(**********************************************
 ** EXTENDED_FLOAT.sml
 ** sml
 **
 ** Aleksandar Nanevski
 **
 ** A set of primitives needed for writting 
 ** adaptive floating point code.
 **********************************************)


signature EXTENDED_FLOAT =
sig
    structure XFloat : XFLOAT

    type quad

    val sum : real * real -> quad
    val diff : real * real -> quad
    val sumfast : real * real -> quad
    val diffast : real * real -> quad
    val prod : real * real -> quad
    val sq : real -> quad

    val fromReal : real -> quad
    val toXFloat : quad -> XFloat.xfloat
    val approx : quad -> real
    val err : quad -> real 
    val toResErr : quad -> {res : real, err : real}
	
    val + : quad * quad -> XFloat.xfloat
    val - : quad * quad -> XFloat.xfloat
    val * : quad * quad -> XFloat.xfloat
    val ~ : quad -> quad
    val double : quad -> quad
    val sq2 : quad -> XFloat.xfloat
    val abs : quad -> quad

    val add : quad * real -> XFloat.xfloat
    val sub : quad * real -> XFloat.xfloat
    val isub : real * quad -> XFloat.xfloat
    val scale : real * quad -> XFloat.xfloat

    val add2 : XFloat.xfloat * quad -> XFloat.xfloat
    val sub2 : XFloat.xfloat * quad -> XFloat.xfloat
    val isub2 : quad * XFloat.xfloat -> XFloat.xfloat
    val scale2 : quad * XFloat.xfloat -> XFloat.xfloat


    val toString : quad -> string
end