36 lines
617 B
Crystal
36 lines
617 B
Crystal
require "./token"
|
|
|
|
class CBOR::Lexer
|
|
@current_byte : UInt8
|
|
|
|
def initialize(@io : IO)
|
|
@current_byte = 0x0
|
|
end
|
|
|
|
def next_token : Token?
|
|
byte = @io.read_byte
|
|
return nil if byte.nil?
|
|
|
|
@current_byte = byte
|
|
|
|
# See: RFC7049 Appedix B
|
|
case @current_byte
|
|
when .<= 0x17
|
|
Token.new(kind: Token::Kind::UInt, value: @curren_byte)
|
|
when 0x18
|
|
read_uint8
|
|
end
|
|
end
|
|
|
|
private def read_uint8
|
|
byte = @io.read_byte
|
|
return unexpect_eof if byte.nil?
|
|
|
|
Token.new(kind: Token::Kind::UInt, value: byte)
|
|
end
|
|
|
|
private def unexpected_eof
|
|
raise "Unexpected EOF"
|
|
end
|
|
end
|