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Diffstat (limited to 'include/llvm/ADT/StringRef.h')
| -rw-r--r-- | include/llvm/ADT/StringRef.h | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/include/llvm/ADT/StringRef.h b/include/llvm/ADT/StringRef.h new file mode 100644 index 0000000..aa7d577 --- /dev/null +++ b/include/llvm/ADT/StringRef.h @@ -0,0 +1,335 @@ +//===--- StringRef.h - Constant String Reference Wrapper --------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#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. + /// + /// This class does not own the string data, it is expected to be used in + /// situations where the character data resides in some other buffer, whose + /// lifetime extends past that of the StringRef. For this reason, it is not in + /// general safe to store a StringRef. + 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. + size_t Length; + + public: + /// @name Constructors + /// @{ + + /// Construct an empty string ref. + /*implicit*/ StringRef() : Data(0), Length(0) {} + + /// Construct a string ref from a cstring. + /*implicit*/ StringRef(const char *Str) + : Data(Str) { if (Str) Length = ::strlen(Str); else Length = 0; } + + /// Construct a string ref from a pointer and length. + /*implicit*/ StringRef(const char *data, unsigned length) + : Data(data), Length(length) {} + + /// Construct a string ref from an std::string. + /*implicit*/ StringRef(const std::string &Str) + : Data(Str.c_str()), Length(Str.length()) {} + + /// @} + /// @name Iterators + /// @{ + + iterator begin() const { return Data; } + + iterator end() const { return Data + Length; } + + /// @} + /// @name String Operations + /// @{ + + /// data - Get a pointer to the start of the string (which may not be null + /// terminated). + const char *data() const { return Data; } + + /// empty - Check if the string is empty. + bool empty() const { return Length == 0; } + + /// size - Get the string size. + 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. + int compare(const StringRef &RHS) const { + // Check the prefix for a mismatch. + if (int Res = memcmp(Data, RHS.Data, std::min(Length, RHS.Length))) + return Res < 0 ? -1 : 1; + + // Otherwise the prefixes match, so we only need to check the lengths. + if (Length == RHS.Length) + return 0; + return Length < RHS.Length ? -1 : 1; + } + + /// str - Get the contents as an std::string. + std::string str() const { return std::string(Data, Length); } + + /// @} + /// @name Operator Overloads + /// @{ + + char operator[](size_t Index) const { + assert(Index < Length && "Invalid index!"); + return Data[Index]; + } + + /// @} + /// @name Type Conversions + /// @{ + + operator std::string() const { + return str(); + } + + /// @} + /// @name String Predicates + /// @{ + + /// startswith - Check if this string starts with the given \arg Prefix. + bool startswith(const StringRef &Prefix) const { + return substr(0, Prefix.Length).equals(Prefix); + } + + /// 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); + } + + /// @} + /// @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 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; + + // 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 |
