Does ruby support anything like #line directives in C or Perl? or
any other way to dynamically change what ruby thinks is the current
sourcefile and sourceline in its warning and error reporting?
What exactly do you need it for?
If it’s for reporting exceptions, you can manipulate the info returned
by Kernel::caller with the third argument of Kernel::raise. E.g.:
define stuff for a nice call stack:
irb(main):007:0> def f
irb(main):008:1> g
irb(main):009:1> end
=> nil
irb(main):014:0> def g
irb(main):015:1> raise StandardError
irb(main):016:1> end
=> nil
irb(main):017:0> f
StandardError: StandardError
from (irb):15:in g' from (irb):8:in f’
from (irb):17
but if we define g to muck up the caller argument:
irb(main):010:0> def g
irb(main):011:1> raise StandardError, “”,
“my_ficticious_script:imaginary_line: Go look here!\n\t” + caller[1]
irb(main):012:1> end
=> nil
irb(main):013:0> f
StandardError:
from my_ficticious_script:imaginary_line: Go look here!
(irb):13