| //===--- StringView.h -------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| // |
| // This file is copied from llvm/lib/Demangle/StringView.h. |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LIBCXX_DEMANGLE_STRINGVIEW_H |
| #define LIBCXX_DEMANGLE_STRINGVIEW_H |
| |
| #include <algorithm> |
| #include <cassert> |
| #include <cstring> |
| |
| namespace { |
| class StringView { |
| const char *First; |
| const char *Last; |
| |
| public: |
| template <size_t N> |
| StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {} |
| StringView(const char *First_, const char *Last_) |
| : First(First_), Last(Last_) {} |
| StringView(const char *First_, size_t Len) |
| : First(First_), Last(First_ + Len) {} |
| StringView(const char *Str) : First(Str), Last(Str + std::strlen(Str)) {} |
| StringView() : First(nullptr), Last(nullptr) {} |
| |
| StringView substr(size_t From) const { |
| return StringView(begin() + From, size() - From); |
| } |
| |
| StringView substr(size_t From, size_t To) const { |
| if (To >= size()) |
| To = size() - 1; |
| if (From >= size()) |
| From = size() - 1; |
| return StringView(First + From, First + To); |
| } |
| |
| StringView dropFront(size_t N = 1) const { |
| if (N >= size()) |
| N = size() - 1; |
| return StringView(First + N, Last); |
| } |
| |
| char front() const { |
| assert(!empty()); |
| return *begin(); |
| } |
| |
| char popFront() { |
| assert(!empty()); |
| return *First++; |
| } |
| |
| bool consumeFront(char C) { |
| if (!startsWith(C)) |
| return false; |
| *this = dropFront(1); |
| return true; |
| } |
| |
| bool consumeFront(StringView S) { |
| if (!startsWith(S)) |
| return false; |
| *this = dropFront(S.size()); |
| return true; |
| } |
| |
| bool startsWith(char C) const { return !empty() && *begin() == C; } |
| |
| bool startsWith(StringView Str) const { |
| if (Str.size() > size()) |
| return false; |
| return std::equal(Str.begin(), Str.end(), begin()); |
| } |
| |
| const char &operator[](size_t Idx) const { return *(begin() + Idx); } |
| |
| const char *begin() const { return First; } |
| const char *end() const { return Last; } |
| size_t size() const { return static_cast<size_t>(Last - First); } |
| bool empty() const { return First == Last; } |
| }; |
| |
| inline bool operator==(const StringView &LHS, const StringView &RHS) { |
| return LHS.size() == RHS.size() && |
| std::equal(LHS.begin(), LHS.end(), RHS.begin()); |
| } |
| } // namespace |
| |
| #endif |