llvm-toolchain-10/lldb/source/Utility/StringLexer.cpp

85 lines
1.8 KiB
C++

//===--------------------- StringLexer.cpp -----------------------*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/StringLexer.h"
#include <algorithm>
#include <assert.h>
using namespace lldb_private;
StringLexer::StringLexer(std::string s) : m_data(s), m_position(0) {}
StringLexer::Character StringLexer::Peek() { return m_data[m_position]; }
bool StringLexer::NextIf(Character c) {
auto val = Peek();
if (val == c) {
Next();
return true;
}
return false;
}
std::pair<bool, StringLexer::Character>
StringLexer::NextIf(std::initializer_list<Character> cs) {
auto val = Peek();
for (auto c : cs) {
if (val == c) {
Next();
return {true, c};
}
}
return {false, 0};
}
bool StringLexer::AdvanceIf(const std::string &token) {
auto pos = m_position;
bool matches = true;
for (auto c : token) {
if (!NextIf(c)) {
matches = false;
break;
}
}
if (!matches) {
m_position = pos;
return false;
}
return true;
}
StringLexer::Character StringLexer::Next() {
auto val = Peek();
Consume();
return val;
}
bool StringLexer::HasAtLeast(Size s) {
return (m_data.size() - m_position) >= s;
}
void StringLexer::PutBack(Size s) {
assert(m_position >= s);
m_position -= s;
}
std::string StringLexer::GetUnlexed() {
return std::string(m_data, m_position);
}
void StringLexer::Consume() { m_position++; }
StringLexer &StringLexer::operator=(const StringLexer &rhs) {
if (this != &rhs) {
m_data = rhs.m_data;
m_position = rhs.m_position;
}
return *this;
}