clone)]
+pub(crate) struct MKeyMap<'help> {
+    /// All of the arguments.
+    args: Vec<Arg<'help>>,
+
+    // Cache part:
+    /// Will be set after `_build()`.
+    keys: Vec<Key>,
+}
+
+#[derive(Debug, PartialEq, Eq, Hash, Clone)]
+pub(crate) enum KeyType {
+    Short(char),
+    Long(OsString),
+    Position(usize),
+}
+
+impl KeyType {
+    pub(crate) fn is_position(&self) -> bool {
+        matches!(self, KeyType::Position(_))
+    }
+}
+
+impl PartialEq<usize> for KeyType {
+    fn eq(&self, rhs: &usize) -> bool {
+        match self {
+            KeyType::Position(x) => x == rhs,
+            _ => false,
+        }
+    }
+}
+
+impl PartialEq<&str> for KeyType {
+    fn eq(&self, rhs: &&str) -> bool {
+        match self {
+            KeyType::Long(l) => l == rhs,
+            _ => false,
+        }
+    }
+}
+
+impl PartialEq<str> for KeyType {
+    fn eq(&self, rhs: &str) -> bool {
+        match self {
+            KeyType::Long(l) => l == rhs,
+            _ => false,
+        }
+    }
+}
+
+impl PartialEq<OsStr> for KeyType {
+    fn eq(&self, rhs: &OsStr) -> bool {
+        match self {
+            KeyType::Long(l) => l == rhs,
+            _ => false,
+        }
+    }
+}
+
+impl PartialEq<char> for KeyType {
+    fn eq(&self, rhs: &char) -> bool {
+        match self {
+            KeyType::Short(c) => c == rhs,
+            _ => false,
+        }
+    }
+}
+
+impl<'help> MKeyMap<'help> {
+    /// If any arg has corresponding key in this map, we can search the key with
+    /// u64(for positional argument), char(for short flag), &str and OsString
+    /// (for long flag)
+    pub(crate) fn contains<K>(&self, key: K) -> bool
+    where
+        KeyType: PartialEq<K>,
+    {
+        self.keys.iter().any(|x| x.key == key)
+    }
+
+    /// Reserves capacity for at least additional more elements to be inserted
+    pub(crate) fn reserve(&mut self, additional: usize) {
+        self.args.reserve(additional);
+    }
+
+    /// Push an argument in the map.
+    pub(crate) fn push(&mut self, new_arg: Arg<'help>) {
+        self.args.push(new_arg);
+    }
+
+    /// Find the arg have corresponding key in this map, we can search the key
+    /// with u64(for positional argument), char(for short flag), &str and
+    /// OsString (for long flag)
+    pub(crate) fn get<K: ?Sized>(&self, key: &K) -> Option<&Arg<'help>>
+    where
+        KeyType: PartialEq<K>,
+    {
+        self.keys
+            .iter()
+            .find(|k| &k.key == key)
+            .map(|k| &self.args[k.index])
+    }
+
+    /// Find out if the map have no arg.
+    pub(crate) fn is_empty(&self) -> bool {
+        self.args.is_empty()
+    }
+
+    /// Return iterators of all keys.
+    pub(crate) fn keys(&self) -> impl Iterator<Item = &KeyType> {
+        self.keys.iter().map(|x| &x.key)
+    }
+
+    /// Return iterators of all args.
+    pub(crate) fn args(&self) -> impl Iterator<Item = &Arg<'help>> {
+        self.args.iter()
+    }
+
+    /// Return mutable iterators of all args.
+    pub(crate) fn args_mut<'map>(&'map mut self) -> impl Iterator<Item = &'map mut Arg<'help>> {
+        self.args.iter_mut()
+    }
+
+    /// We need a lazy build here since some we may change args after creating
+    /// the map, you can checkout who uses `args_mut`.
+    pub(crate) fn _build(&mut self) {
+        for (i, arg) in self.args.iter().enumerate() {
+            append_keys(&mut self.keys, arg, i);
+        }
+    }
+
+    /// Remove an arg in the graph by Id, usually used by `mut_arg`. Return
+    /// `Some(arg)` if removed.
+    pub(crate) fn remove_by_name(&mut self, name: &Id) -> Option<Arg<'help>> {
+        self.args
+            .iter()
+            .position(|arg| &arg.id == name)
+            // since it's a cold function, using this wouldn't hurt much
+            .map(|i| self.args.remove(i))
+    }
+
+    /// Remove an arg based on index
+    pub(crate) fn remove(&mut self, index: usize) -> Arg<'help> {
+        self.args.remove(index)
+    }
+}
+
+impl<'help> Index<&'_ KeyType> for MKeyMap<'help> {
+    type Output = Arg<'help>;
+
+    fn index(&self, key: &KeyType) -> &Self::Output {
+        self.get(key).expect(INTERNAL_ERROR_MSG)
+    }
+}
+
+/// Generate key types for an specific Arg.
+fn append_keys(keys: &mut Vec<Key>, arg: &Arg, index: usize) {
+    if let Some(pos_index) = arg.index {
+        let key = KeyType::Position(pos_index);
+        keys.push(Key { key, index });
+    } else {
+        if let Some(short) = arg.short {
+            let key = KeyType::Short(short);
+            keys.push(Key { key, index });
+        }
+        if let Some(long) = arg.long {
+            let key = KeyType::Long(OsString::from(long));
+            keys.push(Key { key, index });
+        }
+
+        for (short, _) in arg.short_aliases.iter() {
+            let key = KeyType::Short(*short);
+            keys.push(Key { key, index });
+        }
+        for (long, _) in arg.aliases.iter() {
+            let key = KeyType::Long(OsString::from(long));
+            keys.push(Key { key, index });
+        }
+    }
+}