Closes this IO.

IO defines this is a no-op method, but including types may override.

Flushes buffered data, if any.

IO defines this is a no-op method, but including types may override.

Peeks into this IO, if possible.

It returns:

• nil if this IO isn't peekable at this moment or at all
• an empty slice if it is, but EOF was reached
• a non-empty slice if some data can be peeked

The returned bytes are only valid data until a next call to any method that reads from this IO is invoked.

By default this method returns nil, but IO implementations that provide buffering or wrap other IOs should override this method.

Reads at most slice.size bytes from this IO into slice. Returns the number of bytes read, which is 0 if and only if there is no more data to read (so checking for 0 is the way to detect end of file).

io = IO::Memory.new "hello"
slice = Bytes.new(4)
io.read(slice) # => 4
slice          # => Bytes[104, 101, 108, 108]
io.read(slice) # => 1
slice          # => Bytes[111, 101, 108, 108]
io.read(slice) # => 0

Rewinds this IO. By default this method raises, but including types may implement it.

Appends a short String representation of this object which includes its class name and its object address.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).to_s # => #<Person:0x10a199f20>

Returns a nicely readable and concise string representation of this object, typically intended for users.

This method should usually not be overridden. It delegates to #to_s(IO) which can be overridden for custom implementations.

Also see #inspect.

Writes the contents of slice into this IO.

io = IO::Memory.new
slice = Bytes.new(4) { |i| ('a'.ord + i).to_u8 }
io.write(slice)
io.to_s # => "abcd"