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 #ifndef SKSL_REGEXNODE 9 #define SKSL_REGEXNODE 10 11 #include <string> 12 #include <vector> 13 14 struct NFA; 15 16 /** 17 * Represents a node in the parse tree of a regular expression. 18 */ 19 struct RegexNode { 20 enum Kind { 21 kChar_Kind, 22 kCharset_Kind, 23 kConcat_Kind, 24 kDot_Kind, 25 kOr_Kind, 26 kPlus_Kind, 27 kRange_Kind, 28 kQuestion_Kind, 29 kStar_Kind 30 }; 31 32 RegexNode(Kind kind) 33 : fKind(kind) {} 34 35 RegexNode(Kind kind, char payload) 36 : fKind(kind) { 37 fPayload.fChar = payload; 38 } 39 40 RegexNode(Kind kind, const char* children) 41 : fKind(kind) { 42 fPayload.fBool = false; 43 while (*children != '\0') { 44 fChildren.emplace_back(kChar_Kind, *children); 45 ++children; 46 } 47 } 48 49 RegexNode(Kind kind, RegexNode child) 50 : fKind(kind) { 51 fChildren.push_back(std::move(child)); 52 } 53 54 RegexNode(Kind kind, RegexNode child1, RegexNode child2) 55 : fKind(kind) { 56 fChildren.push_back(std::move(child1)); 57 fChildren.push_back(std::move(child2)); 58 } 59 60 /** 61 * Creates NFA states for this node, with a successful match against this node resulting in a 62 * transition to all of the states in the accept vector. 63 */ 64 std::vector<int> createStates(NFA* nfa, const std::vector<int>& accept) const; 65 66 std::string description() const; 67 68 Kind fKind; 69 70 union Payload { 71 char fChar; 72 bool fBool; 73 } fPayload; 74 75 std::vector<RegexNode> fChildren; 76 }; 77 78 #endif 79
