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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>
#include <util/string/join.h>
namespace NSQLTranslationV1 {
using NSQLReflect::TLexerGrammar;
using NSQLTranslation::TParsedToken;
using NSQLTranslation::TParsedTokenList;
size_t MatchANSIMultilineComment(TStringBuf remaining);
TTokenMatcher ANSICommentMatcher(TString name, TTokenMatcher defaultComment) {
return [defaultComment, name = std::move(name)](TStringBuf prefix) -> TMaybe<TGenericToken> {
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->Content <= ll1Content);
if (ll1Content == 0) {
return basic;
}
return TGenericToken{
.Name = name,
.Content = 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;
}
}
TTokenMatcher KeywordMatcher(const NSQLReflect::TLexerGrammar& grammar) {
auto keyword = Compile("Keyword", KeywordPattern(grammar));
return [keyword = std::move(keyword)](TStringBuf content) -> TMaybe<TGenericToken> {
if (auto token = keyword(content)) {
return TGenericToken{
.Name = TLexerGrammar::KeywordNameByBlock(token->Content),
.Content = token->Content,
};
}
return Nothing();
};
}
TRegexPattern KeywordPattern(const NSQLReflect::TLexerGrammar& grammar) {
TVector<TRegexPattern> patterns;
patterns.reserve(grammar.KeywordNames.size());
for (const auto& keyword : grammar.KeywordNames) {
const TStringBuf content = TLexerGrammar::KeywordBlockByName(keyword);
patterns.push_back({
.Body = TString(content),
.IsCaseInsensitive = true,
});
}
return Merged(std::move(patterns));
}
TTokenMatcher PuntuationMatcher(const NSQLReflect::TLexerGrammar& grammar) {
THashMap<TString, TString> nameByBlock;
nameByBlock.reserve(grammar.PunctuationNames.size());
for (const auto& name : grammar.PunctuationNames) {
const auto& block = grammar.BlockByName.at(name);
nameByBlock[block] = name;
}
auto punct = Compile("Punctuation", PuntuationPattern(grammar));
return [nameByBlock = std::move(nameByBlock),
punct = std::move(punct)](TStringBuf content) -> TMaybe<TGenericToken> {
if (auto token = punct(content)) {
return TGenericToken{
.Name = nameByBlock.at(token->Content),
.Content = token->Content,
};
}
return Nothing();
};
}
TRegexPattern PuntuationPattern(const NSQLReflect::TLexerGrammar& grammar) {
TVector<TRegexPattern> patterns;
patterns.reserve(grammar.PunctuationNames.size());
for (const auto& name : grammar.PunctuationNames) {
patterns.push_back({RE2::QuoteMeta(grammar.BlockByName.at(name))});
}
return Merged(std::move(patterns));
}
TGenericLexerGrammar MakeGenericLexerGrammar(
bool ansi,
const TLexerGrammar& grammar,
const TVector<std::tuple<TString, TString>>& regexByOtherName) {
TGenericLexerGrammar generic;
generic.emplace_back(KeywordMatcher(grammar));
generic.emplace_back(PuntuationMatcher(grammar));
for (const auto& [name, regex] : regexByOtherName) {
generic.emplace_back(Compile(name, {regex}));
if (name == "COMMENT" && ansi) {
generic.back() = ANSICommentMatcher(name, std::move(generic.back()));
}
}
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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