# enumerator.txt

Path: | enumerator/enumerator.txt
Last Update: | Sat Oct 18 00:09:43 AUS Eastern Standard Time 2003

.\" enumerator.txt - -*- Indented-Text -*- $Idaemons: /home/cvs/rb/enumerator/enumerator.txt,v 1.2 2001/07/15 10:19:24 knu Exp $ $RoughId: enumerator.txt,v 1.5 2003/02/20 12:24:51 knu Exp $ $Id: enumerator.txt,v 1.2 2003/10/17 14:09:43 knu Exp $

** Enumerable::Enumerator(Class)

A class which provides a method `each’ to be used as an Enumerable object.

Superclass: Object

Mix-ins: Enumerable

require ‘enumerator’

Class Methods:

        new(obj, method = :each, *args)

            Creates a new Enumerable::Enumerator object, which is to be
            used as an Enumerable object using the given object's given
            method with the given arguments.

            e.g.:
                str = "xyz"

                enum = Enumerable::Enumerator.new(str, :each_byte)
                a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]

Methods:

        each {...}

            Iterates the given block using the object and the method
            specified in the first place.

Requiring this module also adds some methods to the Object class:

        to_enum(method = :each, *args)
        enum_for(method = :each, *args)

            Returns Enumerable::Enumerator.new(self, method, *args).

            e.g.:
                str = "xyz"

                enum = str.enum_for(:each_byte)
                a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]

                # protects an array from being modified
                a = [1, 2, 3]
                some_method(a.to_enum)

And the Enumerable module.

        each_slice(n) {...}

            Iterates the given block for each slice of <n> elements.

            e.g.:
                (1..10).each_slice(3) {|a| p a}
                # outputs below
                [1, 2, 3]
                [4, 5, 6]
                [7, 8, 9]
                [10]

        enum_slice(n)

            Returns Enumerable::Enumerator.new(self, :each_slice, n).

        each_cons(n) {...}

            Iterates the given block for each array of consecutive <n>
            elements.

            e.g.:
                (1..10).each_cons(3) {|a| p a}
                # outputs below
                [1, 2, 3]
                [2, 3, 4]
                [3, 4, 5]
                [4, 5, 6]
                [5, 6, 7]
                [6, 7, 8]
                [7, 8, 9]
                [8, 9, 10]

        enum_cons(n)

            Returns Enumerable::Enumerator.new(self, :each_cons, n).

        enum_with_index

            Returns Enumerable::Enumerator.new(self, :each_with_index).

Local variables: fill-column: 70 end:

[Validate]