diff --git a/modules/gdscript/gd_compiler.cpp b/modules/gdscript/gd_compiler.cpp index 8e9e94cc484..a5351a584bb 100644 --- a/modules/gdscript/gd_compiler.cpp +++ b/modules/gdscript/gd_compiler.cpp @@ -1099,7 +1099,72 @@ Error GDCompiler::_parse_block(CodeGen& codegen,const GDParser::BlockNode *p_blo switch(cf->cf_type) { + case GDParser::ControlFlowNode::CF_MATCH: { + GDParser::MatchNode *match = cf->match; + + GDParser::IdentifierNode *id = memnew(GDParser::IdentifierNode); + id->name = "#match_value"; + + // var #match_value + // copied because there is no _parse_statement :( + codegen.add_stack_identifier(id->name, p_stack_level++); + codegen.alloc_stack(p_stack_level); + new_identifiers++; + GDParser::OperatorNode *op = memnew(GDParser::OperatorNode); + op->op=GDParser::OperatorNode::OP_ASSIGN; + op->arguments.push_back(id); + op->arguments.push_back(match->val_to_match); + + int ret = _parse_expression(codegen, op, p_stack_level); + if (ret < 0) { + return ERR_PARSE_ERROR; + } + + // break address + codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); + codegen.opcodes.push_back(codegen.opcodes.size() + 3); + int break_addr = codegen.opcodes.size(); + codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); + codegen.opcodes.push_back(0); // break addr + + for (int j = 0; j < match->compiled_pattern_branches.size(); j++) { + GDParser::MatchNode::CompiledPatternBranch branch = match->compiled_pattern_branches[j]; + + // jump over continue + // jump unconditionally + // continue address + // compile the condition + int ret = _parse_expression(codegen, branch.compiled_pattern, p_stack_level); + if (ret < 0) { + return ERR_PARSE_ERROR; + } + + codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF); + codegen.opcodes.push_back(ret); + codegen.opcodes.push_back(codegen.opcodes.size() + 3); + int continue_addr = codegen.opcodes.size(); + codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); + codegen.opcodes.push_back(0); + + + + Error err = _parse_block(codegen, branch.body, p_stack_level, p_break_addr, continue_addr); + if (err) { + return ERR_PARSE_ERROR; + } + + codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); + codegen.opcodes.push_back(break_addr); + + codegen.opcodes[continue_addr + 1] = codegen.opcodes.size(); + } + + codegen.opcodes[break_addr + 1] = codegen.opcodes.size(); + + + } break; + case GDParser::ControlFlowNode::CF_IF: { #ifdef DEBUG_ENABLED diff --git a/modules/gdscript/gd_parser.cpp b/modules/gdscript/gd_parser.cpp index c783fac4292..031f106df0b 100644 --- a/modules/gdscript/gd_parser.cpp +++ b/modules/gdscript/gd_parser.cpp @@ -1679,6 +1679,542 @@ bool GDParser::_recover_from_completion() { return true; } +GDParser::PatternNode *GDParser::_parse_pattern(bool p_static) +{ + + PatternNode *pattern = alloc_node(); + + GDTokenizer::Token token = tokenizer->get_token(); + if (error_set) + return NULL; + + if (token == GDTokenizer::TK_EOF) { + return NULL; + } + + switch (token) { + // dictionary + case GDTokenizer::TK_BRACKET_OPEN: { + tokenizer->advance(); + pattern->pt_type = GDParser::PatternNode::PT_ARRAY; + while (true) { + + if (tokenizer->get_token() == GDTokenizer::TK_BRACKET_CLOSE) { + tokenizer->advance(); + break; + } + + if (tokenizer->get_token() == GDTokenizer::TK_PERIOD && tokenizer->get_token(1) == GDTokenizer::TK_PERIOD) { + // match everything + tokenizer->advance(2); + PatternNode *sub_pattern = alloc_node(); + sub_pattern->pt_type = GDParser::PatternNode::PT_IGNORE_REST; + pattern->array.push_back(sub_pattern); + if (tokenizer->get_token() == GDTokenizer::TK_COMMA && tokenizer->get_token(1) == GDTokenizer::TK_BRACKET_CLOSE) { + tokenizer->advance(2); + break; + } else if (tokenizer->get_token() == GDTokenizer::TK_BRACKET_CLOSE) { + tokenizer->advance(1); + break; + } else { + _set_error("'..' pattern only allowed at the end of an array pattern"); + return NULL; + } + } + + PatternNode *sub_pattern = _parse_pattern(p_static); + if (!sub_pattern) { + return NULL; + } + + pattern->array.push_back(sub_pattern); + + if (tokenizer->get_token() == GDTokenizer::TK_COMMA) { + tokenizer->advance(); + continue; + } else if (tokenizer->get_token() == GDTokenizer::TK_BRACKET_CLOSE) { + tokenizer->advance(); + break; + } else { + _set_error("Not a valid pattern"); + return NULL; + } + } + } break; + // bind + case GDTokenizer::TK_PR_VAR: { + tokenizer->advance(); + pattern->pt_type = GDParser::PatternNode::PT_BIND; + pattern->bind = tokenizer->get_token_identifier(); + tokenizer->advance(); + } break; + // array + case GDTokenizer::TK_CURLY_BRACKET_OPEN: { + tokenizer->advance(); + pattern->pt_type = GDParser::PatternNode::PT_DICTIONARY; + while (true) { + + if (tokenizer->get_token() == GDTokenizer::TK_CURLY_BRACKET_CLOSE) { + tokenizer->advance(); + break; + } + + if (tokenizer->get_token() == GDTokenizer::TK_PERIOD && tokenizer->get_token(1) == GDTokenizer::TK_PERIOD) { + // match everything + tokenizer->advance(2); + PatternNode *sub_pattern = alloc_node(); + sub_pattern->pt_type = PatternNode::PT_IGNORE_REST; + pattern->array.push_back(sub_pattern); + if (tokenizer->get_token() == GDTokenizer::TK_COMMA && tokenizer->get_token(1) == GDTokenizer::TK_CURLY_BRACKET_CLOSE) { + tokenizer->advance(2); + break; + } else if (tokenizer->get_token() == GDTokenizer::TK_CURLY_BRACKET_CLOSE) { + tokenizer->advance(1); + break; + } else { + _set_error("'..' pattern only allowed at the end of an dictionary pattern"); + return NULL; + } + } + + Node *key = _parse_and_reduce_expression(pattern, p_static); + if (!key) { + _set_error("Not a valid key in pattern"); + return NULL; + } + + if (key->type != GDParser::Node::TYPE_CONSTANT) { + _set_error("Not a constant expression as key"); + return NULL; + } + + if (tokenizer->get_token() == GDTokenizer::TK_COLON) { + tokenizer->advance(); + + PatternNode *value = _parse_pattern(p_static); + if (!value) { + _set_error("Expected pattern in dictionary value"); + return NULL; + } + + pattern->dictionary.insert(static_cast(key), value); + } else { + pattern->dictionary.insert(static_cast(key), NULL); + } + + + if (tokenizer->get_token() == GDTokenizer::TK_COMMA) { + tokenizer->advance(); + continue; + } else if (tokenizer->get_token() == GDTokenizer::TK_CURLY_BRACKET_CLOSE) { + tokenizer->advance(); + break; + } else { + _set_error("Not a valid pattern"); + return NULL; + } + } + } break; + // all the constants like strings and numbers + default: { + Node *value = _parse_and_reduce_expression(pattern, p_static); + if (error_set) { + return NULL; + } + if (value->type == Node::TYPE_IDENTIFIER && static_cast(value)->name == "_") { + // wildcard pattern + pattern->pt_type = PatternNode::PT_WILDCARD; + break; + } + + if (value->type != Node::TYPE_IDENTIFIER && value->type != Node::TYPE_CONSTANT) { + _set_error("Only constant expressions or variables allowed in a pattern"); + return NULL; + } + + pattern->pt_type = PatternNode::PT_CONSTANT; + pattern->constant = value; + } break; + } + + return pattern; +} + +void GDParser::_parse_pattern_block(BlockNode *p_block, Vector &p_branches, bool p_static) +{ + int indent_level = tab_level.back()->get(); + + while (true) { + + while (tokenizer->get_token() == GDTokenizer::TK_NEWLINE && _parse_newline()); + + // GDTokenizer::Token token = tokenizer->get_token(); + if (error_set) + return; + + if (indent_level > tab_level.back()->get()) { + return; // go back a level + } + + if (pending_newline!=-1) { + pending_newline=-1; + } + + PatternBranchNode *branch = alloc_node(); + + branch->patterns.push_back(_parse_pattern(p_static)); + if (!branch->patterns[0]) { + return; + } + + while (tokenizer->get_token() == GDTokenizer::TK_COMMA) { + tokenizer->advance(); + branch->patterns.push_back(_parse_pattern(p_static)); + if (!branch->patterns[branch->patterns.size() - 1]) { + return; + } + } + + if(!_enter_indent_block()) { + _set_error("Expected block in pattern branch"); + return; + } + + branch->body = alloc_node(); + branch->body->parent_block = p_block; + p_block->sub_blocks.push_back(branch->body); + current_block = branch->body; + + _parse_block(branch->body, p_static); + + current_block = p_block; + + p_branches.push_back(branch); + } +} + + +void GDParser::_generate_pattern(PatternNode *p_pattern, Node *p_node_to_match, Node *&p_resulting_node, Map &p_bindings) +{ + switch (p_pattern->pt_type) { + case PatternNode::PT_CONSTANT: { + + // typecheck + BuiltInFunctionNode *typeof_node = alloc_node(); + typeof_node->function = GDFunctions::TYPE_OF; + + OperatorNode *typeof_match_value = alloc_node(); + typeof_match_value->op = OperatorNode::OP_CALL; + typeof_match_value->arguments.push_back(typeof_node); + typeof_match_value->arguments.push_back(p_node_to_match); + + OperatorNode *typeof_pattern_value = alloc_node(); + typeof_pattern_value->op = OperatorNode::OP_CALL; + typeof_pattern_value->arguments.push_back(typeof_node); + typeof_pattern_value->arguments.push_back(p_pattern->constant); + + OperatorNode *type_comp = alloc_node(); + type_comp->op = OperatorNode::OP_EQUAL; + type_comp->arguments.push_back(typeof_match_value); + type_comp->arguments.push_back(typeof_pattern_value); + + + // comare the actual values + OperatorNode *value_comp = alloc_node(); + value_comp->op = OperatorNode::OP_EQUAL; + value_comp->arguments.push_back(p_pattern->constant); + value_comp->arguments.push_back(p_node_to_match); + + + OperatorNode *comparison = alloc_node(); + comparison->op = OperatorNode::OP_AND; + comparison->arguments.push_back(type_comp); + comparison->arguments.push_back(value_comp); + + p_resulting_node = comparison; + + } break; + case PatternNode::PT_BIND: { + p_bindings[p_pattern->bind] = p_node_to_match; + + // a bind always matches + ConstantNode *true_value = alloc_node(); + true_value->value = Variant(true); + p_resulting_node = true_value; + } break; + case PatternNode::PT_ARRAY: { + + bool open_ended = false; + + if (p_pattern->array.size() > 0) { + if (p_pattern->array[p_pattern->array.size() - 1]->pt_type == PatternNode::PT_IGNORE_REST) { + open_ended = true; + } + } + + // typeof(value_to_match) == TYPE_ARRAY && value_to_match.size() >= length + // typeof(value_to_match) == TYPE_ARRAY && value_to_match.size() == length + + { + // typecheck + BuiltInFunctionNode *typeof_node = alloc_node(); + typeof_node->function = GDFunctions::TYPE_OF; + + OperatorNode *typeof_match_value = alloc_node(); + typeof_match_value->op = OperatorNode::OP_CALL; + typeof_match_value->arguments.push_back(typeof_node); + typeof_match_value->arguments.push_back(p_node_to_match); + + IdentifierNode *typeof_array = alloc_node(); + typeof_array->name = "TYPE_ARRAY"; + + OperatorNode *type_comp = alloc_node(); + type_comp->op = OperatorNode::OP_EQUAL; + type_comp->arguments.push_back(typeof_match_value); + type_comp->arguments.push_back(typeof_array); + + + // size + ConstantNode *length = alloc_node(); + length->value = Variant(open_ended ? p_pattern->array.size() - 1 : p_pattern->array.size()); + + OperatorNode *call = alloc_node(); + call->op = OperatorNode::OP_CALL; + call->arguments.push_back(p_node_to_match); + + IdentifierNode *size = alloc_node(); + size->name = "size"; + call->arguments.push_back(size); + + OperatorNode *length_comparison = alloc_node(); + length_comparison->op = open_ended ? OperatorNode::OP_GREATER_EQUAL : OperatorNode::OP_EQUAL; + length_comparison->arguments.push_back(call); + length_comparison->arguments.push_back(length); + + OperatorNode *type_and_length_comparison = alloc_node(); + type_and_length_comparison->op = OperatorNode::OP_AND; + type_and_length_comparison->arguments.push_back(type_comp); + type_and_length_comparison->arguments.push_back(length_comparison); + + p_resulting_node = type_and_length_comparison; + } + + + + for (int i = 0; i < p_pattern->array.size(); i++) { + PatternNode *pattern = p_pattern->array[i]; + + Node *condition = NULL; + + ConstantNode *index = alloc_node(); + index->value = Variant(i); + + OperatorNode *indexed_value = alloc_node(); + indexed_value->op = OperatorNode::OP_INDEX; + indexed_value->arguments.push_back(p_node_to_match); + indexed_value->arguments.push_back(index); + + _generate_pattern(pattern, indexed_value, condition, p_bindings); + + // concatenate all the patterns with && + OperatorNode *and_node = alloc_node(); + and_node->op = OperatorNode::OP_AND; + and_node->arguments.push_back(p_resulting_node); + and_node->arguments.push_back(condition); + + p_resulting_node = and_node; + } + + + } break; + case PatternNode::PT_DICTIONARY: { + + bool open_ended = false; + + if (p_pattern->array.size() > 0) { + open_ended = true; + } + + // typeof(value_to_match) == TYPE_DICTIONARY && value_to_match.size() >= length + // typeof(value_to_match) == TYPE_DICTIONARY && value_to_match.size() == length + + + { + // typecheck + BuiltInFunctionNode *typeof_node = alloc_node(); + typeof_node->function = GDFunctions::TYPE_OF; + + OperatorNode *typeof_match_value = alloc_node(); + typeof_match_value->op = OperatorNode::OP_CALL; + typeof_match_value->arguments.push_back(typeof_node); + typeof_match_value->arguments.push_back(p_node_to_match); + + IdentifierNode *typeof_dictionary = alloc_node(); + typeof_dictionary->name = "TYPE_DICTIONARY"; + + OperatorNode *type_comp = alloc_node(); + type_comp->op = OperatorNode::OP_EQUAL; + type_comp->arguments.push_back(typeof_match_value); + type_comp->arguments.push_back(typeof_dictionary); + + // size + ConstantNode *length = alloc_node(); + length->value = Variant(open_ended ? p_pattern->dictionary.size() - 1 : p_pattern->dictionary.size()); + + OperatorNode *call = alloc_node(); + call->op = OperatorNode::OP_CALL; + call->arguments.push_back(p_node_to_match); + + IdentifierNode *size = alloc_node(); + size->name = "size"; + call->arguments.push_back(size); + + OperatorNode *length_comparison = alloc_node(); + length_comparison->op = open_ended ? OperatorNode::OP_GREATER_EQUAL : OperatorNode::OP_EQUAL; + length_comparison->arguments.push_back(call); + length_comparison->arguments.push_back(length); + + OperatorNode *type_and_length_comparison = alloc_node(); + type_and_length_comparison->op = OperatorNode::OP_AND; + type_and_length_comparison->arguments.push_back(type_comp); + type_and_length_comparison->arguments.push_back(length_comparison); + + p_resulting_node = type_and_length_comparison; + } + + + + for (Map::Element *e = p_pattern->dictionary.front(); e; e = e->next()) { + + Node *condition = NULL; + + // chech for has, then for pattern + + IdentifierNode *has = alloc_node(); + has->name = "has"; + + OperatorNode *has_call = alloc_node(); + has_call->op = OperatorNode::OP_CALL; + has_call->arguments.push_back(p_node_to_match); + has_call->arguments.push_back(has); + has_call->arguments.push_back(e->key()); + + + if (e->value()) { + + OperatorNode *indexed_value = alloc_node(); + indexed_value->op = OperatorNode::OP_INDEX; + indexed_value->arguments.push_back(p_node_to_match); + indexed_value->arguments.push_back(e->key()); + + _generate_pattern(e->value(), indexed_value, condition, p_bindings); + + OperatorNode *has_and_pattern = alloc_node(); + has_and_pattern->op = OperatorNode::OP_AND; + has_and_pattern->arguments.push_back(has_call); + has_and_pattern->arguments.push_back(condition); + + condition = has_and_pattern; + + } else { + condition = has_call; + } + + + + // concatenate all the patterns with && + OperatorNode *and_node = alloc_node(); + and_node->op = OperatorNode::OP_AND; + and_node->arguments.push_back(p_resulting_node); + and_node->arguments.push_back(condition); + + p_resulting_node = and_node; + } + + } break; + case PatternNode::PT_IGNORE_REST: + case PatternNode::PT_WILDCARD: { + // simply generate a `true` + ConstantNode *true_value = alloc_node(); + true_value->value = Variant(true); + p_resulting_node = true_value; + } break; + default: { + + } break; + } +} + +void GDParser::_transform_match_statment(BlockNode *p_block, MatchNode *p_match_statement) +{ + IdentifierNode *id = alloc_node(); + id->name = "#match_value"; + + for (int i = 0; i < p_match_statement->branches.size(); i++) { + + PatternBranchNode *branch = p_match_statement->branches[i]; + + MatchNode::CompiledPatternBranch compiled_branch; + compiled_branch.compiled_pattern = NULL; + + Map binding; + + for (int j = 0; j < branch->patterns.size(); j++) { + PatternNode *pattern = branch->patterns[j]; + + Map bindings; + Node *resulting_node; + _generate_pattern(pattern, id, resulting_node, bindings); + + if (!binding.empty() && !bindings.empty()) { + _set_error("Multipatterns can't contain bindings"); + return; + } else { + binding = bindings; + } + + if (compiled_branch.compiled_pattern) { + OperatorNode *or_node = alloc_node(); + or_node->op = OperatorNode::OP_OR; + or_node->arguments.push_back(compiled_branch.compiled_pattern); + or_node->arguments.push_back(resulting_node); + + compiled_branch.compiled_pattern = or_node; + } else { + // single pattern | first one + compiled_branch.compiled_pattern = resulting_node; + } + + } + + + // prepare the body ...hehe + for (Map::Element *e = binding.front(); e; e = e->next()) { + LocalVarNode *local_var = alloc_node(); + local_var->name = e->key(); + local_var->assign = e->value(); + + + IdentifierNode *id = alloc_node(); + id->name = local_var->name; + + OperatorNode *op = alloc_node(); + op->op=OperatorNode::OP_ASSIGN; + op->arguments.push_back(id); + op->arguments.push_back(local_var->assign); + + branch->body->statements.push_front(op); + branch->body->statements.push_front(local_var); + } + + compiled_branch.body = branch->body; + + + p_match_statement->compiled_pattern_branches.push_back(compiled_branch); + } + +} + void GDParser::_parse_block(BlockNode *p_block,bool p_static) { int indent_level = tab_level.back()->get(); @@ -2165,6 +2701,46 @@ void GDParser::_parse_block(BlockNode *p_block,bool p_static) { } + } break; + case GDTokenizer::TK_CF_MATCH: { + + tokenizer->advance(); + + MatchNode *match_node = alloc_node(); + + Node *val_to_match = _parse_and_reduce_expression(p_block, p_static); + + if (!val_to_match) { + if (_recover_from_completion()) { + break; + } + return; + } + + match_node->val_to_match = val_to_match; + + if (!_enter_indent_block()) { + _set_error("Expected indented pattern matching block after 'match'"); + return; + } + + BlockNode *compiled_branches = alloc_node(); + compiled_branches->parent_block = p_block; + compiled_branches->parent_class = p_block->parent_class; + + p_block->sub_blocks.push_back(compiled_branches); + + _parse_pattern_block(compiled_branches, match_node->branches, p_static); + + _transform_match_statment(compiled_branches, match_node); + + ControlFlowNode *match_cf_node = alloc_node(); + match_cf_node->cf_type = ControlFlowNode::CF_MATCH; + match_cf_node->match = match_node; + + p_block->statements.push_back(match_cf_node); + + _end_statement(); } break; case GDTokenizer::TK_PR_ASSERT: { diff --git a/modules/gdscript/gd_parser.h b/modules/gdscript/gd_parser.h index e8f5f0f9815..7968bf85dfb 100644 --- a/modules/gdscript/gd_parser.h +++ b/modules/gdscript/gd_parser.h @@ -258,6 +258,44 @@ public: Vector arguments; 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 dictionary; + Vector array; + + }; + + struct PatternBranchNode : public Node { + Vector patterns; + BlockNode *body; + }; + + struct MatchNode : public Node { + Node *val_to_match; + Vector branches; + + struct CompiledPatternBranch { + Node *compiled_pattern; + BlockNode *body; + }; + + Vector compiled_pattern_branches; + }; struct ControlFlowNode : public Node { enum CFType { @@ -267,13 +305,16 @@ public: CF_SWITCH, CF_BREAK, CF_CONTINUE, - CF_RETURN + CF_RETURN, + CF_MATCH }; CFType cf_type; Vector 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;} @@ -452,6 +493,15 @@ private: 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); + + + + PatternNode *_parse_pattern(bool p_static); + void _parse_pattern_block(BlockNode *p_block, Vector &p_branches, bool p_static); + void _transform_match_statment(BlockNode *p_block, MatchNode *p_match_statement); + void _generate_pattern(PatternNode *p_pattern, Node *p_node_to_match, Node *&p_resulting_node, Map &p_bindings); + + void _parse_block(BlockNode *p_block,bool p_static); void _parse_extends(ClassNode *p_class); void _parse_class(ClassNode *p_class); diff --git a/modules/gdscript/gd_script.cpp b/modules/gdscript/gd_script.cpp index b216ef42b96..d9a3dd13f0d 100644 --- a/modules/gdscript/gd_script.cpp +++ b/modules/gdscript/gd_script.cpp @@ -1938,6 +1938,7 @@ void GDScriptLanguage::get_reserved_words(List *p_words) const { "for", "pass", "return", + "match", "while", "remote", "sync", diff --git a/modules/gdscript/gd_tokenizer.cpp b/modules/gdscript/gd_tokenizer.cpp index 5dabf50ba12..70fc991bcc8 100644 --- a/modules/gdscript/gd_tokenizer.cpp +++ b/modules/gdscript/gd_tokenizer.cpp @@ -85,6 +85,7 @@ const char* GDTokenizer::token_names[TK_MAX]={ "continue", "pass", "return", +"match", "func", "class", "extends", @@ -894,6 +895,7 @@ void GDTokenizerText::_advance() { {TK_CF_BREAK,"break"}, {TK_CF_CONTINUE,"continue"}, {TK_CF_RETURN,"return"}, + {TK_CF_MATCH, "match"}, {TK_CF_PASS,"pass"}, {TK_SELF,"self"}, {TK_CONST_PI,"PI"}, diff --git a/modules/gdscript/gd_tokenizer.h b/modules/gdscript/gd_tokenizer.h index 18e5547d36c..9a6f4df9c42 100644 --- a/modules/gdscript/gd_tokenizer.h +++ b/modules/gdscript/gd_tokenizer.h @@ -92,6 +92,7 @@ public: TK_CF_CONTINUE, TK_CF_PASS, TK_CF_RETURN, + TK_CF_MATCH, TK_PR_FUNCTION, TK_PR_CLASS, TK_PR_EXTENDS,