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lib/optimist.rb

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# lib/optimist.rb -- optimist command-line processing library
# Copyright (c) 2008-2014 William Morgan.
# Copyright (c) 2014 Red Hat, Inc.
# optimist is licensed under the MIT license.

require 'date'

module Optimist
  # note: this is duplicated in gemspec
  # please change over there too
VERSION = "3.0.1"

## Thrown by Parser in the event of a commandline error. Not needed if
## you're using the Optimist::options entry.
class CommandlineError < StandardError
  attr_reader :error_code

  def initialize(msg, error_code = nil)
    super(msg)
    @error_code = error_code
  end
end

## Thrown by Parser if the user passes in '-h' or '--help'. Handled
## automatically by Optimist#options.
class HelpNeeded < StandardError
end

## Thrown by Parser if the user passes in '-v' or '--version'. Handled
## automatically by Optimist#options.
class VersionNeeded < StandardError
end

## Regex for floating point numbers
FLOAT_RE = /^-?((\d+(\.\d+)?)|(\.\d+))([eE][-+]?[\d]+)?$/

## Regex for parameters
PARAM_RE = /^-(-|\.$|[^\d\.])/

## The commandline parser. In typical usage, the methods in this class
## will be handled internally by Optimist::options. In this case, only the
## #opt, #banner and #version, #depends, and #conflicts methods will
## typically be called.
##
## If you want to instantiate this class yourself (for more complicated
## argument-parsing logic), call #parse to actually produce the output hash,
## and consider calling it from within
## Optimist::with_standard_exception_handling.
class Parser

  ## The registry is a class-instance-variable map of option aliases to their subclassed Option class.
  @registry = {}

  ## The Option subclasses are responsible for registering themselves using this function.
  def self.register(lookup, klass)
    @registry[lookup.to_sym] = klass
  end

  ## Gets the class from the registry.
  ## Can be given either a class-name, e.g. Integer, a string, e.g "integer", or a symbol, e.g :integer
  def self.registry_getopttype(type)
    return nil unless type
    if type.respond_to?(:name)
      type = type.name
      lookup = type.downcase.to_sym
    else
      lookup = type.to_sym
    end
    raise ArgumentError, "Unsupported argument type '#{type}', registry lookup '#{lookup}'" unless @registry.has_key?(lookup)
    return @registry[lookup].new
  end

  INVALID_SHORT_ARG_REGEX = /[\d-]/ #:nodoc:

  ## The values from the commandline that were not interpreted by #parse.
  attr_reader :leftovers

  ## The complete configuration hashes for each option. (Mainly useful
  ## for testing.)
  attr_reader :specs

  ## A flag that determines whether or not to raise an error if the parser is passed one or more
  ##  options that were not registered ahead of time.  If 'true', then the parser will simply
  ##  ignore options that it does not recognize.
  attr_accessor :ignore_invalid_options

  ## Initializes the parser, and instance-evaluates any block given.
  def initialize(*a, &b)
    @version = nil
    @leftovers = []
    @specs = {}
    @long = {}
    @short = {}
    @order = []
    @constraints = []
    @stop_words = []
    @stop_on_unknown = false
    @educate_on_error = false
    @synopsis = nil
    @usage = nil

    # instance_eval(&b) if b # can't take arguments
    cloaker(&b).bind(self).call(*a) if b
  end

  ## Define an option. +name+ is the option name, a unique identifier
  ## for the option that you will use internally, which should be a
  ## symbol or a string. +desc+ is a string description which will be
  ## displayed in help messages.
  ##
  ## Takes the following optional arguments:
  ##
  ## [+:long+] Specify the long form of the argument, i.e. the form with two dashes. If unspecified, will be automatically derived based on the argument name by turning the +name+ option into a string, and replacing any _'s by -'s.
  ## [+:short+] Specify the short form of the argument, i.e. the form with one dash. If unspecified, will be automatically derived from +name+. Use :none: to not have a short value.
  ## [+:type+] Require that the argument take a parameter or parameters of type +type+. For a single parameter, the value can be a member of +SINGLE_ARG_TYPES+, or a corresponding Ruby class (e.g. +Integer+ for +:int+). For multiple-argument parameters, the value can be any member of +MULTI_ARG_TYPES+ constant. If unset, the default argument type is +:flag+, meaning that the argument does not take a parameter. The specification of +:type+ is not necessary if a +:default+ is given.
  ## [+:default+] Set the default value for an argument. Without a default value, the hash returned by #parse (and thus Optimist::options) will have a +nil+ value for this key unless the argument is given on the commandline. The argument type is derived automatically from the class of the default value given, so specifying a +:type+ is not necessary if a +:default+ is given. (But see below for an important caveat when +:multi+: is specified too.) If the argument is a flag, and the default is set to +true+, then if it is specified on the the commandline the value will be +false+.
  ## [+:required+] If set to +true+, the argument must be provided on the commandline.
  ## [+:multi+] If set to +true+, allows multiple occurrences of the option on the commandline. Otherwise, only a single instance of the option is allowed. (Note that this is different from taking multiple parameters. See below.)
  ##
  ## Note that there are two types of argument multiplicity: an argument
  ## can take multiple values, e.g. "--arg 1 2 3". An argument can also
  ## be allowed to occur multiple times, e.g. "--arg 1 --arg 2".
  ##
  ## Arguments that take multiple values should have a +:type+ parameter
  ## drawn from +MULTI_ARG_TYPES+ (e.g. +:strings+), or a +:default:+
  ## value of an array of the correct type (e.g. [String]). The
  ## value of this argument will be an array of the parameters on the
  ## commandline.
  ##
  ## Arguments that can occur multiple times should be marked with
  ## +:multi+ => +true+. The value of this argument will also be an array.
  ## In contrast with regular non-multi options, if not specified on
  ## the commandline, the default value will be [], not nil.
  ##
  ## These two attributes can be combined (e.g. +:type+ => +:strings+,
  ## +:multi+ => +true+), in which case the value of the argument will be
  ## an array of arrays.
  ##
  ## There's one ambiguous case to be aware of: when +:multi+: is true and a
  ## +:default+ is set to an array (of something), it's ambiguous whether this
  ## is a multi-value argument as well as a multi-occurrence argument.
  ## In thise case, Optimist assumes that it's not a multi-value argument.
  ## If you want a multi-value, multi-occurrence argument with a default
  ## value, you must specify +:type+ as well.

  def opt(name, desc = "", opts = {}, &b)
    opts[:callback] ||= b if block_given?
    opts[:desc] ||= desc

    o = Option.create(name, desc, opts)

    raise ArgumentError, "you already have an argument named '#{name}'" if @specs.member? o.name
    raise ArgumentError, "long option name #{o.long.inspect} is already taken; please specify a (different) :long" if @long[o.long]
    raise ArgumentError, "short option name #{o.short.inspect} is already taken; please specify a (different) :short" if @short[o.short]
    @long[o.long] = o.name
    @short[o.short] = o.name if o.short?
    @specs[o.name] = o
    @order << [:opt, o.name]
  end

  ## Sets the version string. If set, the user can request the version
  ## on the commandline. Should probably be of the form "<program name>
  ## <version number>".
  def version(s = nil)
    s ? @version = s : @version
  end

  ## Sets the usage string. If set the message will be printed as the
  ## first line in the help (educate) output and ending in two new
  ## lines.
  def usage(s = nil)
    s ? @usage = s : @usage
  end

  ## Adds a synopsis (command summary description) right below the
  ## usage line, or as the first line if usage isn't specified.
  def synopsis(s = nil)
    s ? @synopsis = s : @synopsis
  end

  ## Adds text to the help display. Can be interspersed with calls to
  ## #opt to build a multi-section help page.
  def banner(s)
    @order << [:text, s]
  end
  alias_method :text, :banner

  ## Marks two (or more!) options as requiring each other. Only handles
  ## undirected (i.e., mutual) dependencies. Directed dependencies are
  ## better modeled with Optimist::die.
  def depends(*syms)
    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
    @constraints << [:depends, syms]
  end

  ## Marks two (or more!) options as conflicting.
  def conflicts(*syms)
    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
    @constraints << [:conflicts, syms]
  end

  ## Marks two (or more!) options as required but mutually exclusive.
  def either(*syms)
    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
    @constraints << [:conflicts, syms]
    @constraints << [:either, syms]
  end

  ## Defines a set of words which cause parsing to terminate when
  ## encountered, such that any options to the left of the word are
  ## parsed as usual, and options to the right of the word are left
  ## intact.
  ##
  ## A typical use case would be for subcommand support, where these
  ## would be set to the list of subcommands. A subsequent Optimist
  ## invocation would then be used to parse subcommand options, after
  ## shifting the subcommand off of ARGV.
  def stop_on(*words)
    @stop_words = [*words].flatten
  end

  ## Similar to #stop_on, but stops on any unknown word when encountered
  ## (unless it is a parameter for an argument). This is useful for
  ## cases where you don't know the set of subcommands ahead of time,
  ## i.e., without first parsing the global options.
  def stop_on_unknown
    @stop_on_unknown = true
  end

  ## Instead of displaying "Try --help for help." on an error
  ## display the usage (via educate)
  def educate_on_error
    @educate_on_error = true
  end

  ## Parses the commandline. Typically called by Optimist::options,
  ## but you can call it directly if you need more control.
  ##
  ## throws CommandlineError, HelpNeeded, and VersionNeeded exceptions.
  def parse(cmdline = ARGV)
    vals = {}
    required = {}

    opt :version, "Print version and exit" if @version && ! (@specs[:version] || @long["version"])
    opt :help, "Show this message" unless @specs[:help] || @long["help"]

    @specs.each do |sym, opts|
      required[sym] = true if opts.required?
      vals[sym] = opts.default
      vals[sym] = [] if opts.multi && !opts.default # multi arguments default to [], not nil
    end

    resolve_default_short_options!

    ## resolve symbols
    given_args = {}
    @leftovers = each_arg cmdline do |arg, params|
      ## handle --no- forms
      arg, negative_given = if arg =~ /^--no-([^-]\S*)$/
        ["--#{$1}", true]
      else
        [arg, false]
      end

      sym = case arg
        when /^-([^-])$/      then @short[$1]
        when /^--([^-]\S*)$/  then @long[$1] || @long["no-#{$1}"]
        else                       raise CommandlineError, "invalid argument syntax: '#{arg}'"
      end

      sym = nil if arg =~ /--no-/ # explicitly invalidate --no-no- arguments

      next nil if ignore_invalid_options && !sym
      raise CommandlineError, "unknown argument '#{arg}'" unless sym

      if given_args.include?(sym) && !@specs[sym].multi?
        raise CommandlineError, "option '#{arg}' specified multiple times"
      end

      given_args[sym] ||= {}
      given_args[sym][:arg] = arg
      given_args[sym][:negative_given] = negative_given
      given_args[sym][:params] ||= []

      # The block returns the number of parameters taken.
      num_params_taken = 0

      unless params.empty?
        if @specs[sym].single_arg?
          given_args[sym][:params] << params[0, 1]  # take the first parameter
          num_params_taken = 1
        elsif @specs[sym].multi_arg?
          given_args[sym][:params] << params        # take all the parameters
          num_params_taken = params.size
        end
      end

      num_params_taken
    end

    ## check for version and help args
    raise VersionNeeded if given_args.include? :version
    raise HelpNeeded if given_args.include? :help

    ## check constraint satisfaction
    @constraints.each do |type, syms|
      constraint_sym = syms.find { |sym| given_args[sym] }

      case type
      when :depends
        next unless constraint_sym
        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} requires --#{@specs[sym].long}" unless given_args.include? sym }
      when :conflicts
        next unless constraint_sym
        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym].long} conflicts with --#{@specs[sym].long}" if given_args.include?(sym) && (sym != constraint_sym) }
      when :either
        raise CommandlineError, "one of #{syms.map { |sym| "--#{@specs[sym].long}" }.join(', ') } is required" if (syms & given_args.keys).size != 1
      end
    end

    required.each do |sym, val|
      raise CommandlineError, "option --#{@specs[sym].long} must be specified" unless given_args.include? sym
    end

    ## parse parameters
    given_args.each do |sym, given_data|
      arg, params, negative_given = given_data.values_at :arg, :params, :negative_given

      opts = @specs[sym]
      if params.empty? && !opts.flag?
        raise CommandlineError, "option '#{arg}' needs a parameter" unless opts.default
        params << (opts.array_default? ? opts.default.clone : [opts.default])
      end

      vals["#{sym}_given".intern] = true # mark argument as specified on the commandline

      vals[sym] = opts.parse(params, negative_given)

      if opts.single_arg?
        if opts.multi?        # multiple options, each with a single parameter
          vals[sym] = vals[sym].map { |p| p[0] }
        else                  # single parameter
          vals[sym] = vals[sym][0][0]
        end
      elsif opts.multi_arg? && !opts.multi?
        vals[sym] = vals[sym][0]  # single option, with multiple parameters
      end
      # else: multiple options, with multiple parameters

      opts.callback.call(vals[sym]) if opts.callback
    end

    ## modify input in place with only those
    ## arguments we didn't process
    cmdline.clear
    @leftovers.each { |l| cmdline << l }

    ## allow openstruct-style accessors
    class << vals
      def method_missing(m, *_args)
        self[m] || self[m.to_s]
      end
    end
    vals
  end

  ## Print the help message to +stream+.
  def educate(stream = $stdout)
    width # hack: calculate it now; otherwise we have to be careful not to
          # call this unless the cursor's at the beginning of a line.

    left = {}
    @specs.each { |name, spec| left[name] = spec.educate }

    leftcol_width = left.values.map(&:length).max || 0
    rightcol_start = leftcol_width + 6 # spaces

    unless @order.size > 0 && @order.first.first == :text
      command_name = File.basename($0).gsub(/\.[^.]+$/, '')
      stream.puts "Usage: #{command_name} #{@usage}\n" if @usage
      stream.puts "#{@synopsis}\n" if @synopsis
      stream.puts if @usage || @synopsis
      stream.puts "#{@version}\n" if @version
      stream.puts "Options:"
    end

    @order.each do |what, opt|
      if what == :text
        stream.puts wrap(opt)
        next
      end

      spec = @specs[opt]
      stream.printf "  %-#{leftcol_width}s    ", left[opt]
      desc = spec.description_with_default

      stream.puts wrap(desc, :width => width - rightcol_start - 1, :prefix => rightcol_start)
    end
  end

  def width #:nodoc:
    @width ||= if $stdout.tty?
      begin
        require 'io/console'
        w = IO.console.winsize.last
        w.to_i > 0 ? w : 80
      rescue LoadError, NoMethodError, Errno::ENOTTY, Errno::EBADF, Errno::EINVAL
        legacy_width
      end
    else
      80
    end
  end

  def legacy_width
    # Support for older Rubies where io/console is not available
    `tput cols`.to_i
  rescue Errno::ENOENT
    80
  end
  private :legacy_width

  def wrap(str, opts = {}) # :nodoc:
    if str == ""
      [""]
    else
      inner = false
      str.split("\n").map do |s|
        line = wrap_line s, opts.merge(:inner => inner)
        inner = true
        line
      end.flatten
    end
  end

  ## The per-parser version of Optimist::die (see that for documentation).
  def die(arg, msg = nil, error_code = nil)
    msg, error_code = nil, msg if msg.kind_of?(Integer)
    if msg
      $stderr.puts "Error: argument --#{@specs[arg].long} #{msg}."
    else
      $stderr.puts "Error: #{arg}."
    end
    if @educate_on_error
      $stderr.puts
      educate $stderr
    else
      $stderr.puts "Try --help for help."
    end
    exit(error_code || -1)
  end

private

  ## yield successive arg, parameter pairs
  def each_arg(args)
    remains = []
    i = 0

    until i >= args.length
      return remains += args[i..-1] if @stop_words.member? args[i]
      case args[i]
      when /^--$/ # arg terminator
        return remains += args[(i + 1)..-1]
      when /^--(\S+?)=(.*)$/ # long argument with equals
        num_params_taken = yield "--#{$1}", [$2]
        if num_params_taken.nil?
          remains << args[i]
          if @stop_on_unknown
            return remains += args[i + 1..-1]
          end
        end
        i += 1
      when /^--(\S+)$/ # long argument
        params = collect_argument_parameters(args, i + 1)
        num_params_taken = yield args[i], params

        if num_params_taken.nil?
          remains << args[i]
          if @stop_on_unknown
            return remains += args[i + 1..-1]
          end
        else
          i += num_params_taken
        end
        i += 1
      when /^-(\S+)$/ # one or more short arguments
        short_remaining = ""
        shortargs = $1.split(//)
        shortargs.each_with_index do |a, j|
          if j == (shortargs.length - 1)
            params = collect_argument_parameters(args, i + 1)

            num_params_taken = yield "-#{a}", params
            unless num_params_taken
              short_remaining << a
              if @stop_on_unknown
                remains << "-#{short_remaining}"
                return remains += args[i + 1..-1]
              end
            else
              i += num_params_taken
            end
          else
            unless yield "-#{a}", []
              short_remaining << a
              if @stop_on_unknown
                short_remaining += shortargs[j + 1..-1].join
                remains << "-#{short_remaining}"
                return remains += args[i + 1..-1]
              end
            end
          end
        end

        unless short_remaining.empty?
          remains << "-#{short_remaining}"
        end
        i += 1
      else
        if @stop_on_unknown
          return remains += args[i..-1]
        else
          remains << args[i]
          i += 1
        end
      end
    end

    remains
  end

  def collect_argument_parameters(args, start_at)
    params = []
    pos = start_at
    while args[pos] && args[pos] !~ PARAM_RE && !@stop_words.member?(args[pos]) do
      params << args[pos]
      pos += 1
    end
    params
  end

  def resolve_default_short_options!
    @order.each do |type, name|
      opts = @specs[name]
      next if type != :opt || opts.short

      c = opts.long.split(//).find { |d| d !~ INVALID_SHORT_ARG_REGEX && !@short.member?(d) }
      if c # found a character to use
        opts.short = c
        @short[c] = name
      end
    end
  end

  def wrap_line(str, opts = {})
    prefix = opts[:prefix] || 0
    width = opts[:width] || (self.width - 1)
    start = 0
    ret = []
    until start > str.length
      nextt =
        if start + width >= str.length
          str.length
        else
          x = str.rindex(/\s/, start + width)
          x = str.index(/\s/, start) if x && x < start
          x || str.length
        end
      ret << ((ret.empty? && !opts[:inner]) ? "" : " " * prefix) + str[start...nextt]
      start = nextt + 1
    end
    ret
  end

  ## instance_eval but with ability to handle block arguments
  ## thanks to _why: http://redhanded.hobix.com/inspect/aBlockCostume.html
  def cloaker(&b)
    (class << self; self; end).class_eval do
      define_method :cloaker_, &b
      meth = instance_method :cloaker_
      remove_method :cloaker_
      meth
    end
  end
end

class Option

  attr_accessor :name, :short, :long, :default
  attr_writer :multi_given

  def initialize
    @long = nil
    @short = nil
    @name = nil
    @multi_given = false
    @hidden = false
    @default = nil
    @optshash = Hash.new()
  end

  def opts(key)
    @optshash[key]
  end

  def opts=(o)
    @optshash = o
  end

  ## Indicates a flag option, which is an option without an argument
  def flag? ; false ; end
  def single_arg?
    !self.multi_arg? && !self.flag?
  end

  def multi ; @multi_given ; end
  alias multi? multi

  ## Indicates that this is a multivalued (Array type) argument
  def multi_arg? ; false ; end
  ## note: Option-Types with both multi_arg? and flag? false are single-parameter (normal) options.

  def array_default? ; self.default.kind_of?(Array) ; end

  def short? ; short && short != :none ; end

  def callback ; opts(:callback) ; end
  def desc ; opts(:desc) ; end

  def required? ; opts(:required) ; end

  def parse(_paramlist, _neg_given)
    raise NotImplementedError, "parse must be overridden for newly registered type"
  end

  # provide type-format string.  default to empty, but user should probably override it
  def type_format ; "" ; end

  def educate
    (short? ? "-#{short}, " : "") + "--#{long}" + type_format + (flag? && default ? ", --no-#{long}" : "")
  end

  ## Format the educate-line description including the default-value(s)
  def description_with_default
    return desc unless default
    default_s = case default
                when $stdout   then '<stdout>'
                when $stdin    then '<stdin>'
                when $stderr   then '<stderr>'
                when Array
                  default.join(', ')
                else
                  default.to_s
                end
    defword = desc.end_with?('.') ? 'Default' : 'default'
    return "#{desc} (#{defword}: #{default_s})"
  end

  ## Provide a way to register symbol aliases to the Parser
  def self.register_alias(*alias_keys)
    alias_keys.each do |alias_key|
      # pass in the alias-key and the class
      Parser.register(alias_key, self)
    end
  end

  ## Factory class methods ...

  # Determines which type of object to create based on arguments passed
  # to +Optimist::opt+.  This is trickier in Optimist, than other cmdline
  # parsers (e.g. Slop) because we allow the +default:+ to be able to
  # set the option's type.
  def self.create(name, desc="", opts={}, settings={})

    opttype = Optimist::Parser.registry_getopttype(opts[:type])
    opttype_from_default = get_klass_from_default(opts, opttype)

    raise ArgumentError, ":type specification and default type don't match (default type is #{opttype_from_default.class})" if opttype && opttype_from_default && (opttype.class != opttype_from_default.class)

    opt_inst = (opttype || opttype_from_default || Optimist::BooleanOption.new)

    ## fill in :long
    opt_inst.long = handle_long_opt(opts[:long], name)

    ## fill in :short
    opt_inst.short = handle_short_opt(opts[:short])

    ## fill in :multi
    multi_given = opts[:multi] || false
    opt_inst.multi_given = multi_given

    ## fill in :default for flags
    defvalue = opts[:default] || opt_inst.default

    ## autobox :default for :multi (multi-occurrence) arguments
    defvalue = [defvalue] if defvalue && multi_given && !defvalue.kind_of?(Array)
    opt_inst.default = defvalue
    opt_inst.name = name
    opt_inst.opts = opts
    opt_inst
  end

  private

  def self.get_type_from_disdef(optdef, opttype, disambiguated_default)
    if disambiguated_default.is_a? Array
      return(optdef.first.class.name.downcase + "s") if !optdef.empty?
      if opttype
        raise ArgumentError, "multiple argument type must be plural" unless opttype.multi_arg?
        return nil
      else
        raise ArgumentError, "multiple argument type cannot be deduced from an empty array"
      end
    end
    return disambiguated_default.class.name.downcase
  end

  def self.get_klass_from_default(opts, opttype)
    ## for options with :multi => true, an array default doesn't imply
    ## a multi-valued argument. for that you have to specify a :type
    ## as well. (this is how we disambiguate an ambiguous situation;
    ## see the docs for Parser#opt for details.)

    disambiguated_default = if opts[:multi] && opts[:default].is_a?(Array) && opttype.nil?
                              opts[:default].first
                            else
                              opts[:default]
                            end

    return nil if disambiguated_default.nil?
    type_from_default = get_type_from_disdef(opts[:default], opttype, disambiguated_default)
    return Optimist::Parser.registry_getopttype(type_from_default)
  end

  def self.handle_long_opt(lopt, name)
    lopt = lopt ? lopt.to_s : name.to_s.gsub("_", "-")
    lopt = case lopt
           when /^--([^-].*)$/ then $1
           when /^[^-]/        then lopt
           else                     raise ArgumentError, "invalid long option name #{lopt.inspect}"
           end
  end

  def self.handle_short_opt(sopt)
    sopt = sopt.to_s if sopt && sopt != :none
    sopt = case sopt
           when /^-(.)$/          then $1
           when nil, :none, /^.$/ then sopt
           else                   raise ArgumentError, "invalid short option name '#{sopt.inspect}'"
           end

    if sopt
      raise ArgumentError, "a short option name can't be a number or a dash" if sopt =~ ::Optimist::Parser::INVALID_SHORT_ARG_REGEX
    end
    return sopt
  end

end

# Flag option.  Has no arguments. Can be negated with "no-".
class BooleanOption < Option
  register_alias :flag, :bool, :boolean, :trueclass, :falseclass
  def initialize
    super()
    @default = false
  end
  def flag? ; true ; end
  def parse(_paramlist, neg_given)
    return(self.name.to_s =~ /^no_/ ? neg_given : !neg_given)
  end
end

# Floating point number option class.
class FloatOption < Option
  register_alias :float, :double
  def type_format ; "=<f>" ; end
  def parse(paramlist, _neg_given)
    paramlist.map do |pg|
      pg.map do |param|
        raise CommandlineError, "option '#{self.name}' needs a floating-point number" unless param.is_a?(Numeric) || param =~ FLOAT_RE
        param.to_f
      end
    end
  end
end

# Integer number option class.
class IntegerOption < Option
  register_alias :int, :integer, :fixnum
  def type_format ; "=<i>" ; end
  def parse(paramlist, _neg_given)
    paramlist.map do |pg|
      pg.map do |param|
        raise CommandlineError, "option '#{self.name}' needs an integer" unless param.is_a?(Numeric) || param =~ /^-?[\d_]+$/
        param.to_i
      end
    end
  end
end

# Option class for handling IO objects and URLs.
# Note that this will return the file-handle, not the file-name
# in the case of file-paths given to it.
class IOOption < Option
  register_alias :io
  def type_format ; "=<filename/uri>" ; end
  def parse(paramlist, _neg_given)
    paramlist.map do |pg|
      pg.map do |param|
        if param =~ /^(stdin|-)$/i
          $stdin
        else
          require 'open-uri'
          begin
            open param
          rescue SystemCallError => e
            raise CommandlineError, "file or url for option '#{self.name}' cannot be opened: #{e.message}"
          end
        end
      end
    end
  end
end

# Option class for handling Strings.
class StringOption < Option
  register_alias :string
  def type_format ; "=<s>" ; end
  def parse(paramlist, _neg_given)
    paramlist.map { |pg| pg.map(&:to_s) }
  end
end

# Option for dates.  Uses Chronic if it exists.
class DateOption < Option
  register_alias :date
  def type_format ; "=<date>" ; end
  def parse(paramlist, _neg_given)
    paramlist.map do |pg|
      pg.map do |param|
        next param if param.is_a?(Date)
        begin
          begin
            require 'chronic'
            time = Chronic.parse(param)
          rescue LoadError
            # chronic is not available
          end
          time ? Date.new(time.year, time.month, time.day) : Date.parse(param)
        rescue ArgumentError
          raise CommandlineError, "option '#{self.name}' needs a date"
        end
      end
    end
  end
end

### MULTI_OPT_TYPES :
## The set of values that indicate a multiple-parameter option (i.e., that
## takes multiple space-separated values on the commandline) when passed as
## the +:type+ parameter of #opt.

# Option class for handling multiple Integers
class IntegerArrayOption < IntegerOption
  register_alias :fixnums, :ints, :integers
  def type_format ; "=<i+>" ; end
  def multi_arg? ; true ; end
end

# Option class for handling multiple Floats
class FloatArrayOption < FloatOption
  register_alias :doubles, :floats
  def type_format ; "=<f+>" ; end
  def multi_arg? ; true ; end
end

# Option class for handling multiple Strings
class StringArrayOption < StringOption
  register_alias :strings
  def type_format ; "=<s+>" ; end
  def multi_arg? ; true ; end
end

# Option class for handling multiple dates
class DateArrayOption < DateOption
  register_alias :dates
  def type_format ; "=<date+>" ; end
  def multi_arg? ; true ; end
end

# Option class for handling Files/URLs via 'open'
class IOArrayOption < IOOption
  register_alias :ios
  def type_format ; "=<filename/uri+>" ; end
  def multi_arg? ; true ; end
end

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

## If Optimist::options doesn't do quite what you want, you can create a Parser
## object and call Parser#parse on it. That method will throw CommandlineError,
## HelpNeeded and VersionNeeded exceptions when necessary; if you want to
## have these handled for you in the standard manner (e.g. show the help
## and then exit upon an HelpNeeded exception), call your code from within
## a block passed to this method.
##
## Note that this method will call System#exit after handling an exception!
##
## Usage example:
##
##   require 'optimist'
##   p = Optimist::Parser.new do
##     opt :monkey, "Use monkey mode"                     # a flag --monkey, defaulting to false
##     opt :goat, "Use goat mode", :default => true       # a flag --goat, defaulting to true
##   end
##
##   opts = Optimist::with_standard_exception_handling p do
##     o = p.parse ARGV
##     raise Optimist::HelpNeeded if ARGV.empty? # show help screen
##     o
##   end
##
## Requires passing in the parser object.

def with_standard_exception_handling(parser)
  yield
rescue CommandlineError => e
  parser.die(e.message, nil, e.error_code)
rescue HelpNeeded
  parser.educate
  exit
rescue VersionNeeded
  puts parser.version
  exit
end

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

## Displays the help message and dies. Example:
##
##   options do
##     opt :volume, :default => 0.0
##     banner <<-EOS
##   Usage:
##          #$0 [options] <name>
##   where [options] are:
##   EOS
##   end
##
##   Optimist::educate if ARGV.empty?
def educate
  if @last_parser
    @last_parser.educate
    exit
  else
    raise ArgumentError, "Optimist::educate can only be called after Optimist::options"
  end
end

module_function :options, :die, :educate, :with_standard_exception_handling
end # module