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"
17 using 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.
StrInStrNoCase(StringRef s1,StringRef s2)22 StringRef::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.
getToken(StringRef Source,StringRef Delimiters)38 std::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.
SplitString(StringRef Source,SmallVectorImpl<StringRef> & OutFragments,StringRef Delimiters)51 void 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
split(SmallVectorImpl<StringRef> & A,StringRef Separators,int MaxSplit,bool KeepEmpty) const61 void 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