syntax-node.hpp

/* Copyright 2025 Jonathan S. Arney
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      https://github.com/jarney/gyoji/blob/master/LICENSE
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
#ifndef _GYOJI_INTERNAL
#error "This header is intended to be used internally as a part of the Gyoji front-end.  Please include frontend.hpp instead."
#endif
#pragma once
 
namespace Gyoji::frontend::ast {
    
    class SyntaxNode {
    public:
    typedef std::variant<GYOJI_SYNTAX_NODE_VARIANT_LIST> specific_type_t;
    
    SyntaxNode(Gyoji::context::TokenID _type, specific_type_t _data, const Gyoji::context::SourceReference & _source_ref);
    ~SyntaxNode();
    
    
    const std::vector<std::reference_wrapper<const SyntaxNode>> & get_children() const;
    
    const Gyoji::context::TokenID & get_type() const;
    
    template <class T> bool has_data() const {
        return std::holds_alternative<T*>(data);
    }
    
    template <class T> const T &get_data() const {
        const T *d = std::get<T*>(data);
        return *d;
    }
    
    const SyntaxNode & get_syntax_node() const;
    
    const Gyoji::context::SourceReference & get_source_ref() const;
    
    private:
    // This list does NOT own its children, so
    // the class deriving from this one must
    // agree to own the pointers separately.
    std::vector<std::reference_wrapper<const SyntaxNode>> children; 
    const Gyoji::context::SourceReference & source_ref;
    
    protected:
    // Children are owned by their parents, so this is
    // private and can only be called by the
    // deriving class.
    void add_child(const SyntaxNode & node);
    void prepend_child(const SyntaxNode & node);
    
    Gyoji::context::TokenID type;
    specific_type_t data;
    
    };
    
};