1 //===--------------------- StringLexer.cpp -----------------------*- C++-*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Utility/StringLexer.h"
11 
12 #include <algorithm>
13 #include <assert.h>
14 
15 using namespace lldb_utility;
16 
StringLexer(std::string s)17 StringLexer::StringLexer(std::string s) : m_data(s), m_position(0) {}
18 
StringLexer(const StringLexer & rhs)19 StringLexer::StringLexer(const StringLexer &rhs)
20     : m_data(rhs.m_data), m_position(rhs.m_position) {}
21 
Peek()22 StringLexer::Character StringLexer::Peek() { return m_data[m_position]; }
23 
NextIf(Character c)24 bool StringLexer::NextIf(Character c) {
25   auto val = Peek();
26   if (val == c) {
27     Next();
28     return true;
29   }
30   return false;
31 }
32 
33 std::pair<bool, StringLexer::Character>
NextIf(std::initializer_list<Character> cs)34 StringLexer::NextIf(std::initializer_list<Character> cs) {
35   auto val = Peek();
36   for (auto c : cs) {
37     if (val == c) {
38       Next();
39       return {true, c};
40     }
41   }
42   return {false, 0};
43 }
44 
AdvanceIf(const std::string & token)45 bool StringLexer::AdvanceIf(const std::string &token) {
46   auto pos = m_position;
47   bool matches = true;
48   for (auto c : token) {
49     if (!NextIf(c)) {
50       matches = false;
51       break;
52     }
53   }
54   if (!matches) {
55     m_position = pos;
56     return false;
57   }
58   return true;
59 }
60 
Next()61 StringLexer::Character StringLexer::Next() {
62   auto val = Peek();
63   Consume();
64   return val;
65 }
66 
HasAtLeast(Size s)67 bool StringLexer::HasAtLeast(Size s) {
68   return (m_data.size() - m_position) >= s;
69 }
70 
PutBack(Size s)71 void StringLexer::PutBack(Size s) {
72   assert(m_position >= s);
73   m_position -= s;
74 }
75 
GetUnlexed()76 std::string StringLexer::GetUnlexed() {
77   return std::string(m_data, m_position);
78 }
79 
Consume()80 void StringLexer::Consume() { m_position++; }
81 
operator =(const StringLexer & rhs)82 StringLexer &StringLexer::operator=(const StringLexer &rhs) {
83   if (this != &rhs) {
84     m_data = rhs.m_data;
85     m_position = rhs.m_position;
86   }
87   return *this;
88 }
89