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Serenity Operating System
1/*
2 * Copyright (c) 2020, the SerenityOS developers.
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/DeprecatedString.h>
10#include <AK/GenericLexer.h>
11#include <AK/HashMap.h>
12#include <AK/StringBuilder.h>
13
14namespace AK {
15
16class SourceGenerator {
17 AK_MAKE_NONCOPYABLE(SourceGenerator);
18
19public:
20 using MappingType = HashMap<StringView, DeprecatedString>;
21
22 explicit SourceGenerator(StringBuilder& builder, char opening = '@', char closing = '@')
23 : m_builder(builder)
24 , m_opening(opening)
25 , m_closing(closing)
26 {
27 }
28 explicit SourceGenerator(StringBuilder& builder, MappingType const& mapping, char opening = '@', char closing = '@')
29 : m_builder(builder)
30 , m_mapping(mapping)
31 , m_opening(opening)
32 , m_closing(closing)
33 {
34 }
35
36 SourceGenerator(SourceGenerator&&) = default;
37
38 SourceGenerator fork() { return SourceGenerator { m_builder, m_mapping, m_opening, m_closing }; }
39
40 void set(StringView key, DeprecatedString value)
41 {
42 if (key.contains(m_opening) || key.contains(m_closing)) {
43 warnln("SourceGenerator keys cannot contain the opening/closing delimiters `{}` and `{}`. (Keys are only wrapped in these when using them, not when setting them.)", m_opening, m_closing);
44 VERIFY_NOT_REACHED();
45 }
46 m_mapping.set(key, move(value));
47 }
48
49 DeprecatedString get(StringView key) const
50 {
51 auto result = m_mapping.get(key);
52 if (!result.has_value()) {
53 warnln("No key named `{}` set on SourceGenerator", key);
54 VERIFY_NOT_REACHED();
55 }
56 return result.release_value();
57 }
58
59 StringView as_string_view() const { return m_builder.string_view(); }
60 DeprecatedString as_string() const { return m_builder.to_deprecated_string(); }
61
62 void append(StringView pattern)
63 {
64 GenericLexer lexer { pattern };
65
66 while (!lexer.is_eof()) {
67 // FIXME: It is a bit inconvenient, that 'consume_until' also consumes the 'stop' character, this makes
68 // the method less generic because there is no way to check if the 'stop' character ever appeared.
69 auto const consume_until_without_consuming_stop_character = [&](char stop) {
70 return lexer.consume_while([&](char ch) { return ch != stop; });
71 };
72
73 m_builder.append(consume_until_without_consuming_stop_character(m_opening));
74
75 if (lexer.consume_specific(m_opening)) {
76 auto const placeholder = consume_until_without_consuming_stop_character(m_closing);
77
78 if (!lexer.consume_specific(m_closing))
79 VERIFY_NOT_REACHED();
80
81 m_builder.append(get(placeholder));
82 } else {
83 VERIFY(lexer.is_eof());
84 }
85 }
86 }
87
88 void appendln(StringView pattern)
89 {
90 append(pattern);
91 m_builder.append('\n');
92 }
93
94 template<size_t N>
95 DeprecatedString get(char const (&key)[N])
96 {
97 return get(StringView { key, N - 1 });
98 }
99
100 template<size_t N>
101 void set(char const (&key)[N], DeprecatedString value)
102 {
103 set(StringView { key, N - 1 }, value);
104 }
105
106 template<size_t N>
107 void append(char const (&pattern)[N])
108 {
109 append(StringView { pattern, N - 1 });
110 }
111
112 template<size_t N>
113 void appendln(char const (&pattern)[N])
114 {
115 appendln(StringView { pattern, N - 1 });
116 }
117
118private:
119 StringBuilder& m_builder;
120 MappingType m_mapping;
121 char m_opening, m_closing;
122};
123
124}
125
126#if USING_AK_GLOBALLY
127using AK::SourceGenerator;
128#endif