string_to_real Subroutine

  1. json_string_utilities.F90
  2. json_string_utilities
  3. string_to_real

public subroutine string_to_real(str, use_quiet_nan, rval, status_ok)

Convert a string into a real(RK).

History

  • Jacob Williams, 10/27/2015 : Now using fmt=*, rather than fmt=real_fmt, since it doesn’t work for some unusual cases (e.g., when str='1E-5').
  • Jacob Williams : 2/6/2017 : moved core logic to this routine.

Arguments

Type IntentOptional AttributesName
character(kind=CK,len=*), intent(in) :: str

the string to convert to a real
logical(kind=LK), intent(in) :: use_quiet_nan

if true, return NaN’s as ieee_quiet_nan. otherwise, use ieee_signaling_nan.
real(kind=RK), intent(out) :: rval

str converted to a real value
logical(kind=LK), intent(out) :: status_ok

true if there were no errors

Called by

proc~~string_to_real~~CalledByGraph proc~string_to_real string_to_real proc~string_to_dble string_to_dble proc~string_to_dble->proc~string_to_real proc~json_get_real json_get_real proc~json_get_real->proc~string_to_real

Contents

Source Code

string_to_real

Source Code

    subroutine string_to_real(str,use_quiet_nan,rval,status_ok)

    implicit none

    character(kind=CK,len=*),intent(in) :: str           !! the string to convert to a real
    logical(LK),intent(in)              :: use_quiet_nan !! if true, return NaN's as `ieee_quiet_nan`.
                                                         !! otherwise, use `ieee_signaling_nan`.
    real(RK),intent(out)                :: rval          !! `str` converted to a real value
    logical(LK),intent(out)             :: status_ok     !! true if there were no errors

    integer(IK) :: ierr  !! read iostat error code

    read(str,fmt=*,iostat=ierr) rval
    status_ok = (ierr==0)
    if (.not. status_ok) then
        rval = 0.0_RK
    else
        if (ieee_support_nan(rval)) then
            if (ieee_is_nan(rval)) then
                ! make sure to return the correct NaN
                if (use_quiet_nan) then
                    rval = ieee_value(rval,ieee_quiet_nan)
                else
                    rval = ieee_value(rval,ieee_signaling_nan)
                end if
            end if
        end if
    end if

    end subroutine string_to_real