stream-read1 ( stream -- elt )
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Vocabulary
io

Inputs

stream

an input stream

Outputs

elt	an element or f

Generic word contract
Reads an element from the stream. Outputs f on stream exhaustion.

Notes
Most code only works on one stream at a time and should instead use read1; see Default input and output streams.

Errors
Throws an error if the I/O operation fails.

Definition

IN: io

GENERIC: stream-read1 ( stream -- elt )

Methods

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

M: byte-reader stream-read1 sequence-read1 ;


USING: accessors destructors io io.streams.c ;

M: c-reader stream-read1 check-disposed handle>> fgetc ;


USING: accessors io io.streams.counting kernel math ;

M:: counting-stream stream-read1 ( stream -- elt )
    stream stream>> stream-read1 dup
    [ stream [ 1 + ] change-in-count drop ] when ;


USING: io io.encodings io.encodings.private kernel ;

M: decoder stream-read1 dup decode1 fix-cr ; inline


USING: accessors io io.streams.duplex kernel ;

M: duplex-stream stream-read1
    [ in>> ] call \ stream-read1 execute ;


USING: io kernel ;

M: f stream-read1 drop f ; inline


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

M: input-port stream-read1
    check-disposed dup wait-to-read
    [ drop f ] [ buffer>> buffer-pop ] if ; inline


USING: combinators io kernel sequences ui.tools.listener ;

M: interactor stream-read1
    dup interactor-read {
        { [ dup not ] [ 2drop f ] }
        { [ dup empty? ] [ drop stream-read1 ] }
        { [ dup first empty? ] [ 2drop 10 ] }
        [ nip first first ]
    } cond ;


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

M: limited-stream stream-read1
    1 swap [ nip stream-read1 ] maybe-read ;


USING: accessors alien alien.accessors io io.streams.memory
kernel ;

M: memory-stream stream-read1
    [ 1 over <displaced-alien> ] change-alien drop
    0 alien-unsigned-1 ; inline


USING: io io.streams.null kernel ;

M: null-reader stream-read1 drop f ;


USING: accessors io io.streams.peek kernel sequences ;

M: peek-stream stream-read1
    dup peeked>> [ stream>> stream-read1 ] [ pop nip ] if-empty
    ;


USING: io io.streams.random kernel random ;

M: random-stream stream-read1 drop 256 random ;


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

M: string-reader stream-read1 sequence-read1 ;


USING: io io.streams.tee io.streams.tee.private ;

M: tee-stream stream-read1
    [ stream-read1 ] [ stream-write1 ] tee1 ;


USING: accessors io io.streams.throwing kernel ;

M:: throws-on-eof-stream stream-read1 ( stream -- elt )
    stream stream>> stream-read1
    [ 1 stream \ read1 stream-exhausted ] unless* ;


USING: io io.streams.zeros kernel ;

M: zero-stream stream-read1 drop 0 ;