Method: Trollop::Parser#parse

Defined in:

lib/sfp/trollop.rb

#parse(cmdline = ARGV) ⇒ Object

Parses the commandline. Typically called by Trollop::options, but you can call it directly if you need more control.

throws CommandlineError, HelpNeeded, and VersionNeeded exceptions.

Raises:

• (VersionNeeded)

# File 'lib/sfp/trollop.rb', line 280

def parse cmdline=ARGV
  vals = {}
  required = {}

  opt :version, "Print version and exit" if @version unless @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 /^-([^-])$/; @short[$1]
      when /^--([^-]\S*)$/; @long[$1] || @long["no-#{$1}"]
      else; raise CommandlineError, "invalid argument syntax: '#{arg}'"
    end

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

    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.nil?
      if SINGLE_ARG_TYPES.include?(@specs[sym][:type])
        given_args[sym][:params] << params[0, 1]  # take the first parameter
        num_params_taken = 1
      elsif MULTI_ARG_TYPES.include?(@specs[sym][:type])
        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] }
    next unless constraint_sym

    case type
    when :depends
      syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} requires --#{@specs[sym][:long]}" unless given_args.include? sym }
    when :conflicts
      syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} conflicts with --#{@specs[sym][:long]}" if given_args.include?(sym) && (sym != constraint_sym) }
    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]
    raise CommandlineError, "option '#{arg}' needs a parameter" if params.empty? && opts[:type] != :flag

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

    case opts[:type]
    when :flag
      vals[sym] = (sym.to_s =~ /^no_/ ? negative_given : !negative_given)
    when :int, :ints
      vals[sym] = params.map { |pg| pg.map { |p| parse_integer_parameter p, arg } }
    when :float, :floats
      vals[sym] = params.map { |pg| pg.map { |p| parse_float_parameter p, arg } }
    when :string, :strings
      vals[sym] = params.map { |pg| pg.map { |p| p.to_s } }
    when :io, :ios
      vals[sym] = params.map { |pg| pg.map { |p| parse_io_parameter p, arg } }
    when :date, :dates
      vals[sym] = params.map { |pg| pg.map { |p| parse_date_parameter p, arg } }
    end

    if SINGLE_ARG_TYPES.include?(opts[:type])
      unless opts[:multi]       # single parameter
        vals[sym] = vals[sym][0][0]
      else                      # multiple options, each with a single parameter
        vals[sym] = vals[sym].map { |p| p[0] }
      end
    elsif MULTI_ARG_TYPES.include?(opts[:type]) && !opts[:multi]
      vals[sym] = vals[sym][0]  # single option, with multiple parameters
    end
    # else: multiple options, with multiple parameters
  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