#ifndef LLVM_ADT_STRINGREF_H
#define LLVM_ADT_STRINGREF_H
+#include <algorithm>
+#include <cassert>
#include <cstring>
#include <string>
namespace llvm {
+
/// StringRef - Represent a constant reference to a string, i.e. a character
/// array and a length, which need not be null terminated.
///
class StringRef {
public:
typedef const char *iterator;
-
+ static const size_t npos = ~size_t(0);
+ typedef size_t size_type;
+
private:
/// The start of the string, in an external buffer.
const char *Data;
/// The length of the string.
- unsigned Length;
+ size_t Length;
public:
/// @name Constructors
bool empty() const { return Length == 0; }
/// size - Get the string size.
- unsigned size() const { return Length; }
+ size_t size() const { return Length; }
+
+ /// front - Get the first character in the string.
+ char front() const {
+ assert(!empty());
+ return Data[0];
+ }
+
+ /// back - Get the last character in the string.
+ char back() const {
+ assert(!empty());
+ return Data[Length-1];
+ }
+
+ /// equals - Check for string equality, this is more efficient than
+ /// compare() when the relative ordering of inequal strings isn't needed.
+ bool equals(const StringRef &RHS) const {
+ return (Length == RHS.Length &&
+ memcmp(Data, RHS.Data, RHS.Length) == 0);
+ }
/// compare - Compare two strings; the result is -1, 0, or 1 if this string
/// is lexicographically less than, equal to, or greater than the \arg RHS.
/// @name Operator Overloads
/// @{
- bool operator==(const StringRef &RHS) const {
- return Length == RHS.Length && memcmp(Data, RHS.Data, Length) == 0;
+ char operator[](size_t Index) const {
+ assert(Index < Length && "Invalid index!");
+ return Data[Index];
}
- bool operator!=(const StringRef &RHS) const { return !(*this == RHS); }
+ /// @}
+ /// @name Type Conversions
+ /// @{
- bool operator<(const StringRef &RHS) const { return compare(RHS) == -1; }
+ operator std::string() const {
+ return str();
+ }
- bool operator<=(const StringRef &RHS) const { return compare(RHS) != 1; }
+ /// @}
+ /// @name String Predicates
+ /// @{
- bool operator>(const StringRef &RHS) const { return compare(RHS) == 1; }
+ /// startswith - Check if this string starts with the given \arg Prefix.
+ bool startswith(const StringRef &Prefix) const {
+ return substr(0, Prefix.Length).equals(Prefix);
+ }
- bool operator>=(const StringRef &RHS) const { return compare(RHS) != -1; }
+ /// endswith - Check if this string ends with the given \arg Suffix.
+ bool endswith(const StringRef &Suffix) const {
+ return slice(size() - Suffix.Length, size()).equals(Suffix);
+ }
- char operator[](size_t Index) const {
- assert(Index < Length && "Invalid index!");
- return Data[Index];
+ /// @}
+ /// @name String Searching
+ /// @{
+
+ /// find - Search for the first character \arg C in the string.
+ ///
+ /// \return - The index of the first occurence of \arg C, or npos if not
+ /// found.
+ size_t find(char C) const {
+ for (size_t i = 0, e = Length; i != e; ++i)
+ if (Data[i] == C)
+ return i;
+ return npos;
}
+ /// find - Search for the first string \arg Str in the string.
+ ///
+ /// \return - The index of the first occurence of \arg Str, or npos if not
+ /// found.
+ size_t find(const StringRef &Str) const;
+
+ /// rfind - Search for the last character \arg C in the string.
+ ///
+ /// \return - The index of the last occurence of \arg C, or npos if not
+ /// found.
+ size_t rfind(char C, size_t From = npos) const {
+ From = std::min(From, Length);
+ size_t i = From;
+ while (i != 0) {
+ --i;
+ if (Data[i] == C)
+ return i;
+ }
+ return npos;
+ }
+
+ /// rfind - Search for the last string \arg Str in the string.
+ ///
+ /// \return - The index of the last occurence of \arg Str, or npos if not
+ /// found.
+ size_t rfind(const StringRef &Str) const;
+
+ /// find_first_of - Find the first instance of the specified character or
+ /// return npos if not in string. Same as find.
+ size_type find_first_of(char C) const { return find(C); }
+
+ /// find_first_of - Find the first character from the string 'Chars' in the
+ /// current string or return npos if not in string.
+ size_type find_first_of(StringRef Chars) const;
+
+ /// find_first_not_of - Find the first character in the string that is not
+ /// in the string 'Chars' or return npos if all are in string. Same as find.
+ size_type find_first_not_of(StringRef Chars) const;
+
/// @}
- /// @name Type Conversions
+ /// @name Helpful Algorithms
/// @{
+
+ /// count - Return the number of occurrences of \arg C in the string.
+ size_t count(char C) const {
+ size_t Count = 0;
+ for (size_t i = 0, e = Length; i != e; ++i)
+ if (Data[i] == C)
+ ++Count;
+ return Count;
+ }
+
+ /// count - Return the number of non-overlapped occurrences of \arg Str in
+ /// the string.
+ size_t count(const StringRef &Str) const;
+
+ /// getAsInteger - Parse the current string as an integer of the specified
+ /// radix. If Radix is specified as zero, this does radix autosensing using
+ /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
+ ///
+ /// If the string is invalid or if only a subset of the string is valid,
+ /// this returns true to signify the error. The string is considered
+ /// erroneous if empty.
+ ///
+ bool getAsInteger(unsigned Radix, long long &Result) const;
+ bool getAsInteger(unsigned Radix, unsigned long long &Result) const;
+ bool getAsInteger(unsigned Radix, int &Result) const;
+ bool getAsInteger(unsigned Radix, unsigned &Result) const;
- operator std::string() const {
- return str();
+ // TODO: Provide overloads for int/unsigned that check for overflow.
+
+ /// @}
+ /// @name Substring Operations
+ /// @{
+
+ /// substr - Return a reference to the substring from [Start, Start + N).
+ ///
+ /// \param Start - The index of the starting character in the substring; if
+ /// the index is npos or greater than the length of the string then the
+ /// empty substring will be returned.
+ ///
+ /// \param N - The number of characters to included in the substring. If N
+ /// exceeds the number of characters remaining in the string, the string
+ /// suffix (starting with \arg Start) will be returned.
+ StringRef substr(size_t Start, size_t N = npos) const {
+ Start = std::min(Start, Length);
+ return StringRef(Data + Start, std::min(N, Length - Start));
+ }
+
+ /// slice - Return a reference to the substring from [Start, End).
+ ///
+ /// \param Start - The index of the starting character in the substring; if
+ /// the index is npos or greater than the length of the string then the
+ /// empty substring will be returned.
+ ///
+ /// \param End - The index following the last character to include in the
+ /// substring. If this is npos, or less than \arg Start, or exceeds the
+ /// number of characters remaining in the string, the string suffix
+ /// (starting with \arg Start) will be returned.
+ StringRef slice(size_t Start, size_t End) const {
+ Start = std::min(Start, Length);
+ End = std::min(std::max(Start, End), Length);
+ return StringRef(Data + Start, End - Start);
+ }
+
+ /// split - Split into two substrings around the first occurence of a
+ /// separator character.
+ ///
+ /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+ /// such that (*this == LHS + Separator + RHS) is true and RHS is
+ /// maximal. If \arg Separator is not in the string, then the result is a
+ /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+ ///
+ /// \param Separator - The character to split on.
+ /// \return - The split substrings.
+ std::pair<StringRef, StringRef> split(char Separator) const {
+ size_t Idx = find(Separator);
+ if (Idx == npos)
+ return std::make_pair(*this, StringRef());
+ return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
+ }
+
+ /// rsplit - Split into two substrings around the last occurence of a
+ /// separator character.
+ ///
+ /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+ /// such that (*this == LHS + Separator + RHS) is true and RHS is
+ /// minimal. If \arg Separator is not in the string, then the result is a
+ /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+ ///
+ /// \param Separator - The character to split on.
+ /// \return - The split substrings.
+ std::pair<StringRef, StringRef> rsplit(char Separator) const {
+ size_t Idx = rfind(Separator);
+ if (Idx == npos)
+ return std::make_pair(*this, StringRef());
+ return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
}
/// @}
};
+
+ /// @name StringRef Comparison Operators
+ /// @{
+
+ inline bool operator==(const StringRef &LHS, const StringRef &RHS) {
+ return LHS.equals(RHS);
+ }
+
+ inline bool operator!=(const StringRef &LHS, const StringRef &RHS) {
+ return !(LHS == RHS);
+ }
+
+ inline bool operator<(const StringRef &LHS, const StringRef &RHS) {
+ return LHS.compare(RHS) == -1;
+ }
+
+ inline bool operator<=(const StringRef &LHS, const StringRef &RHS) {
+ return LHS.compare(RHS) != 1;
+ }
+
+ inline bool operator>(const StringRef &LHS, const StringRef &RHS) {
+ return LHS.compare(RHS) == 1;
+ }
+
+ inline bool operator>=(const StringRef &LHS, const StringRef &RHS) {
+ return LHS.compare(RHS) != -1;
+ }
+
+ /// @}
+
}
#endif
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