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. 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. 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. 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 61 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
