sem-diff

Purpose

Use sem when you need to understand code changes semantically: functions, classes, methods, types, and structured sections instead of raw line hunks.

sem is an entity-level layer on top of Git. It uses tree-sitter parsing and AST-normalized structural hashes to distinguish cosmetic edits from structural changes.

When to use

• Reviewing a diff and needing a concise "what changed" summary.
• Explaining staged, working tree, commit, or range changes to a user.
• Finding who last touched an entity.
• Estimating dependency impact from a changed function/class/method.
• Building AI context around an entity and its related code.

Do not replace tests, typechecks, or domain reasoning with sem; use it to focus investigation.

Install and setup