@param b BAM alignment record
@param state The base modification state pointer.
@param mods A supplied array for returning base modifications
@param n_mods The size of the mods array
@return The number of modifications found on success,
-1 on failure.
This is intended to be used as an iterator, with one call per location
along the query sequence.
If no modifications are found, the returned value is zero.
If more than n_mods modifications are found, the total found is returned.
Note this means the caller needs to check whether this is higher than
n_mods.
@param b BAM alignment record @param state The base modification state pointer. @param mods A supplied array for returning base modifications @param n_mods The size of the mods array @return The number of modifications found on success, -1 on failure.
This is intended to be used as an iterator, with one call per location along the query sequence.
If no modifications are found, the returned value is zero. If more than n_mods modifications are found, the total found is returned. Note this means the caller needs to check whether this is higher than n_mods.