1 files changed, 75 insertions, 0 deletions
diff --git a/src/unist.rs b/src/unist.rs
new file mode 100644
index 0000000..75ef359
--- /dev/null
+++ b/src/unist.rs
@@ -0,0 +1,75 @@
+//! abstract syntax trees: [unist][].
+//!
+//! [unist]: https://github.com/syntax-tree/unist
+
+use alloc::fmt;
+
+/// One place in a source file.
+#[derive(Clone, Eq, PartialEq)]
+pub struct Point {
+    /// 1-indexed integer representing a line in a source file.
+    pub line: usize,
+    /// 1-indexed integer representing a column in a source file.
+    pub column: usize,
+    /// 0-indexed integer representing a character in a source file.
+    pub offset: usize,
+}
+
+impl Point {
+    #[must_use]
+    pub fn new(line: usize, column: usize, offset: usize) -> Point {
+        Point {
+            line,
+            column,
+            offset,
+        }
+    }
+}
+
+impl fmt::Debug for Point {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{} ({})", self.line, self.column, self.offset)
+    }
+}
+
+/// Location of a node in a source file.
+#[derive(Clone, Eq, PartialEq)]
+pub struct Position {
+    /// Represents the place of the first character of the parsed source region.
+    pub start: Point,
+    /// Represents the place of the first character after the parsed source
+    /// region, whether it exists or not.
+    pub end: Point,
+}
+
+impl Position {
+    #[must_use]
+    pub fn new(
+        start_line: usize,
+        start_column: usize,
+        start_offset: usize,
+        end_line: usize,
+        end_column: usize,
+        end_offset: usize,
+    ) -> Position {
+        Position {
+            start: Point::new(start_line, start_column, start_offset),
+            end: Point::new(end_line, end_column, end_offset),
+        }
+    }
+}
+
+impl fmt::Debug for Position {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}:{}-{}:{} ({}-{})",
+            self.start.line,
+            self.start.column,
+            self.end.line,
+            self.end.column,
+            self.start.offset,
+            self.end.offset
+        )
+    }
+}