module Optimist

# Optimist::die "need at least one filename", -2 if ARGV.empty?
#
# An exit code can be provide if needed
#
# Optimist::die "need at least one filename" if ARGV.empty?
#
# end
# opt :whatever # ...
# options do
#
# about -h, and die. Example:
# In the one-argument case, simply print that message, a notice
#
# die :volume, "too soft" if opts[:volume] < 0.1
# die :volume, "too loud" if opts[:volume] > 10.0
#
# end
# opt :volume, :default => 0.0
# options do
#
# 'msg', and dies. Example:
# Informs the user that their usage of 'arg' was wrong, as detailed by

def die(arg, msg = nil, error_code = nil)
  if @last_parser
    @last_parser.die arg, msg, error_code
  else
    raise ArgumentError, "Optimist::die can only be called after Optimist::options"
  end
end

# Optimist::educate if ARGV.empty?
#
# end
# EOS
# where [options] are:
# #$0 [options]
# Usage:
# banner <<-EOS
# opt :volume, :default => 0.0
# options do
#
# Displays the help message and dies. Example:

def educate
  if @last_parser
    @last_parser.educate
    exit
  else
    raise ArgumentError, "Optimist::educate can only be called after Optimist::options"
  end
end

# See more examples at http://optimist.rubyforge.org.
#
# p opts # => {:monkey=>true, :name=>nil, :num_limbs=>4, :help=>false, :monkey_given=>true}
# ## if called with --monkey
#
# p opts # => {:monkey=>false, :name=>nil, :num_limbs=>4, :help=>false}
# ## if called with no arguments
#
# end
# opt :num_limbs, "Number of limbs", :default => 4 # an integer --num-limbs , defaulting to 4
# opt :name, "Monkey name", :type => :string # a string --name , defaulting to nil
# opt :monkey, "Use monkey mode" # a flag --monkey, defaulting to false
# opts = Optimist::options do
# require 'optimist'
#
# Example:
#
# name>_given" will also be set in the hash.
# every option specified on the commandline, a key "# default value if the option was not specified on the commandline. For
# +opt+. The value will be the value given on the commandline, or the
# The returned block contains a value for every option specified with
#
# probably a call to +version+ (Parser#version).
# (Parser#opt), zero or more calls to +text+ (Parser#text), and
# The block passed in should contain zero or more calls to +opt+
#
# Modifies +args+ in place. Returns a hash of option values.
# requests for help or version information appropriately (and then exiting).
# passes the block to it, then parses +args+ with it, handling any errors or
# The easy, syntactic-sugary entry method into Optimist. Creates a Parser,

def options(args = ARGV, *a, &b)
  @last_parser = Parser.new(*a, &b)
  with_standard_exception_handling(@last_parser) { @last_parser.parse args }
end