# Rule String Transform

> Apply ordered rules for string transformations like pig latin, atbash, or rot. Use when translating words with specific prefix/suffix rules and ordered predicate matching.

- Skill: `knoopx/rule-string-transform` (Agent Skill)
- Install (CLI): `npx skillmds@latest add knoopx/rule-string-transform`
- Raw SKILL.md: https://api.skillmd.com/api/skills/knoopx/rule-string-transform/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: knoopx (https://skillmd.com/u/knoopx)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/knoopx/rule-string-transform

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## When to use

For rule-based string transforms (pig latin, atbash, rot, etc.).

## Rules

- Encode the rules as an ordered list of (predicate, transform) pairs
- For each word, walk the list; apply the FIRST matching rule and stop
- Order matters — specific rules MUST come before general ones
- ALWAYS test each rule in isolation before combining
- NEVER apply multiple rules to the same word

## Pig latin specifics

1. "qu" or consonant-cluster-ending-in-qu counts as a unit — "quick" → "ickquay", "square" → "aresquay"
2. "y" acts as a consonant at the start but a vowel in the middle — "yellow" → "ellowyay", "rhythm" → "ythmrhay"
3. Rule order: starts-with-vowel-or-xr-or-yt → append "ay"; starts-with-consonant(s)-then-"qu" → move cluster+qu, append "ay"; starts-with-consonants-up-to-first-"y"-or-vowel → move the consonants, append "ay"; fallback → append "ay"

## Example

Pig latin: "quick" starts with "qu" consonant cluster → "ickquay". "apple" starts with vowel → "appleay". "yellow" starts with consonant "y" → "ellowyay".