Visitor.h

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// Copyright Contributors to the OpenVDB Project
// SPDX-License-Identifier: MPL-2.0


#ifndef OPENVDB_AX_AST_VISITOR_HAS_BEEN_INCLUDED
#define OPENVDB_AX_AST_VISITOR_HAS_BEEN_INCLUDED

#include "AST.h"
#include "Tokens.h"

#include <openvdb/version.h>

#include <type_traits>

namespace openvdb {
OPENVDB_USE_VERSION_NAMESPACE
namespace OPENVDB_VERSION_NAME {

namespace ax {
namespace ast {

template <typename Derived, bool ConstVisit=true>
struct Visitor
{
    template <typename NodeT>
    using NodeType = typename std::conditional<ConstVisit, const NodeT, NodeT>::type;

    inline Derived& derived() {
        return *static_cast<Derived*>(this);
    }


    inline bool postOrderNodes() const { return true; }

    inline bool reverseChildVisits() const { return false; }

    inline bool visitNodeHierarchies() const { return false; }

    inline bool reverseHierarchyVisits() const { return false; }




    bool traverse(NodeType<ast::Tree>* tree) {
        return this->defaultTraversal<ast::Tree>(tree);
    }

    bool traverse(NodeType<ast::StatementList>* cond) {
        return this->defaultTraversal<ast::StatementList>(cond);
    }

    bool traverse(NodeType<ast::Block>* block) {
        return this->defaultTraversal<ast::Block>(block);
    }

    bool traverse(NodeType<ast::CommaOperator>* comma) {
        return this->defaultTraversal<ast::CommaOperator>(comma);
    }

    bool traverse(NodeType<ast::Loop>* loop) {
        return this->defaultTraversal<ast::Loop>(loop);
    }

    bool traverse(NodeType<ast::Keyword>* keyw) {
        return this->defaultTraversal<ast::Keyword>(keyw);
    }

    bool traverse(NodeType<ast::ConditionalStatement>* cond) {
        return this->defaultTraversal<ast::ConditionalStatement>(cond);
    }

    bool traverse(NodeType<ast::AssignExpression>* asgn) {
        return this->defaultTraversal<ast::AssignExpression>(asgn);
    }

    bool traverse(NodeType<ast::Crement>* crmt) {
        return this->defaultTraversal<ast::Crement>(crmt);
    }

    bool traverse(NodeType<ast::UnaryOperator>* unry) {
        return this->defaultTraversal<ast::UnaryOperator>(unry);
    }

    bool traverse(NodeType<ast::BinaryOperator>* bin) {
        return this->defaultTraversal<ast::BinaryOperator>(bin);
    }

    bool traverse(NodeType<ast::TernaryOperator>* tern) {
        return this->defaultTraversal<ast::TernaryOperator>(tern);
    }

    bool traverse(NodeType<ast::Cast>* cast) {
        return this->defaultTraversal<ast::Cast>(cast);
    }

    bool traverse(NodeType<ast::FunctionCall>* call) {
        return this->defaultTraversal<ast::FunctionCall>(call);
    }

    bool traverse(NodeType<ast::Attribute>* attr) {
        return this->defaultTraversal<ast::Attribute>(attr);
    }

    bool traverse(NodeType<ast::ExternalVariable>* ext) {
        return this->defaultTraversal<ast::ExternalVariable>(ext);
    }

    bool traverse(NodeType<ast::DeclareLocal>* decl) {
        return this->defaultTraversal<ast::DeclareLocal>(decl);
    }

    bool traverse(NodeType<ast::Local>* loc) {
        return this->defaultTraversal<ast::Local>(loc);
    }

    bool traverse(NodeType<ast::ArrayPack>* pack) {
        return this->defaultTraversal<ast::ArrayPack>(pack);
    }

    bool traverse(NodeType<ast::ArrayUnpack>* pack) {
        return this->defaultTraversal<ast::ArrayUnpack>(pack);
    }

    bool traverse(NodeType<ast::Value<bool>>* val) {
        return this->defaultTraversal<ast::Value<bool>>(val);
    }

    bool traverse(NodeType<ast::Value<int16_t>>* val) {
        return this->defaultTraversal<ast::Value<int16_t>>(val);
    }

    bool traverse(NodeType<ast::Value<int32_t>>* val) {
        return this->defaultTraversal<ast::Value<int32_t>>(val);
    }

    bool traverse(NodeType<ast::Value<int64_t>>* val) {
        return this->defaultTraversal<ast::Value<int64_t>>(val);
    }

    bool traverse(NodeType<ast::Value<float>>* val) {
        return this->defaultTraversal<ast::Value<float>>(val);
    }

    bool traverse(NodeType<ast::Value<double>>* val) {
        return this->defaultTraversal<ast::Value<double>>(val);
    }

    bool traverse(NodeType<ast::Value<std::string>>* val) {
        return this->defaultTraversal<ast::Value<std::string>>(val);
    }

    bool traverse(NodeType<ast::Node>* node) {
        if (!node) return true;
        switch (node->nodetype()) {
            case Node::TreeNode : return this->derived().traverse(static_cast<NodeType<ast::Tree>*>(node));
            case Node::StatementListNode : return this->derived().traverse(static_cast<NodeType<ast::StatementList>*>(node));
            case Node::BlockNode : return this->derived().traverse(static_cast<NodeType<ast::Block>*>(node));
            case Node::CommaOperatorNode : return this->derived().traverse(static_cast<NodeType<ast::CommaOperator>*>(node));
            case Node::LoopNode : return this->derived().traverse(static_cast<NodeType<ast::Loop>*>(node));
            case Node::KeywordNode : return this->derived().traverse(static_cast<NodeType<ast::Keyword>*>(node));
            case Node::ConditionalStatementNode : return this->derived().traverse(static_cast<NodeType<ast::ConditionalStatement>*>(node));
            case Node::AssignExpressionNode : return this->derived().traverse(static_cast<NodeType<ast::AssignExpression>*>(node));
            case Node::CrementNode : return this->derived().traverse(static_cast<NodeType<ast::Crement>*>(node));
            case Node::UnaryOperatorNode : return this->derived().traverse(static_cast<NodeType<ast::UnaryOperator>*>(node));
            case Node::BinaryOperatorNode : return this->derived().traverse(static_cast<NodeType<ast::BinaryOperator>*>(node));
            case Node::TernaryOperatorNode : return this->derived().traverse(static_cast<NodeType<ast::TernaryOperator>*>(node));
            case Node::CastNode : return this->derived().traverse(static_cast<NodeType<ast::Cast>*>(node));
            case Node::AttributeNode : return this->derived().traverse(static_cast<NodeType<ast::Attribute>*>(node));
            case Node::FunctionCallNode : return this->derived().traverse(static_cast<NodeType<ast::FunctionCall>*>(node));
            case Node::ExternalVariableNode : return this->derived().traverse(static_cast<NodeType<ast::ExternalVariable>*>(node));
            case Node::DeclareLocalNode : return this->derived().traverse(static_cast<NodeType<ast::DeclareLocal>*>(node));
            case Node::ArrayPackNode : return this->derived().traverse(static_cast<NodeType<ast::ArrayPack>*>(node));
            case Node::ArrayUnpackNode : return this->derived().traverse(static_cast<NodeType<ast::ArrayUnpack>*>(node));
            case Node::LocalNode : return this->derived().traverse(static_cast<NodeType<ast::Local>*>(node));
            case Node::ValueBoolNode : return this->derived().traverse(static_cast<NodeType<ast::Value<bool>>*>(node));
            case Node::ValueInt16Node : return this->derived().traverse(static_cast<NodeType<ast::Value<int16_t>>*>(node));
            case Node::ValueInt32Node : return this->derived().traverse(static_cast<NodeType<ast::Value<int32_t>>*>(node));
            case Node::ValueInt64Node : return this->derived().traverse(static_cast<NodeType<ast::Value<int64_t>>*>(node));
            case Node::ValueFloatNode : return this->derived().traverse(static_cast<NodeType<ast::Value<float>>*>(node));
            case Node::ValueDoubleNode : return this->derived().traverse(static_cast<NodeType<ast::Value<double>>*>(node));
            case Node::ValueStrNode : return this->derived().traverse(static_cast<NodeType<ast::Value<std::string>>*>(node));
            default : return true;
        }
    }



    inline bool visit(NodeType<ast::Node>*) { return true; }
    inline bool visit(NodeType<ast::Statement>*) { return true; }
    inline bool visit(NodeType<ast::Expression>*) { return true; }
    inline bool visit(NodeType<ast::Variable>*) { return true; }
    inline bool visit(NodeType<ast::ValueBase>*) { return true; }

    inline bool visit(NodeType<ast::Tree>*) { return true; }
    inline bool visit(NodeType<ast::StatementList>*) { return true; }
    inline bool visit(NodeType<ast::Block>*) { return true; }
    inline bool visit(NodeType<ast::CommaOperator>*) { return true; }
    inline bool visit(NodeType<ast::Loop>*) { return true; }
    inline bool visit(NodeType<ast::Keyword>*) { return true; }
    inline bool visit(NodeType<ast::ConditionalStatement>*) { return true; }
    inline bool visit(NodeType<ast::AssignExpression>*) { return true; }
    inline bool visit(NodeType<ast::Crement>*) { return true; }
    inline bool visit(NodeType<ast::UnaryOperator>*) { return true; }
    inline bool visit(NodeType<ast::BinaryOperator>*) { return true; }
    inline bool visit(NodeType<ast::TernaryOperator>*) { return true; }
    inline bool visit(NodeType<ast::Cast>*) { return true; }
    inline bool visit(NodeType<ast::FunctionCall>*) { return true; }
    inline bool visit(NodeType<ast::Attribute>*) { return true; }
    inline bool visit(NodeType<ast::ExternalVariable>*) { return true; }
    inline bool visit(NodeType<ast::DeclareLocal>*) { return true; }
    inline bool visit(NodeType<ast::Local>*) { return true; }
    inline bool visit(NodeType<ast::ArrayPack>*) { return true; }
    inline bool visit(NodeType<ast::ArrayUnpack>*) { return true; }
    inline bool visit(NodeType<ast::Value<bool>>*) { return true; }
    inline bool visit(NodeType<ast::Value<int16_t>>*) { return true; }
    inline bool visit(NodeType<ast::Value<int32_t>>*) { return true; }
    inline bool visit(NodeType<ast::Value<int64_t>>*) { return true; }
    inline bool visit(NodeType<ast::Value<float>>*) { return true; }
    inline bool visit(NodeType<ast::Value<double>>*) { return true; }
    inline bool visit(NodeType<ast::Value<std::string>>*) { return true; }


private:
    template <bool V, typename NodeT>
    inline typename std::enable_if<V, const NodeT*>::type
    strip(const NodeT& node) {
        return &node;
    }

    template <bool V, typename NodeT>
    inline typename std::enable_if<!V, typename std::remove_const<NodeT>::type*>::type
    strip(const NodeT& node) {
        return &(const_cast<NodeT&>(node));
    }

    template <typename NodeT>
    bool hierarchyVisits(NodeT& node)
    {
        if (this->derived().reverseHierarchyVisits()) {
            if (auto base = node.NodeT::basetype()) {
                if (!hierarchyVisits(*base)) return false;
            }
            if (!this->derived().visit(this->strip<ConstVisit>(node))) return false;
        }
        else {
            if (!this->derived().visit(this->strip<ConstVisit>(node))) return false;
            if (auto base = node.NodeT::basetype()) {
                return hierarchyVisits(*base);
            }
        }
        return true;
    }

    template <typename NodeT>
    inline bool defaultTraversal(NodeType<NodeT>* node)
    {
        if (!node) return true;
        const size_t children = node->children();

        if (this->derived().postOrderNodes()) {
            if (this->derived().reverseChildVisits()) {
                if (children != 0) {
                    for (int64_t i = static_cast<int64_t>(children - 1); i >= 0; --i) {
                        auto child = this->strip<ConstVisit>(*(node->child(i)));
                        if (!this->derived().traverse(child)) {
                            return false;
                        }
                    }
                }
            }
            else {
                for (size_t i = 0; i < children; ++i) {
                    auto child = this->strip<ConstVisit>(*(node->child(i)));
                    if (!this->derived().traverse(child)) {
                        return false;
                    }
                }
            }
            if (this->derived().visitNodeHierarchies()) {
                return this->hierarchyVisits(*node);
            }
            else {
                return this->derived().visit(node);
            }
        }
        else {
            if (this->derived().visitNodeHierarchies()) {
                if (!this->hierarchyVisits(*node)) return false;
            }
            else {
                if (!this->derived().visit(node)) return false;
            }
            if (this->derived().reverseChildVisits()) {
                if (children != 0) {
                    for (int64_t i = static_cast<int64_t>(children - 1); i >= 0; --i) {
                        auto child = this->strip<ConstVisit>(*(node->child(i)));
                        if (!this->derived().traverse(child)) {
                            return false;
                        }
                    }
                }
            }
            else {
                for (size_t i = 0; i < children; ++i) {
                    auto child = this->strip<ConstVisit>(*(node->child(i)));
                    if (!this->derived().traverse(child)) {
                        return false;
                    }
                }
            }
            return true;
        }
    }
};

} // namespace ast
} // namespace ax

} // namespace OPENVDB_VERSION_NAME
} // namespace openvdb

#endif // OPENVDB_AX_AST_VISITOR_HAS_BEEN_INCLUDED