Regular Expression Builder

Use the material below to complete **regular expression builder**. The useful outcome is not generic advice; it is a decision-ready result for the query “regular expression builder prompt”.

## Details that matter — Regular Expression Builder
- [LANGUAGE] — for Regular Expression Builder, supply the relevant language. If unavailable, label [LANGUAGE] `unknown`; never infer it.
- [EXPECTED_BEHAVIOR] — for Regular Expression Builder, supply the relevant expected behavior. If unavailable, label [EXPECTED_BEHAVIOR] `unknown`; never infer it.
- [REPRODUCTION_STEPS] — for Regular Expression Builder, supply the relevant reproduction steps. If unavailable, label [REPRODUCTION_STEPS] `unknown`; never infer it.
- [CODE] — for Regular Expression Builder, supply the relevant code. If unavailable, label [CODE] `unknown`; never infer it.
- [RUNTIME] — for Regular Expression Builder, supply the relevant runtime. If unavailable, label [RUNTIME] `unknown`; never infer it.
- [ERROR_OUTPUT] — for Regular Expression Builder, supply the relevant error output. If unavailable, label [ERROR_OUTPUT] `unknown`; never infer it.

## Method for this job — Regular Expression Builder
1. Clarify the practical decision or artifact before producing it.
2. Return the finished artifact with the assumptions that affect its use.
3. Separate confirmed behavior from hypotheses.
4. Consider edge cases, security, and backward compatibility.
5. Show a minimal change before optional refactoring.
6. Include tests that would fail before the correction.
7. Boundary for Regular Expression Builder: Do not invent APIs, packages, files, runtime behavior, command output, or successful test results.

## Useful output — Regular Expression Builder
- **Technical finding for Regular Expression Builder** — material inputs for Regular Expression Builder, each connected to regular expression builder prompt.
- **Evidence or reproduction for Regular Expression Builder** — ready-to-use Regular Expression Builder, formatted for regular expression builder prompt.
- **Minimal change for Regular Expression Builder** — Regular Expression Builder weak points, unknowns, and regular expression builder prompt limits.
- **Test coverage for Regular Expression Builder** — regular expression builder prompt → verify Regular Expression Builder before use.
- **Verification command for Regular Expression Builder** — regular expression builder prompt evidence → Regular Expression Builder; omit preamble.

## Verification — Regular Expression Builder
Confirm that the finished Regular Expression Builder answers the stated query, uses no unsupported facts, and can be acted on without guessing what comes next.