pub fn ngram_ids(dims: &NgramDims, ctx: &[u32]) -> Vec<Vec<u64>>Expand description
Compute the row ids for EVERY table over ctx (the n-1 cached context
tokens followed by the new tokens). Returns num_tables vectors of
ctx.len() ids each, table-major in reference index order
((ngram-2)*K + split); callers slice the last seq_len entries.