🔴 There is no index, and that is a decision rather than an omission. An
index derived from decrypted history is plaintext by another name: it
would have to be sealed as carefully as the vault, taken by
forgetEverything, and kept consistent with the threads — a second copy
of everything anybody ever wrote, with its own ways to go wrong. This
reads what already exists and throws the plaintext away.
⚠️ It costs more here than on iOS, and the code says so. The iPhone app
keeps the whole decrypted history in memory; Android decrypts each
thread on demand. Hence a two-character minimum, a bound, a 250ms
debounce, and Dispatchers.IO.
🔴 Folding is length-preserving on purpose: the snippet slices the
ORIGINAL string at an index found in the folded one, so a fold that
dropped characters would cut in the wrong place — and for an accented
character, mid-character. There is a test with accents before the match.
Accent-insensitive because somebody typing "cafe" means "café", and a
search that knows the difference quietly fails in every language with
accents — Spanish is next on the localisation list.
Refs paulhitt/flamenet-messenger-ios#25
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
