stream-peek ( n stream -- seq )

Vocabulary

io.streams.peek

Inputs

n	an object
stream	an object

Outputs

seq

an object

Definition

USING: accessors combinators.short-circuit io io.private kernel
math sequences ;

IN: io.streams.peek

: stream-peek ( n stream -- seq )
    2dup peeked>> { [ length <= ] [ length 0 > ] } 1&& [
        [ peeked>> <reversed> swap head ]
        [ stream-exemplar like ] bi
    ] [
        [ nip ] [ stream-read ] 2bi
        [ reverse swap peeked>> push-all ] keep
    ] if ;