llvm-6502/include/llvm/ADT/StringExtras.h
Alp Toker 810a9cffb4 Move true/false StringRef helper to StringExtras
StringRef is a low-level data wrapper that shouldn't know about language
strings like 'true' and 'false' whereas StringExtras is just the place for
higher-level utilities.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200188 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-27 04:07:36 +00:00

213 lines
6.3 KiB
C++

//===-- llvm/ADT/StringExtras.h - Useful string functions -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains some functions that are useful when dealing with strings.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_STRINGEXTRAS_H
#define LLVM_ADT_STRINGEXTRAS_H
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/DataTypes.h"
#include <iterator>
namespace llvm {
template<typename T> class SmallVectorImpl;
/// hexdigit - Return the hexadecimal character for the
/// given number \p X (which should be less than 16).
static inline char hexdigit(unsigned X, bool LowerCase = false) {
const char HexChar = LowerCase ? 'a' : 'A';
return X < 10 ? '0' + X : HexChar + X - 10;
}
/// Construct a string ref from a boolean.
static inline StringRef toStringRef(bool B) {
return StringRef(B ? "true" : "false");
}
/// Interpret the given character \p C as a hexadecimal digit and return its
/// value.
///
/// If \p C is not a valid hex digit, -1U is returned.
static inline unsigned hexDigitValue(char C) {
if (C >= '0' && C <= '9') return C-'0';
if (C >= 'a' && C <= 'f') return C-'a'+10U;
if (C >= 'A' && C <= 'F') return C-'A'+10U;
return -1U;
}
/// utohex_buffer - Emit the specified number into the buffer specified by
/// BufferEnd, returning a pointer to the start of the string. This can be used
/// like this: (note that the buffer must be large enough to handle any number):
/// char Buffer[40];
/// printf("0x%s", utohex_buffer(X, Buffer+40));
///
/// This should only be used with unsigned types.
///
template<typename IntTy>
static inline char *utohex_buffer(IntTy X, char *BufferEnd) {
char *BufPtr = BufferEnd;
*--BufPtr = 0; // Null terminate buffer.
if (X == 0) {
*--BufPtr = '0'; // Handle special case.
return BufPtr;
}
while (X) {
unsigned char Mod = static_cast<unsigned char>(X) & 15;
*--BufPtr = hexdigit(Mod);
X >>= 4;
}
return BufPtr;
}
static inline std::string utohexstr(uint64_t X) {
char Buffer[17];
return utohex_buffer(X, Buffer+17);
}
static inline std::string utostr_32(uint32_t X, bool isNeg = false) {
char Buffer[11];
char *BufPtr = Buffer+11;
if (X == 0) *--BufPtr = '0'; // Handle special case...
while (X) {
*--BufPtr = '0' + char(X % 10);
X /= 10;
}
if (isNeg) *--BufPtr = '-'; // Add negative sign...
return std::string(BufPtr, Buffer+11);
}
static inline std::string utostr(uint64_t X, bool isNeg = false) {
char Buffer[21];
char *BufPtr = Buffer+21;
if (X == 0) *--BufPtr = '0'; // Handle special case...
while (X) {
*--BufPtr = '0' + char(X % 10);
X /= 10;
}
if (isNeg) *--BufPtr = '-'; // Add negative sign...
return std::string(BufPtr, Buffer+21);
}
static inline std::string itostr(int64_t X) {
if (X < 0)
return utostr(static_cast<uint64_t>(-X), true);
else
return utostr(static_cast<uint64_t>(X));
}
/// StrInStrNoCase - Portable version of strcasestr. Locates the first
/// occurrence of string 's1' in string 's2', ignoring case. Returns
/// the offset of s2 in s1 or npos if s2 cannot be found.
StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2);
/// getToken - This function extracts one token from source, ignoring any
/// leading characters that appear in the Delimiters string, and ending the
/// token at any of the characters that appear in the Delimiters string. If
/// there are no tokens in the source string, an empty string is returned.
/// The function returns a pair containing the extracted token and the
/// remaining tail string.
std::pair<StringRef, StringRef> getToken(StringRef Source,
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.
void SplitString(StringRef Source,
SmallVectorImpl<StringRef> &OutFragments,
StringRef Delimiters = " \t\n\v\f\r");
/// HashString - Hash function for strings.
///
/// This is the Bernstein hash function.
//
// FIXME: Investigate whether a modified bernstein hash function performs
// better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx
// X*33+c -> X*33^c
static inline unsigned HashString(StringRef Str, unsigned Result = 0) {
for (unsigned i = 0, e = Str.size(); i != e; ++i)
Result = Result * 33 + (unsigned char)Str[i];
return Result;
}
/// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
static inline StringRef getOrdinalSuffix(unsigned Val) {
// It is critically important that we do this perfectly for
// user-written sequences with over 100 elements.
switch (Val % 100) {
case 11:
case 12:
case 13:
return "th";
default:
switch (Val % 10) {
case 1: return "st";
case 2: return "nd";
case 3: return "rd";
default: return "th";
}
}
}
template <typename IteratorT>
inline std::string join_impl(IteratorT Begin, IteratorT End,
StringRef Separator, std::input_iterator_tag) {
std::string S;
if (Begin == End)
return S;
S += (*Begin);
while (++Begin != End) {
S += Separator;
S += (*Begin);
}
return S;
}
template <typename IteratorT>
inline std::string join_impl(IteratorT Begin, IteratorT End,
StringRef Separator, std::forward_iterator_tag) {
std::string S;
if (Begin == End)
return S;
size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
for (IteratorT I = Begin; I != End; ++I)
Len += (*Begin).size();
S.reserve(Len);
S += (*Begin);
while (++Begin != End) {
S += Separator;
S += (*Begin);
}
return S;
}
/// Joins the strings in the range [Begin, End), adding Separator between
/// the elements.
template <typename IteratorT>
inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
typedef typename std::iterator_traits<IteratorT>::iterator_category tag;
return join_impl(Begin, End, Separator, tag());
}
} // End llvm namespace
#endif