style(xatu): format source ranges

src/xatu/ast.rs

@@ -16,6 +16,12 @@ pub struct SourceRange {
     pub end: usize,
 }
 
+impl std::fmt::Display for SourceRange {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(formatter, "{}..{}", self.start, self.end)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Node {
     pub range: SourceRange,

src/xatu/rules.rs

@@ -19,12 +19,11 @@ pub struct Diagnostic {
 
 impl std::fmt::Display for Diagnostic {
     fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let start = self.finding.range.start;
-        let end = self.finding.range.end;
-        let rule_id = self.finding.rule_id;
-        let message = self.finding.message;
-
-        write!(formatter, "{start}..{end}: {rule_id}: {message}")
+        write!(
+            formatter,
+            "{}: {}: {}",
+            self.finding.range, self.finding.rule_id, self.finding.message,
+        )
     }
 }