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//===-- 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 {
class raw_ostream;
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;
}
static inline std::string utohexstr(uint64_t X, bool LowerCase = false) {
char Buffer[17];
char *BufPtr = std::end(Buffer);
if (X == 0) *--BufPtr = '0';
while (X) {
unsigned char Mod = static_cast<unsigned char>(X) & 15;
*--BufPtr = hexdigit(Mod, LowerCase);
X >>= 4;
}
return std::string(BufPtr, std::end(Buffer));
}
/// Convert buffer \p Input to its hexadecimal representation.
/// The returned string is double the size of \p Input.
static inline std::string toHex(StringRef Input) {
static const char *const LUT = "0123456789ABCDEF";
size_t Length = Input.size();
std::string Output;
Output.reserve(2 * Length);
for (size_t i = 0; i < Length; ++i) {
const unsigned char c = Input[i];
Output.push_back(LUT[c >> 4]);
Output.push_back(LUT[c & 15]);
}
return Output;
}
static inline std::string utostr(uint64_t X, bool isNeg = false) {
char Buffer[21];
char *BufPtr = std::end(Buffer);
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, std::end(Buffer));
}
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 (StringRef::size_type 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";
}
}
}
/// PrintEscapedString - Print each character of the specified string, escaping
/// it if it is not printable or if it is an escape char.
void PrintEscapedString(StringRef Name, raw_ostream &Out);
namespace detail {
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;
}
template <typename Sep>
inline void join_items_impl(std::string &Result, Sep Separator) {}
template <typename Sep, typename Arg>
inline void join_items_impl(std::string &Result, Sep Separator,
const Arg &Item) {
Result += Item;
}
template <typename Sep, typename Arg1, typename... Args>
inline void join_items_impl(std::string &Result, Sep Separator, const Arg1 &A1,
Args &&... Items) {
Result += A1;
Result += Separator;
join_items_impl(Result, Separator, std::forward<Args>(Items)...);
}
inline size_t join_one_item_size(char C) { return 1; }
inline size_t join_one_item_size(const char *S) { return S ? ::strlen(S) : 0; }
template <typename T> inline size_t join_one_item_size(const T &Str) {
return Str.size();
}
inline size_t join_items_size() { return 0; }
template <typename A1> inline size_t join_items_size(const A1 &A) {
return join_one_item_size(A);
}
template <typename A1, typename... Args>
inline size_t join_items_size(const A1 &A, Args &&... Items) {
return join_one_item_size(A) + join_items_size(std::forward<Args>(Items)...);
}
}
/// 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 detail::join_impl(Begin, End, Separator, tag());
}
/// Joins the strings in the parameter pack \p Items, adding \p Separator
/// between the elements. All arguments must be implicitly convertible to
/// std::string, or there should be an overload of std::string::operator+=()
/// that accepts the argument explicitly.
template <typename Sep, typename... Args>
inline std::string join_items(Sep Separator, Args &&... Items) {
std::string Result;
if (sizeof...(Items) == 0)
return Result;
size_t NS = detail::join_one_item_size(Separator);
size_t NI = detail::join_items_size(std::forward<Args>(Items)...);
Result.reserve(NI + (sizeof...(Items) - 1) * NS + 1);
detail::join_items_impl(Result, Separator, std::forward<Args>(Items)...);
return Result;
}
} // End llvm namespace
#endif