Regex builder

Goal

Produce a correct, testable regex with rationale and runnable verification.

Inputs to confirm (ask if missing)

• •Target regex flavor/engine (PCRE, Python, JavaScript, .NET, RE2, etc.).
• •Example matches and non-matches (at least 3 each when possible).
• •Scope: single-line vs multi-line; file types/paths.
• •Output needs: capture groups, named groups, replacement template.

Workflow

1. •Gather samples
   • •Ask for sample text or identify files.
   • •If files exist, locate with rg --files and preview with rg -n.
2. •Choose tool
   • •Prefer rg for quick match checks; use rg -P for PCRE features.
   • •Use Python for detailed group inspection when needed.
3. •Build incrementally
   • •Start with a minimal literal anchor; expand piece by piece.
   • •Add anchors/boundaries; handle whitespace and separators explicitly.
4. •Validate
   • •Show a command to test against samples.
   • •Confirm no false positives by testing non-matches.
5. •Deliver
   • •Provide final regex, flags, and explanation.
   • •Include a test command and expected match summary.
   • •Note any tradeoffs/backtracking risks.

CLI snippets (use as needed)

• •Ripgrep check:
  • •rg -n "<regex>" path\\to\\file
  • •rg -n -P "<regex>" path\\to\\file
• •Python quick test (adjust quoting for the shell):
  • •python -c "import re,sys;pat=re.compile(r'<regex>');data=sys.stdin.read();print([m.group(0) for m in pat.finditer(data)])" < path\\to\\file

Deliverables

• •Regex + flags and any capture group map.
• •Test command(s) and summary of matches/non-matches.
• •Short explanation of the approach and known limitations.