(* vi: ft=ebnf
 *)

program
	= {'pub', declaration}
	;

declaration
	= mutdecl
	| constdecl
	;

assignment
	= expression, '=', expression, ';'
	;

mutdecl
	= IDENT, ':', type, ';'
	| IDENT, ':', [type], '=', expression | ellipsis, ';'
	;

constdecl
	= IDENT, ':', [type], ':', (expression, ';') | function
	;

function
	= prototype, '{', {statement}, '}'
	;

prototype
	= '(', ')', [type]
	;

statement
	= declaration
	| assignment
	| funcall
	| 'return', [expression], ';'
	;

expression
	= IDENT
	| number
	| unop, expression
	| expression, binop, expression
	| '(', expression, ')'
	| funcall
	;

funcall
	= expression '(' ')'
	;

unop
	= '-' | '&' | '+' | '~'
	;

binop
	= '+'  | '!=' | '%' | '&'
	| '*'  | '-'  | '/' | '<<'
	| '==' | '>>' | '|' | '~'
	;

number
	= integer
	| floating
	;

integer
	= ['0d'], decdigit, {decdigit}
	|  '0b',  bindigit, {bindigit}
	|  '0o',  octdigit, {octdigit}
	|  '0x',  hexdigit, {hexdigit}
	;

floating
	=  integer,  '.', [integer]
	| [integer], '.',  integer
	;

bindigit
	= '0' | '1'
	;

octdigit
	= '0' | '1' | '2' | '3'
	| '4' | '5' | '6' | '7'
	;

decdigit
	= '0' | '1' | '2' | '3' | '4'
	| '5' | '6' | '7' | '8' | '9'
	;

hexdigit
	= '0' | '1' | '2' | '3'
	| '4' | '5' | '6' | '7'
	| '8' | '9' | 'A' | 'B'
	| 'C' | 'D' | 'E' | 'F'
	;

type
	= IDENT
	;

ellipsis
	= '…'
	| '...'
	;