npython

#!/usr/bin/env ruby
require_relative "lib/dsl/python"
require_relative "lib/dsl/python/version"

VERSION=Dsl::Python::VERSION

def open_repl
  text = <<~TEXT
  nPython #{VERSION} (main, Nov 16 1970) [GCC] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  TEXT
  puts text
  system("irb --prompt simple --nocolorize --noecho-on-assignment -Ilib -rdsl/python")
end

def show_version
  puts "npython (#{VERSION})"
end

def show_help
  text = <<~TEXT
  usage: npython [option | file ]
  Options:
  -h     : print this help message and exit (also -? or --help)
  -v     : show current version (also -V or --version)
  
  Arguments:
  file   : program read from script file
  TEXT
  puts text  
end

def run_program(name)
  unless File.exist? name
    puts "npython: can't open file '#{name}': [Errno 2] No such file or directory"
    exit 1
  end

  content = File.read(name)
  eval(content)
end

if ARGV.size.zero?
  open_repl
elsif ["-v", "--version", "-V"].include? ARGV.first
  show_version
elsif ["-h", "--help", "-?"].include? ARGV.first
  show_help
else
  run_program ARGV.first
end