Advanced Pattern Search

About This Tool

Purpose

Advanced Pattern Search is a power-user tool for performing sophisticated regex-based searches across Claude Code transcripts. It supports modern JavaScript regex features including lookahead/lookbehind assertions, named capturing groups, and all regex flags for maximum search precision.

Features

• Advanced Regex Support - Lookahead, lookbehind, named groups, unicode escapes
• Real-time Validation - Live validation of regex patterns as you type
• All Regex Flags - Support for g, i, m, s, u flags with descriptions
• Pattern Library - Pre-built patterns for common searches (errors, files, code blocks)
• Capture Group Display - Visual highlighting of matched groups and named captures
• Live Regex Tester - Test patterns against sample text before searching
• Match Statistics - Count, position, and context for every match
• Export Capability - Export matches as JSON for further analysis

Web Research Integration

Source: MDN - JavaScript Regular Expressions Guide

Techniques Applied:

• Lookahead/Lookbehind Assertions - Implemented positive/negative lookahead ((?=...), (?!...)) and lookbehind ((?<=...), (?<!...)) for context-aware matching without consuming characters
• Named Capturing Groups - Support for (?<name>...) syntax with visual display of named captures and backreferences \k<name>
• Modern Regex Flags - Complete flag support including dotAll mode (s flag) for matching newlines and unicode mode (u flag) for proper unicode handling

Pattern Library Examples

• Error Messages - (?<=Error:\s).*?(?=\n|$) - Uses lookbehind to match text after "Error: " and lookahead to stop at newline
• File Paths - (?<path>[\w/.-]+\.(?<ext>\w+)) - Named groups for full path and extension
• Code Blocks - ```(?<lang>\w+)\n(?<code>[\s\S]*?)``` - Named captures for language and code content
• URLs - https?://(?<domain>[\w.-]+)(?<path>/[\w/.-]*)? - Separate domain and path captures
• Email Addresses - (?<user>[\w.+-]+)@(?<domain>[\w.-]+) - User and domain named groups

Usage

1. Enter Pattern - Type your regex pattern or select from the pattern library
2. Configure Flags - Select appropriate flags (global, case-insensitive, multiline, etc.)
3. Test Pattern - Use the live tester to verify your pattern works as expected
4. Search - Execute search against sample data or loaded transcript sessions
5. Analyze Results - Review matches with highlighted capture groups and context
6. Export - Export results as JSON for further processing

Advanced Regex Tips

• Lookahead - foo(?=bar) matches "foo" only when followed by "bar", without consuming "bar"
• Lookbehind - (?<=foo)bar matches "bar" only when preceded by "foo"
• Negative Lookahead - foo(?!bar) matches "foo" NOT followed by "bar"
• Named Groups - (?<year>\d{4})-(?<month>\d{2}) creates accessible named captures
• Lazy Quantifiers - Add ? after * or + for minimal matching