1 /*
2   ==============================================================================
3 
4    This file is part of the Water library.
5    Copyright (c) 2016 ROLI Ltd.
6    Copyright (C) 2017 Filipe Coelho <falktx@falktx.com>
7 
8    Permission is granted to use this software under the terms of the ISC license
9    http://www.isc.org/downloads/software-support-policy/isc-license/
10 
11    Permission to use, copy, modify, and/or distribute this software for any
12    purpose with or without fee is hereby granted, provided that the above
13    copyright notice and this permission notice appear in all copies.
14 
15    THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
16    TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
17    FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
18    OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
19    USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
20    TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
21    OF THIS SOFTWARE.
22 
23   ==============================================================================
24 */
25 
26 #ifndef WATER_IDENTIFIER_H_INCLUDED
27 #define WATER_IDENTIFIER_H_INCLUDED
28 
29 #include "String.h"
30 
31 namespace water {
32 
33 //==============================================================================
34 /**
35     Represents a string identifier, designed for accessing properties by name.
36 
37     Comparing two Identifier objects is very fast (an O(1) operation), but creating
38     them can be slower than just using a String directly, so the optimal way to use them
39     is to keep some static Identifier objects for the things you use often.
40 
41     @see NamedValueSet, ValueTree
42 */
43 class Identifier
44 {
45 public:
46     /** Creates a null identifier. */
47     Identifier() noexcept;
48 
49     /** Creates an identifier with a specified name.
50         Because this name may need to be used in contexts such as script variables or XML
51         tags, it must only contain ascii letters and digits, or the underscore character.
52     */
53     Identifier (const char* name);
54 
55     /** Creates an identifier with a specified name.
56         Because this name may need to be used in contexts such as script variables or XML
57         tags, it must only contain ascii letters and digits, or the underscore character.
58     */
59     Identifier (const String& name);
60 
61     /** Creates an identifier with a specified name.
62         Because this name may need to be used in contexts such as script variables or XML
63         tags, it must only contain ascii letters and digits, or the underscore character.
64     */
65     Identifier (String::CharPointerType nameStart, String::CharPointerType nameEnd);
66 
67     /** Creates a copy of another identifier. */
68     Identifier (const Identifier& other) noexcept;
69 
70     /** Creates a copy of another identifier. */
71     Identifier& operator= (const Identifier& other) noexcept;
72 
73    #if WATER_COMPILER_SUPPORTS_MOVE_SEMANTICS
74     /** Creates a copy of another identifier. */
75     Identifier (Identifier&& other) noexcept;
76 
77     /** Creates a copy of another identifier. */
78     Identifier& operator= (Identifier&& other) noexcept;
79    #endif
80 
81     /** Destructor */
82     ~Identifier() noexcept;
83 
84     /** Compares two identifiers. This is a very fast operation. */
85     inline bool operator== (const Identifier& other) const noexcept     { return name == other.name; }
86 
87     /** Compares two identifiers. This is a very fast operation. */
88     inline bool operator!= (const Identifier& other) const noexcept     { return name != other.name; }
89 
90     /** Compares the identifier with a string. */
91     inline bool operator== (StringRef other) const noexcept             { return name == other; }
92 
93     /** Compares the identifier with a string. */
94     inline bool operator!= (StringRef other) const noexcept             { return name != other; }
95 
96     /** Compares the identifier with a string. */
97     inline bool operator<  (StringRef other) const noexcept             { return name <  other; }
98 
99     /** Compares the identifier with a string. */
100     inline bool operator<= (StringRef other) const noexcept             { return name <= other; }
101 
102     /** Compares the identifier with a string. */
103     inline bool operator>  (StringRef other) const noexcept             { return name >  other; }
104 
105     /** Compares the identifier with a string. */
106     inline bool operator>= (StringRef other) const noexcept             { return name >= other; }
107 
108     /** Returns this identifier as a string. */
toString()109     const String& toString() const noexcept                             { return name; }
110 
111     /** Returns this identifier as a StringRef. */
StringRef()112     operator StringRef() const noexcept                                 { return name; }
113 
114     /** Returns true if this Identifier is not null */
isValid()115     bool isValid() const noexcept                                       { return name.isNotEmpty(); }
116 
117     /** Returns true if this Identifier is null */
isNull()118     bool isNull() const noexcept                                        { return name.isEmpty(); }
119 
120     /** Checks a given string for characters that might not be valid in an Identifier.
121         Since Identifiers are used as a script variables and XML attributes, they should only contain
122         alphanumeric characters, underscores, or the '-' and ':' characters.
123     */
124     static bool isValidIdentifier (const String& possibleIdentifier) noexcept;
125 
126 private:
127     String name;
128 };
129 
130 }
131 
132 #endif // WATER_IDENTIFIER_H_INCLUDED
133