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Diffstat (limited to '')
| -rw-r--r-- | third_party/rust/clap_builder/src/builder/resettable.rs | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/third_party/rust/clap_builder/src/builder/resettable.rs b/third_party/rust/clap_builder/src/builder/resettable.rs new file mode 100644 index 0000000000..057274012c --- /dev/null +++ b/third_party/rust/clap_builder/src/builder/resettable.rs @@ -0,0 +1,212 @@ +// Unlike `impl Into<Option<T>>` or `Option<impl Into<T>>`, this isn't ambiguous for the `None` +// case. + +use crate::builder::ArgAction; +use crate::builder::OsStr; +use crate::builder::Str; +use crate::builder::StyledStr; +use crate::builder::ValueHint; +use crate::builder::ValueParser; +use crate::builder::ValueRange; + +/// Clearable builder value +/// +/// This allows a builder function to both accept any value that can [`Into::into`] `T` (like +/// `&str` into `OsStr`) as well as `None` to reset it to the default. This is needed to +/// workaround a limitation where you can't have a function argument that is `impl Into<Option<T>>` +/// where `T` is `impl Into<S>` accept `None` as its type is ambiguous. +/// +/// # Example +/// +/// ```rust +/// # use clap_builder as clap; +/// # use clap::Command; +/// # use clap::Arg; +/// fn common() -> Command { +/// Command::new("cli") +/// .arg(Arg::new("input").short('i').long("input")) +/// } +/// let mut command = common(); +/// command.mut_arg("input", |arg| arg.short(None)); +/// ``` +#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub enum Resettable<T> { + /// Overwrite builder value + Value(T), + /// Reset builder value + Reset, +} + +impl<T> Resettable<T> { + pub(crate) fn into_option(self) -> Option<T> { + match self { + Self::Value(t) => Some(t), + Self::Reset => None, + } + } +} + +impl<T> From<T> for Resettable<T> { + fn from(other: T) -> Self { + Self::Value(other) + } +} + +impl<T> From<Option<T>> for Resettable<T> { + fn from(other: Option<T>) -> Self { + match other { + Some(inner) => Self::Value(inner), + None => Self::Reset, + } + } +} + +/// Convert to the intended resettable type +pub trait IntoResettable<T> { + /// Convert to the intended resettable type + fn into_resettable(self) -> Resettable<T>; +} + +impl IntoResettable<char> for Option<char> { + fn into_resettable(self) -> Resettable<char> { + match self { + Some(s) => Resettable::Value(s), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<usize> for Option<usize> { + fn into_resettable(self) -> Resettable<usize> { + match self { + Some(s) => Resettable::Value(s), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<ArgAction> for Option<ArgAction> { + fn into_resettable(self) -> Resettable<ArgAction> { + match self { + Some(s) => Resettable::Value(s), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<ValueHint> for Option<ValueHint> { + fn into_resettable(self) -> Resettable<ValueHint> { + match self { + Some(s) => Resettable::Value(s), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<ValueParser> for Option<ValueParser> { + fn into_resettable(self) -> Resettable<ValueParser> { + match self { + Some(s) => Resettable::Value(s), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<StyledStr> for Option<&'static str> { + fn into_resettable(self) -> Resettable<StyledStr> { + match self { + Some(s) => Resettable::Value(s.into()), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<OsStr> for Option<&'static str> { + fn into_resettable(self) -> Resettable<OsStr> { + match self { + Some(s) => Resettable::Value(s.into()), + None => Resettable::Reset, + } + } +} + +impl IntoResettable<Str> for Option<&'static str> { + fn into_resettable(self) -> Resettable<Str> { + match self { + Some(s) => Resettable::Value(s.into()), + None => Resettable::Reset, + } + } +} + +impl<T> IntoResettable<T> for Resettable<T> { + fn into_resettable(self) -> Resettable<T> { + self + } +} + +impl IntoResettable<char> for char { + fn into_resettable(self) -> Resettable<char> { + Resettable::Value(self) + } +} + +impl IntoResettable<usize> for usize { + fn into_resettable(self) -> Resettable<usize> { + Resettable::Value(self) + } +} + +impl IntoResettable<ArgAction> for ArgAction { + fn into_resettable(self) -> Resettable<ArgAction> { + Resettable::Value(self) + } +} + +impl IntoResettable<ValueHint> for ValueHint { + fn into_resettable(self) -> Resettable<ValueHint> { + Resettable::Value(self) + } +} + +impl<I: Into<ValueRange>> IntoResettable<ValueRange> for I { + fn into_resettable(self) -> Resettable<ValueRange> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<ValueParser>> IntoResettable<ValueParser> for I { + fn into_resettable(self) -> Resettable<ValueParser> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<String>> IntoResettable<String> for I { + fn into_resettable(self) -> Resettable<String> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<StyledStr>> IntoResettable<StyledStr> for I { + fn into_resettable(self) -> Resettable<StyledStr> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<OsStr>> IntoResettable<OsStr> for I { + fn into_resettable(self) -> Resettable<OsStr> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<Str>> IntoResettable<Str> for I { + fn into_resettable(self) -> Resettable<Str> { + Resettable::Value(self.into()) + } +} + +impl<I: Into<crate::Id>> IntoResettable<crate::Id> for I { + fn into_resettable(self) -> Resettable<crate::Id> { + Resettable::Value(self.into()) + } +} |