templates support

Inspectron.Epson.Templates/Validation/TemplateError.cs

@@ -0,0 +1,28 @@
+using Inspectron.Epson.Templates.Language;
+
+namespace Inspectron.Epson.Templates.Validation;
+
+public enum TemplateErrorCode
+{
+    // Syntax errors (RTL001-RTL010)
+    RTL001_UnexpectedToken = 1,
+    RTL002_UnclosedBlock = 2,
+    RTL003_InvalidDirective = 3,
+    RTL004_InvalidBinding = 4,
+    RTL005_InvalidForeachSyntax = 5,
+    RTL006_InvalidCondition = 6,
+    RTL007_UnclosedStyleBlock = 7,
+    RTL008_InvalidColumnSpec = 8,
+    RTL009_InvalidSeparator = 9,
+    RTL010_UnexpectedEndOfFile = 10
+}
+
+public record TemplateError(
+    TemplateErrorCode Code,
+    string Message,
+    SourcePosition Position)
+{
+    public string CodeString => Code.ToString().Split('_')[0];
+
+    public override string ToString() => $"{CodeString}: {Message} at {Position}";
+}