Class: Optimist::Parser

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

Overview

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.

Constant Summary collapse

INVALID_SHORT_ARG_REGEX =

:nodoc:

/[\d-]/

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*a, &b) ⇒ Parser

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



86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
 
# File 'lib/optimist.rb', line 86

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

Instance Attribute Details

#ignore_invalid_options ⇒ Object

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.



83
84
85
 
# File 'lib/optimist.rb', line 83

def ignore_invalid_options
  @ignore_invalid_options
end

#leftovers ⇒ Object (readonly)

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



74
75
76
 
# File 'lib/optimist.rb', line 74

def leftovers
  @leftovers
end

#specs ⇒ Object (readonly)

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



78
79
80
 
# File 'lib/optimist.rb', line 78

def specs
  @specs
end

Class Method Details

.register(lookup, klass) ⇒ Object

The Option subclasses are responsible for registering themselves using this function.



53
54
55
 
# File 'lib/optimist.rb', line 53

def self.register(lookup, klass)
  @registry[lookup.to_sym] = klass
end

.registry_getopttype(type) ⇒ Object

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

Raises:

  • (ArgumentError) 


59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/optimist.rb', line 59

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

Instance Method Details

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



181
182
183
 
# File 'lib/optimist.rb', line 181

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

#conflicts(*syms) ⇒ Object

Marks two (or more!) options as conflicting.



195
196
197
198
 
# File 'lib/optimist.rb', line 195

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



189
190
191
192
 
# File 'lib/optimist.rb', line 189

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

#die(arg, msg = nil, error_code = nil) ⇒ Object

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



435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
 
# File 'lib/optimist.rb', line 435

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

#educate(stream = $stdout) ⇒ Object

Print the help message to stream.



366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
 
# File 'lib/optimist.rb', line 366

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

#educate_on_error ⇒ Object

Instead of displaying “Try –help for help.” on an error display the usage (via educate)



230
231
232
 
# File 'lib/optimist.rb', line 230

def educate_on_error
  @educate_on_error = true
end

#either(*syms) ⇒ Object

Marks two (or more!) options as required but mutually exclusive.



201
202
203
204
205
 
# File 'lib/optimist.rb', line 201

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

#opt(name, desc = "", opts = {}, &b) ⇒ 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. 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.

Raises:

  • (ArgumentError) 


144
145
146
147
148
149
150
151
152
153
154
155
156
157
 
# File 'lib/optimist.rb', line 144

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

#parse(cmdline = ARGV) ⇒ Object

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.

Raises:



238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
 
# File 'lib/optimist.rb', line 238

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

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



216
217
218
 
# File 'lib/optimist.rb', line 216

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

#stop_on_unknown ⇒ Object

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.



224
225
226
 
# File 'lib/optimist.rb', line 224

def stop_on_unknown
  @stop_on_unknown = true
end

#synopsis(s = nil) ⇒ Object

Adds a synopsis (command summary description) right below the usage line, or as the first line if usage isn’t specified.



175
176
177
 
# File 'lib/optimist.rb', line 175

def synopsis(s = nil)
  s ? @synopsis = s : @synopsis
end

#usage(s = nil) ⇒ Object

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.



169
170
171
 
# File 'lib/optimist.rb', line 169

def usage(s = nil)
  s ? @usage = s : @usage
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>”.



162
163
164
 
# File 'lib/optimist.rb', line 162

def version(s = nil)
  s ? @version = s : @version
end

#width ⇒ Object

:nodoc:



399
400
401
402
403
404
405
406
407
408
409
410
411
 
# File 'lib/optimist.rb', line 399

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

#wrap(str, opts = {}) ⇒ Object

:nodoc:



421
422
423
424
425
426
427
428
429
430
431
432
 
# File 'lib/optimist.rb', line 421

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