_define_block_seq (
        block_tag,
        block_group,
        item,
        )

Define a Martel grouping that can parse a block of groups.

Many of the KEGG entries are formatted as:

TAG blah blah blah blah blah blah blah blah blah blah zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Where blah blah... and zzzz... are identically formatted items that can wrap over multiple lines. This function defines a consistent grouping for these blocks.

Arguments: o block_tag - A string of length <= INDENT giving the block tag (i.e. TAG in the example above). o block_group - A callbakc tag for the entire block. o item - A Martel group/expression for a single instance of the data item in this block. (Must NOT include the final newline character).