-?>>

    macro
    boot.janet on line 1090, column 1

    (-?>> x & forms)
    
    Short circuit threading macro. Inserts x as the last value in the
    first form in forms, and inserts the modified first form into the
    second form in the same manner, and so on. The pipeline will return nil
    if an intermediate value is nil. Useful for expressing pipelines of
    data.