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compiler/NubLang/Code/SourceSpan.cs

@@ -0,0 +1,57 @@
+namespace NubLang.Code;
+
+public readonly struct SourceSpan : IEquatable<SourceSpan>
+{
+    public static SourceSpan Zero => new(SourceLocation.Zero, SourceLocation.Zero);
+
+    public static SourceSpan Merge(params IEnumerable<SourceSpan> spans)
+    {
+        var spanArray = spans as SourceSpan[] ?? spans.ToArray();
+
+        if (spanArray.Length == 0)
+        {
+            return Zero;
+        }
+
+        var minStart = spanArray.Min(s => s.Start);
+        var maxEnd = spanArray.Max(s => s.End);
+
+        return new SourceSpan(minStart, maxEnd);
+    }
+
+    public SourceSpan(SourceLocation start, SourceLocation end)
+    {
+        if (start > end)
+        {
+            throw new ArgumentException("Start location cannot be after end location");
+        }
+
+        Start = start;
+        End = end;
+    }
+
+    public SourceLocation Start { get; }
+    public SourceLocation End { get; }
+
+    public override string ToString()
+    {
+        if (Start == End)
+        {
+            return $"{Start}";
+        }
+
+        if (Start.Line == End.Line)
+        {
+            return Start.Column == End.Column ? $"{Start}" : $"{Start.Line}:{Start.Column}-{End.Column}";
+        }
+
+        return $"{Start}-{End}";
+    }
+
+    public bool Equals(SourceSpan other) => Start == other.Start && End == other.End;
+    public override bool Equals(object? obj) => obj is SourceSpan other && Equals(other);
+    public override int GetHashCode() => HashCode.Combine(typeof(SourceSpan), Start, End);
+
+    public static bool operator ==(SourceSpan left, SourceSpan right) => Equals(left, right);
+    public static bool operator !=(SourceSpan left, SourceSpan right) => !Equals(left, right);
+}