TUI search and RE2

Historical prototype record: This page preserves the July 27, 2026 TUI experiment. It is not current supported-product guidance or a Windows-release blocker.

Search modes

Plain literal search is the default. A user must deliberately select fuzzy or regex mode. The shared search control keeps query, mode, case choice, RE2 flags, validation, and the full builder synchronized on each connected collection surface.

Literal/substring compares ordinary text and does not compile a pattern.
Fuzzy ranks ordered character matches for navigation-oriented filtering.
Regex uses google-re2, the RE2 dialect—not Python re, PCRE, or JavaScript regular expressions.

Patterns and sample text are evaluated locally. They are not sent to GitHub or persisted merely because the user previews them.

Builder

The Regex tab provides:

raw pattern input;
i, m, and s flags;
guided literal, character-class, anchor, group, alternation, and quantifier construction;
sample text;
syntax feedback;
live match ranges and capture previews;
a copy/export path through the terminal clipboard behavior.

RE2 deliberately rejects constructs such as backreferences and look-around. The builder reports those as dialect errors; it never falls back to a more permissive engine.

Safety bounds

Bound	Value
pattern	1,000 characters
one candidate/sample	100,000 characters
total collection input	1,000,000 characters
match count	5,000
capture work	50,000 match×group units
capture previews	24
one capture preview	120 characters
RE2 memory option	8 MiB

Capture-heavy expressions lower the effective match limit. Candidate keys are bounded before evaluation. The match iterator advances safely after a zero-width match, including at end of input, so a pattern cannot loop forever on the same offset.

Escaping and flags

The pattern field contains raw RE2 syntax. Shell quoting is irrelevant because the pattern is not interpolated into a shell command. A literal builder token is escaped for RE2 before insertion.

i: case-insensitive matching;
m: ^ and $ operate by line;
s: dot matches newline.

Unsupported flag letters fail validation. Unicode behavior is RE2 behavior; users should not assume PCRE locale classes or Python-specific semantics.

Failure and recovery

Invalid syntax leaves the previous collection visible and reports the error; it does not reinterpret the pattern as literal text. Over-limit input reports the exact bound. Switch explicitly to Literal to search the pattern characters as ordinary text.

Tests cover valid/invalid syntax, no match, Unicode, multiline, zero-width, captures, adversarial forms, and literal-versus-regex behavior. The generated parity ledger links builder and shared-service evidence but does not prove that every one of the desktop edition's 51 search surfaces already exists in the TUI.