finally remove kaspers example from which the oprerator stuff is copied

lib/parser/copied_parser.rb

@@ -1,70 +0,0 @@
-#start from an example of parslet (assumed to be checked out at the same level as crystal for now)
-
-$:.unshift File.dirname(__FILE__) + "/../../../parslet/lib"
-
-require 'pp'
-require 'rspec'
-require 'parslet'
-require 'parslet/rig/rspec'
-require 'parslet/convenience'
-
-class InfixExpressionParser < Parslet::Parser
-  root :variable_assignment_list
-
-  rule(:space) { match[' '] }
-
-  def cts atom
-    atom >> space.repeat
-  end
-  def infix *args
-    Infix.new(*args)
-  end
-
-  # This is the heart of the infix expression parser: real simple definitions
-  # for all the pieces we need. 
-  rule(:mul_op) { cts match['*/'] }
-  rule(:add_op) { cts match['+-'] }
-  rule(:digit) { match['0-9'] }
-  rule(:integer) { cts digit.repeat(1).as(:int) }
-
-  rule(:expression) { infix_expression(integer, 
-    [mul_op, 2, :left], 
-    [add_op, 1, :right]) }
-
-  # And now adding variable assignments to that, just to a) demonstrate this
-  # embedded in a bigger parser, and b) make the example interesting. 
-  rule(:variable_assignment_list) { 
-    variable_assignment.repeat(1) }
-  rule(:variable_assignment) {
-    identifier.as(:ident) >> equal_sign >> expression.as(:exp) >> eol }
-  rule(:identifier) {
-    cts (match['a-z'] >> match['a-zA-Z0-9'].repeat) }
-  rule(:equal_sign) {
-    cts str('=') }
-  rule(:eol) {
-    cts(str("\n")) | any.absent? }
-end
-
-class InfixInterpreter < Parslet::Transform
-  rule(int: simple(:int)) { Integer(int) }
-  rule(ident: simple(:ident), exp: simple(:result)) { |d| 
-    d[:doc][d[:ident].to_s.strip.to_sym] = d[:result] }
-
-  rule(l: simple(:l), o: /^\*/, r: simple(:r)) { l * r }
-  rule(l: simple(:l), o: /^\+/, r: simple(:r)) { l + r }
-end
-
-input = <<ASSIGNMENTS
-a = 1
-b = 2
-c = 3 * 25
-d = 100 + 3*4
-ASSIGNMENTS
-
-puts input
-
-int_tree = InfixExpressionParser.new.parse_with_debug(input)
-bindings = {}
-result   = InfixInterpreter.new.apply(int_tree, doc: bindings)
-
-pp bindings