regex-vs-llm-structured-text

Parse structured text with regex and conditional LLM validation.

Updated May 9, 2026
One-click install
npx skills add https://github.com/kk20300113-png/my-claude-skills --skill regex-vs-llm-structured-text-kk20300113-png
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: regex-vs-llm-structured-text
Source: https://github.com/kk20300113-png/my-claude-skills/tree/main/regex-vs-llm-structured-text
Command: npx skills add https://github.com/kk20300113-png/my-claude-skills --skill regex-vs-llm-structured-text-kk20300113-png

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Manually choosing between regex and LLM for structured text parsing often leads to either excessive costs from overusing LLMs or poor accuracy from poorly written regex rules. This Skill eliminates that guesswork with a proven decision framework to balance speed, cost, and accuracy for consistent text formats.

Core Features & Use Cases

  • Hybrid Parsing Pipeline: Uses regex to handle 95-98% of structured text extractions deterministically, and only routes low-confidence edge cases to an LLM for correction.
  • Built-in Confidence Scoring: Automatically flags malformed or incomplete extractions (e.g., missing answers, too few choices) to identify exactly which items need LLM review.
  • Real-World Use Case: Parse 1000 quiz questions from a consistent text format, extract questions, choices, and answers with 98% accuracy via regex, and only send 2% of malformed items to an LLM, cutting total processing costs by ~95% compared to using an LLM for all items.

Quick Start

Use the regex-vs-llm-structured-text skill to parse the attached quiz document, extract all question text, multiple-choice options, and correct answers, and flag any low-confidence extractions for optional LLM review.

Frequently Asked Questions about regex-vs-llm-structured-text

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I optimize structured text parsing costs when extracting repeating patterns?

Structured text parsing cost optimization is achieved by using a hybrid pipeline where regex handles 95-98% of deterministic extractions, routing only low-confidence edge cases to an LLM for correction. This approach cuts total processing costs by approximately 95% compared to using an LLM for all items.

What is the best way to parse quiz questions or invoice data with consistent formats?

The best way to parse consistent formats like quiz questions or invoice data is applying regex extraction with built-in confidence scoring to flag malformed items, conditionally routing only those incomplete extractions to an LLM for validation to minimize call costs.

How does confidence scoring work in a regex and LLM hybrid pipeline?

Confidence scoring in a hybrid pipeline automatically flags malformed or incomplete structured text extractions, such as missing answers or too few choices, to identify exactly which items need LLM review. This ensures only low-confidence edge cases incur LLM processing costs.

When should I use regex versus an LLM for document structure parsing?

Regex should be used for the 95-98% of document structure parsing with consistent repeating patterns, while an LLM is reserved for conditional validation of low-confidence edge cases. This decision framework balances speed, cost, and accuracy without excessive LLM overuse.

Can I extract form data and multiple-choice options without overusing LLMs?

You can extract form data and multiple-choice options deterministically using regex rules, sending only the 2% of malformed items to an LLM. This hybrid approach maintains high accuracy while drastically reducing the total volume of LLM calls required.