1Date::Manip::InterfacesU(s3e)r Contributed Perl DocumentaDtaitoen::Manip::Interfaces(3)
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6 Date::Manip::Interfaces - A description of functional and OO interfaces
7
9 There are three different ways to use Date::Manip . A complete
10 description of each is included below. They are:
11 Functional interface (version 5)
13 Date::Manip version 5 runs on very old versions of perl. If you
14 need to use Date::Manip with a version of perl older than 5.10,
15 this is the only interface available.
16 Functional interface (version 6)
18 When Date::Manip was rewritten (version 6), it made use of some
19 features of perl 5.10 . This is the recommended interface if you
20 are supporting a script that uses the functional interface, but
21 where a newer version of perl is available.
22 Object-oriented interface
24 The OO interface is the recommended interface wherever possible.
25 It is the only one with access to the full functionality of the
26 module.
27
29 Date::Manip version 5.xx was available for many years, but suffered
30 from several weaknesses. It was slow, and did not handle timezones or
31 daylight saving time correctly. It was written as a functional
32 interface, even though an object-oriented interface would have been
33 better. It did have the advantage of running on very old versions of
34 perl (it is known to work on perl 5.6 and may work on even older
35 versions of perl).
36 Date::Manip version 6.00 was a complete rewrite of the module. For
38 detailed information about the differences, please refer to the
39 Date::Manip::Changes5to6 document. The rewrite was needed in order to
40 handle timezone operations, in addition to many other improvements
41 including much better performance and more robust parsing.
42 The rewrite made use of features introduced in perl 5.10 which made the
44 date parsing routines significantly cleaner. In addition, the 6.xx
45 release was written as an object oriented set of modules which are much
46 more powerful than the older functional interface. For backward
47 compatibility, a new functional interface was rewritten (which is
48 simply a set of wrapper functions which call the OO methods) which is
49 almost entirely backward compatible with the version 5.xx interface.
50 The Date::Manip distribution includes all three of these interfaces:
52 the older version 5 interface, and both the new OO interface and the
53 backward compatible functional interface. Also, all three are
54 installed, so you can use whichever interface is appropriate.
55 Since there are three different interfaces available, choosing the
57 interface is the necessary.
58 If you are running on a system with a very old version of perl (older
60 than 5.10), the version 5 interface is your only option.
61 If you are on a system running a newer version of perl, but need to
63 support a script that was written using the functional interface, then
64 you can use the version 6 functional interface.
65 For everyone else, it is strongly recommended that you use the object-
67 oriented interface.
68 A more detailed description of each interface is included below. If
70 you already know which interface you want to use, just go to the "SEE
71 ALSO" in Date::Manip section for documentation for each interface.
72
74 When using a version of perl older than 5.10, this is the only
75 interface available. This interface is documented in the
76 "Date::Manip::DM5 document". This interface has several weaknesses
77 that need to be understood when using it:
78 Limited Support
80 The version 5 functional interface is no longer being developed,
81 and only limited support is available for it.
82 As of December 2012, no development will be done, and I will not
84 correct any remaining bugs in version 5. If a patch is supplied by
85 someone else to fix bugs, I will apply it, provided it applies
86 cleanly, and the resulting code continues to pass all tests. I
87 will not apply patches to add features.
88 I will continue to distribute version 5 for several years. I do
90 not have a date in mind where version 5 will be removed.
91 Limited Time Zone Support
93 Time zone support is extremely limited, and is often incorrect. The
94 lack of time zone support was the primary reason for rewriting
95 Date::Manip.
96 The version 5 interface does not handle daylight saving time
98 changes correctly.
99 Performance Issues
101 Considerable time has been spent speeding up Date::Manip, and
102 fairly simple benchmarks show that version 6 is around twice as
103 fast as version 5.
104 Feel free to email me concerns and comments.
106
108 The version 6 functional interface is almost completely identical to
109 the version 5 functional interface, except that it uses the object-
110 oriented modules to do all the real work.
111 Time zone support is greatly improved, but is still somewhat limited.
113 Since the version 6 interface is backward compatible, dates do not
114 store time zone information in them, so the programmer is responsible
115 for keeping track of what time zone each date is in. If you want full
116 access to the time zone support offered in Date::Manip, you have to use
117 the object-oriented interface.
118 For the most part, scripts written for older versions of Date::Manip
120 will continue to work (and scripts written for the version 6 functional
121 interface will run with the version 5 interface), however in a few
122 cases, you may need to modify your scripts. Please refer to the
123 Date::Manip::Migration5to6 document for a list of changes which may be
124 necessary.
125
127 As of 6.00, Date::Manip consists of a set of OO modules. Each have
128 their own document (see the "SEE ALSO" in Date::Manip section).
129 The OO interface consists of the following modules: Date::Manip::Date,
131 Date::Manip::Delta, Date::Manip::Recur, Date::Manip::TZ, and
132 Date::Manip::Base.
133 The object-oriented interface is the only way to get the full
135 functionality of Date::Manip. It fully support time zones (and daylight
136 saving time).
137
139 If you are running an older version of perl, the version 5 functional
140 interface is the only one available to you, and it will automatically
141 be used.
142 If you are running a newer version of perl (5.10 or higher), you can
144 use the object-oriented modules by loading them directly, or you can
145 use a functional interface.
146 If you use a functional interface, it will default to the version 6
148 interface, but you can choose to run the version 5 interface in one of
149 three ways:
150 Using the OO interface
152 By including any of the following:
153 use Date::Manip::Date;
155 use Date::Manip::Delta;
156 use Date::Manip::Recur;
157 use Date::Manip::TZ;
158 use Date::Manip::Base;
159 you have access to the OO interface for the appropriate types of
161 objects.
162 Use the default functional interface
164 By including:
165 use Date::Manip;
167 in your script, one of the functional interfaces will be loaded.
169 If you are running a version of perl older than 5.10, it will
170 automatically be the version 5 interface. If you are running a
171 newer version of perl, it will automatically load the version 6
172 interface.
173 DATE_MANIP environment variable
175 By setting the DATE_MANIP environment variable to 'DM5' before
176 running the perl script, the version 5 interface will be used.
177 Date::Manip::Backend variable
179 Alternately, you can set the Date::Manip::Backend variable to be
180 'DM5' before loading the module. Typically, this will be done in
181 the following way:
182 BEGIN {
184 $Date::Manip::Backend = 'DM5';
185 }
186 use Date::Manip;
187 Once a functional interface is loaded, you cannot switch between the
189 version 5 and version 6 interfaces.
190
192 Date::Manip - main module documentation
193
195 This script is free software; you can redistribute it and/or modify it
196 under the same terms as Perl itself.
197
199 Sullivan Beck (sbeck@cpan.org)
200perl v5.26.3 2017-06-01 Date::Manip::Interfaces(3)