Grammar.ebnf

identifier          = ? C#: Char.IsLetter ?, { ? C#: Char.IsLetterOrDigit ? }

binary_digit        = '0' | '1'
binary_integer      = '0b', binary_digit, { binary_digit }
octal_digit         = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7'
octal_integer       = '0o', octal_digit, { octal_digit }
decimal_digit       = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
decimal_integer     = decimal_digit, { decimal_digit }
decimal_number      = ( decimal_integer, [ '.', decimal_integer ] | '.', decimal_integer ), [ ( 'e' | 'E' ), [ '_' | '+' ], decimal_integer ]
hexadecimal_digit   = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
                    | [ 'a' | 'A' ] | [ 'b' | 'B' ] | [ 'c' | 'C' ] | [ 'd' | 'D' ] | [ 'e' | 'E' ] | [ 'f' | 'F' ]
hexadecimal_integer = '0x', hexadecimal_digit, { hexadecimal_digit }
number              = binary_integer | octal_integer | decimal_number | hexadecimal_integer

function_call       = identifier, '(', [ expression, { ',', expression } ]  , ')'

atomic              = '(', expression, ')' | function_call | identifier | number

prefix_unary_operator = ? user-defined ?
prefixed_expression = prefix_unary_operator, prefixed_expression
                    | atomic

suffix_unary_operator = ? user-defined ?
suffixed_expression = suffixed_expression, suffix_unary_operator
                    | prefixed_expression

binary_operator = ? user-defined ?
binary_expression = binary_expression, binary_operator, binary_expression
                  | suffixed_expression