If the constant SCRIPT_LINES__ is defined and holds a hash, for each
file
loaded after the constant definition the hash gets an entry that maps
the
file name to an array of strings: the file lines.
Does anybody have a use case for this constant, or know the rationale
behind this feature?
You can use this for debugging. If you extract the file name and line
number from the stracktrace of an error, you can print out the actual
line from SCRIPT_LINES__.