ahem/lib/ahem/ast/binary.rb

class AST::Binary
  attr_reader :operation, :left, :right

  def initialize(operation, left, right)
    @operation = operation
    @left = left
    @right = right
  end

  def ==(other)
    other.operation == @operation && other.left == @left &&
      other.right == @right
  end

  def execute(env)
    case @operation
    when AST::Operators::ADD
      @left.execute(env) + @right.execute(env)
    when AST::Operators::SUBTRACT
      @left.execute(env) - @right.execute(env)
    when AST::Operators::MULTIPLY
      @left.execute(env) * @right.execute(env)
    when AST::Operators::DIVIDE
      @left.execute(env) / @right.execute(env)
    when AST::Operators::LESS_THAN
      @left.execute(env) < @right.execute(env)
    when AST::Operators::LESS_THAN_OR_EQUAL
      @left.execute(env) <= @right.execute(env)
    when AST::Operators::GREATER_THAN
      @left.execute(env) > @right.execute(env)
    when AST::Operators::GREATER_THAN_OR_EQUAL
      @left.execute(env) >= @right.execute(env)
    when AST::Operators::DOUBLE_EQUALS
      @left.execute(env) == @right.execute(env)
    when AST::Operators::OR
      @left.execute(env) || @right.execute(env)
    when AST::Operators::AND
      @left.execute(env) && @right.execute(env)
    end
  end
end