table xAli
"An alignment - like psl but includes the sequence itself"
    (
    uint match;  "Number of bases that match that aren't repeats"
    uint misMatch; "Number of bases that don't match"
    uint repMatch; "Number of bases that match but are part of repeats"
    uint nCount;  "Number of 'N' bases"
    uint qNumInsert; "Number of inserts in query"
    int qBaseInsert; "Number of bases inserted in query"
    uint tNumInsert; "Number of inserts in target"
    int tBaseInsert; "Number of bases inserted in target"
    char[2] strand; "+ or - for strand. First character query, second target (optional)"
    string qName; "Query sequence name"
    uint qSize; "Query sequence size"
    uint qStart; "Alignment start position in query"
    uint qEnd; "Alignment end position in query"
    string tName; "Target sequence name"
    uint tSize; "Target sequence size"
    uint tStart; "Alignment start position in target"
    uint tEnd; "Alignment end position in target"
    uint blockCount; "Number of blocks in alignment"
    uint[blockCount] blockSizes; "Size of each block"
    uint[blockCount] qStarts; "Start of each block in query."
    uint[blockCount] tStarts; "Start of each block in target."
    lstring[blockCount] qSeq; "Query sequence for each block."
    lstring[blockCount] tSeq; "Target sequence for each block."
    )