Update syntax to Lua 5.4

Author: Azganoth

docs/extended_bnf.md

@@ -11,20 +11,22 @@ block = return_statement | statement {statement} [return_statement];
 (* statements *)
 return_statement = "return" [expression_list] [empty_statement];
 
-statement = do_statement | if_statement | for_numeric_statement
-  | for_generic_statement | while_statement | repeat_statement | break_statement
-  | label_statement | goto_statement | variable_assignment
-  | scoped_variable_declaration | function_declaration | scoped_function_declaration
-  | function_call | empty_statement;
+statement = do_statement | if_statement | for_numeric_statement | for_generic_statement
+  | while_statement | repeat_statement | break_statement | label_statement | goto_statement
+  | variable_assignment | scoped_variable_declaration | function_definition_statement
+  | scoped_function_definition_statement | function_call | empty_statement;
 
 empty_statement = ";";
 
-scoped_function_declaration = "local" "function" identifier function_body;
+scoped_function_definition_statement = "local" "function" identifier function_body;
 
-function_declaration = "function" function_identifier function_body;
+function_definition_statement = "function" function_identifier function_body;
 function_identifier = identifier {"." identifier} [":" identifier];
 
-scoped_variable_declaration = "local" identifier_list ["=" expression_list];
+scoped_variable_declaration = "local" scoped_variable_list ["=" expression_list];
+scoped_variable_list = scoped_variable {',' scoped_variable};
+scoped_variable = identifier [attribute];
+attribute = '<' identifier '>';
 
 variable_assignment = variable_list "=" expression_list;
 variable_list = variable {"," variable};
@@ -35,24 +37,20 @@ label_statement = "::" identifier "::";
 break_statement = "break";
 repeat_statement = "repeat" [block] "until" expression;
 while_statement = "while" expression "do" [block] "end";
-for_generic_statement = "for" identifier_list "in" expression_list
-  "do" [block] "end";
-for_numeric_statement = "for" identifier "=" expression "," expression ["," expression]
-  "do" [block] "end";
+for_generic_statement = "for" identifier_list "in" expression_list "do" [block] "end";
+for_numeric_statement = "for" identifier "=" expression "," expression ["," expression] "do" [block] "end";
 
 if_statement = "if" expression "then" [block] {"elseif" expression "then" [block]}
   ["else" [block]] "end";
 
 do_statement = "do" [block] "end";
 
 (* expressions *)
-expression = nil | boolean | number | string | unary_expression
-  | binary_expression | table | vararg_expression | function_definition
-  | prefix_expression;
+expression = nil | boolean | number | string | unary_expression | binary_expression
+  | table | vararg_expression | function_definition | prefix_expression;
 
 prefix_expression = variable | function_call | "(" expression ")";
-variable = identifier | prefix_expression "." identifier
-  | prefix_expression "[" expression "]";
+variable = identifier | prefix_expression "." identifier | prefix_expression "[" expression "]";
 function_call = prefix_expression [":" identifier] argument_list;
 argument_list = string | table | "(" [expression_list] ")";
 expression_list = expression {"," expression};
@@ -76,8 +74,7 @@ binary_operator = "or" | "and" | "==" | "~=" | "<" | ">" | "<=" | ">=" | "|"
 unary_expression = unary_operator expression;
 unary_operator = "not" | "#" | "-" | "~";
 
-string = "'" {, inline_character - "'"}, "'"
-  | '"' {, inline_character - '"'}, '"'
+string = "'" {, inline_character - "'"}, "'" | '"' {, inline_character - '"'}, '"'
   | multiline_start {, character}, multiline_end;
 inline_character = ? any character except a newline ?;
 character = ? any character ?;
@@ -106,13 +103,12 @@ identifier = (letter | "_") {, letter | decimal_digit | "_"};
 letter = ? case insensitive alphabetic character ?;
 
 (* extras *)
-comment = "--" {, inline_character}
-  | "--", multiline_start {, character}, multiline_end;
+comment = "--" {, inline_character} | "--", multiline_start {, character}, multiline_end;
 
 (* "start" and "end" must have the same number of equal signs ("=") *)
 multiline_start = "[" {, "="}, "[";
 multiline_end = "]" {, "="}, "]";
 ```
 
 [extended bnf]: https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form
-[lua manual]: http://www.lua.org/manual/5.3/manual.html#9
+[lua manual]: http://www.lua.org/manual/5.4/manual.html#9