================ @@ -0,0 +1,114 @@ +//===--- 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 +// +// The Template class is container class outputs the Mustache template string +// and is main class for users. It stores all the lambdas and the ASTNode Tree. +// When the Template is instantiated it tokenize the Template String and +// creates a vector of Tokens. Then it calls a basic recursive descent parser +// to construct the ASTNode Tree. The ASTNodes are all stored in an arena +// allocator which is freed once the template class goes out of scope +// +// Usage: +// \code +// // Creating a simple template and rendering it +// auto Template = Template("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("{{>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("{{#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/Allocator.h" +#include "llvm/Support/JSON.h" +#include "llvm/Support/StringSaver.h" +#include <vector> + +namespace llvm { +namespace mustache { + +using Accessor = SmallVector<std::string>; +using Lambda = std::function<llvm::json::Value()>; +using SectionLambda = std::function<llvm::json::Value(std::string)>; + +class ASTNode; + +// A Template represents the container for the AST and the partials +// and Lambdas that are registered with it. +class Template { +public: + Template(std::string TemplateStr); ---------------- nicovank wrote:
The benefit of passing by value and moving is allowing users to have **zero** copies by moving directly into the member. For large template text strings, copies are expensive. Passing by StringRef and copying **always** forces one copy. For example, the user may want: ```cpp std::string readSomeFile(); // Passing by StringRef, this will generate an unnecessary copy. std::string templateText = readSomeFile(); Template template(std::move(templateText)); // Even more sneaky, this will read the file into a string, and duplicate that string to create the template. Template template(readSomeFile()); ``` Maybe there is a way to restructure the API to use non-owning view members only? This is probably a non-trivial change to this work. I’ll try to have another look and post some review comments by end of week. https://github.com/llvm/llvm-project/pull/105893 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
