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 /// getToken - This function extracts one token from source, ignoring any 20 /// leading characters that appear in the Delimiters string, and ending the 21 /// token at any of the characters that appear in the Delimiters string. If 22 /// there are no tokens in the source string, an empty string is returned. 23 /// The function returns a pair containing the extracted token and the 24 /// remaining tail string. 25 std::pair<StringRef, StringRef> llvm::getToken(StringRef Source, 26 StringRef Delimiters) { 27 // Figure out where the token starts. 28 StringRef::size_type Start = Source.find_first_not_of(Delimiters); 29 if (Start == StringRef::npos) Start = Source.size(); 30 31 // Find the next occurrence of the delimiter. 32 StringRef::size_type End = Source.find_first_of(Delimiters, Start); 33 if (End == StringRef::npos) End = Source.size(); 34 35 return std::make_pair(Source.substr(Start, End), Source.substr(End)); 36 } 37 38 /// SplitString - Split up the specified string according to the specified 39 /// delimiters, appending the result fragments to the output list. 40 void llvm::SplitString(StringRef Source, 41 SmallVectorImpl<StringRef> &OutFragments, 42 StringRef Delimiters) { 43 StringRef S2, S; 44 tie(S2, S) = getToken(Source, Delimiters); 45 while (!S2.empty()) { 46 OutFragments.push_back(S2); 47 tie(S2, S) = getToken(S, Delimiters); 48 } 49 } 50 51 void llvm::StringRef::split(SmallVectorImpl<StringRef> &A, 52 StringRef Separators, int MaxSplit, 53 bool KeepEmpty) const { 54 StringRef rest = *this; 55 56 // rest.data() is used to distinguish cases like "a," that splits into 57 // "a" + "" and "a" that splits into "a" + 0. 58 for (int splits = 0; 59 rest.data() != NULL && (MaxSplit < 0 || splits < MaxSplit); 60 ++splits) { 61 std::pair<llvm::StringRef, llvm::StringRef> p = rest.split(Separators); 62 63 if (p.first.size() != 0 || KeepEmpty) 64 A.push_back(p.first); 65 rest = p.second; 66 } 67 // If we have a tail left, add it. 68 if (rest.data() != NULL && (rest.size() != 0 || KeepEmpty)) 69 A.push_back(rest); 70 } 71