gramdex

gramdex provides small, dependency-light primitives for approximate string matching:

• Unicode-scalar (Rust char) (k)-gram generation
• A minimal grams → document-ids index (GramDex) for candidate generation
• An exact (verification) trigram Jaccard helper (trigram_jaccard)

Quickstart

[dependencies]
gramdex = "0.1.0"

use gramdex::{GramDex, trigram_jaccard};

let mut ix = GramDex::new();
ix.add_document_trigrams(1, "hello");
ix.add_document_trigrams(2, "yellow");

let candidates = ix.candidates_union_trigrams("mellow");
let mut verified: Vec<u32> = candidates
    .into_iter()
    .filter(|&doc| match doc {
        1 => trigram_jaccard("mellow", "hello") >= 0.2,
        2 => trigram_jaccard("mellow", "yellow") >= 0.2,
        _ => false,
    })
    .collect();
verified.sort_unstable();
assert_eq!(verified, vec![2]);

Best starting points

• Gram generation: char_kgrams / char_trigrams
• Candidate index: GramDex (union candidates, scored candidates, bailout planning)
• Verification: trigram_jaccard

Design notes

• This crate focuses on candidate generation; you bring your own verification policy.
• Offsets/spans are naturally expressed in Unicode scalar values (char count), not bytes.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.