YiniParser.g4

/*
 YINI grammar in ANTLR 4.
 
 Apache License, Version 2.0, January 2004,
 http://www.apache.org/licenses/
 Copyright 2024 Gothenburg, Marko K. S. (Sweden via
 Finland).
 */

/* 
 This grammar aims to follow, as closely as possible, the YINI specification v1.0.0 Alpha 3.
 
 Feedback, bug reports and improvements are welcomed here https://github.com/YINI-lang/YINI-spec
 
 http://yini-lang.org
 */

parser grammar YiniParser;
options {
	tokenVocab = YiniLexer;
	caseInsensitive = false;
}

//comment: BLOCK_COMMENT | LINE_COMMENT; NL: LINE_COMMENT+ | NL+;

yini: SHEBANG? COMMENT* NL* section+ NL* EOF;

section:
	SECTION_HEAD section_members
	| SECTION_HEAD section
	| terminal_line;

terminal_line: TERMINAL_TOKEN (NL+ | COMMENT? NL*);

section_members: member+;

member:
	member_explicit_string
	| member_explicit_real_number
	| member_explicit_integer_number
	| member_explicit_boolean
	| member_explicit_array
	//| IDENT EQ NL+ // Empty value is treated as NULL.
	| (IDENT | KEY) EQ value? NL+ // Empty value is treated as NULL.
	//| IDENT COLON elements? NL+
	| member_colon_list;
//| STRING COLON value? NL+; // ???

member_colon_list: (IDENT | KEY) COLON elements? NL+;

member_explicit_string: DOLLAR IDENT EQ string_literal? NL+;
member_explicit_real_number: SS IDENT EQ number_literal? NL+;
member_explicit_integer_number: SS IDENT EQ number_literal? NL+;
member_explicit_boolean: PC IDENT EQ boolean_literal? NL+;
member_explicit_array:
	AT IDENT EQ list_in_brackets? NL+
	| AT IDENT COLON elements? NL+; // ? reactor to colon list

key: IDENT;
//key: (IDENT | STRING); 

//key: (IDENT | RAW_STRING);

value:
	list_in_brackets
	| string_literal
	| number_literal
	| boolean_literal
	| NULL; // NOTE: In specs NULL should be case-insensitive.

list: elements | list_in_brackets;

list_in_brackets: OB NL* elements NL* CB | EMPTY_LIST;

elements: element COMMA? | element COMMA elements;

element: NL* value NL* | NL* list_in_brackets NL*;

number_literal: NUMBER;

string_literal: STRING string_concat*;
string_concat: NL* PLUS NL* STRING;

// NOTE: In specs boolean literals should be case-insensitive.
boolean_literal: BOOLEAN_FALSE | BOOLEAN_TRUE;