peekable

From peek +‎ -able.

peekable (comparative more peekable, superlative most peekable)

1. (informal) Capable of being peeked at or into.
   • 1972, New York Magazine, volume 5, number 31, page 45:

     Her fourteen dollhouses range in sophistication from a child-made primitive (1887) to an electrified manse set on a low table and peekable from all sides.

2. (computing) Of a stream or other sequence: from which the next value can be retrieved without advancing the pointer from its current position.
   • 2012, John Hunt, Smalltalk and Object Orientation: An Introduction, page 130:

     Peekable streams also have an internal record of their current position and can look ahead in the stream for information.

• keepable