factor/library/io/logging.factor

! Copyright (C) 2003, 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
IN: streams
USING: kernel namespaces stdio strings unparser ;

! A simple logging framework.
SYMBOL: log-stream

: log ( msg -- )
    #! Log a message to the log stream, either stdio or a file.
    log-stream get dup [
        tuck stream-print stream-flush
    ] [
        2drop
    ] ifte ;

: with-logging ( file quot -- )
    #! Calls to log inside quot will output to a file.
    [ swap <file-writer> log-stream set call ] with-scope ;

! Helpful words.

: log-error ( error -- ) "Error: " swap cat2 log ;

: log-client ( client-stream -- )
    [
        "Accepted connection from " %
        ( dup ) client-stream-host %
       ! CHAR: : ,
       ! client-stream-port unparse % 
    ] make-string log ;