method

make_switch

v2_6_3 - Show latest stable - 0 notes - Class: OptionParser

make_switch(opts, block = nil) public

Creates an OptionParser::Switch from the parameters. The parsed argument value is passed to the given block, where it can be processed.

See at the beginning of OptionParser for some full examples.

opts can include the following elements:

Argument style:

One of the following:

:NONE, :REQUIRED, :OPTIONAL

Argument pattern:

Acceptable option argument format, must be pre-defined with OptionParser.accept or OptionParser#accept, or Regexp. This can appear once or assigned as String if not present, otherwise causes an ArgumentError. Examples:

Float, Time, Array

Possible argument values:

Hash or Array.

[:text, :binary, :auto]
%w[iso-2022-jp shift_jis euc-jp utf8 binary]
{ "jis" => "iso-2022-jp", "sjis" => "shift_jis" }

Long style switch:

Specifies a long style switch which takes a mandatory, optional or no argument. It’s a string of the following form:

"--switch=MANDATORY" or "--switch MANDATORY"
"--switch[=OPTIONAL]"
"--switch"

Short style switch:

Specifies short style switch which takes a mandatory, optional or no argument. It’s a string of the following form:

"-xMANDATORY"
"-x[OPTIONAL]"
"-x"

There is also a special form which matches character range (not full set of regular expression):

"-[a-z]MANDATORY"
"-[a-z][OPTIONAL]"
"-[a-z]"

Argument style and description:

Instead of specifying mandatory or optional arguments directly in the switch parameter, this separate parameter can be used.

"=MANDATORY"
"=[OPTIONAL]"

Description:

Description string for the option.

"Run verbosely"

If you give multiple description strings, each string will be printed line by line.

Handler:

Handler for the parsed argument value. Either give a block or pass a Proc or Method as an argument.

Show source

# File lib/optparse.rb, line 1362
  def make_switch(opts, block = nil)
    short, long, nolong, style, pattern, conv, not_pattern, not_conv, not_style = [], [], []
    ldesc, sdesc, desc, arg = [], [], []
    default_style = Switch::NoArgument
    default_pattern = nil
    klass = nil
    q, a = nil
    has_arg = false

    opts.each do |o|
      # argument class
      next if search(:atype, o) do |pat, c|
        klass = notwice(o, klass, 'type')
        if not_style and not_style != Switch::NoArgument
          not_pattern, not_conv = pat, c
        else
          default_pattern, conv = pat, c
        end
      end

      # directly specified pattern(any object possible to match)
      if (!(String === o || Symbol === o)) and o.respond_to?(:match)
        pattern = notwice(o, pattern, 'pattern')
        if pattern.respond_to?(:convert)
          conv = pattern.method(:convert).to_proc
        else
          conv = SPLAT_PROC
        end
        next
      end

      # anything others
      case o
      when Proc, Method
        block = notwice(o, block, 'block')
      when Array, Hash
        case pattern
        when CompletingHash
        when nil
          pattern = CompletingHash.new
          conv = pattern.method(:convert).to_proc if pattern.respond_to?(:convert)
        else
          raise ArgumentError, "argument pattern given twice"
        end
        o.each {|pat, *v| pattern[pat] = v.fetch(0) {pat}}
      when Module
        raise ArgumentError, "unsupported argument type: #{o}", ParseError.filter_backtrace(caller(4))
      when *ArgumentStyle.keys
        style = notwice(ArgumentStyle[o], style, 'style')
      when /^--no-([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        o = notwice(a ? Object : TrueClass, klass, 'type')
        not_pattern, not_conv = search(:atype, o) unless not_style
        not_style = (not_style || default_style).guess(arg = a) if a
        default_style = Switch::NoArgument
        default_pattern, conv = search(:atype, FalseClass) unless default_pattern
        ldesc << "--no-#{q}"
        (q = q.downcase).tr!('_', '-')
        long << "no-#{q}"
        nolong << q
      when /^--\[no-\]([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        o = notwice(a ? Object : TrueClass, klass, 'type')
        if a
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        ldesc << "--[no-]#{q}"
        (o = q.downcase).tr!('_', '-')
        long << o
        not_pattern, not_conv = search(:atype, FalseClass) unless not_style
        not_style = Switch::NoArgument
        nolong << "no-#{o}"
      when /^--([^\[\]=\s]*)(.+)?/
        q, a = $1, $2
        if a
          o = notwice(NilClass, klass, 'type')
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        ldesc << "--#{q}"
        (o = q.downcase).tr!('_', '-')
        long << o
      when /^-(\[\^?\]?(?:[^\\\]]|\\.)*\])(.+)?/
        q, a = $1, $2
        o = notwice(Object, klass, 'type')
        if a
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        else
          has_arg = true
        end
        sdesc << "-#{q}"
        short << Regexp.new(q)
      when /^-(.)(.+)?/
        q, a = $1, $2
        if a
          o = notwice(NilClass, klass, 'type')
          default_style = default_style.guess(arg = a)
          default_pattern, conv = search(:atype, o) unless default_pattern
        end
        sdesc << "-#{q}"
        short << q
      when /^=/
        style = notwice(default_style.guess(arg = o), style, 'style')
        default_pattern, conv = search(:atype, Object) unless default_pattern
      else
        desc.push(o)
      end
    end

    default_pattern, conv = search(:atype, default_style.pattern) unless default_pattern
    if !(short.empty? and long.empty?)
      if has_arg and default_style == Switch::NoArgument
        default_style = Switch::RequiredArgument
      end
      s = (style || default_style).new(pattern || default_pattern,
                                       conv, sdesc, ldesc, arg, desc, block)
    elsif !block
      if style or pattern
        raise ArgumentError, "no switch given", ParseError.filter_backtrace(caller)
      end
      s = desc
    else
      short << pattern
      s = (style || default_style).new(pattern,
                                       conv, nil, nil, arg, desc, block)
    end
    return s, short, long,
      (not_style.new(not_pattern, not_conv, sdesc, ldesc, nil, desc, block) if not_style),
      nolong
  end

make_switch

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