LLVM  3.7.0
StringExtras.h
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1 //===-- llvm/ADT/StringExtras.h - Useful string functions -------*- C++ -*-===//
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 contains some functions that are useful when dealing with strings.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ADT_STRINGEXTRAS_H
15 #define LLVM_ADT_STRINGEXTRAS_H
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/Support/DataTypes.h"
19 #include <iterator>
20 
21 namespace llvm {
22 template<typename T> class SmallVectorImpl;
23 
24 /// hexdigit - Return the hexadecimal character for the
25 /// given number \p X (which should be less than 16).
26 static inline char hexdigit(unsigned X, bool LowerCase = false) {
27  const char HexChar = LowerCase ? 'a' : 'A';
28  return X < 10 ? '0' + X : HexChar + X - 10;
29 }
30 
31 /// Construct a string ref from a boolean.
32 static inline StringRef toStringRef(bool B) {
33  return StringRef(B ? "true" : "false");
34 }
35 
36 /// Interpret the given character \p C as a hexadecimal digit and return its
37 /// value.
38 ///
39 /// If \p C is not a valid hex digit, -1U is returned.
40 static inline unsigned hexDigitValue(char C) {
41  if (C >= '0' && C <= '9') return C-'0';
42  if (C >= 'a' && C <= 'f') return C-'a'+10U;
43  if (C >= 'A' && C <= 'F') return C-'A'+10U;
44  return -1U;
45 }
46 
47 /// utohex_buffer - Emit the specified number into the buffer specified by
48 /// BufferEnd, returning a pointer to the start of the string. This can be used
49 /// like this: (note that the buffer must be large enough to handle any number):
50 /// char Buffer[40];
51 /// printf("0x%s", utohex_buffer(X, Buffer+40));
52 ///
53 /// This should only be used with unsigned types.
54 ///
55 template<typename IntTy>
56 static inline char *utohex_buffer(IntTy X, char *BufferEnd, bool LowerCase = false) {
57  char *BufPtr = BufferEnd;
58  *--BufPtr = 0; // Null terminate buffer.
59  if (X == 0) {
60  *--BufPtr = '0'; // Handle special case.
61  return BufPtr;
62  }
63 
64  while (X) {
65  unsigned char Mod = static_cast<unsigned char>(X) & 15;
66  *--BufPtr = hexdigit(Mod, LowerCase);
67  X >>= 4;
68  }
69  return BufPtr;
70 }
71 
72 static inline std::string utohexstr(uint64_t X, bool LowerCase = false) {
73  char Buffer[17];
74  return utohex_buffer(X, Buffer+17, LowerCase);
75 }
76 
77 static inline std::string utostr_32(uint32_t X, bool isNeg = false) {
78  char Buffer[11];
79  char *BufPtr = Buffer+11;
80 
81  if (X == 0) *--BufPtr = '0'; // Handle special case...
82 
83  while (X) {
84  *--BufPtr = '0' + char(X % 10);
85  X /= 10;
86  }
87 
88  if (isNeg) *--BufPtr = '-'; // Add negative sign...
89 
90  return std::string(BufPtr, Buffer+11);
91 }
92 
93 static inline std::string utostr(uint64_t X, bool isNeg = false) {
94  char Buffer[21];
95  char *BufPtr = Buffer+21;
96 
97  if (X == 0) *--BufPtr = '0'; // Handle special case...
98 
99  while (X) {
100  *--BufPtr = '0' + char(X % 10);
101  X /= 10;
102  }
103 
104  if (isNeg) *--BufPtr = '-'; // Add negative sign...
105  return std::string(BufPtr, Buffer+21);
106 }
107 
108 
109 static inline std::string itostr(int64_t X) {
110  if (X < 0)
111  return utostr(static_cast<uint64_t>(-X), true);
112  else
113  return utostr(static_cast<uint64_t>(X));
114 }
115 
116 /// StrInStrNoCase - Portable version of strcasestr. Locates the first
117 /// occurrence of string 's1' in string 's2', ignoring case. Returns
118 /// the offset of s2 in s1 or npos if s2 cannot be found.
119 StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2);
120 
121 /// getToken - This function extracts one token from source, ignoring any
122 /// leading characters that appear in the Delimiters string, and ending the
123 /// token at any of the characters that appear in the Delimiters string. If
124 /// there are no tokens in the source string, an empty string is returned.
125 /// The function returns a pair containing the extracted token and the
126 /// remaining tail string.
127 std::pair<StringRef, StringRef> getToken(StringRef Source,
128  StringRef Delimiters = " \t\n\v\f\r");
129 
130 /// SplitString - Split up the specified string according to the specified
131 /// delimiters, appending the result fragments to the output list.
132 void SplitString(StringRef Source,
133  SmallVectorImpl<StringRef> &OutFragments,
134  StringRef Delimiters = " \t\n\v\f\r");
135 
136 /// HashString - Hash function for strings.
137 ///
138 /// This is the Bernstein hash function.
139 //
140 // FIXME: Investigate whether a modified bernstein hash function performs
141 // better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx
142 // X*33+c -> X*33^c
143 static inline unsigned HashString(StringRef Str, unsigned Result = 0) {
144  for (StringRef::size_type i = 0, e = Str.size(); i != e; ++i)
145  Result = Result * 33 + (unsigned char)Str[i];
146  return Result;
147 }
148 
149 /// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
150 static inline StringRef getOrdinalSuffix(unsigned Val) {
151  // It is critically important that we do this perfectly for
152  // user-written sequences with over 100 elements.
153  switch (Val % 100) {
154  case 11:
155  case 12:
156  case 13:
157  return "th";
158  default:
159  switch (Val % 10) {
160  case 1: return "st";
161  case 2: return "nd";
162  case 3: return "rd";
163  default: return "th";
164  }
165  }
166 }
167 
168 template <typename IteratorT>
169 inline std::string join_impl(IteratorT Begin, IteratorT End,
170  StringRef Separator, std::input_iterator_tag) {
171  std::string S;
172  if (Begin == End)
173  return S;
174 
175  S += (*Begin);
176  while (++Begin != End) {
177  S += Separator;
178  S += (*Begin);
179  }
180  return S;
181 }
182 
183 template <typename IteratorT>
184 inline std::string join_impl(IteratorT Begin, IteratorT End,
185  StringRef Separator, std::forward_iterator_tag) {
186  std::string S;
187  if (Begin == End)
188  return S;
189 
190  size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
191  for (IteratorT I = Begin; I != End; ++I)
192  Len += (*Begin).size();
193  S.reserve(Len);
194  S += (*Begin);
195  while (++Begin != End) {
196  S += Separator;
197  S += (*Begin);
198  }
199  return S;
200 }
201 
202 /// Joins the strings in the range [Begin, End), adding Separator between
203 /// the elements.
204 template <typename IteratorT>
205 inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
206  typedef typename std::iterator_traits<IteratorT>::iterator_category tag;
207  return join_impl(Begin, End, Separator, tag());
208 }
209 
210 } // End llvm namespace
211 
212 #endif
static unsigned HashString(StringRef Str, unsigned Result=0)
HashString - Hash function for strings.
Definition: StringExtras.h:143
size_t size() const
size - Get the string size.
Definition: StringRef.h:113
std::pair< StringRef, StringRef > getToken(StringRef Source, StringRef Delimiters=" \t\n\v\f\r")
getToken - This function extracts one token from source, ignoring any leading characters that appear ...
std::string join(IteratorT Begin, IteratorT End, StringRef Separator)
Joins the strings in the range [Begin, End), adding Separator between the elements.
Definition: StringExtras.h:205
static std::string utostr(uint64_t X, bool isNeg=false)
Definition: StringExtras.h:93
static StringRef getOrdinalSuffix(unsigned Val)
Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
Definition: StringExtras.h:150
std::string join_impl(IteratorT Begin, IteratorT End, StringRef Separator, std::input_iterator_tag)
Definition: StringExtras.h:169
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang","erlang-compatible garbage collector")
static std::string itostr(int64_t X)
Definition: StringExtras.h:109
static std::string utostr_32(uint32_t X, bool isNeg=false)
Definition: StringExtras.h:77
void SplitString(StringRef Source, SmallVectorImpl< StringRef > &OutFragments, StringRef Delimiters=" \t\n\v\f\r")
SplitString - Split up the specified string according to the specified delimiters, appending the result fragments to the output list.
static char * utohex_buffer(IntTy X, char *BufferEnd, bool LowerCase=false)
utohex_buffer - Emit the specified number into the buffer specified by BufferEnd, returning a pointer...
Definition: StringExtras.h:56
static StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:32
static char hexdigit(unsigned X, bool LowerCase=false)
hexdigit - Return the hexadecimal character for the given number X (which should be less than 16)...
Definition: StringExtras.h:26
size_t size_type
Definition: StringRef.h:45
#define I(x, y, z)
Definition: MD5.cpp:54
StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2)
StrInStrNoCase - Portable version of strcasestr.
static std::string utohexstr(uint64_t X, bool LowerCase=false)
Definition: StringExtras.h:72
static unsigned hexDigitValue(char C)
Interpret the given character C as a hexadecimal digit and return its value.
Definition: StringExtras.h:40
C - The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40