Module tag_normalizer 

Tag normalization with fuzzy matching.

When a user adds a tag, this module checks if a similar tag already exists in the task list and normalizes it automatically.

Rules

1. Exact match — tag already exists as-is → use it unchanged
2. Case-insensitive match — Rust matches rust → normalize to existing
3. Fuzzy match — edit distance ≤ threshold → normalize to closest match
4. No match — tag is new → accept as-is

Threshold

• Tags ≤ 4 chars: distance ≤ 1
• Tags ≥ 5 chars: distance ≤ 2

This avoids false positives like rust → just (distance 2 on a 4-char tag).

Enums

NormalizeResult

Result of normalizing a single tag.

Functions

collect_existing_tags

Collect all unique tags from a task list.

normalize_tag

Normalize a single tag against the list of existing tags.

normalize_tags

Normalize a list of tags against existing tags.