Add missing Issue methods, update changelog

Author: alessiostalla

CHANGELOG.md

@@ -2,6 +2,15 @@
 All notable changes to this project from version 0.4.0 upwards are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [0.9.1] – Not yet released
+
+### Added
+- Include the source in ANTLR parse errors, if available
+- Missing `lexical` and `syntactic` methods in `Issue`
+
+### Fixed
+- `Position`'s printed representation
+
 ## [0.9.0] – 2025-07-23
 
 ### Added

pylasu/validation/validation.py

@@ -30,6 +30,14 @@ def __str__(self):
             msg += f" @ {self.position}"
         return msg
 
+    @staticmethod
+    def lexical(message: str, severity: IssueSeverity = IssueSeverity.ERROR, position: Position = None):
+        return Issue(IssueType.LEXICAL, message, severity, position)
+
+    @staticmethod
+    def syntactic(message: str, severity: IssueSeverity = IssueSeverity.ERROR, position: Position = None):
+        return Issue(IssueType.SYNTACTIC, message, severity, position)
+
     @staticmethod
     def semantic(message: str, severity: IssueSeverity = IssueSeverity.ERROR, position: Position = None):
         return Issue(IssueType.SEMANTIC, message, severity, position)