inconsistent escaping of string literals

[krux02]

import macros, strutils

const separator = repeat("=", 60)

macro foobar(arg: untyped): untyped =
  echo separator
  for x in arg:
    echo x.repr
    echo x.lispRepr
    echo x.treeRepr
    echo x.astGenRepr
    echo separator


foobar:
  "  \n  \r  \t  \\  "
  "  \x0A  \x0D  \x09  \\  "
  "  \L  \c  \t  \\  "
  """  \n  \r  \t  \\  """
  r"  \n  \r  \t  \\  "

this is the output:

============================================================
"  \L  \c  \t  \\  "
StrLit(  
  	  \  )
StrLit   
  	  \  
newLit("  \x0A  \x0D  \x09  \\  ")
============================================================
"  \L  \c  \t  \\  "
StrLit(  
  	  \  )
StrLit   
  	  \  
newLit("  \x0A  \x0D  \x09  \\  ")
============================================================
"  \L  \c  \t  \\  "
StrLit(  
  	  \  )
StrLit   
  	  \  
newLit("  \x0A  \x0D  \x09  \\  ")
============================================================
"""  \n  \r  \t  \\  """
TripleStrLit(  \n  \r  \t  \\  )
TripleStrLit   \n  \r  \t  \\  
newLit("  \\n  \\r  \\t  \\\\  ")
============================================================
r"  \n  \r  \t  \\  "
RStrLit(  \n  \r  \t  \\  )
RStrLit   \n  \r  \t  \\  
newLit("  \\n  \\r  \\t  \\\\  ")
============================================================

In my opinion the escaping works unnecessarily complicated. This looks like the escaping is implemented in several different locations in the source with code duplication, and then it diverged over time.