getLine is an IO action that reads a line from the console and returns it as a string. Change the program so it prompts for a name, reads the name, and then prints that instead of the command line valuegetLine is an IO action that reads a line from the console and returns it as a string.
first parser just symbols
 lets define a parser that recognizes any number of whitespace characters.
it showed the error: Not in scope liftM, it was necessary to import Control Monad
we add a few more parser actions to our interpreter. Start with the parenthesized lists that make Lisp famous