feat: Handlebars API

include/mrdox/Support/Handlebars.hpp

@@ -0,0 +1,135 @@
+//
+// This is a derivative work. originally part of the LLVM Project.
+// Licensed 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
+//
+// Copyright (c) 2023 Vinnie Falco ([email protected])
+//
+// Official repository: https://github.com/cppalliance/mrdox
+//
+
+#ifndef MRDOX_SUPPORT_HANDLEBARS_HPP
+#define MRDOX_SUPPORT_HANDLEBARS_HPP
+
+#include <mrdox/Platform.hpp>
+#include <cstddef>
+#include <string_view>
+#include <system_error>
+
+namespace clang {
+namespace mrdox {
+namespace hbs {
+
+struct Access;
+class Object;
+
+//------------------------------------------------
+
+/** A reference to an instance of the Javascript interpreter.
+*/
+class Context
+{
+    struct Impl;
+
+    Impl* impl_;
+
+    friend struct Access;
+
+public:
+    Context& operator=(Context const&) = delete;
+
+    MRDOX_DECL ~Context();
+    MRDOX_DECL Context();
+    MRDOX_DECL Context(Context const&) noexcept;
+
+    MRDOX_DECL std::error_code eval(std::string_view js);
+    MRDOX_DECL std::error_code eval_file(std::string_view path);
+};
+
+//------------------------------------------------
+
+/** An ECMAScript Array.
+*/
+class Array
+{
+    Context ctx_;
+    int idx_;
+
+    friend struct Access;
+
+public:
+    Array(Array const&) = delete;
+    Array& operator=(Array const&) = delete;
+
+    MRDOX_DECL ~Array();
+    MRDOX_DECL Array(Context const& ctx);
+    MRDOX_DECL void append(std::string_view value) const;
+    MRDOX_DECL void append(Array const& value) const;
+    MRDOX_DECL void append(Object const& value) const;
+};
+
+//------------------------------------------------
+
+/** An ECMAScript Object
+*/
+class Object
+{
+    Context ctx_;
+    int idx_;
+
+    friend struct Access;
+
+public:
+    Object(Object const&) = delete;
+    Object& operator=(Object const&) = delete;
+
+    MRDOX_DECL ~Object();
+    MRDOX_DECL Object(Context const& ctx);
+    MRDOX_DECL void insert(std::string_view key, std::string_view value) const;
+    MRDOX_DECL void insert(std::string_view key, Array const& value) const;
+    MRDOX_DECL void insert(std::string_view key, Object const& value) const;
+};
+
+//------------------------------------------------
+
+/** A compiled Handlebars template.
+*/
+class Template
+{
+public:
+};
+
+/** A compiled Handlebars partial.
+*/
+class Partial
+{
+public:
+};
+
+//------------------------------------------------
+
+/** An instance of the handlebars template engine.
+*/
+class Handlebars
+{
+    Context ctx_;
+
+public:
+    explicit
+    Handlebars(Context const& ctx) noexcept;
+
+    /** Return the loaded handlebars script.
+    */
+    friend
+    Handlebars
+    loadHandlebarsScript(
+        std::string_view path,
+        std::error_code& ec);
+};
+
+} // hbs
+} // mrdox
+} // clang
+
+#endif

source/Support/Handlebars.cpp

@@ -0,0 +1,207 @@
+//
+// This is a derivative work. originally part of the LLVM Project.
+// Licensed 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
+//
+// Copyright (c) 2023 Vinnie Falco ([email protected])
+//
+// Official repository: https://github.com/cppalliance/mrdox
+//
+
+#include <mrdox/Support/Handlebars.hpp>
+#include "duktape.h"
+#include <llvm/Support/MemoryBuffer.h>
+
+namespace clang {
+namespace mrdox {
+namespace hbs {
+
+//------------------------------------------------
+
+// The current duk_context
+thread_local static ::duk_context* ctx_ = nullptr;
+
+//------------------------------------------------
+
+struct Context::Impl
+{
+    std::size_t refs;
+    ::duk_context* ctx;
+
+    ~Impl()
+    {
+        ::duk_destroy_heap(ctx_);
+    }
+
+    Impl()
+        : refs(1)
+        , ctx(::duk_create_heap_default())
+    {
+    }
+};
+
+Context::
+~Context()
+{
+    if(--impl_->refs == 0)
+        delete impl_;
+}
+
+Context::
+Context()
+    : impl_(new Impl)
+{
+}
+
+Context::
+Context(
+    Context const& other) noexcept
+    : impl_(other.impl_)
+{
+    ++impl_->refs;
+}
+
+std::error_code
+Context::
+eval(
+    std::string_view js)
+{
+    // VFALCO How do we handle the error if any?
+    duk_eval_lstring_noresult(impl_->ctx, js.data(), js.size());
+    return {};
+}
+
+std::error_code
+Context::
+eval_file(
+    std::string_view path)
+{
+    auto js = llvm::MemoryBuffer::getFile(path);
+    if(! js)
+        return js.getError();
+    return eval(js->get()->getBuffer());
+}
+
+//------------------------------------------------
+
+struct Access
+{
+    static int idx(Array const& arr) noexcept
+    {
+        return arr.idx_;
+    }
+
+    static int idx(Object const& obj) noexcept
+    {
+        return obj.idx_;
+    }
+
+    static ::duk_context* ctx(Context const& ctx) noexcept
+    {
+        return ctx.impl_->ctx;
+    }
+};
+
+//------------------------------------------------
+
+Array::
+~Array()
+{
+    if(idx_ != DUK_INVALID_INDEX)
+    {
+        // remove idx_ from stack?
+    }
+}
+
+Array::
+Array(
+    Context const& ctx)
+    : ctx_(ctx)
+    , idx_(::duk_push_array(Access::ctx(ctx)))
+{
+}
+
+void
+Array::
+append(
+    std::string_view value) const
+{
+}
+
+void
+Array::
+append(
+    Array const& value) const
+{
+}
+
+void
+Array::
+append(
+    Object const& value) const
+{
+}
+
+//------------------------------------------------
+
+Object::
+~Object()
+{
+    if(idx_ != DUK_INVALID_INDEX)
+    {
+        // remove idx_ from stack?
+    }
+}
+
+Object::
+Object(
+    Context const& ctx)
+    : ctx_(ctx)
+    , idx_(::duk_push_object(Access::ctx(ctx)))
+{
+}
+
+void
+Object::
+insert(
+    std::string_view key,
+    std::string_view value) const
+{
+    ::duk_push_lstring(Access::ctx(ctx_), value.data(), value.size());
+    ::duk_put_prop_lstring(Access::ctx(ctx_), idx_, key.data(), key.size());
+}
+
+void
+Object::
+insert(
+    std::string_view key,
+    Array const& value) const
+{
+    ::duk_dup(Access::ctx(ctx_), Access::idx(value));
+    ::duk_put_prop_lstring(Access::ctx(ctx_), idx_, key.data(), key.size());
+}
+
+void
+Object::
+insert(
+    std::string_view key,
+    Object const& value) const
+{
+    ::duk_dup(Access::ctx(ctx_), Access::idx(value));
+    ::duk_put_prop_lstring(Access::ctx(ctx_), idx_, key.data(), key.size());
+}
+
+//------------------------------------------------
+
+Handlebars::
+Handlebars(
+    Context const& ctx) noexcept
+    : ctx_(ctx)
+{
+
+}
+
+} // hbs
+} // mrdox
+} // clang