Modules/Tokenizer/public/RegularExpression.h
2023-07-30 08:28:31 +03:00

521 lines
No EOL
14 KiB
C++

#pragma once
#include "AutomataGraph.h"
namespace tp {
extern ModuleManifest gModuleTokenizer;
}
namespace tp::RegEx {
struct AstNode {
enum Type {
NONE,
ANY,
OR,
IF,
CLASS,
COMPOUND,
REPEAT,
VAL,
} mType = NONE;
AstNode() = default;
virtual ~AstNode() = default;
};
template <typename tAlphabetType>
struct AstVal : public AstNode {
explicit AstVal(tAlphabetType val) : mVal(val) { mType = VAL; }
~AstVal() override = default;
tAlphabetType mVal;
};
struct AstCompound : public AstNode {
AstCompound() { mType = COMPOUND; }
~AstCompound() override {
for (auto iter : mChilds) {
delete iter.data();
}
mChilds.removeAll();
}
List<AstNode*> mChilds;
};
struct AstAlternation : public AstNode {
AstAlternation() { mType = OR; }
~AstAlternation() override {
delete mFirst;
delete mSecond;
}
AstNode* mFirst = nullptr;
AstNode* mSecond = nullptr;
};
struct AstIf : public AstNode {
AstIf() { mType = IF; }
~AstIf() override { delete mNode; }
AstNode* mNode = nullptr;
};
struct AstAny : public AstNode {
AstAny() { mType = ANY; }
~AstAny() override = default;
};
struct AstRepetition : public AstNode {
AstRepetition() { mType = REPEAT; }
~AstRepetition() override { delete mNode; }
AstNode* mNode = nullptr;
bool mPlus = false;
};
template <typename tAlphabetType>
struct AstClass : public AstNode {
AstClass() { mType = CLASS; }
~AstClass() override { mRanges.removeAll(); }
List<Range<tAlphabetType>> mRanges;
bool mExclude = false;
};
struct ParseError {
const char* description = nullptr;
uhalni offset = 0;
[[nodiscard]] bool isError() const { return description != nullptr; }
};
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal>
class Parser {
enum TokType : uint1 {
TOK_COMPOUND_START = 0,
TOK_COMPOUND_END,
TOK_CLASS_START,
TOK_CLASS_END,
TOK_CLASS_START_EXCLUDE,
TOK_CLASS_END_EXCLUDE,
TOK_OR,
TOK_IF,
TOK_ANY,
TOK_REPEAT,
TOK_REPEAT_PLUS,
TOK_HYPHEN,
TOK_SPECIALS_END_,
TOK_VAL,
TOK_NONE,
};
tAlphabetType SpecialSymbols[TOK_SPECIALS_END_] = {
'(', ')', '[', ']', '{', '}', '|', '?', '.', '*', '+', '-',
};
tAlphabetType mEscapeSymbol = '\\';
struct Token {
TokType type;
tAlphabetType val;
};
const tAlphabetType* mSource = nullptr;
uhalni mOffset = 0;
Token mCurToken;
uhalni mTokLength = 0;
public:
ParseError mError;
// regular expression must be a zero termination string
AstCompound* parse(const tAlphabetType* regex) {
mSource = regex;
return parseRegEx();
}
private:
AstCompound* parseRegEx() {
auto out = new AstCompound();
for (AstNode* node = parseElement(); node; node = parseElement()) {
out->mChilds.pushBack(node);
}
if (!out->mChilds.length()) {
genError("Expected A Expression");
}
if (mError.description) {
delete out;
return nullptr;
}
return out;
}
AstNode* parseElement() {
AstNode* out = nullptr;
switch (readTok().type) {
case TOK_COMPOUND_START: out = parseCompound(); break;
case TOK_CLASS_START: out = parseClass(); break;
case TOK_CLASS_START_EXCLUDE: out = parseClass(true); break;
case TOK_ANY: out = parseAny(); break;
case TOK_VAL: out = parseVal(); break;
case TOK_NONE: { discardTok(); return nullptr; };
default: break;
}
if (!out) {
discardTok();
return nullptr;
}
switch (readTok().type) {
case TOK_OR: out = parseAlternation(out); break;
case TOK_REPEAT: out = parseRepetition(out); break;
case TOK_REPEAT_PLUS: out = parseRepetition(out, true); break;
case TOK_IF: out = parseIf(out); break;
case TOK_NONE: break;
default: { discardTok(); }
}
return out;
}
AstCompound* parseCompound() {
auto out = new AstCompound();
for (AstNode* node = parseElement(); node; node = parseElement()) {
out->mChilds.pushBack(node);
}
if (readTok().type != TOK_COMPOUND_END) {
genError("Expected Compound End");
}
if (mError.description) {
delete out;
return nullptr;
}
return out;
}
AstClass<tAlphabetType>* parseClass(bool exclude = false) {
auto out = new AstClass<tAlphabetType>();
out->mExclude = exclude;
auto& ranges = out->mRanges;
readTok();
READ_VAL:
if (mCurToken.type != TOK_VAL) {
delete out;
genError("Expected A Value");
return nullptr;
}
char range_start = mCurToken.val;
readTok();
if (mCurToken.type != TOK_HYPHEN) {
delete out;
genError("Expected A Range");
return nullptr;
}
readTok();
if (mCurToken.type != TOK_VAL) {
delete out;
genError("Expected A Value");
return nullptr;
}
char range_end = mCurToken.val;
ranges.pushBack({ range_start, range_end });
readTok();
if ((mCurToken.type == TOK_CLASS_END && !exclude) || (mCurToken.type == TOK_CLASS_END_EXCLUDE && exclude)) {
return out;
}
else {
goto READ_VAL;
}
}
AstAny* parseAny() {
return new AstAny();
}
AstVal<tAlphabetType>* parseVal() {
auto out = new AstVal<tAlphabetType>(mCurToken.val);
return out;
}
AstAlternation* parseAlternation(AstNode* left) {
auto right = parseElement();
if (!right) {
genError("Expected Alternation right Side");
delete left;
return nullptr;
}
auto out = new AstAlternation();
out->mFirst = left;
out->mSecond = right;
return out;
}
AstRepetition* parseRepetition(AstNode* left, bool plus = false) {
auto out = new AstRepetition();
out->mNode = left;
out->mPlus = plus;
return out;
}
AstIf* parseIf(AstNode* left) {
auto out = new AstIf();
out->mNode = left;
return out;
}
void genError(const char* desc) {
mError = { desc, mOffset };
}
Token& readTok() {
const tAlphabetType* crs = mSource + mOffset;
// zero termination string
if (*crs == 0) {
mCurToken.type = TOK_NONE;
return mCurToken;
}
mTokLength = 1;
mCurToken.type = TOK_VAL;
mCurToken.val = crs[0];
if (crs[0] == mEscapeSymbol) {
mCurToken.val = crs[1];
mTokLength = 2;
}
else {
for (uhalni tok = 0; tok < TOK_SPECIALS_END_; tok++) {
if (SpecialSymbols[tok] == mCurToken.val) {
mCurToken.type = TokType(tok);
break;
}
}
}
mOffset += mTokLength;
return mCurToken;
}
void discardTok() {
mOffset -= mTokLength;
mTokLength = 0;
}
};
template <typename tStateType>
struct CompileError {
ParseError mParseError;
uhalni mRuleIndex = 0;
tStateType mRuleState;
const char* description = nullptr;
[[nodiscard]] bool isError() const { return description; }
};
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal, tStateType tFailedStateVal>
class Compiler {
typedef NFA<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal> Graph;
typedef typename Graph::Vertex Vertex;
typedef Parser<tAlphabetType, tStateType, tNoStateVal> Parser;
struct Node {
Vertex* left = nullptr;
Vertex* right = nullptr;
};
private:
Graph* mGraph = nullptr;
public:
CompileError<tStateType> mError;
Node compile(Graph& graph, const tAlphabetType* regex, tStateType state) {
mGraph = &graph;
return compileUtil(regex, state);
}
Node compile(Graph& aGraph, InitialierList<Pair<const tAlphabetType*, tStateType>> aRules) {
mGraph = &aGraph;
auto left = mGraph->addVertex();
auto right = mGraph->addVertex();
halni idx = 0;
for (auto rule: aRules) {
auto node = idx ? compileUtil(rule.head, rule.tail) : compileUtil(rule.head, rule.tail, left, right);
if (!(node.left && node.right)) {
mError.mRuleIndex = idx;
return {};
}
if (idx) {
transitionAny(left, node.left);
transitionAny(node.right, right);
}
idx++;
}
mGraph->setStartVertex(left);
return { left, right };
}
private:
Node compileUtil(const tAlphabetType* regex, tStateType state, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
Parser parser;
auto astNode = parser.parse(regex);
if (parser.mError.isError()) {
mGraph->setStartVertex(nullptr);
mError.description = "Parsing Of Regular Expression Failed";
mError.mRuleState = state;
mError.mParseError = parser.mError;
return {};
}
auto node = compileNode(astNode, aLeft, aRight);
delete astNode;
mGraph->setVertexState(node.right, state);
mGraph->setStartVertex(node.left);
return node;
}
Node compileVal(AstVal<tAlphabetType>* val, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
auto left = aLeft ? aLeft : mGraph->addVertex();
auto right = aRight ? aRight : mGraph->addVertex();
transitionVal(left, right, val->mVal);
return { left, right };
}
Node compileAlternation(AstAlternation* alt, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
auto first_node = compileNode(alt->mFirst, aLeft, aRight);
auto second_node = compileNode(alt->mSecond);
transitionAny(first_node.left, second_node.left);
transitionAny(second_node.right, first_node.right);
return first_node;
}
Node compileAny(AstAny*, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
auto left = aLeft ? aLeft : mGraph->addVertex();
auto right = aRight ? aRight : mGraph->addVertex();
transitionAny(left, right, true);
return { left, right };
}
Node compileRepeat(AstRepetition* repeat, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
if (repeat->mPlus) {
auto middle = mGraph->addVertex();
auto left_node = compileNode(repeat->mNode, aLeft, middle);
auto right_node = compileNode(repeat->mNode, middle, aRight);
transitionAny(right_node.right, right_node.left);
transitionAny(right_node.left, right_node.right);
return { left_node.left, right_node.right };
}
else {
auto node = compileNode(repeat->mNode, aLeft, aRight);
transitionAny(node.right, node.left);
transitionAny(node.left, node.right);
return node;
}
}
Node compileIf(AstIf* ifNode, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
auto node = compileNode(ifNode->mNode, aLeft, aRight);
transitionAny(node.left, node.right);
return node;
}
Node compileClass(AstClass<tAlphabetType>* node, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
auto left = aLeft ? aLeft : mGraph->addVertex();
auto right = aRight ? aRight : mGraph->addVertex();
if (node->mRanges.length() == 1) {
auto const& range = node->mRanges.first()->data;
transitionRange(left, right, { range.mBegin, range.mEnd }, node->mExclude);
return { left, right };
}
for (auto range : node->mRanges) {
auto middle = mGraph->addVertex();
transitionRange(left, middle, { range.data().mBegin, range.data().mEnd }, node->mExclude);
transitionAny(middle, right);
}
return { left, right };
}
Node compileCompound(AstCompound* compound, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
Vertex* left = nullptr;
Vertex* rigth = nullptr;
ualni idx = 0;
for (auto child : compound->mChilds) {
auto pass_left = idx == 0 ? aLeft : rigth;
auto pass_right = idx == compound->mChilds.length() - 1 ? aRight : nullptr;
auto node = compileNode(child.data(), pass_left, pass_right);
if (!left) left = node.left;
rigth = node.right;
idx++;
}
return { left, rigth };
}
Node compileNode(AstNode* node, Vertex* aLeft = nullptr, Vertex* aRight = nullptr) {
switch (node->mType) {
case AstNode::CLASS: return compileClass((AstClass<tAlphabetType>*)node, aLeft, aRight);
case AstNode::COMPOUND: return compileCompound((AstCompound*)node, aLeft, aRight);
case AstNode::IF: return compileIf((AstIf*)node, aLeft, aRight);
case AstNode::REPEAT: return compileRepeat((AstRepetition*)node, aLeft, aRight);
case AstNode::ANY: return compileAny((AstAny*)node, aLeft, aRight);
case AstNode::OR: return compileAlternation((AstAlternation*)node, aLeft, aRight);
case AstNode::VAL: return compileVal((AstVal<tAlphabetType>*)node, aLeft, aRight);
case AstNode::NONE:
break;
}
ASSERT(0)
return {};
}
void transitionAny(Vertex* from, Vertex* to, bool consumes = false) {
mGraph->addTransition(from, to, {}, consumes, true, false);
}
void transitionVal(Vertex* from, Vertex* to, tAlphabetType val) {
mGraph->addTransition(from, to, { val, val }, true, false, false);
}
void transitionRange(Vertex* from, Vertex* to, Range<tAlphabetType> range, bool exclude) {
mGraph->addTransition(from, to, range, true, false, exclude);
}
};
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal, tStateType tFailedStateVal>
CompileError<tStateType> compile(NFA<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal>& out, const tAlphabetType* regex, tStateType state) {
Compiler<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal> compiler;
compiler.compile(out, regex, state);
return compiler.mError;
}
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal, tStateType tFailedStateVal>
CompileError<tStateType> compile(NFA<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal>& out, const InitialierList<Pair<const tAlphabetType*, tStateType>>& rules) {
Compiler<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal> compiler;
compiler.compile(out, rules);
return compiler.mError;
}
}