test_16 Subroutine

    subroutine test_16(error_cnt)

    !! Test the `swap` function.

    implicit none

    integer,intent(out) :: error_cnt !! report number of errors to caller

    type(json_core) :: json
    type(json_value),pointer :: p,p1,p2

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') '================================='
    write(error_unit,'(A)') '   TEST 16'
    write(error_unit,'(A)') '================================='
    write(error_unit,'(A)') ''

    error_cnt = 0

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Original:'
    call json%parse(p, '{"cities": ["New York","Los Angeles","Chicago"], '//&
                       '"value": 1, "iflag": true, "struct":{"vec":[1,2,3]}}')
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,error_unit)

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: cities <-> iflag'
    call json%get(p,'cities',p1)
    call json%get(p,'iflag',p2)
    call json%swap(p1,p2)
    call json%print(p,output_unit)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    nullify(p1)
    nullify(p2)

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: iflag <-> value'
    call json%get(p,'iflag',p1)
    call json%get(p,'value',p2)
    call json%swap(p1,p2)
    call json%print(p,output_unit)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    nullify(p1)
    nullify(p2)

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: iflag <-> struct.vec'
    call json%get(p,'iflag',p1)
    call json%get(p,'struct.vec',p2)
    call json%swap(p1,p2)
    call json%print(p,output_unit)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    nullify(p1)
    nullify(p2)

    call json%destroy(p)

    !...........................................................................
    ! another case

    write(error_unit,'(A)') ''
    write(error_unit,'(A)') '.....................................'
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Original:'
    call json%parse(p, '{ "stats": { "iflag": 0, "str": "ok" },'//&
                        '"vars": [{ "label": "r", "value": 0.0 }, '//&
                                 '{ "label": "v", "value": 0.0 }],'//&
                        '"empty": { } }')
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,error_unit)

    !this one is not allowed, and should fail:
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: vars(1).label <-> vars'
    call json%get(p,'vars(1).label',p1)
    call json%get(p,'vars',p2)
    call json%swap(p1,p2)
    call json%print(p,output_unit)
    if (.not. json%failed()) then
        write(error_unit,'(A)') 'Error: this should have failed.'
        error_cnt = error_cnt + 1
    else
        call json%clear_exceptions()
    end if
    nullify(p1)
    nullify(p2)

    !this one should work:
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: empty <-> stats.str'
    call json%get(p,'empty',p1)
    call json%get(p,'stats.str',p2)
    call json%swap(p1,p2)
    call json%print(p,output_unit)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    nullify(p1)
    nullify(p2)

    call json%destroy(p)

    !...........................................................................
    ! other special cases:

    !swap first and last items in a list
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') '.....................................'
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Original:'
    call json%parse(p, '{ "color": "red", "width": 10, "height": 2 }')
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,error_unit)
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: color <-> height'
    call json%get(p,'color',p1)
    call json%get(p,'height',p2)
    call json%swap(p1,p2)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,output_unit)
    nullify(p1)
    nullify(p2)
    call json%destroy(p)

    !p2 is first child:
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') '.....................................'
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Original:'
    call json%parse(p, '{ "color": "red", "width": 10, "height": 2 }')
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,error_unit)
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: width <-> color'
    call json%get(p,'width',p1)
    call json%get(p,'color',p2)
    call json%swap(p1,p2)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,output_unit)
    nullify(p1)
    nullify(p2)
    call json%destroy(p)

    !p2 is last child:
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') '.....................................'
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Original:'
    call json%parse(p, '{ "color": "red", "width": 10, "height": 2 }')
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,error_unit)
    write(error_unit,'(A)') ''
    write(error_unit,'(A)') 'Swap: width <-> height'
    call json%get(p,'width',p1)
    call json%get(p,'height',p2)
    call json%swap(p1,p2)
    if (json%failed()) then
        call json%print_error_message(error_unit)
        error_cnt = error_cnt + 1
    end if
    call json%print(p,output_unit)
    nullify(p1)
    nullify(p2)
    call json%destroy(p)

    end subroutine test_16