Support suffix and wildcard matching (currently prefix-only)

[micheleriva]

Summary

zbsearch currently supports prefix matching (search-as-you-type) via the radix tree, but has no way to match by suffix ("ends-with") or by an infix/wildcard pattern. Several competitors offer this:

• Fuse.js — $ (suffix-exact) and !$ (not-suffix) extended-search operators
• FlexSearch — reverse/bidirectional tokenizer for suffix matching
• Lunr — wildcard queries: *oo (suffix), f*o (infix), foo* (prefix)

Motivation

Matching the tail of a term (file extensions like .js, suffix-heavy morphology, part numbers/SKUs) is impossible today without indexing tricks on the user's side.

Proposed direction

• Consider a reverse radix index (à la FlexSearch reverse) to make suffix lookups cheap, opt-in per field to avoid the memory cost.
• Alternatively/additionally, support a limited wildcard syntax (*term, te*rm) in the query, expanded against the radix tree.

Notes / trade-offs

• Suffix indexing roughly doubles the string index memory for fields it's enabled on; should be opt-in.
• Infix/full-substring matching is the most expensive; scope carefully.

Related

Part of a competitive feature-gap review vs Fuse.js, MiniSearch, FlexSearch, Lunr.