module Guide

# File lib/guide.rb, line 20
def print_error(invalid_input)
  puts ''
  puts 'Error:'
  puts "         > The input of \"#{invalid_input}\" is neither a valid"
  puts '         > fixnum, operator nor command. Valid inputs include: '
  puts '         > whole numbers (e.g. 0-9), floats (e.g. 0.50) '
  puts "         > or operators: #{ReversePolishCalculator::OPERATORS} "
  puts ''
end

# File lib/guide.rb, line 2
def print_introduction
  puts ''
  puts '================================================================================='
  puts '>>>>>>>>>>>>>>>>>>>>>>>>> Reverse Polish notation (RPN)<<<<<<<<<<<<<<<<<<<<<<<<<<'
  puts '================================================================================='
  puts ''
  puts 'The mathematical notation in which every operator follows all of its operands, in'
  puts 'contrast to Polish notation (PN), which puts the operator before its operands. '
  puts 'It is also known as postfix notation. It does not need any parentheses as long as'
  puts 'each operator has a fixed number of operands.'
  puts ''
  puts '- From Wikipedia, the free encyclopedia'
  puts '(https://en.wikipedia.org/wiki/Reverse_Polish_notation)'
  puts ''
  puts "Type 'help' for a list of valid commands."
  puts ''
end

# File lib/guide.rb, line 30
def print_operation_guide
  puts ''
  puts '================================================================================='
  puts '>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Valid Inputs <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<'
  puts '================================================================================='
  puts ''
  puts 'To exit program:'
  ReversePolishCalculator::VALID_EXITS.each { |exit| puts "  > #{exit}" }
  puts 'Valid integer examples:'
  puts '  > 0'
  puts '  > 0.25'
  puts '  > 0.5'
  (1..9).each { |i| puts "  > #{i}" }
  puts '  > 9.99'
  puts 'Valid operators:'
  ReversePolishCalculator::OPERATORS.each { |operator| puts "  > #{operator}" }
  puts 'Reset evaluation:'
  puts '  > clear'
  puts 'Request example:'
  puts '  > example'
  puts ''
  clear_evaluation
end

# File lib/guide.rb, line 54
def run_example
  clear_evaluation
  @expression = ReversePolishCalculator::EXAMPLES.sample
  puts "example input > #{@expression}"
  evaluate_expression(expression_array)
  clear_evaluation
end