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#include "lexer.h"
#include "generic.h"
#include "regex.h"
#include <contrib/libs/re2/re2/re2.h>
#include <yql/essentials/core/issue/yql_issue.h>
#include <yql/essentials/sql/v1/reflect/sql_reflect.h>
#include <util/generic/algorithm.h>
#include <util/generic/string.h>
#include <util/generic/maybe.h>
#include <util/string/subst.h>
#include <util/string/ascii.h>
namespace NSQLTranslationV1 {
using NSQLReflect::TLexerGrammar;
using NSQLTranslation::TParsedToken;
using NSQLTranslation::TParsedTokenList;
size_t MatchANSIMultilineComment(TStringBuf remaining);
TTokenMatcher ANSICommentMatcher(TTokenMatcher defaultComment) {
return [defaultComment](TStringBuf prefix) -> TMaybe<TStringBuf> {
const auto basic = defaultComment(prefix);
if (basic.Empty()) {
return Nothing();
}
if (!prefix.StartsWith("/*")) {
return basic;
}
size_t ll1Length = MatchANSIMultilineComment(prefix);
TStringBuf ll1Content = prefix.SubString(0, ll1Length);
Y_ENSURE(ll1Content == 0 || basic <= ll1Content);
if (ll1Content == 0) {
return basic;
}
return ll1Content;
};
}
size_t MatchANSIMultilineComment(TStringBuf prefix) {
if (!prefix.StartsWith("/*")) {
return 0;
}
size_t skipped = 0;
prefix.Skip(2);
skipped += 2;
for (;;) {
if (prefix.StartsWith("*/")) {
prefix.Skip(2);
skipped += 2;
return skipped;
}
bool isSkipped = false;
if (prefix.StartsWith("/*")) {
size_t limit = prefix.rfind("*/");
if (limit == std::string::npos) {
return 0;
}
size_t len = MatchANSIMultilineComment(prefix.Head(limit));
prefix.Skip(len);
skipped += len;
isSkipped = len != 0;
}
if (isSkipped) {
continue;
}
if (prefix.size() == 0) {
return 0;
}
prefix.Skip(1);
skipped += 1;
}
}
TGenericLexerGrammar MakeGenericLexerGrammar(
bool ansi,
const TLexerGrammar& grammar,
const TVector<std::tuple<TString, TString>>& regexByOtherName) {
TGenericLexerGrammar generic;
for (const auto& name : grammar.KeywordNames) {
auto matcher = Compile({
.Body = TString(TLexerGrammar::KeywordBlock(name)),
.IsCaseInsensitive = true,
});
generic.emplace_back(name, std::move(matcher));
}
for (const auto& name : grammar.PunctuationNames) {
generic.emplace_back(
name, Compile({RE2::QuoteMeta(grammar.BlockByName.at(name))}));
}
for (const auto& [name, regex] : regexByOtherName) {
auto matcher = Compile({
.Body = regex,
});
generic.emplace_back(name, std::move(matcher));
}
if (ansi) {
auto it = FindIf(generic, [](const auto& m) {
return m.TokenName == "COMMENT";
});
Y_ENSURE(it != std::end(generic));
it->Match = ANSICommentMatcher(it->Match);
}
return generic;
}
class TRegexLexer: public NSQLTranslation::ILexer {
public:
TRegexLexer(IGenericLexer::TPtr lexer)
: Lexer_(std::move(lexer))
{
}
bool Tokenize(
const TString& query,
const TString& queryName,
const TTokenCallback& onNextToken,
NYql::TIssues& issues,
size_t maxErrors) override {
bool isFailed = false;
const auto onNext = [&](TGenericToken&& token) {
if (token.Name == TGenericToken::Error) {
NYql::TPosition pos(token.Begin, 0, queryName);
TString message = TString("no candidates, skipping ") + token.Content;
issues.AddIssue(std::move(pos), std::move(message));
isFailed = true;
return;
}
onNextToken({
.Name = TString(token.Name),
.Content = TString(token.Content),
});
};
Lexer_->Tokenize(query, onNext, maxErrors);
return !isFailed;
}
private:
IGenericLexer::TPtr Lexer_;
};
namespace {
class TFactory final: public NSQLTranslation::ILexerFactory {
public:
explicit TFactory(bool ansi) {
auto grammar = NSQLReflect::LoadLexerGrammar();
auto regexes = MakeRegexByOtherName(grammar, ansi);
Lexer_ = MakeGenericLexer(MakeGenericLexerGrammar(ansi, grammar, regexes));
}
NSQLTranslation::ILexer::TPtr MakeLexer() const override {
return NSQLTranslation::ILexer::TPtr(
new TRegexLexer(Lexer_));
}
private:
IGenericLexer::TPtr Lexer_;
};
} // namespace
NSQLTranslation::TLexerFactoryPtr MakeRegexLexerFactory(bool ansi) {
return NSQLTranslation::TLexerFactoryPtr(new TFactory(ansi));
}
} // namespace NSQLTranslationV1
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