[clang-tools-extra] [llvm] [llvm] add support for mustache templating language (PR #105893)
Paul Kirth via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 6 17:14:24 PDT 2024
================
@@ -0,0 +1,446 @@
+//===-- Mustache.cpp ------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Mustache.h"
+#include "llvm/Support/Error.h"
+
+using namespace llvm;
+using namespace llvm::json;
+using namespace llvm::mustache;
+
+SmallString<128> escapeString(StringRef Input,
+ DenseMap<char, StringRef> &Escape) {
+ SmallString<128> EscapedString("");
+ for (char C : Input) {
+ if (Escape.find(C) != Escape.end())
+ EscapedString += Escape[C];
+ else
+ EscapedString += C;
+ }
+ return EscapedString;
+}
+
+std::vector<SmallString<128>> split(StringRef Str, char Delimiter) {
+ std::vector<SmallString<128>> Tokens;
+ if (Str == ".") {
+ Tokens.push_back(Str);
+ return Tokens;
+ }
+ StringRef Ref(Str);
+ while (!Ref.empty()) {
+ llvm::StringRef Part;
+ std::tie(Part, Ref) = Ref.split(Delimiter);
+ Tokens.push_back(Part.trim());
+ }
+ return Tokens;
+}
+
+Token::Token(StringRef RawBody, StringRef InnerBody, char Identifier)
+ : RawBody(RawBody), TokenBody(InnerBody) {
+
+ TokenType = getTokenType(Identifier);
+ if (TokenType == Type::Comment)
+ return;
+
+ StringRef AccessorStr = InnerBody;
+ if (TokenType != Type::Variable)
+ AccessorStr = InnerBody.substr(1);
+
+ Accessor = split(AccessorStr.trim(), '.');
+}
+
+Token::Token(StringRef Str)
+ : RawBody(Str), TokenType(Type::Text), TokenBody(Str), Accessor({}) {}
+
+Token::Type Token::getTokenType(char Identifier) {
+ switch (Identifier) {
+ case '#':
+ return Type::SectionOpen;
+ case '/':
+ return Type::SectionClose;
+ case '^':
+ return Type::InvertSectionOpen;
+ case '!':
+ return Type::Comment;
+ case '>':
+ return Type::Partial;
+ case '&':
+ return Type::UnescapeVariable;
+ default:
+ return Type::Variable;
+ }
+}
+
+std::vector<Token> tokenize(StringRef Template) {
+ // Simple tokenizer that splits the template into tokens
+ // the mustache spec allows {{{ }}} to unescape variables
+ // but we don't support that here unescape variable
+ // is represented only by {{& variable}}
+ std::vector<Token> Tokens;
+ SmallString<128> Open("{{");
+ SmallString<128> Close("}}");
+ std::size_t Start = 0;
+ std::size_t DelimiterStart = Template.find(Open);
+ if (DelimiterStart == StringRef::npos) {
+ Tokens.push_back(Token(Template));
+ return Tokens;
+ }
+ while (DelimiterStart != StringRef::npos) {
+ if (DelimiterStart != Start) {
+ Token TextToken = Token(Template.substr(Start, DelimiterStart - Start));
+ Tokens.push_back(TextToken);
+ }
+
+ std::size_t DelimiterEnd = Template.find(Close, DelimiterStart);
+ if (DelimiterEnd == StringRef::npos) {
+ break;
+ }
+
+ SmallString<128> Interpolated =
+ Template.substr(DelimiterStart + Open.size(),
+ DelimiterEnd - DelimiterStart - Close.size());
+ SmallString<128> RawBody;
+ RawBody += Open;
+ RawBody += Interpolated;
+ RawBody += Close;
+
+ Tokens.push_back(Token(RawBody, Interpolated, Interpolated[0]));
+ Start = DelimiterEnd + Close.size();
+ DelimiterStart = Template.find(Open, Start);
+ }
+
+ if (Start < Template.size())
+ Tokens.push_back(Token(Template.substr(Start)));
+
+ // fix up white spaces for
+ // open sections/inverted sections/close section/comment
+ for (std::size_t I = 0; I < Tokens.size(); I++) {
+ Token::Type CurrentType = Tokens[I].getType();
+ bool RequiresCleanUp = CurrentType == Token::Type::SectionOpen ||
+ CurrentType == Token::Type::InvertSectionOpen ||
+ CurrentType == Token::Type::SectionClose ||
+ CurrentType == Token::Type::Comment ||
+ CurrentType == Token::Type::Partial;
+
+ bool NoTextBehind = false;
+ bool NoTextAhead = false;
+ if (I > 0 && Tokens[I - 1].getType() == Token::Type::Text &&
+ RequiresCleanUp) {
+ Token &PrevToken = Tokens[I - 1];
+ StringRef TokenBody = PrevToken.getRawBody().rtrim(" \t\v\t");
+ if (TokenBody.ends_with("\n") || TokenBody.ends_with("\r\n") ||
+ (TokenBody.empty() && I == 1))
+ NoTextBehind = true;
+ }
+ if (I < Tokens.size() - 1 && Tokens[I + 1].getType() == Token::Type::Text &&
+ RequiresCleanUp) {
+ Token &NextToken = Tokens[I + 1];
+ StringRef TokenBody = NextToken.getRawBody().ltrim(" ");
+ if (TokenBody.starts_with("\r\n") || TokenBody.starts_with("\n"))
+ NoTextAhead = true;
+ }
+
+ if ((NoTextBehind && NoTextAhead) || (NoTextAhead && I == 0)) {
+ Token &NextToken = Tokens[I + 1];
+ StringRef NextTokenBody = NextToken.getTokenBody();
+ if (NextTokenBody.starts_with("\r\n"))
+ NextToken.setTokenBody(NextTokenBody.substr(2));
+ else if (NextToken.getTokenBody().starts_with("\n"))
+ NextToken.setTokenBody(NextTokenBody.substr(1));
+ }
+ if ((NoTextBehind && NoTextAhead) ||
+ (NoTextBehind && I == Tokens.size() - 1)) {
+ Token &PrevToken = Tokens[I - 1];
+ StringRef PrevTokenBody = PrevToken.getTokenBody();
+ PrevToken.setTokenBody(PrevTokenBody.rtrim(" \t\v\t"));
+ }
+ }
+ return Tokens;
+}
+
+class Parser {
+public:
+ Parser(StringRef TemplateStr) : TemplateStr(TemplateStr) {}
+
+ std::shared_ptr<ASTNode> parse();
+
+private:
+ void parseMustache(std::shared_ptr<ASTNode> Parent);
+
+ std::vector<Token> Tokens;
+ std::size_t CurrentPtr;
+ StringRef TemplateStr;
+};
+
+std::shared_ptr<ASTNode> Parser::parse() {
+ Tokens = tokenize(TemplateStr);
+ CurrentPtr = 0;
+ std::shared_ptr<ASTNode> Root = std::make_shared<ASTNode>();
+ parseMustache(Root);
+ return Root;
+}
+
+void Parser::parseMustache(std::shared_ptr<ASTNode> Parent) {
+
+ while (CurrentPtr < Tokens.size()) {
+ Token CurrentToken = Tokens[CurrentPtr];
+ CurrentPtr++;
+ Accessor A = CurrentToken.getAccessor();
+ std::shared_ptr<ASTNode> CurrentNode;
+
+ switch (CurrentToken.getType()) {
+ case Token::Type::Text: {
+ CurrentNode =
+ std::make_shared<ASTNode>(CurrentToken.getTokenBody(), Parent);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::Variable: {
+ CurrentNode = std::make_shared<ASTNode>(ASTNode::Variable, A, Parent);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::UnescapeVariable: {
+ CurrentNode =
+ std::make_shared<ASTNode>(ASTNode::UnescapeVariable, A, Parent);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::Partial: {
+ CurrentNode = std::make_shared<ASTNode>(ASTNode::Partial, A, Parent);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::SectionOpen: {
+ CurrentNode = std::make_shared<ASTNode>(ASTNode::Section, A, Parent);
+ std::size_t Start = CurrentPtr;
+ parseMustache(CurrentNode);
+ std::size_t End = CurrentPtr;
+ SmallString<128> RawBody;
+ if (Start + 1 < End - 1)
+ for (std::size_t I = Start + 1; I < End - 1; I++)
+ RawBody += Tokens[I].getRawBody();
+ else if (Start + 1 == End - 1)
+ RawBody = Tokens[Start].getRawBody();
+ CurrentNode->setRawBody(RawBody);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::InvertSectionOpen: {
+ CurrentNode =
+ std::make_shared<ASTNode>(ASTNode::InvertSection, A, Parent);
+ std::size_t Start = CurrentPtr;
+ parseMustache(CurrentNode);
+ std::size_t End = CurrentPtr;
+ SmallString<128> RawBody;
+ if (Start + 1 < End - 1)
+ for (std::size_t I = Start + 1; I < End - 1; I++)
+ RawBody += Tokens[I].getRawBody();
+ else if (Start + 1 == End - 1)
+ RawBody = Tokens[Start].getRawBody();
+ CurrentNode->setRawBody(RawBody);
+ Parent->addChild(CurrentNode);
+ break;
+ }
+ case Token::Type::SectionClose:
+ return;
+ default:
+ break;
+ }
+ }
+}
+
+Template Template::createTemplate(StringRef TemplateStr) {
+ Parser P = Parser(TemplateStr);
+ std::shared_ptr<ASTNode> MustacheTree = P.parse();
+ Template T = Template(MustacheTree);
+ // the default behaviour is to escape html entities
+ DenseMap<char, StringRef> HtmlEntities = {{'&', "&"},
+ {'<', "<"},
+ {'>', ">"},
+ {'"', """},
+ {'\'', "'"}};
+ T.registerEscape(HtmlEntities);
+ return T;
+}
+
+SmallString<128> Template::render(Value Data) {
+ return Tree->render(Data, Partials, Lambdas, SectionLambdas, Escapes);
+}
+
+void Template::registerPartial(StringRef Name, StringRef Partial) {
+ Parser P = Parser(Partial);
+ std::shared_ptr<ASTNode> PartialTree = P.parse();
+ Partials[Name] = PartialTree;
+}
+
+void Template::registerLambda(StringRef Name, Lambda L) { Lambdas[Name] = L; }
+
+void Template::registerLambda(StringRef Name, SectionLambda L) {
+ SectionLambdas[Name] = L;
+}
+
+void Template::registerEscape(DenseMap<char, StringRef> E) { Escapes = E; }
+
+SmallString<128> printJson(Value &Data) {
+
+ SmallString<128> Result;
+ if (Data.getAsNull())
+ return Result;
+ if (auto *Arr = Data.getAsArray())
+ if (Arr->empty())
----------------
ilovepi wrote:
Can we combine these? I never remember if that's allowed until I try it.
https://github.com/llvm/llvm-project/pull/105893
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