IsStream C
Streams are GAP objects and all open streams, input, output, text and binary, lie in this category.
IsClosedStream C
When a stream is closed, its type changes to lie in 'IsClosedStream'. This category is used to install methods that trap accesses to closed streams.
IsInputStream C
All input streams lie in this category, and support input
operations such as ReadByte (see Operations for Input Streams)
IsInputTextStream C
All text input streams lie in this category. They translate new-line characters read.
IsInputTextNone C
It is convenient to use a category to distinguish dummy streams (see Dummy Streams) from others. Other distinctions are usually made using representations
IsOutputStream C
All output streams lie in this category and support basic
operations such as WriteByte (see Operations for Output Streams)
IsOutputTextStream C
All text output streams lie in this category and translate new-line characters on output.
IsOutputTextNone C
It is convenient to use a category to distinguish dummy streams (see Dummy Streams) from others. Other distinctions are usually made using representations
StreamsFamily V
All streams lie in the StreamsFamily
GAP 4 manual