[clang-tools-extra] [llvm] [llvm] add support for mustache templating language (PR #105893)

[Paul Kirth via cfe-commits]

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@@ -0,0 +1,189 @@
+//===--- Mustache.h ---------------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of the Mustache templating language supports version 1.4.2
+// currently relies on llvm::json::Value for data input
+// see the Mustache spec for more information
+// (https://mustache.github.io/mustache.5.html).
+//
+// Current Features Supported:
+// - Variables
+// - Sections
+// - Inverted Sections
+// - Partials
+// - Comments
+// - Lambdas
+// - Unescaped Variables
+//
+// Features Not Supported:
+// - Set Delimiter
+// - Blocks
+// - Parents
+// - Dynamic Names
+//
+// Usage:
+// \code
+//   // Creating a simple template and rendering it
+//   auto Template = Template::createTemplate("Hello, {{name}}!");
+//   Value Data = {{"name", "World"}};
+//   StringRef Rendered = Template.render(Data);
+//   // Rendered == "Hello, World!"
+//
+//   // Creating a template with a partial and rendering it
+//   auto Template = Template::createTemplate("{{>partial}}");
+//   Template.registerPartial("partial", "Hello, {{name}}!");
+//   Value Data = {{"name", "World"}};
+//   StringRef Rendered = Template.render(Data);
+//   // Rendered == "Hello, World!"
+//
+//   // Creating a template with a lambda and rendering it
+//   auto Template = Template::createTemplate("{{#lambda}}Hello,
+//                                             {{name}}!{{/lambda}}");
+//   Template.registerLambda("lambda", []() { return true; });
+//   Value Data = {{"name", "World"}};
+//   StringRef Rendered = Template.render(Data);
+//   // Rendered == "Hello, World!"
+// \endcode
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_MUSTACHE
+#define LLVM_SUPPORT_MUSTACHE
+
+#include "Error.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/JSON.h"
+#include <vector>
+
+namespace llvm {
+namespace mustache {
+
+using Accessor = std::vector<SmallString<128>>;
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ilovepi wrote:

`SmallVector<>` is probably better. Do you need copies of the string in the vector? or would StringRef work?

https://github.com/llvm/llvm-project/pull/105893