stdlib_codata_type.fypp Source File

Source Code

#:include "common.fypp"
module stdlib_codata_type
    !! Codata constant type
    !! ([Specification](../page/specs/stdlib_constants.html))
    use stdlib_kinds, only: #{for k in KINDS[:-1]}#${k}$, #{endfor}#${KINDS[-1]}$
    use stdlib_io, only: FMT_REAL_DP
    use stdlib_optval, only: optval 

    type, public :: codata_constant_type
        !! version: experimental
        !! Derived type for representing a Codata constant.
        !! ([Specification](../page/specs/stdlib_constants.html))
        character(len=64) :: name
        real(dp) :: value
        real(dp) :: uncertainty
        character(len=32) :: unit
        procedure :: print
        #:for k in KINDS
        procedure :: to_real_${k}$
        generic :: to_real => #{for k in KINDS[:-1]}#to_real_${k}$, #{endfor}#to_real_${KINDS[-1]}$
    end type

    interface to_real
        !! Get the constant value or uncertainty.
        #:for k in KINDS
        module procedure to_real_${k}$
    end interface

    public :: to_real

subroutine print(self)
    !! Print out the constant's name, value, uncertainty and unit.
    class(codata_constant_type), intent(in) :: self
    print "(A64, SP, "//FMT_REAL_DP//", A5, "//FMT_REAL_DP//", 1X, A32)", self%name, self%value, "+/-", self%uncertainty, self%unit 
end subroutine

#:for k in KINDS
elemental pure real(${k}$) function to_real_${k}$(self, mold, uncertainty) result(r)
    !! version: experimental
    !! Get the constant value or uncertainty for the kind ${k}$
    !! ([Specification](../page/specs/stdlib_constants.html))
    class(codata_constant_type), intent(in) :: self !! Codata constant
    real(${k}$), intent(in) :: mold !! dummy argument to disambiguate at compile time the generic interface
    logical, intent(in), optional :: uncertainty !! Set to true if the uncertainty is required. Default to .false..
    logical :: u
    u = optval(uncertainty, .false.)

    if(u .eqv. .false.)then
        r = real(self%value, kind(mold))
        r = real(self%uncertainty, kind(mold))
    end if
end function

end module stdlib_codata_type