File: iwyu_string_util.h

package info (click to toggle)
iwyu 3.9-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 4,136 kB
  • ctags: 2,911
  • sloc: cpp: 13,393; python: 4,425; ansic: 397; makefile: 23; sh: 11
file content (204 lines) | stat: -rw-r--r-- 6,029 bytes parent folder | download | duplicates (2)
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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
//===--- iwyu_string_util.h - string utilities for include-what-you-use ---===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// String utilities for the IWYU checker.
//

#ifndef INCLUDE_WHAT_YOU_USE_IWYU_STRING_UTIL_H_
#define INCLUDE_WHAT_YOU_USE_IWYU_STRING_UTIL_H_

#include <cctype>
#include <cstddef>
#include <string>
#include <vector>

#include "port.h"

namespace include_what_you_use {

using std::string;
using std::vector;

// Returns true if str starts with prefix.
inline bool StartsWith(const string& str, const string& prefix) {
  return str.substr(0, prefix.length()) == prefix;
}

// Returns true if str ends with suffix.
inline bool EndsWith(const string& str, const string& suffix) {
  if (suffix.length() > str.length())
    return false;
  return str.substr(str.length() - suffix.length()) == suffix;
}

// If *str starts with prefix, removes the prefix and returns true.
inline bool StripLeft(string* str, const string& prefix) {
  if (StartsWith(*str, prefix)) {
    *str = str->substr(prefix.length());
    return true;
  }

  return false;
}

// If *str ends with suffix, removes the suffix and returns true.
inline bool StripRight(string* str, const string& suffix) {
  if (str->length() >= suffix.length() &&
      str->substr(str->length() - suffix.length()) == suffix) {
    *str = str->substr(0, str->length() - suffix.length());
    return true;
  }

  return false;
}

// Truncate str to width with ellipses to indicate truncation.
// Return str unchanged if it fits within width.
// Return empty string if width is too short to fit anything meaningful.
// Otherwise return str truncated to width chars.
inline string Ellipsize(const string& str, size_t width) {
  if (str.length() <= width)
    return str;

  // If we truncate strings too short, we'll end up with nonsense abbreviations
  // like '...', 'T...' or 'Ty...' so make sure we have at least three chars
  // from str and three chars for ellipsis.
  if (width < 6)
    return string();

  return str.substr(0, width - 3) + "...";
}

// Finds the first occurrence of substr in *str and removes from *str
// everything before the occurrence and the occurrence itself.  For
// example, string s = "What a hat!"; StripPast(&s, "hat"); will make s
// " a hat!".
inline bool StripPast(string* str, const string& substr) {
  const size_t pos = str->find(substr);
  if (pos == string::npos)
    return false;

  *str = str->substr(pos + substr.length());
  return true;
}

// Removes leading whitespace.
inline void StripWhiteSpaceLeft(string* str) {
  for (string::size_type i = 0; i < str->size(); ++i) {
    if (!isspace((*str)[i])) {
      *str = str->substr(i);
      return;
    }
  }
  // Everything is whitespace. Return with an empty string.
  str->clear();
}

// Removes trailing whitespace.
inline void StripWhiteSpaceRight(string* str) {
  for (string::size_type end_of_string = str->size();
       end_of_string > 0; --end_of_string) {
    if (!isspace((*str)[end_of_string - 1])) {
      *str = str->substr(0, end_of_string);
      return;
    }
  }
  // Everything is whitespace. Return with an empty string.
  str->clear();
}

// Removes both leading and trailing whitespace.
inline void StripWhiteSpace(string* str) {
  StripWhiteSpaceLeft(str);
  StripWhiteSpaceRight(str);
}

// This is the same as split() in Python.  If max_segs is 0, there's
// no limit on the number of the generated segments.
inline vector<string> Split(
    string str, const string& divider, size_t max_segs) {
  CHECK_(!divider.empty());
  vector<string> retval;
  size_t pos;
  // If max_segs is 0, the first part of the condition will always be true.
  while (retval.size() + 1 != max_segs &&
         (pos = str.find(divider)) != string::npos) {
    retval.push_back(str.substr(0, pos));
    str = str.substr(pos + divider.length());
  }
  retval.push_back(str);
  return retval;
}

// Like Split, but using a divider of arbitrary whitespace.
// Whitespace at the beginning and end is ignored.
inline vector<string> SplitOnWhiteSpace(const string& str, size_t max_segs) {
  vector<string> retval;
  size_t tokstart = string::npos;
  for (size_t pos = 0; pos < str.size(); ++pos) {
    if (isspace(str[pos])) {
      if (tokstart != string::npos) {
        retval.push_back(str.substr(tokstart, pos - tokstart));
        if (retval.size() == max_segs) {
          return retval;
        }
        tokstart = string::npos;
      }
    } else {
      if (tokstart == string::npos) {
        tokstart = pos;
      }
    }
  }
  if (tokstart != string::npos) {
    retval.push_back(str.substr(tokstart));
  }
  return retval;
}

// Like SplitOnWhiteSpace, but double-quoted and bracketed strings are
// preserved. No error checking with respect to closing quotes is done.
inline vector<string> SplitOnWhiteSpacePreservingQuotes(
    const string& str, size_t max_segs) {
  vector<string> retval;
  size_t tokstart = string::npos;
  char closing_quote = '\0';
  for (size_t pos = 0; pos < str.size(); ++pos) {
    if (isspace(str[pos])) {
      if (tokstart != string::npos && closing_quote == '\0') {
        retval.push_back(str.substr(tokstart, pos - tokstart));
        if (retval.size() == max_segs) {
          return retval;
        }
        tokstart = string::npos;
      }
    } else {
      if (tokstart == string::npos) {
        tokstart = pos;
        if (str[pos] == '"') {
          closing_quote = '"';
        } else if (str[pos] == '<') {
          closing_quote = '>';
        } else {
          closing_quote = '\0';
        }
      } else if (str[pos] == closing_quote) {
        closing_quote = '\0';
      }
    }
  }
  if (tokstart != string::npos) {
    retval.push_back(str.substr(tokstart));
  }
  return retval;
}

}  // namespace include_what_you_use

#endif  // INCLUDE_WHAT_YOU_USE_IWYU_STRING_UTIL_H_