Function diff_splice 

pub fn diff_splice(
    fit: &MArrayLM,
    geneid: &[String],
    exonid: Option<&[String]>,
    robust: bool,
    legacy: bool,
) -> Result<DiffSplice>

diffSplice — test for differential exon usage from an exon-level fit.

• fit — an MArrayLM with one row per exon (from lmFit on exon data).
• geneid — gene label for each exon (length = fit rows).
• exonid — optional exon label per exon; defaults to 1-based row indices.
• robust / legacy — forwarded to squeezeVar (R defaults: FALSE).