text: /*************************************************************************/
  /*  gdscript_parser.h                                                    */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #ifndef GDSCRIPT_PARSER_H
  #define GDSCRIPT_PARSER_H
  
  #include "core/map.h"
  #include "core/object.h"
  #include "core/script_language.h"
  #include "gdscript_functions.h"
  #include "gdscript_tokenizer.h"
  
  struct GDScriptDataType;
  struct GDScriptWarning;
  
  class GDScriptParser {
  public:
  	struct ClassNode;
  
  	struct DataType {
  		enum {
  			BUILTIN,
  			NATIVE,
  			SCRIPT,
  			GDSCRIPT,
  			CLASS,
  			UNRESOLVED
  		} kind;
  
  		bool has_type;
  		bool is_constant;
  		bool is_meta_type; // Whether the value can be used as a type
  		bool infer_type;
  		bool may_yield; // For function calls
  
  		Variant::Type builtin_type;
  		StringName native_type;
  		Ref<Script> script_type;
  		ClassNode *class_type;
  
  		String to_string() const;
  
  		bool operator==(const DataType &other) const {
  			if (!has_type || !other.has_type) {
  				return true; // Can be considered equal for parsing purpose
  			}
  			if (kind != other.kind) {
  				return false;
  			}
  			switch (kind) {
  				case BUILTIN: {
  					return builtin_type == other.builtin_type;
  				} break;
  				case NATIVE: {
  					return native_type == other.native_type;
  				} break;
  				case GDSCRIPT:
  				case SCRIPT: {
  					return script_type == other.script_type;
  				} break;
  				case CLASS: {
  					return class_type == other.class_type;
  				} break;
  				case UNRESOLVED: {
  				} break;
  			}
  			return false;
  		}
  
  		DataType() :
  				kind(UNRESOLVED),
  				has_type(false),
  				is_constant(false),
  				is_meta_type(false),
  				infer_type(false),
  				may_yield(false),
  				builtin_type(Variant::NIL),
  				class_type(NULL) {}
  	};
  
  	struct Node {
  
  		enum Type {
  			TYPE_CLASS,
  			TYPE_FUNCTION,
  			TYPE_BUILT_IN_FUNCTION,
  			TYPE_BLOCK,
  			TYPE_IDENTIFIER,
  			TYPE_TYPE,
  			TYPE_CONSTANT,
  			TYPE_ARRAY,
  			TYPE_DICTIONARY,
  			TYPE_SELF,
  			TYPE_OPERATOR,
  			TYPE_CONTROL_FLOW,
  			TYPE_LOCAL_VAR,
  			TYPE_CAST,
  			TYPE_ASSERT,
  			TYPE_BREAKPOINT,
  			TYPE_NEWLINE,
  		};
  
  		Node *next;
  		int line;
  		int column;
  		Type type;
  
  		virtual DataType get_datatype() const { return DataType(); }
  		virtual void set_datatype(const DataType &p_datatype) {}
  
  		virtual ~Node() {}
  	};
  
  	struct FunctionNode;
  	struct BlockNode;
  	struct ConstantNode;
  	struct LocalVarNode;
  	struct OperatorNode;
  
  	struct ClassNode : public Node {
  
  		bool tool;
  		StringName name;
  		bool extends_used;
  		bool classname_used;
  		StringName extends_file;
  		Vector<StringName> extends_class;
  		DataType base_type;
  		String icon_path;
  
  		struct Member {
  			PropertyInfo _export;
  #ifdef TOOLS_ENABLED
  			Variant default_value;
  #endif
  			StringName identifier;
  			DataType data_type;
  			StringName setter;
  			StringName getter;
  			int line;
  			Node *expression;
  			OperatorNode *initial_assignment;
  			MultiplayerAPI::RPCMode rpc_mode;
  			int usages;
  		};
  
  		struct Constant {
  			Node *expression;
  			DataType type;
  		};
  
  		struct Signal {
  			StringName name;
  			Vector<StringName> arguments;
  			int emissions;
  			int line;
  		};
  
  		Vector<ClassNode *> subclasses;
  		Vector<Member> variables;
  		Map<StringName, Constant> constant_expressions;
  		Vector<FunctionNode *> functions;
  		Vector<FunctionNode *> static_functions;
  		Vector<Signal> _signals;
  		BlockNode *initializer;
  		BlockNode *ready;
  		ClassNode *owner;
  		//Vector<Node*> initializers;
  		int end_line;
  
  		ClassNode() {
  			tool = false;
  			type = TYPE_CLASS;
  			extends_used = false;
  			classname_used = false;
  			end_line = -1;
  			owner = NULL;
  		}
  	};
  
  	struct FunctionNode : public Node {
  
  		bool _static;
  		MultiplayerAPI::RPCMode rpc_mode;
  		bool has_yield;
  		bool has_unreachable_code;
  		StringName name;
  		DataType return_type;
  		Vector<StringName> arguments;
  		Vector<DataType> argument_types;
  		Vector<Node *> default_values;
  		BlockNode *body;
  #ifdef DEBUG_ENABLED
  		Vector<int> arguments_usage;
  #endif // DEBUG_ENABLED
  
  		virtual DataType get_datatype() const { return return_type; }
  		virtual void set_datatype(const DataType &p_datatype) { return_type = p_datatype; }
  		int get_required_argument_count() { return arguments.size() - default_values.size(); }
  
  		FunctionNode() {
  			type = TYPE_FUNCTION;
  			_static = false;
  			rpc_mode = MultiplayerAPI::RPC_MODE_DISABLED;
  			has_yield = false;
  			has_unreachable_code = false;
  		}
  	};
  
  	struct BlockNode : public Node {
  
  		ClassNode *parent_class;
  		BlockNode *parent_block;
  		List<Node *> statements;
  		Map<StringName, LocalVarNode *> variables;
  		bool has_return = false;
  		bool can_break = false;
  		bool can_continue = false;
  
  		Node *if_condition; //tiny hack to improve code completion on if () blocks
  
  		//the following is useful for code completion
  		List<BlockNode *> sub_blocks;
  		int end_line;
  		BlockNode() {
  			if_condition = NULL;
  			type = TYPE_BLOCK;
  			end_line = -1;
  			parent_block = NULL;
  			parent_class = NULL;
  		}
  	};
  
  	struct TypeNode : public Node {
  
  		Variant::Type vtype;
  		TypeNode() { type = TYPE_TYPE; }
  	};
  	struct BuiltInFunctionNode : public Node {
  		GDScriptFunctions::Function function;
  		BuiltInFunctionNode() { type = TYPE_BUILT_IN_FUNCTION; }
  	};
  
  	struct IdentifierNode : public Node {
  
  		StringName name;
  		BlockNode *declared_block; // Simplify lookup by checking if it is declared locally
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		IdentifierNode() {
  			type = TYPE_IDENTIFIER;
  			declared_block = NULL;
  		}
  	};
  
  	struct LocalVarNode : public Node {
  
  		StringName name;
  		Node *assign;
  		OperatorNode *assign_op;
  		int assignments;
  		int usages;
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		LocalVarNode() {
  			type = TYPE_LOCAL_VAR;
  			assign = NULL;
  			assign_op = NULL;
  			assignments = 0;
  			usages = 0;
  		}
  	};
  
  	struct ConstantNode : public Node {
  		Variant value;
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		ConstantNode() { type = TYPE_CONSTANT; }
  	};
  
  	struct ArrayNode : public Node {
  
  		Vector<Node *> elements;
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		ArrayNode() {
  			type = TYPE_ARRAY;
  			datatype.has_type = true;
  			datatype.kind = DataType::BUILTIN;
  			datatype.builtin_type = Variant::ARRAY;
  		}
  	};
  
  	struct DictionaryNode : public Node {
  
  		struct Pair {
  
  			Node *key;
  			Node *value;
  		};
  
  		Vector<Pair> elements;
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		DictionaryNode() {
  			type = TYPE_DICTIONARY;
  			datatype.has_type = true;
  			datatype.kind = DataType::BUILTIN;
  			datatype.builtin_type = Variant::DICTIONARY;
  		}
  	};
  
  	struct SelfNode : public Node {
  		SelfNode() { type = TYPE_SELF; }
  	};
  
  	struct OperatorNode : public Node {
  		enum Operator {
  			//call/constructor operator
  			OP_CALL,
  			OP_PARENT_CALL,
  			OP_YIELD,
  			OP_IS,
  			OP_IS_BUILTIN,
  			//indexing operator
  			OP_INDEX,
  			OP_INDEX_NAMED,
  			//unary operators
  			OP_NEG,
  			OP_POS,
  			OP_NOT,
  			OP_BIT_INVERT,
  			//binary operators (in precedence order)
  			OP_IN,
  			OP_EQUAL,
  			OP_NOT_EQUAL,
  			OP_LESS,
  			OP_LESS_EQUAL,
  			OP_GREATER,
  			OP_GREATER_EQUAL,
  			OP_AND,
  			OP_OR,
  			OP_ADD,
  			OP_SUB,
  			OP_MUL,
  			OP_DIV,
  			OP_MOD,
  			OP_SHIFT_LEFT,
  			OP_SHIFT_RIGHT,
  			OP_INIT_ASSIGN,
  			OP_ASSIGN,
  			OP_ASSIGN_ADD,
  			OP_ASSIGN_SUB,
  			OP_ASSIGN_MUL,
  			OP_ASSIGN_DIV,
  			OP_ASSIGN_MOD,
  			OP_ASSIGN_SHIFT_LEFT,
  			OP_ASSIGN_SHIFT_RIGHT,
  			OP_ASSIGN_BIT_AND,
  			OP_ASSIGN_BIT_OR,
  			OP_ASSIGN_BIT_XOR,
  			OP_BIT_AND,
  			OP_BIT_OR,
  			OP_BIT_XOR,
  			//ternary operators
  			OP_TERNARY_IF,
  			OP_TERNARY_ELSE,
  		};
  
  		Operator op;
  
  		Vector<Node *> arguments;
  		DataType datatype;
  		virtual DataType get_datatype() const { return datatype; }
  		virtual void set_datatype(const DataType &p_datatype) { datatype = p_datatype; }
  		OperatorNode() { type = TYPE_OPERATOR; }
  	};
  
  	struct PatternNode : public Node {
  
  		enum PatternType {
  			PT_CONSTANT,
  			PT_BIND,
  			PT_DICTIONARY,
  			PT_ARRAY,
  			PT_IGNORE_REST,
  			PT_WILDCARD
  		};
  
  		PatternType pt_type;
  
  		Node *constant;
  		StringName bind;
  		Map<ConstantNode *, PatternNode *> dictionary;
  		Vector<PatternNode *> array;
  	};
  
  	struct PatternBranchNode : public Node {
  		Vector<PatternNode *> patterns;
  		BlockNode *body;
  	};
  
  	struct MatchNode : public Node {
  		Node *val_to_match;
  		Vector<PatternBranchNode *> branches;
  
  		struct CompiledPatternBranch {
  			Node *compiled_pattern;
  			BlockNode *body;
  		};
  
  		Vector<CompiledPatternBranch> compiled_pattern_branches;
  	};
  
  	struct ControlFlowNode : public Node {
  		enum CFType {
  			CF_IF,
  			CF_FOR,
  			CF_WHILE,
  			CF_BREAK,
  			CF_CONTINUE,
  			CF_RETURN,
  			CF_MATCH
  		};
  
  		CFType cf_type;
  		Vector<Node *> arguments;
  		BlockNode *body;
  		BlockNode *body_else;
  
  		MatchNode *match;
  
  		ControlFlowNode *_else; //used for if
  		ControlFlowNode() {
  			type = TYPE_CONTROL_FLOW;
  			cf_type = CF_IF;
  			body = NULL;
  			body_else = NULL;
  		}
  	};
  
  	struct CastNode : public Node {
  		Node *source_node;
  		DataType cast_type;
  		DataType return_type;
  		virtual DataType get_datatype() const { return return_type; }
  		virtual void set_datatype(const DataType &p_datatype) { return_type = p_datatype; }
  		CastNode() { type = TYPE_CAST; }
  	};
  
  	struct AssertNode : public Node {
  		Node *condition;
  		Node *message;
  		AssertNode() :
  				condition(0),
  				message(0) {
  			type = TYPE_ASSERT;
  		}
  	};
  
  	struct BreakpointNode : public Node {
  		BreakpointNode() { type = TYPE_BREAKPOINT; }
  	};
  
  	struct NewLineNode : public Node {
  		NewLineNode() { type = TYPE_NEWLINE; }
  	};
  
  	struct Expression {
  
  		bool is_op;
  		union {
  			OperatorNode::Operator op;
  			Node *node;
  		};
  	};
  
  	enum CompletionType {
  		COMPLETION_NONE,
  		COMPLETION_BUILT_IN_TYPE_CONSTANT,
  		COMPLETION_GET_NODE,
  		COMPLETION_FUNCTION,
  		COMPLETION_IDENTIFIER,
  		COMPLETION_PARENT_FUNCTION,
  		COMPLETION_METHOD,
  		COMPLETION_CALL_ARGUMENTS,
  		COMPLETION_RESOURCE_PATH,
  		COMPLETION_INDEX,
  		COMPLETION_VIRTUAL_FUNC,
  		COMPLETION_YIELD,
  		COMPLETION_ASSIGN,
  		COMPLETION_TYPE_HINT,
  		COMPLETION_TYPE_HINT_INDEX,
  	};
  
  private:
  	GDScriptTokenizer *tokenizer;
  
  	Node *head;
  	Node *list;
  	template <class T>
  	T *alloc_node();
  
  	bool validating;
  	bool for_completion;
  	int parenthesis;
  	bool error_set;
  	String error;
  	int error_line;
  	int error_column;
  	bool check_types;
  	bool dependencies_only;
  	List<String> dependencies;
  #ifdef DEBUG_ENABLED
  	Set<int> *safe_lines;
  #endif // DEBUG_ENABLED
  
  #ifdef DEBUG_ENABLED
  	List<GDScriptWarning> warnings;
  #endif // DEBUG_ENABLED
  
  	int pending_newline;
  
  	struct IndentLevel {
  		int indent;
  		int tabs;
  
  		bool is_mixed(IndentLevel other) {
  			return (
  					(indent == other.indent && tabs != other.tabs) ||
  					(indent > other.indent && tabs < other.tabs) ||
  					(indent < other.indent && tabs > other.tabs));
  		}
  
  		IndentLevel() :
  				indent(0),
  				tabs(0) {}
  
  		IndentLevel(int p_indent, int p_tabs) :
  				indent(p_indent),
  				tabs(p_tabs) {}
  	};
  
  	List<IndentLevel> indent_level;
  
  	String base_path;
  	String self_path;
  
  	ClassNode *current_class;
  	FunctionNode *current_function;
  	BlockNode *current_block;
  
  	bool _get_completable_identifier(CompletionType p_type, StringName &identifier);
  	void _make_completable_call(int p_arg);
  
  	CompletionType completion_type;
  	StringName completion_cursor;
  	Variant::Type completion_built_in_constant;
  	Node *completion_node;
  	ClassNode *completion_class;
  	FunctionNode *completion_function;
  	BlockNode *completion_block;
  	int completion_line;
  	int completion_argument;
  	bool completion_found;
  	bool completion_ident_is_call;
  
  	PropertyInfo current_export;
  
  	MultiplayerAPI::RPCMode rpc_mode;
  
  	void _set_error(const String &p_error, int p_line = -1, int p_column = -1);
  #ifdef DEBUG_ENABLED
  	void _add_warning(int p_code, int p_line = -1, const String &p_symbol1 = String(), const String &p_symbol2 = String(), const String &p_symbol3 = String(), const String &p_symbol4 = String());
  	void _add_warning(int p_code, int p_line, const Vector<String> &p_symbols);
  #endif // DEBUG_ENABLED
  	bool _recover_from_completion();
  
  	bool _parse_arguments(Node *p_parent, Vector<Node *> &p_args, bool p_static, bool p_can_codecomplete = false, bool p_parsing_constant = false);
  	bool _enter_indent_block(BlockNode *p_block = NULL);
  	bool _parse_newline();
  	Node *_parse_expression(Node *p_parent, bool p_static, bool p_allow_assign = false, bool p_parsing_constant = false);
  	Node *_reduce_expression(Node *p_node, bool p_to_const = false);
  	Node *_parse_and_reduce_expression(Node *p_parent, bool p_static, bool p_reduce_const = false, bool p_allow_assign = false);
  	bool _reduce_export_var_type(Variant &p_value, int p_line = 0);
  
  	PatternNode *_parse_pattern(bool p_static);
  	void _parse_pattern_block(BlockNode *p_block, Vector<PatternBranchNode *> &p_branches, bool p_static);
  	void _transform_match_statment(MatchNode *p_match_statement);
  	void _generate_pattern(PatternNode *p_pattern, Node *p_node_to_match, Node *&p_resulting_node, Map<StringName, Node *> &p_bindings);
  
  	void _parse_block(BlockNode *p_block, bool p_static);
  	void _parse_extends(ClassNode *p_class);
  	void _parse_class(ClassNode *p_class);
  	bool _end_statement();
  	void _set_end_statement_error(String p_name);
  
  	void _determine_inheritance(ClassNode *p_class, bool p_recursive = true);
  	bool _parse_type(DataType &r_type, bool p_can_be_void = false);
  	DataType _resolve_type(const DataType &p_source, int p_line);
  	DataType _type_from_variant(const Variant &p_value) const;
  	DataType _type_from_property(const PropertyInfo &p_property, bool p_nil_is_variant = true) const;
  	DataType _type_from_gdtype(const GDScriptDataType &p_gdtype) const;
  	DataType _get_operation_type(const Variant::Operator p_op, const DataType &p_a, const DataType &p_b, bool &r_valid) const;
  	Variant::Operator _get_variant_operation(const OperatorNode::Operator &p_op) const;
  	bool _get_function_signature(DataType &p_base_type, const StringName &p_function, DataType &r_return_type, List<DataType> &r_arg_types, int &r_default_arg_count, bool &r_static, bool &r_vararg) const;
  	bool _get_member_type(const DataType &p_base_type, const StringName &p_member, DataType &r_member_type, bool *r_is_const = nullptr) const;
  	bool _is_type_compatible(const DataType &p_container, const DataType &p_expression, bool p_allow_implicit_conversion = false) const;
  	Node *_get_default_value_for_type(const DataType &p_type, int p_line = -1);
  
  	DataType _reduce_node_type(Node *p_node);
  	DataType _reduce_function_call_type(const OperatorNode *p_call);
  	DataType _reduce_identifier_type(const DataType *p_base_type, const StringName &p_identifier, int p_line, bool p_is_indexing);
  	void _check_class_level_types(ClassNode *p_class);
  	void _check_class_blocks_types(ClassNode *p_class);
  	void _check_function_types(FunctionNode *p_function);
  	void _check_block_types(BlockNode *p_block);
  	_FORCE_INLINE_ void _mark_line_as_safe(int p_line) const {
  #ifdef DEBUG_ENABLED
  		if (safe_lines) safe_lines->insert(p_line);
  #endif // DEBUG_ENABLED
  	}
  	_FORCE_INLINE_ void _mark_line_as_unsafe(int p_line) const {
  #ifdef DEBUG_ENABLED
  		if (safe_lines) safe_lines->erase(p_line);
  #endif // DEBUG_ENABLED
  	}
  
  	Error _parse(const String &p_base_path);
  
  public:
  	bool has_error() const;
  	String get_error() const;
  	int get_error_line() const;
  	int get_error_column() const;
  #ifdef DEBUG_ENABLED
  	const List<GDScriptWarning> &get_warnings() const { return warnings; }
  #endif // DEBUG_ENABLED
  	Error parse(const String &p_code, const String &p_base_path = "", bool p_just_validate = false, const String &p_self_path = "", bool p_for_completion = false, Set<int> *r_safe_lines = NULL, bool p_dependencies_only = false);
  	Error parse_bytecode(const Vector<uint8_t> &p_bytecode, const String &p_base_path = "", const String &p_self_path = "");
  
  	bool is_tool_script() const;
  	const Node *get_parse_tree() const;
  
  	//completion info
  
  	CompletionType get_completion_type();
  	StringName get_completion_cursor();
  	int get_completion_line();
  	Variant::Type get_completion_built_in_constant();
  	Node *get_completion_node();
  	ClassNode *get_completion_class();
  	BlockNode *get_completion_block();
  	FunctionNode *get_completion_function();
  	int get_completion_argument_index();
  	int get_completion_identifier_is_function();
  
  	const List<String> &get_dependencies() const { return dependencies; }
  
  	void clear();
  	GDScriptParser();
  	~GDScriptParser();
  };
  
  #endif // GDSCRIPT_PARSER_H
  