1//===-- StringExtras.cpp - Implement the StringExtras header --------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the StringExtras.h header
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/ADT/StringExtras.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/Support/raw_ostream.h"
16#include <cctype>
17
18using namespace llvm;
19
20/// StrInStrNoCase - Portable version of strcasestr. Locates the first
21/// occurrence of string 's1' in string 's2', ignoring case. Returns
22/// the offset of s2 in s1 or npos if s2 cannot be found.
23StringRef::size_type llvm::StrInStrNoCase(StringRef s1, StringRef s2) {
24 size_t N = s2.size(), M = s1.size();
25 if (N > M)
26 return StringRef::npos;
27 for (size_t i = 0, e = M - N + 1; i != e; ++i)
28 if (s1.substr(Start: i, N).equals_insensitive(RHS: s2))
29 return i;
30 return StringRef::npos;
31}
32
33/// getToken - This function extracts one token from source, ignoring any
34/// leading characters that appear in the Delimiters string, and ending the
35/// token at any of the characters that appear in the Delimiters string. If
36/// there are no tokens in the source string, an empty string is returned.
37/// The function returns a pair containing the extracted token and the
38/// remaining tail string.
39std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,
40 StringRef Delimiters) {
41 // Figure out where the token starts.
42 StringRef::size_type Start = Source.find_first_not_of(Chars: Delimiters);
43
44 // Find the next occurrence of the delimiter.
45 StringRef::size_type End = Source.find_first_of(Chars: Delimiters, From: Start);
46
47 return std::make_pair(x: Source.slice(Start, End), y: Source.substr(Start: End));
48}
49
50/// SplitString - Split up the specified string according to the specified
51/// delimiters, appending the result fragments to the output list.
52void llvm::SplitString(StringRef Source,
53 SmallVectorImpl<StringRef> &OutFragments,
54 StringRef Delimiters) {
55 std::pair<StringRef, StringRef> S = getToken(Source, Delimiters);
56 while (!S.first.empty()) {
57 OutFragments.push_back(Elt: S.first);
58 S = getToken(Source: S.second, Delimiters);
59 }
60}
61
62void llvm::printEscapedString(StringRef Name, raw_ostream &Out) {
63 for (unsigned char C : Name) {
64 if (C == '\\')
65 Out << '\\' << C;
66 else if (isPrint(C) && C != '"')
67 Out << C;
68 else
69 Out << '\\' << hexdigit(X: C >> 4) << hexdigit(X: C & 0x0F);
70 }
71}
72
73void llvm::printHTMLEscaped(StringRef String, raw_ostream &Out) {
74 for (char C : String) {
75 if (C == '&')
76 Out << "&amp;";
77 else if (C == '<')
78 Out << "&lt;";
79 else if (C == '>')
80 Out << "&gt;";
81 else if (C == '\"')
82 Out << "&quot;";
83 else if (C == '\'')
84 Out << "&apos;";
85 else
86 Out << C;
87 }
88}
89
90void llvm::printLowerCase(StringRef String, raw_ostream &Out) {
91 for (const char C : String)
92 Out << toLower(x: C);
93}
94
95std::string llvm::convertToSnakeFromCamelCase(StringRef input) {
96 if (input.empty())
97 return "";
98
99 std::string snakeCase;
100 snakeCase.reserve(res: input.size());
101 auto check = [&input](size_t j, function_ref<bool(int)> predicate) {
102 return j < input.size() && predicate(input[j]);
103 };
104 for (size_t i = 0; i < input.size(); ++i) {
105 snakeCase.push_back(c: tolower(c: input[i]));
106 // Handles "runs" of capitals, such as in OPName -> op_name.
107 if (check(i, isupper) && check(i + 1, isupper) && check(i + 2, islower))
108 snakeCase.push_back(c: '_');
109 if ((check(i, islower) || check(i, isdigit)) && check(i + 1, isupper))
110 snakeCase.push_back(c: '_');
111 }
112 return snakeCase;
113}
114
115std::string llvm::convertToCamelFromSnakeCase(StringRef input,
116 bool capitalizeFirst) {
117 if (input.empty())
118 return "";
119
120 std::string output;
121 output.reserve(res: input.size());
122
123 // Push the first character, capatilizing if necessary.
124 if (capitalizeFirst && std::islower(input.front()))
125 output.push_back(c: llvm::toUpper(x: input.front()));
126 else
127 output.push_back(c: input.front());
128
129 // Walk the input converting any `*_[a-z]` snake case into `*[A-Z]` camelCase.
130 for (size_t pos = 1, e = input.size(); pos < e; ++pos) {
131 if (input[pos] == '_' && pos != (e - 1) && std::islower(input[pos + 1]))
132 output.push_back(c: llvm::toUpper(x: input[++pos]));
133 else
134 output.push_back(c: input[pos]);
135 }
136 return output;
137}
138

source code of llvm/lib/Support/StringExtras.cpp