Class: ShellOpts::Args

Inherits:
Array
  • Object
show all
Defined in:
lib/shellopts/args.rb

Overview

Specialization of Array for arguments lists. Args extends Array with a #extract and an #expect method to extract elements from the array. The methods raise a ShellOpts::Error exception in case of errors

Instance Method Summary collapse

Constructor Details

#initialize(*args, exception: false) ⇒ Args

Returns a new instance of Args.



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# File 'lib/shellopts/args.rb', line 8

def initialize(*args, exception: false)
  super(*args)
  @exception = exception
end

Instance Method Details

#expect(count_or_range, message = nil) ⇒ Object

As #extract except the array is expected to be emptied by the operation. Raise a #inoa exception if count is negative

#expect raise a ShellOpts::Error exception if the array is not emptied by the operation

TODO: Better handling of ranges. Allow: 2..-1, -2..-4, etc.



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# File 'lib/shellopts/args.rb', line 58

def expect(count_or_range, message = nil)
  case count_or_range
    when Range
      count_or_range === self.size or inoa(message)
      return self.to_a if count_or_range.end.nil?
    when Integer
      count_or_range >= 0 or inoa(message)
      count_or_range.abs == self.size or inoa(message)
  end
  extract(count_or_range) # Can't fail
end

#extract(count_or_range, message = nil) ⇒ Object

:call-seq:

extract(count, message = nil)
extract(range, message = nil)

Remove and return elements from beginning of the array

If count_or_range is a number, that number of elements will be returned. If the count is one, a simple value is returned instead of an array. If the count is negative, the elements will be removed from the end of the array. If count_or_range is a range, the number of elements returned will be in that range. Note that the range can’t contain negative numbers

#extract raise a ShellOpts::Error exception if there’s is not enough elements in the array to satisfy the request

TODO: Better handling of ranges. Allow: 2..-1, -2..-4, etc.



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# File 'lib/shellopts/args.rb', line 30

def extract(count_or_range, message = nil)
  case count_or_range
    when Range
      range = count_or_range
      range.min <= self.size or inoa(message)
      return self.to_a if range.end.nil?
      n_extract = [self.size, range.max].min
      n_extend = range.max > self.size ? range.max - self.size : 0
      r = self.shift(n_extract) + Array.new(n_extend)
      range.max <= 1 ? r.first : r
    when Integer
      count = count_or_range
      count.abs <= self.size or inoa(message)
      start = count >= 0 ? 0 : size + count
      r = slice!(start, count.abs)
      r.size == 1 ? r.first : r
    else
      raise ArgumentError
  end
end