Initial Commit

src/span.rs

@@ -0,0 +1,42 @@
+use std::ops::Range;
+
+/// Stores the start and end byte position
+#[derive(Clone, Copy, Default, PartialEq, Eq)]
+pub struct Span {
+    pub head: u32,
+    pub tail: u32,
+}
+
+impl std::fmt::Debug for Span {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self { head, tail } = self;
+        write!(f, "[{head}:{tail}]")
+    }
+}
+
+#[allow(non_snake_case)]
+/// Stores the start and end byte position
+pub fn Span(head: u32, tail: u32) -> Span {
+    Span { head, tail }
+}
+
+impl Span {
+    /// Updates `self` to include all but the last byte in `other`
+    pub fn merge(self, other: Span) -> Span {
+        Span { head: self.head.min(other.head), tail: self.tail.max(other.head) }
+    }
+}
+
+impl From<Span> for Range<usize> {
+    fn from(value: Span) -> Self {
+        let Span { head, tail } = value;
+        (head as usize)..(tail as usize)
+    }
+}
+
+impl std::fmt::Display for Span {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self { head, tail } = self;
+        write!(f, "{head}:{tail}")
+    }
+}