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gerrit-public.fairphone.software / platform / external / skia / 33f920e3f1cb8f21d3bb43a470a1dad2dc6a99bc / . / src / sksl / lex / RegexNode.cpp
blob: d2668ddbd6d984b6092140b9e9de230ee07e6b59 [file] [log] [blame]
Ethan Nicholasca82a922017-09-07 09:39:50 -0400[diff] [blame]1/*
2 * Copyright 2017 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "RegexNode.h"
9
10#include "NFA.h"
11
12std::vector<int> RegexNode::createStates(NFA* nfa, const std::vector<int>& accept) const {
13 std::vector<int> result;
14 switch (fKind) {
15 case kChar_Kind:
16 result.push_back(nfa->addState(NFAState(fPayload.fChar, accept)));
17 break;
18 case kCharset_Kind: {
19 std::vector<bool> chars;
20 for (const RegexNode& child : fChildren) {
21 if (child.fKind == kChar_Kind) {
22 while (chars.size() <= (size_t) child.fPayload.fChar) {
23 chars.push_back(false);
24 }
25 chars[child.fPayload.fChar] = true;
26 } else {
Ethan Nicholasd9d33c32018-06-12 11:05:59 -0400[diff] [blame]27 SkASSERT(child.fKind == kRange_Kind);
Ethan Nicholasca82a922017-09-07 09:39:50 -0400[diff] [blame]28 while (chars.size() <= (size_t) child.fChildren[1].fPayload.fChar) {
29 chars.push_back(false);
30 }
31 for (char c = child.fChildren[0].fPayload.fChar;
32 c <= child.fChildren[1].fPayload.fChar;
33 ++c) {
34 chars[c] = true;
35 }
36 }
37 }
38 result.push_back(nfa->addState(NFAState(fPayload.fBool, chars, accept)));
39 break;
40 }
41 case kConcat_Kind: {
42 std::vector<int> right = fChildren[1].createStates(nfa, accept);
43 result = fChildren[0].createStates(nfa, right);
44 break;
45 }
46 case kDot_Kind:
47 result.push_back(nfa->addState(NFAState(NFAState::kDot_Kind, accept)));
48 break;
49 case kOr_Kind: {
50 std::vector<int> states = fChildren[0].createStates(nfa, accept);
51 result.insert(result.end(), states.begin(), states.end());
52 states = fChildren[1].createStates(nfa, accept);
53 result.insert(result.end(), states.begin(), states.end());
54 break;
55 }
56 case kPlus_Kind: {
57 std::vector<int> next = accept;
58 std::vector<int> placeholder;
59 int id = nfa->addState(NFAState(placeholder));
60 next.push_back(id);
61 result = fChildren[0].createStates(nfa, next);
62 nfa->fStates[id] = NFAState(result);
63 break;
64 }
65 case kQuestion_Kind:
66 result = fChildren[0].createStates(nfa, accept);
67 result.insert(result.end(), accept.begin(), accept.end());
68 break;
69 case kRange_Kind:
70 ABORT("unreachable");
71 case kStar_Kind: {
72 std::vector<int> next = accept;
73 std::vector<int> placeholder;
74 int id = nfa->addState(NFAState(placeholder));
75 next.push_back(id);
76 result = fChildren[0].createStates(nfa, next);
77 result.insert(result.end(), accept.begin(), accept.end());
78 nfa->fStates[id] = NFAState(result);
79 break;
80 }
81 }
82 return result;
83}
84
85std::string RegexNode::description() const {
86 switch (fKind) {
87 case kChar_Kind:
88 return std::string(1, fPayload.fChar);
89 case kCharset_Kind: {
90 std::string result("[");
91 if (fPayload.fBool) {
92 result += "^";
93 }
94 for (const RegexNode& c : fChildren) {
95 result += c.description();
96 }
97 result += "]";
98 return result;
99 }
100 case kConcat_Kind:
101 return fChildren[0].description() + fChildren[1].description();
102 case kDot_Kind:
103 return ".";
104 case kOr_Kind:
105 return "(" + fChildren[0].description() + "|" + fChildren[1].description() + ")";
106 case kPlus_Kind:
107 return fChildren[0].description() + "+";
108 case kQuestion_Kind:
109 return fChildren[0].description() + "?";
110 case kRange_Kind:
111 return fChildren[0].description() + "-" + fChildren[1].description();
112 case kStar_Kind:
113 return fChildren[0].description() + "*";
114 default:
115 return "<" + std::to_string(fKind) + ">";
116 }
117}