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Diffstat (limited to '')
-rw-r--r-- | dhall_core/src/label.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/dhall_core/src/label.rs b/dhall_core/src/label.rs new file mode 100644 index 0000000..3633b93 --- /dev/null +++ b/dhall_core/src/label.rs @@ -0,0 +1,38 @@ +use std::fmt::{self, Display}; +use std::rc::Rc; + +// The type for labels throughout the AST +// It owns the data because otherwise lifetimes would make recursive imports impossible +#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)] +pub struct Label(Rc<str>); + +impl From<String> for Label { + fn from(s: String) -> Self { + let s: &str = &s; + Label(s.into()) + } +} + +impl<'a> From<&'a str> for Label { + fn from(s: &'a str) -> Self { + Label(Rc::from(s)) + } +} + +impl From<Label> for String { + fn from(x: Label) -> String { + x.0.as_ref().to_owned() + } +} + +impl Display for Label { + fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { + self.0.as_ref().fmt(f) + } +} + +impl Label { + pub fn from_str(s: &str) -> Label { + Label(s.into()) + } +} |