Methods used internally by the backports.
Used internally to make it easy to deal with optional arguments (from Rubinius)
Used internally. Safe ::alias_method that will only alias if the source exists and destination doesn't
# File lib/backports/tools.rb, line 246 def self.alias_method(mod, new_name, old_name) mod.class_eval do alias_method new_name, old_name if method_defined?(old_name) and not method_defined?(new_name) end end
Modified to avoid polluting Module if so desired (from Rails)
# File lib/backports/tools.rb, line 170 def self.alias_method_chain(mod, target, feature) mod.class_eval do # Strip out punctuation on predicates or bang methods since # e.g. target?_without_feature is not a valid method name. aliased_target, punctuation = target.to_s.sub(%r([?!=])$/, ''), $1 yield(aliased_target, punctuation) if block_given? with_method, without_method = "#{aliased_target}_with_#{feature}#{punctuation}", "#{aliased_target}_without_#{feature}#{punctuation}" alias_method without_method, target alias_method target, with_method case when public_method_defined?(without_method) public target when protected_method_defined?(without_method) protected target when private_method_defined?(without_method) private target end end end
Helper method to coerce a value into a specific class. Raises a TypeError if the coercion fails or the returned value is not of the right class. (from Rubinius)
# File lib/backports/tools.rb, line 197 def self.coerce_to(obj, cls, meth) return obj if obj.kind_of?(cls) begin ret = obj.__send__(meth) rescue Exception => e raise TypeError, "Coercion error: #{obj.inspect}.#{meth} => #{cls} failed:\n" "(#{e.message})" end raise TypeError, "Coercion error: obj.#{meth} did NOT return a #{cls} (was #{ret.class})" unless ret.kind_of? cls ret end
# File lib/backports/tools.rb, line 214 def self.coerce_to_ary(obj) coerce_to(obj, Array, :to_ary) end
Checks for a failed comparison (in which case it throws an ArgumentError) Additionally, it maps any negative value to -1 and any positive value to +1 (from Rubinius)
# File lib/backports/tools.rb, line 233 def self.coerce_to_comparison(a, b, cmp = (a <=> b)) raise ArgumentError, "comparison of #{a} with #{b} failed" if cmp.nil? return 1 if cmp > 0 return -1 if cmp < 0 0 end
# File lib/backports/tools.rb, line 210 def self.coerce_to_int(obj) coerce_to(obj, Integer, :to_int) end
# File lib/backports/tools.rb, line 218 def self.coerce_to_str(obj) coerce_to(obj, String, :to_str) end
Used internally to combine {IO|File} options hash into mode (String or Integer)
# File lib/backports/tools.rb, line 261 def self.combine_mode_and_option(mode = nil, options = Backports::Undefined) # Can't backport autoclose, {internal|external|}encoding mode, options = nil, mode if mode.is_a?(Hash) and options == Backports::Undefined options = {} if options == Backports::Undefined if mode && options[:mode] raise ArgumentError, "mode specified twice" end mode ||= options[:mode] || "r" if options[:textmode] || options[:binmode] text = options[:textmode] || (mode.is_a?(String) && mode =~ %rt/) bin = options[:binmode] || (mode.is_a?(String) ? mode =~ %rb/ : mode & File::Constants::BINARY != 0) if text && bin raise ArgumentError, "both textmode and binmode specified" end case when !options[:binmode] when mode.is_a?(String) mode.insert(1, "b") else mode |= File::Constants::BINARY end end mode end
Used internally to combine {IO|File} options hash into mode (String or Integer) and perm
# File lib/backports/tools.rb, line 287 def self.combine_mode_perm_and_option(mode = nil, perm = Backports::Undefined, options = Backports::Undefined) mode, options = nil, mode if mode.is_a?(Hash) and perm == Backports::Undefined perm, options = nil, perm if perm.is_a?(Hash) and options == Backports::Undefined perm = nil if perm == Backports::Undefined options = {} if options == Backports::Undefined if perm && options[:perm] raise ArgumentError, "perm specified twice" end [combine_mode_and_option(mode, options), perm || options[:perm]] end
Metaprogramming utility to convert all file arguments to paths
# File lib/backports/tools.rb, line 146 def self.convert_all_arguments_to_path(mod, skip, *methods) methods.each do |selector| unless mod.method_defined? selector warn "#{mod}##{selector} is not defined, so arguments can't converted to path" next end first_args = (1..skip).map{|i| "arg_#{i}"}.join(",") + (skip > 0 ? "," : "") alias_method_chain(mod, selector, :potential_path_arguments) do |aliased_target, punctuation| mod.module_eval " def #{aliased_target}_with_potential_path_arguments#{punctuation}(#{first_args}*files, &block) files = files.map{|f| Backports.convert_to_path f} #{aliased_target}_without_potential_path_arguments#{punctuation}(#{first_args}*files, &block) end " end end end
Metaprogramming utility to convert the first file argument to path
# File lib/backports/tools.rb, line 120 def self.convert_first_argument_to_path(mod, *methods) methods.each do |selector| unless mod.method_defined? selector warn "#{mod}##{selector} is not defined, so argument can't converted to path" next end arity = mod.instance_method(selector).arity last_arg = [] if arity < 0 last_arg = ["*rest"] arity = -1-arity end arg_sequence = (["file"] + (1...arity).map{|i| "arg_#{i}"} + last_arg + ["&block"]).join(", ") alias_method_chain(mod, selector, :potential_path_argument) do |aliased_target, punctuation| mod.module_eval " def #{aliased_target}_with_potential_path_argument#{punctuation}(#{arg_sequence}) file = Backports.convert_to_path(file) #{aliased_target}_without_potential_path_argument#{punctuation}(#{arg_sequence}) end " end end end
# File lib/backports/tools.rb, line 164 def self.convert_to_path(file_or_path) file_or_path.respond_to?(:to_path) ? file_or_path.to_path : file_or_path end
Metaprogramming utility to make block optional. Tests first if block is already optional when given options
# File lib/backports/tools.rb, line 83 def self.make_block_optional(mod, *methods) options = methods.last.is_a?(Hash) ? methods.pop : {} methods.each do |selector| unless mod.method_defined? selector warn "#{mod}##{selector} is not defined, so block can't be made optional" next end unless options[:force] # Check if needed test_on = options.fetch(:test_on) result = begin test_on.send(selector, *options.fetch(:arg, [])) rescue LocalJumpError false end next if result.class.name =~ %rEnumerator$/ end arity = mod.instance_method(selector).arity last_arg = [] if arity < 0 last_arg = ["*rest"] arity = -1-arity end arg_sequence = ((0...arity).map{|i| "arg_#{i}"} + last_arg + ["&block"]).join(", ") alias_method_chain(mod, selector, :optional_block) do |aliased_target, punctuation| mod.module_eval " def #{aliased_target}_with_optional_block#{punctuation}(#{arg_sequence}) return to_enum(:#{aliased_target}_without_optional_block#{punctuation}, #{arg_sequence}) unless block_given? #{aliased_target}_without_optional_block#{punctuation}(#{arg_sequence}) end " end end end
Adapted from Pragmatic's "Programming Ruby" (since their version was buggy...)
# File lib/backports/tools.rb, line 4 def self.require_relative(relative_feature) file = caller.first.split(%r:\d/,2).first if %r\A\((.*)\)/ =~ file # eval, etc. raise LoadError, "require_relative is called in #{$1}" end require File.expand_path(relative_feature, File.dirname(file)) end
# File lib/backports/tools.rb, line 12 def self.require_relative_dir(relative_dir) dir = File.expand_path(relative_dir, File.dirname(caller.first.split(%r:\d/,2).first)) Dir.entries(dir). map{|f| Regexp.last_match(1) if %r^(.*)\.rb$/ =~ f}. compact. sort. each do |f| require File.expand_path(f, dir) end end
Used internally to propagate lambda?
# File lib/backports/tools.rb, line 253 def self.track_lambda(from, to, default = false) is_lambda = from.instance_variable_get :@is_lambda is_lambda = default if is_lambda.nil? to.instance_variable_set :@is_lambda, is_lambda to end
# File lib/backports/tools.rb, line 222 def self.try_convert(obj, cls, meth) return obj if obj.kind_of?(cls) return nil unless obj.respond_to?(meth) ret = obj.__send__(meth) raise TypeError, "Coercion error: obj.#{meth} did NOT return a #{cls} (was #{ret.class})" unless ret.nil? || ret.kind_of?(cls) ret end
# File lib/backports/tools.rb, line 298 def self.write(binary, filename, string, offset, options) offset, options = nil, offset if Hash === offset and options == Backports::Undefined options = {} if options == Backports::Undefined options = {:mode => offset.nil? ? "w" : "r+"}.merge(options) args = options[:open_args] || [options] File.open(filename, *args) do |f| f.binmode if binary && f.respond_to?(:binmode) f.seek(offset) unless offset.nil? f.write(string) end end