creates a scan window for a block.

The default arity scans the full block. The extended arities allow the caller to override the scan line range, start column, and optional end column when a smaller suspect region has already been identified.

uses a later correct close delimiter to narrow the suspect scan window

gets the block lines

checks content for irregular blocks

runs the check block loop

helper function for get-errored

groups the lines by colation sections

categorises the blocks

prepares the block entries for a file

prepares the block entries for a file

creates a single block

groups entries by colation

gets the minimum column

allow multiple passes to heal the delimiter

heals the content in a single pass

runs a close-delimiter localization pass before the full structural check

checks if the candidate scan is narrower than the current scan

wraps the heal function to output the diff

print wrapper for the heal function