Class: Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/micro-optparse/parser.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(default_settings = {}) {|_self| ... } ⇒ Parser

Returns a new instance of Parser.

Yields:

  • (_self)

Yield Parameters:

  • _self (Parser) —

    the object that the method was called on



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# File 'lib/micro-optparse/parser.rb', line 5

def initialize(default_settings = {})
  @options = []
  @used_short = []
  @default_values = {}
  @default_settings = default_settings
  yield self if block_given?
end

Instance Attribute Details

Returns the value of attribute banner.



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# File 'lib/micro-optparse/parser.rb', line 4

def banner
  @banner
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/micro-optparse/parser.rb', line 4

def version
  @version
end

Instance Method Details

#option(name, desc, settings = {}) ⇒ Object 



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# File 'lib/micro-optparse/parser.rb', line 13

def option(name, desc, settings = {})
  settings = @default_settings.clone.merge(settings)
  @options << {:name => name, :description => desc, :settings => settings}
end

#process!(arguments = ARGV) ⇒ Object 



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# File 'lib/micro-optparse/parser.rb', line 42

def process!(arguments = ARGV)
  @result = @default_values.clone # reset or new
  @optionparser ||= OptionParser.new do |p| # prepare only once
    @options.each do |o|
      @used_short << short = o[:settings][:no_short] ? nil : o[:settings][:short] || short_from(o[:name])
      @result[o[:name]] = o[:settings][:default] || false unless o[:settings][:optional] # set default
      name = o[:name].to_s.gsub("_", "-")
      klass = o[:settings][:default].is_a?(Integer) ? Integer : o[:settings][:default].class

      args = [o[:description]]
      args << "-" + short if short
      if [TrueClass, FalseClass, NilClass].include?(klass) # boolean switch
        args << "--[no-]" + name
      else # argument with parameter, add class for typecheck
        args << "--" + name + " " + o[:settings][:default].to_s << klass
      end
      p.on(*args) {|x| @result[o[:name]] = x}
    end

    p.banner = @banner unless @banner.nil?
    p.on_tail("-h", "--help", "Show this message") {puts p ; exit}
    short = @used_short.include?("v") ? "-V" : "-v"
    p.on_tail(short, "--version", "Print version") {puts @version ; exit} unless @version.nil?
  end
  @default_values = @result.clone # save default values to reset @result in subsequent calls

  begin
    @optionparser.parse!(arguments)
  rescue OptionParser::ParseError => e
    puts e.message ; exit(1)
  end

  validate(@result) if self.respond_to?("validate")
  @result
end

#short_from(name) ⇒ Object 



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# File 'lib/micro-optparse/parser.rb', line 18

def short_from(name)
  name.to_s.chars.each do |c|
    next if @used_short.include?(c) || c == "_"
    return c # returns from short_from method
  end
  return name.to_s.chars.first
end

#validate(result) ⇒ Object

remove this method if you want fewer lines of code and don't need validations



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# File 'lib/micro-optparse/parser.rb', line 26

def validate(result) # remove this method if you want fewer lines of code and don't need validations
  result.each_pair do |key, value|
    o = @options.find_all{ |option| option[:name] == key }.first
    key = "--" << key.to_s.gsub("_", "-")
    unless o[:settings][:value_in_set].nil? || o[:settings][:value_in_set].include?(value)
      puts "Parameter for #{key} must be in [" << o[:settings][:value_in_set].join(", ") << "]" ; exit(1)
    end
    unless o[:settings][:value_matches].nil? || o[:settings][:value_matches] =~ value
      puts "Parameter for #{key} must match /" << o[:settings][:value_matches].source << "/" ; exit(1)
    end
    unless o[:settings][:value_satisfies].nil? || o[:settings][:value_satisfies].call(value)
      puts "Parameter for #{key} must satisfy given conditions (see description)" ; exit(1)
    end
  end
end