! Copyright (C) 2003, 2010 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien byte-arrays combinators continuations destructors
kernel math namespaces sequences sequences.private ;
IN: io

SYMBOLS: +byte+ +character+ ;

GENERIC: stream-element-type ( stream -- type )

GENERIC: stream-read1 ( stream -- elt )
GENERIC: stream-read-unsafe ( n buf stream -- n' )
GENERIC: stream-read ( n stream -- seq )
GENERIC: stream-read-until ( seps stream -- seq sep/f )
GENERIC: stream-read-partial-unsafe ( n buf stream -- n' )
GENERIC: stream-read-partial ( n stream -- seq )
GENERIC: stream-readln ( stream -- str/f )

GENERIC: stream-write1 ( elt stream -- )
GENERIC: stream-write ( data stream -- )
GENERIC: stream-flush ( stream -- )
GENERIC: stream-nl ( stream -- )

ERROR: bad-seek-type type ;

SINGLETONS: seek-absolute seek-relative seek-end ;

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

: stream-print ( str stream -- ) [ stream-write ] [ stream-nl ] bi ;

! Default streams
SYMBOL: input-stream
SYMBOL: output-stream
SYMBOL: error-stream

: readln ( -- str/f ) input-stream get stream-readln ;
: read1 ( -- elt ) input-stream get stream-read1 ;
: read ( n -- seq ) input-stream get stream-read ;
: read-until ( seps -- seq sep/f ) input-stream get stream-read-until ;
: read-partial ( n -- seq ) input-stream get stream-read-partial ;
: tell-input ( -- n ) input-stream get stream-tell ;
: tell-output ( -- n ) output-stream get stream-tell ;
: seek-input ( n seek-type -- ) input-stream get stream-seek ;
: seek-output ( n seek-type -- ) output-stream get stream-seek ;

: write1 ( elt -- ) output-stream get stream-write1 ;
: write ( seq -- ) output-stream get stream-write ;
: flush ( -- ) output-stream get stream-flush ;

: nl ( -- ) output-stream get stream-nl ;

: with-input-stream* ( stream quot -- )
    input-stream swap with-variable ; inline

: with-input-stream ( stream quot -- )
    [ with-input-stream* ] curry with-disposal ; inline

: with-output-stream* ( stream quot -- )
    output-stream swap with-variable ; inline

: with-output-stream ( stream quot -- )
    [ with-output-stream* ] curry with-disposal ; inline

: with-streams* ( input output quot -- )
    swapd [ with-output-stream* ] curry with-input-stream* ; inline

: with-streams ( input output quot -- )
    #! We have to dispose of the output stream first, so that
    #! if both streams point to the same FD, we get to flush the
    #! buffer before closing the FD.
    swapd [ with-output-stream ] curry with-input-stream ; inline

: print ( str -- ) output-stream get stream-print ;

: bl ( -- ) " " write ;

: each-morsel ( ..a handler: ( ..a data -- ..b ) reader: ( ..b -- ..a data ) -- ..a )
    [ dup ] compose swap while drop ; inline

<PRIVATE

: stream-exemplar ( stream -- exemplar )
    stream-element-type {
        { +byte+ [ B{ } ] }
        { +character+ [ "" ] }
    } case ; inline

: stream-exemplar-growable ( stream -- exemplar )
    stream-element-type {
        { +byte+ [ BV{ } ] }
        { +character+ [ SBUF" " ] }
    } case ; inline

PRIVATE>

: each-stream-line ( ... stream quot: ( ... line -- ... ) -- ... )
    swap [ stream-readln ] curry each-morsel ; inline

: each-line ( ... quot: ( ... line -- ... ) -- ... )
    input-stream get swap each-stream-line ; inline

: stream-lines ( stream -- seq )
    [ [ ] collector [ each-stream-line ] dip { } like ] with-disposal ;

: lines ( -- seq )
    input-stream get stream-lines ; inline

: each-stream-block ( ... stream quot: ( ... block -- ... ) -- ... )
    swap [ 65536 swap stream-read-partial ] curry each-morsel ; inline

: each-block ( ... quot: ( ... block -- ... ) -- ... )
    input-stream get swap each-stream-block ; inline

: stream-contents ( stream -- seq )
    [
        [ [ ] collector [ each-stream-block ] dip { } like ]
        [ stream-exemplar concat-as ] bi
    ] with-disposal ;

: stream-contents-length ( stream -- n )
    [ stream-tell ]
    [ [ 0 seek-end ] dip [ stream-seek ] [ stream-tell ] bi ]
    [ [ swap seek-absolute ] dip stream-seek ] tri ;

: stream-contents* ( stream -- seq )
    [ stream-contents-length dup (byte-array) ]
    [ [ stream-read-unsafe drop ] curry keep ] bi ;

: contents ( -- seq )
    input-stream get stream-contents ; inline

: contents* ( -- seq )
    input-stream get stream-contents* ; inline

: stream-copy ( in out -- )
    [ [ [ write ] each-block ] with-output-stream ]
    curry with-input-stream ;

! Implement stream-read and stream-read-partial in terms of -unsafe

MIXIN: noncopying-reader

: (new-sequence-for-stream) ( n stream -- seq )
    stream-exemplar new-sequence ; inline

: (read-into-new) ( n stream quot -- byte-array/f )
    [ 2dup (new-sequence-for-stream) swap ] dip curry keep
    over 0 = [ 2drop f ] [ resize ] if ; inline

M: noncopying-reader stream-read
    [ stream-read-unsafe ] (read-into-new) ; inline

M: noncopying-reader stream-read-partial
    [ stream-read-partial-unsafe ] (read-into-new) ; inline