1//===-- StringExtras.cpp - Implement the StringExtras header --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the StringExtras.h header
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/ADT/STLExtras.h"
16#include "llvm/ADT/StringExtras.h"
17using namespace llvm;
18
19/// StrInStrNoCase - Portable version of strcasestr.  Locates the first
20/// occurrence of string 's1' in string 's2', ignoring case.  Returns
21/// the offset of s2 in s1 or npos if s2 cannot be found.
22StringRef::size_type llvm::StrInStrNoCase(StringRef s1, StringRef s2) {
23  size_t N = s2.size(), M = s1.size();
24  if (N > M)
25    return StringRef::npos;
26  for (size_t i = 0, e = M - N + 1; i != e; ++i)
27    if (s1.substr(i, N).equals_lower(s2))
28      return i;
29  return StringRef::npos;
30}
31
32/// getToken - This function extracts one token from source, ignoring any
33/// leading characters that appear in the Delimiters string, and ending the
34/// token at any of the characters that appear in the Delimiters string.  If
35/// there are no tokens in the source string, an empty string is returned.
36/// The function returns a pair containing the extracted token and the
37/// remaining tail string.
38std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,
39                                               StringRef Delimiters) {
40  // Figure out where the token starts.
41  StringRef::size_type Start = Source.find_first_not_of(Delimiters);
42
43  // Find the next occurrence of the delimiter.
44  StringRef::size_type End = Source.find_first_of(Delimiters, Start);
45
46  return std::make_pair(Source.slice(Start, End), Source.substr(End));
47}
48
49/// SplitString - Split up the specified string according to the specified
50/// delimiters, appending the result fragments to the output list.
51void llvm::SplitString(StringRef Source,
52                       SmallVectorImpl<StringRef> &OutFragments,
53                       StringRef Delimiters) {
54  std::pair<StringRef, StringRef> S = getToken(Source, Delimiters);
55  while (!S.first.empty()) {
56    OutFragments.push_back(S.first);
57    S = getToken(S.second, Delimiters);
58  }
59}
60
61void llvm::StringRef::split(SmallVectorImpl<StringRef> &A,
62                            StringRef Separators, int MaxSplit,
63                            bool KeepEmpty) const {
64  StringRef rest = *this;
65
66  // rest.data() is used to distinguish cases like "a," that splits into
67  // "a" + "" and "a" that splits into "a" + 0.
68  for (int splits = 0;
69       rest.data() != NULL && (MaxSplit < 0 || splits < MaxSplit);
70       ++splits) {
71    std::pair<llvm::StringRef, llvm::StringRef> p = rest.split(Separators);
72
73    if (p.first.size() != 0 || KeepEmpty)
74      A.push_back(p.first);
75    rest = p.second;
76  }
77  // If we have a tail left, add it.
78  if (rest.data() != NULL && (rest.size() != 0 || KeepEmpty))
79    A.push_back(rest);
80}
81