Class: Trollop::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/convoy/trollop.rb

Overview

The commandline parser. In typical usage, the methods in this class will be handled internally by Trollop::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 Trollop::with_standard_exception_handling.

Constant Summary collapse

FLAG_TYPES =

The set of values that indicate a flag option when passed as the :type parameter of #opt.

[:flag, :bool, :boolean]
SINGLE_ARG_TYPES =

The set of values that indicate a single-parameter (normal) option when passed as the :type parameter of #opt.

A value of io corresponds to a readable IO resource, including a filename, URI, or the strings 'stdin' or '-'.

[:int, :integer, :string, :double, :float, :io, :date]
MULTI_ARG_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.

[:ints, :integers, :strings, :doubles, :floats, :ios, :dates]
TYPES =

The complete set of legal values for the :type parameter of #opt.

FLAG_TYPES + SINGLE_ARG_TYPES + MULTI_ARG_TYPES
INVALID_SHORT_ARG_REGEX =

:nodoc:

/[-]/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*a, &b) ⇒ Parser

Initializes the parser, and instance-evaluates any block given.


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# File 'lib/convoy/trollop.rb', line 75

def initialize *a, &b
    @version         = nil
    @leftovers       = []
    @specs           = {}
    @long            = {}
    @short           = {}
    @order           = []
    @constraints     = []
    @stop_words      = []
    @stop_on_unknown = false
    @help_formatter  = nil

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

Instance Attribute Details

#leftoversObject (readonly)

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


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# File 'lib/convoy/trollop.rb', line 66

def leftovers
  @leftovers
end

#orderObject (readonly)

Returns the value of attribute order


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# File 'lib/convoy/trollop.rb', line 72

def order
  @order
end

#specsObject (readonly)

The complete configuration hashes for each option. (Mainly useful for testing.)


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# File 'lib/convoy/trollop.rb', line 70

def specs
  @specs
end

Instance Method Details

Adds text to the help display. Can be interspersed with calls to #opt to build a multi-section help page.


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# File 'lib/convoy/trollop.rb', line 276

def banner s;
    @order << [:text, s]
end

#conflicts(*syms) ⇒ Object

Marks two (or more!) options as conflicting.


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# File 'lib/convoy/trollop.rb', line 299

def conflicts *syms
    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
    @constraints << [:conflicts, syms]
end

#current_help_formatterObject


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# File 'lib/convoy/trollop.rb', line 286

def current_help_formatter
    @help_formatter
end

#depends(*syms) ⇒ Object

Marks two (or more!) options as requiring each other. Only handles undirected (i.e., mutual) dependencies. Directed dependencies are better modeled with Trollop::die.


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# File 'lib/convoy/trollop.rb', line 293

def depends *syms
    syms.each { |sym| raise ArgumentError, "unknown option '#{sym}'" unless @specs[sym] }
    @constraints << [:depends, syms]
end

#die(arg, msg) ⇒ Object

The per-parser version of Trollop::die (see that for documentation).


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# File 'lib/convoy/trollop.rb', line 597

def die arg, msg
    if msg
        $stderr.puts "Error: argument --#{@specs[arg][:long]} #{msg}."
    else
        $stderr.puts "Error: #{arg}."
    end
    $stderr.puts "Try --help for help."
    exit(1)
end

#educate(stream = $stdout) ⇒ Object

Print the help message to stream.


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# File 'lib/convoy/trollop.rb', line 494

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 do |name, spec|
        left[name] = "--#{spec[:long]}" +
            (spec[:type] == :flag && spec[:default] ? ", --no-#{spec[:long]}" : "") +
            (spec[:short] && spec[:short] != :none ? ", -#{spec[:short]}" : "") +
            case spec[:type]
                when :flag;
                    ""
                when :int;
                    " <i>"
                when :ints;
                    " <i+>"
                when :string;
                    " <s>"
                when :strings;
                    " <s+>"
                when :float;
                    " <f>"
                when :floats;
                    " <f+>"
                when :io;
                    " <filename/uri>"
                when :ios;
                    " <filename/uri+>"
                when :date;
                    " <date>"
                when :dates;
                    " <date+>"
            end
    end

    leftcol_width  = left.values.map { |s| s.length }.max || 0
    rightcol_start = leftcol_width + 6 # spaces

    unless @order.size > 0 && @order.first.first == :text
        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[:desc] + begin
            default_s = case spec[:default]
                            when $stdout;
                                "<stdout>"
                            when $stdin;
                                "<stdin>"
                            when $stderr;
                                "<stderr>"
                            when Array
                                spec[:default].join(", ")
                            else
                                spec[:default].to_s
                        end

            if spec[:default]
                if spec[:desc] =~ /\.$/
                    " (Default: #{default_s})"
                else
                    " (default: #{default_s})"
                end
            else
                ""
            end
        end
        stream.puts wrap(desc, :width => width - rightcol_start - 1, :prefix => rightcol_start)
    end
end

#help_formatter(formatter) ⇒ Object


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# File 'lib/convoy/trollop.rb', line 282

def help_formatter(formatter)
    @help_formatter = formatter
end

#opt(name, desc = "", opts = {}) ⇒ Object

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.

: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 Trollop::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, Trollop 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.

Raises:

  • (ArgumentError)

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# File 'lib/convoy/trollop.rb', line 131

def opt name, desc="", opts={}
    raise ArgumentError, "you already have an argument named '#{name}'" if @specs.member? name

    ## fill in :type
    opts[:type] = # normalize
        case opts[:type]
            when :boolean, :bool;
                :flag
            when :integer;
                :int
            when :integers;
                :ints
            when :double;
                :float
            when :doubles;
                :floats
            when Class
                case opts[:type].name
                    when 'TrueClass', 'FalseClass';
                        :flag
                    when 'String';
                        :string
                    when 'Integer';
                        :int
                    when 'Float';
                        :float
                    when 'IO';
                        :io
                    when 'Date';
                        :date
                    else
                        raise ArgumentError, "unsupported argument type '#{opts[:type].class.name}'"
                end
            when nil;
                nil
            else
                raise ArgumentError, "unsupported argument type '#{opts[:type]}'" unless TYPES.include?(opts[:type])
                opts[:type]
        end

    ## 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) && !opts[:type]
                                opts[:default].first
                            else
                                opts[:default]
                            end

    type_from_default =
        case disambiguated_default
            when Integer;
                :int
            when Numeric;
                :float
            when TrueClass, FalseClass;
                :flag
            when String;
                :string
            when IO;
                :io
            when Date;
                :date
            when Array
                if opts[:default].empty?
                    raise ArgumentError, "multiple argument type cannot be deduced from an empty array for '#{opts[:default][0].class.name}'"
                end
                case opts[:default][0] # the first element determines the types
                    when Integer;
                        :ints
                    when Numeric;
                        :floats
                    when String;
                        :strings
                    when IO;
                        :ios
                    when Date;
                        :dates
                    else
                        raise ArgumentError, "unsupported multiple argument type '#{opts[:default][0].class.name}'"
                end
            when nil;
                nil
            else
                raise ArgumentError, "unsupported argument type '#{opts[:default].class.name}'"
        end

    raise ArgumentError, ":type specification and default type don't match (default type is #{type_from_default})" if opts[:type] && type_from_default && opts[:type] != type_from_default

    opts[:type] = opts[:type] || type_from_default || :flag

    ## fill in :long
    opts[:long] = opts[:long] ? opts[:long].to_s : name.to_s.gsub("_", "-")
    opts[:long] = case opts[:long]
                      when /^--([^-].*)$/;
                          $1
                      when /^[^-]/;
                          opts[:long]
                      else
                          ; raise ArgumentError, "invalid long option name #{opts[:long].inspect}"
                  end
    raise ArgumentError, "long option name #{opts[:long].inspect} is already taken; please specify a (different) :long" if @long[opts[:long]]

    ## fill in :short
    opts[:short] = opts[:short].to_s if opts[:short] unless opts[:short] == :none
    opts[:short] = case opts[:short]
                       when /^-(.)$/;
                           $1
                       when nil, :none, /^.$/;
                           opts[:short]
                       else
                           raise ArgumentError, "invalid short option name '#{opts[:short].inspect}'"
                   end

    if opts[:short]
        raise ArgumentError, "short option name #{opts[:short].inspect} is already taken; please specify a (different) :short" if @short[opts[:short]]
        raise ArgumentError, "a short option name can't be a number or a dash" if opts[:short] =~ INVALID_SHORT_ARG_REGEX
    end

    ## fill in :default for flags
    opts[:default] = false if opts[:type] == :flag && opts[:default].nil?

    ## autobox :default for :multi (multi-occurrence) arguments
    opts[:default] = [opts[:default]] if opts[:default] && opts[:multi] && !opts[:default].is_a?(Array)

    ## fill in :multi
    opts[:multi] ||= false

    opts[:desc]          ||= desc
    @long[opts[:long]]   = name
    @short[opts[:short]] = name if opts[:short] && opts[:short] != :none
    @specs[name]         = opts
    @order << [:opt, name]
end

#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:


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# File 'lib/convoy/trollop.rb', line 329

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

    opt :version, 'Prints version and exits' if @version unless @specs[:version] || @long['version']
    opt :help, "\x1B[38;5;222mShows help message for current command\x1B[0m" 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}'"
                      puts "\n    \x1B[48;5;196m Error \x1B[0m \xe2\x86\x92 Invalid argument syntax: #{arg}\n\n"
                      exit
              end

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

        # raise CommandlineError, "unknown argument '#{arg}'" unless sym
        unless sym
            puts "\n    \x1B[48;5;196m Error \x1B[0m \xe2\x86\x92 Unknown flag: #{arg}\n\n"
            exit
        end

        if given_args.include?(sym) && !@specs[sym][:multi]
            # raise CommandlineError, "option '#{arg}' specified multiple times"
            puts "\n    \x1B[48;5;196m Error \x1B[0m \xe2\x86\x92 Flag specified multiple times: #{arg}\n\n"
            exit
        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|
                    Blufin::Terminal::error('Missing constraint', "--#{@specs[constraint_sym][:long]} requires --#{@specs[sym][:long]}") unless given_args.include? sym
                }
            when :conflicts
                syms.each { |sym|
                    Blufin::Terminal::error('Conflicting constraint', "--#{@specs[constraint_sym][:long]} conflicts with --#{@specs[sym][:long]}") if given_args.include?(sym) && (sym != constraint_sym)
                }
        end
    end

    required.each do |sym, val|
        unless given_args.include? sym
            Blufin::Terminal::error('Missing option', "option --#{@specs[sym][:long]} must be specified")
        end
    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[:type] != :flag
            Blufin::Terminal::error('Missing parameter', "option '#{arg}' needs a parameter")
        end

        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

#parse_date_parameter(param, arg) ⇒ Object

:nodoc:


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# File 'lib/convoy/trollop.rb', line 480

def parse_date_parameter param, arg #:nodoc:
    begin
        begin
            time = Chronic.parse(param)
        rescue NameError
            # chronic is not available
        end
        time ? Date.new(time.year, time.month, time.day) : Date.parse(param)
    rescue ArgumentError
        raise CommandlineError, "option '#{arg}' needs a date"
    end
end

#stop_on(*words) ⇒ Object

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 Trollop invocation would then be used to parse subcommand options, after shifting the subcommand off of ARGV.


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# File 'lib/convoy/trollop.rb', line 313

def stop_on *words
    @stop_words = [*words].flatten
end

#stop_on_unknownObject

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.


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# File 'lib/convoy/trollop.rb', line 321

def stop_on_unknown
    @stop_on_unknown = true
end

#version(s = nil) ⇒ Object

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>”.


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# File 'lib/convoy/trollop.rb', line 270

def version s=nil;
    @version = s if s; @version
end

#widthObject

:nodoc:


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# File 'lib/convoy/trollop.rb', line 572

def width #:nodoc:
    @width ||= if $stdout.tty?
                   begin
                       require 'curses'
                       Curses::init_screen
                       x = Curses::cols
                       Curses::close_screen
                       x
                   rescue Exception
                       80
                   end
               else
                   80
               end
end

#wrap(str, opts = {}) ⇒ Object

:nodoc:


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# File 'lib/convoy/trollop.rb', line 588

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