feat(source): derive common traits for NamedSource, SourceSpan, and SourceOffset (#340)

Author: TheLostLambda

src/named_source.rs

@@ -3,6 +3,7 @@ use crate::{MietteError, MietteSpanContents, SourceCode, SpanContents};
 /// Utility struct for when you have a regular [`SourceCode`] type that doesn't
 /// implement `name`. For example [`String`]. Or if you want to override the
 /// `name` returned by the `SourceCode`.
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct NamedSource<S: SourceCode + 'static> {
     source: S,
     name: String,

src/protocol.rs

@@ -550,7 +550,7 @@ impl<'a> SpanContents<'a> for MietteSpanContents<'a> {
 }
 
 /// Span within a [`SourceCode`]
-#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct SourceSpan {
     /// The start of the span.
@@ -652,7 +652,7 @@ pub type ByteOffset = usize;
 /**
 Newtype that represents the [`ByteOffset`] from the beginning of a [`SourceCode`]
 */
-#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct SourceOffset(ByteOffset);