1 files changed, 56 insertions, 0 deletions
diff --git a/src/marlin.core/util/VariableExpansionException.cs b/src/marlin.core/util/VariableExpansionException.cs
new file mode 100644
index 0000000..3053880
--- /dev/null
+++ b/src/marlin.core/util/VariableExpansionException.cs
@@ -0,0 +1,56 @@
+namespace marlin.core.util;
+
+/// <summary>
+/// Base exception for all variable expansion errors
+/// </summary>
+public class VariableExpansionException(string message) : Exception(message);
+
+/// <summary>
+/// Thrown when a variable is referenced but not found in the variables dictionary
+/// </summary>
+public class VariableNotFoundException : VariableExpansionException
+{
+    public string VariableName { get; }
+
+    public VariableNotFoundException(string variableName)
+        : base($"Variable '{variableName}' not found")
+    {
+        this.VariableName = variableName;
+    }
+}
+
+/// <summary>
+/// Thrown when an expression has invalid syntax or cannot be parsed
+/// </summary>
+public class InvalidExpressionException : VariableExpansionException
+{
+    public string Expression { get; }
+
+    public InvalidExpressionException(string expression)
+        : base($"Invalid expression '{expression}'")
+    {
+        this.Expression = expression;
+    }
+
+    public InvalidExpressionException(string expression, string reason)
+        : base($"Invalid expression '{expression}': {reason}")
+    {
+        this.Expression = expression;
+    }
+}
+
+/// <summary>
+/// Thrown when braces are not properly matched or escaped
+/// </summary>
+public class UnmatchedBraceException : VariableExpansionException
+{
+    public int Position { get; }
+    public string Remainder { get; }
+
+    public UnmatchedBraceException(string message, int position, string remainder)
+        : base(message)
+    {
+        this.Position = position;
+        this.Remainder = remainder;
+    }
+}