# Bengali morphology for search

Status: parked — original work, not a sub-task
Raised: 2026-08-02

Exact-form search is scheduled without this and **documents its own absence**. This file exists so that
"add search" can never be read as having solved it.

## What exact-form search already does

Whitespace tokenising plus the NFC normalisation that is already unconditional (ADR-0015) finds the word you
typed, in English or Bengali, if it appears in that form. That is genuinely useful and it is not
English-only — Bengali separates words with spaces, so this is **not** the CJK segmentation problem.

## What is actually missing

**Morphology.** বই, বইয়ের, বইগুলো are one lemma carrying case and plural suffixes, and exact-form matching
treats them as three unrelated terms. A reader searching for the base form finds none of the inflected uses.
English gets away with naive matching far better than Bengali does, which is why this is not a polish item.

Concretely absent:

- **No mature Go stemmer exists.** Snowball has no Bengali algorithm, so there is nothing to import — this
  is the case ADR-0083's "take the module" rule cannot help with, because there is no module.
- **Suffix stripping needs a real rule set**, not a hand-written list guessed at from a few examples. Getting
  it wrong produces confidently wrong results, which is worse than exact-form matching that is honest about
  what it does.
- **Transliteration search** — typing "boi" to find বই — is a separate feature again, and arguably wanted
  more than stemming by anyone typing on a phone keyboard.
- **Orthographic variation** beyond NFC: the same word written with different but valid conjunct forms.

## Why it is treated as research

`harness/roadmap.md` singles this out: *"Bengali tokenisation for search is the genuinely novel problem here
— solve it well and deliberately, not as a side effect of adding search."* `ideas/exploration.md` repeats it
as the one item nobody else will solve for you.

The failure mode being avoided is specific: a stemmer bolted on during a search feature, tuned until the
author's own test queries pass, then quietly wrong for every word he did not think to try.

## Trigger

Deciding to do the linguistic work — deliberately, as its own piece, with a way to evaluate results beyond
"my queries look right". Until then exact-form search ships and says what it does not do.