1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
# -----------------------------------------------------------------------------
#
# Versionomy schema namespace
#
# -----------------------------------------------------------------------------
# Copyright 2008 Daniel Azuma
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of the copyright holder, nor the names of any other
# contributors to this software, may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# -----------------------------------------------------------------------------
;
module Versionomy
# === Version number schema.
#
# A schema defines the structure and semantics of a version number.
# The schema controls what fields are present in the version, how
# version numbers are compared, what the default values are, and how
# values can change. Version numbers with the same schema can be
# compared with one another, and version numbers can be converted
# trivially to formats that share the same schema, without requiring a
# Conversion implementation.
#
# At its simplest, a version number is defined as a sequence of fields,
# each with a name and data type. These fields may be integer-valued,
# string-valued, or symbolic, though most will probably be integers.
# Symbolic fields are enumerated types that are useful, for example, if
# you want a field to specify the type of prerelease (e.g. "alpha",
# "beta", or "release candidate").
#
# As a simple conceptual example, you could construct a schema for
# version numbers of the form "major.minor.tiny" like this. (This is a
# conceptual diagram, not actual syntax.)
#
# ("major": integer), ("minor": integer), ("tiny": integer)
#
# More generally, fields are actually organized into a DAG (directed
# acyclic graph) in which the "most significant" field is the root, the
# next most significant is a child of that root, and so forth down the
# line. The simple schema above, then, is actually represented as a
# linked list (a graph with one path), like this:
#
# ("major": integer) ->
# ("minor": integer) ->
# ("tiny": integer) ->
# nil
#
# It is, however, possible for the form of a field to depend on the value
# of the previous field. For example, suppose we wanted a schema in which
# if the value of the "minor" field is 0, then the "tiny" field doesn't
# exist. e.g.
#
# ("major": integer) ->
# ("minor": integer) ->
# [value == 0] : nil
# [otherwise] : ("tiny": integer) ->
# nil
#
# The Versionomy::Schema::Field class represents a field in this graph.
# The Versionomy::Schema::Wrapper class represents a full schema object.
#
# Generally, you should create schemas using Versionomy::Schema#create.
# That method provides a DSL that lets you quickly create the fields.
module Schema
end
end
|
