grammar Hadean;

options {
    language=CSharp3;
    TokenLabelType=CommonToken;
    output=AST;
    ASTLabelType=CommonTree;
}

@lexer::namespace  { Hadean.Compiler.ANTLR }
@parser::namespace { Hadean.Compiler.ANTLR }

// PARSER
public
compileUnit
    :	typeSpecification EOF
    ;

modifier
	:	'public'	|	'private'
	|	'const'		|	'static'
	|	'abstract'	|	'sealed'
	;

type
	:	'byte'	|	'sbyte'
	|	'word'	|	'uword'		// Same as short
	|	'int'	|	'uint'
	|	'long'	|	'ulong'
	|	'float'	|	'double'
	|	'char'	|	'string'
	|	'bool'	|	'var'		// Var will be object
	|	IDENT					// Custom types
//	|	typeSpecification
	;

header
	:	/* stmt_Preprocessor* */ stmt_Import
	;

stmt_Preprocessor
	:	'import' IDENT 'from' IDENT ('.' IDENT)* ';'
	;

typeSpecification
	:	header
	(	type_Class
	|	type_Enum
	|	type_Namespace
	|	type_Struct
	)
	;

type_Class
	// IS <interface> EXTENDS <class>
	:	modifier* 'class' IDENT ('is' IDENT (',' IDENT)*)? ('extends' IDENT)? body
	;

type_Enum
	:	modifier* 'enum' IDENT
		SCOPE_BEGIN
			type_Enum_Enumeration (',' type_Enum_Enumeration)*
		SCOPE_END
	;

type_Enum_Enumeration
	:	IDENT ('=' (NUMBER | HEX))?
	;

type_Namespace
	:	'namespace' IDENT body
	;

type_Struct
	:	modifier* 'struct' IDENT body
	;

statement
	:	stmt_Assign
	|	stmt_Decl
	|	stmt_DoWhile
	|	stmt_For
	|	stmt_ForEach
	|	stmt_If
	|	stmt_MethCall
	|	stmt_Property
	|	stmt_While
	;

stmt_Assign
	:	'=' (NUMBER | HEX | STRING_LITERAL | CHAR_LITERAL) ';'
	|	'=' 'new' IDENT '(' parameters? ')' ';'
	|	'=' ('true' | 'false') ';'
	|	'=' expression ';'
	|	'=' stmt_Assign_Array ';'
	;

stmt_Assign_Array
	:	'new' type '['
	;

stmt_Decl
	:	type ('[' ','* ']')? IDENT stmt_Assign? ';'
	;

stmt_DoWhile
	:	'do' body
		'while' '(' expression ')'
	;

stmt_For
	:	'for' '(' type IDENT ';' expression ';' statement* ')' body
	;

stmt_ForEach
	:	'foreach' '(' type IDENT ':' IDENT ')' body
	;

stmt_If
	:	'if' '(' expression ')' body
		( 'elseif' '(' expression ')' body)*
		( 'else' body )?
	;

stmt_MethCall
	:	IDENT '(' parameters ')' ';'
	;

stmt_Property
	:	modifier* type IDENT
	(	SCOPE_BEGIN
			('private'? 'get' (body | ';'))?
			('private'? 'set' (body | ';'))?
		SCOPE_END
	)
	|	';'
	;

expression
	:	stmt_MethCall
	;

parameters
	:	parameter (',' parameter)*
	;

parameter
	:	type IDENT
	;

body
	:	SCOPE_BEGIN statement* SCOPE_END
	;

// LEXER

WS
	:	' '
	|	'\t'
	|	'\r'
	|	'\n'
	;

IDENT
	:	(LETTER | '_') (LETTER | DIGIT | '_')*
	;

NUMBER
	:	DIGIT+
	;

HEX
	:	'0x' (DIGIT | 'a'..'f' | 'A'..'F')+
	;

SCOPE_BEGIN
	:	'{'
	;

SCOPE_END
	:	'}'
	;

fragment DIGIT
	:	'0'..'9'
	;

fragment LETTER
	:	'a'..'z' | 'A'..'Z'
	;