[REBOL] Could anyone explain 'to???

[Petr . Krenzelok]

Hi,


->> source to-integer
to-integer: func ["Converts to integer value." value "Value to
convert"][to integer! value
]
->> source to
to: native [
    {Constructs and returns a new value after conversion.}
    type [any-type!] "The datatype or example value."
    spec [any-type!] "The attributes of the new value."
]
->>

How to define spec? Any example? Anything in common with datatypes
output format, mentioned in 2.1.90.x notes.html? :-)

Also - what is datatype! good for?

Thanks,

-pekr-