| 1 | //===-- StringLexer.cpp ---------------------------------------------------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "lldb/Utility/StringLexer.h" |
| 10 | |
| 11 | #include <algorithm> |
| 12 | #include <cassert> |
| 13 | #include <utility> |
| 14 | |
| 15 | using namespace lldb_private; |
| 16 | |
| 17 | StringLexer::StringLexer(std::string s) : m_data(std::move(s)), m_position(0) {} |
| 18 | |
| 19 | StringLexer::Character StringLexer::Peek() { return m_data[m_position]; } |
| 20 | |
| 21 | bool StringLexer::NextIf(Character c) { |
| 22 | auto val = Peek(); |
| 23 | if (val == c) { |
| 24 | Next(); |
| 25 | return true; |
| 26 | } |
| 27 | return false; |
| 28 | } |
| 29 | |
| 30 | std::pair<bool, StringLexer::Character> |
| 31 | StringLexer::NextIf(std::initializer_list<Character> cs) { |
| 32 | auto val = Peek(); |
| 33 | for (auto c : cs) { |
| 34 | if (val == c) { |
| 35 | Next(); |
| 36 | return {true, c}; |
| 37 | } |
| 38 | } |
| 39 | return {false, 0}; |
| 40 | } |
| 41 | |
| 42 | bool StringLexer::AdvanceIf(const std::string &token) { |
| 43 | auto pos = m_position; |
| 44 | bool matches = true; |
| 45 | for (auto c : token) { |
| 46 | if (!NextIf(c)) { |
| 47 | matches = false; |
| 48 | break; |
| 49 | } |
| 50 | } |
| 51 | if (!matches) { |
| 52 | m_position = pos; |
| 53 | return false; |
| 54 | } |
| 55 | return true; |
| 56 | } |
| 57 | |
| 58 | StringLexer::Character StringLexer::Next() { |
| 59 | auto val = Peek(); |
| 60 | Consume(); |
| 61 | return val; |
| 62 | } |
| 63 | |
| 64 | bool StringLexer::HasAtLeast(Size s) { |
| 65 | return (m_data.size() - m_position) >= s; |
| 66 | } |
| 67 | |
| 68 | void StringLexer::PutBack(Size s) { |
| 69 | assert(m_position >= s); |
| 70 | m_position -= s; |
| 71 | } |
| 72 | |
| 73 | std::string StringLexer::GetUnlexed() { |
| 74 | return std::string(m_data, m_position); |
| 75 | } |
| 76 | |
| 77 | void StringLexer::Consume() { m_position++; } |
| 78 | |
| 79 | StringLexer &StringLexer::operator=(const StringLexer &rhs) { |
| 80 | if (this != &rhs) { |
| 81 | m_data = rhs.m_data; |
| 82 | m_position = rhs.m_position; |
| 83 | } |
| 84 | return *this; |
| 85 | } |
| 86 |