stream-seek ( n seek-type stream -- )
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Vocabulary
io

Inputs

n	an integer
seek-type	a seek singleton
stream	a stream

Outputs
None

Word description
Moves the pointer associated with a stream's handle to an offset n bytes from the seek type so that further reading or writing happens at the new location. For output streams, the buffer is flushed before seeking. Seeking past the end of an output stream will pad the difference with zeros once the stream is written to again.

Three methods of seeking are supported:

•	seek-absolute
•	seek-relative
•	seek-end

Notes
Stream seeking is not supported on streams that do not have a known length, e.g. TCP/IP streams.

See also
stream-tell, stream-seekable?, stream-length

Definition

IN: io

GENERIC: stream-seek ( n seek-type stream -- )

Methods

USING: io io.streams.byte-array io.streams.sequence ;

M: byte-reader stream-seek sequence-seek ;


USING: accessors destructors io io.buffers io.ports
io.ports.private kernel ;

M: input-port stream-seek
    check-disposed do-seek-relative
    [ buffer>> 0 swap buffer-reset ] [ handle>> seek-handle ] bi
    ;


USING: accessors io io.streams.limited
io.streams.limited.private kernel ;

M: limited-stream stream-seek
    >limited-seek
    [ stream>> stream-seek ] [ limited-stream-seek ] 3bi ;


USING: accessors destructors io io.ports io.ports.private kernel
;

M: output-port stream-seek
    check-disposed do-seek-relative
    [ stream-flush ] [ handle>> seek-handle ] bi ;


USING: accessors io io.streams.peek ;

M: peek-stream stream-seek stream>> stream-seek ;


USING: io io.streams.sequence io.streams.string ;

M: string-reader stream-seek sequence-seek ;


USING: accessors io io.streams.throwing ;

M: throws-on-eof-stream stream-seek stream>> stream-seek ;