xref: /llvm-project/llvm/lib/Support/StringExtras.cpp (revision 7c16caa33600bc473532fc2730aad1f62738b3ef)
1 //===-- StringExtras.cpp - Implement the StringExtras header --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the StringExtras.h header
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/StringExtras.h"
15 using namespace llvm;
16 
17 /// getToken - This function extracts one token from source, ignoring any
18 /// leading characters that appear in the Delimiters string, and ending the
19 /// token at any of the characters that appear in the Delimiters string.  If
20 /// there are no tokens in the source string, an empty string is returned.
21 /// The Source source string is updated in place to remove the returned string
22 /// and any delimiter prefix from it.
23 std::string llvm::getToken(std::string &Source, const char *Delimiters) {
24   unsigned NumDelimiters = std::strlen(Delimiters);
25 
26   // Figure out where the token starts.
27   std::string::size_type Start =
28     Source.find_first_not_of(Delimiters, 0, NumDelimiters);
29   if (Start == std::string::npos) Start = Source.size();
30 
31   // Find the next occurance of the delimiter.
32   std::string::size_type End =
33     Source.find_first_of(Delimiters, Start, NumDelimiters);
34   if (End == std::string::npos) End = Source.size();
35 
36   // Create the return token.
37   std::string Result = std::string(Source.begin()+Start, Source.begin()+End);
38 
39   // Erase the token that we read in.
40   Source.erase(Source.begin(), Source.begin()+End);
41 
42   return Result;
43 }
44