module Byebug::ParseFunctions

def get_int(str, cmd, min = nil, max = nil)


min or max is nil, that value has no bound.
Parse 'str' of command 'cmd' as an integer between min and max. If either
def get_int(str, cmd, min = nil, max = nil)
  if str !~ /\A[0-9]+\z/
    return nil, "\"#{cmd}\" argument \"#{str}\" needs to be a number"
  end
  int = str.to_i
  if min && int < min
    return nil, "\"#{cmd}\" argument \"#{str}\" needs to be at least #{min}"
  elsif max && int > max
    return nil, "\"#{cmd}\" argument \"#{str}\" needs to be at most #{max}"
  end
  int
end

def get_line(filename, lineno)


Gets a single line in a source code file
def get_line(filename, lineno)
  lines = get_lines(filename)
  return nil unless lines
  lines[lineno - 1]
end

def get_lines(filename)


Gets all lines in a source code file
def get_lines(filename)
  return nil unless File.exist?(filename)
  lines(filename)
end

def lines(filename)


Fills SCRIPT_LINES__ entry for if not already filled.
def lines(filename)
  SCRIPT_LINES__[filename] ||= File.readlines(filename)
end

def parse_steps(str, cmd)


is empty.
Returns the number of steps specified in as an integer or 1 if 
def parse_steps(str, cmd)
  return 1 unless str
  steps, err = get_int(str, cmd, 1)
  return nil, err unless steps
  steps
end

def syntax_valid?(code)


Returns true if code is syntactically correct for Ruby.
def syntax_valid?(code)
  eval("BEGIN {return true}\n#{code}", nil, '', 0)
rescue SyntaxError
  false
end