Python has them: a = re.compile(r"""\d + # the integral part \. # the decimal po...

zyxley · on March 10, 2014

Coffeescript has similar functionality. From the Coffeescript docs:

    OPERATOR = /// ^ (
      ?: [-=]>             # function
       | [-+*/%<>&|^!?=]=  # compound assign / compare
       | >>>=?             # zero-fill right shift
       | ([-+:])\1         # doubles
       | ([&|<>])\2=?      # logic / shift
       | \?\.              # soak access
       | \.{2,3}           # range or splat
    ) ///

When turned into Javascript it becomes:

    var OPERATOR;
    
    OPERATOR = /^(?:[-=]>|[-+*\/%<>&|^!?=]=|>>>=?|([-+:])\1|([&|<>])\2=?|\?\.|\.{2,3})/;

riffraff · on March 10, 2014

yes, any decent PL nowadays has it, my point was that it should be the default.