use warnings;
use strict;
use Data::IEEE754::Tools qw(to_hex_floatingpoint to_dec_floatingpoint nextUp nextDown);
use 5.022;  # for %a

printf "%-6.6s     %30.30s %30.30s %30.30s %30.30s %30.30s\n", 'approx', '%30.16f', '%30.16e', '%a', 'to_hex_floatingpoint()', 'to_dec_floatingpoint()';
foreach my $v ( map { $_ / 10. } 0 .. 100, 1280, 10240) {     # 0 .. 10, 128, 1024
    my $d = nextDown($v);
    my $u = nextUp($v);
    printf "%-6.1f-ULP %30.16f %30.16e %30.13a %30.30s %30.30s\n", $v, $d, $d, $d, to_hex_floatingpoint($d), to_dec_floatingpoint($d);
    printf "%-6.1f     %30.16f %30.16e %30.13a %30.30s %30.30s\n", $v, $v, $v, $v, to_hex_floatingpoint($v), to_dec_floatingpoint($v);
    printf "%-6.1f+ULP %30.16f %30.16e %30.13a %30.30s %30.30s\n", $v, $u, $u, $u, to_hex_floatingpoint($u), to_dec_floatingpoint($u);
    print "\n";
}
printf "%-6.6s     %30.30s %30.30s %30.30s %30.30s %30.30s\n", 'approx', '%30.16f', '%30.16e', '%a', 'to_hex_floatingpoint()', 'to_dec_floatingpoint()';

##</code><code>##

approx                            %30.16f                        %30.16e                             %a         to_hex_floatingpoint()         to_dec_floatingpoint()
...
0.4   -ULP             0.4000000000000000        3.9999999999999997e-001           0x1.9999999999999p-2       +0x1.9999999999999p-0002    +0d1.5999999999999999p-0002
0.4                    0.4000000000000000        4.0000000000000002e-001           0x1.999999999999ap-2       +0x1.999999999999ap-0002    +0d1.6000000000000001p-0002
0.4   +ULP             0.4000000000000001        4.0000000000000008e-001           0x1.999999999999bp-2       +0x1.999999999999bp-0002    +0d1.6000000000000003p-0002

##</code><code>##

0.5   -ULP             0.4999999999999999        4.9999999999999994e-001           0x1.fffffffffffffp-2       +0x1.fffffffffffffp-0002    +0d1.9999999999999998p-0002
0.5                    0.5000000000000000        5.0000000000000000e-001           0x1.0000000000000p-1       +0x1.0000000000000p-0001    +0d1.0000000000000000p-0001
0.5   +ULP             0.5000000000000001        5.0000000000000011e-001           0x1.0000000000001p-1       +0x1.0000000000001p-0001    +0d1.0000000000000002p-0001

##</code><code>##

...
4.0   -ULP             3.9999999999999996        3.9999999999999996e+000           0x1.fffffffffffffp+1       +0x1.fffffffffffffp+0001    +0d1.9999999999999998p+0001
4.0                    4.0000000000000000        4.0000000000000000e+000           0x1.0000000000000p+2       +0x1.0000000000000p+0002    +0d1.0000000000000000p+0002
4.0   +ULP             4.0000000000000009        4.0000000000000009e+000           0x1.0000000000001p+2       +0x1.0000000000001p+0002    +0d1.0000000000000002p+0002

4.1   -ULP             4.0999999999999988        4.0999999999999988e+000           0x1.0666666666665p+2       +0x1.0666666666665p+0002    +0d1.0249999999999997p+0002
4.1                    4.0999999999999996        4.0999999999999996e+000           0x1.0666666666666p+2       +0x1.0666666666666p+0002    +0d1.0249999999999999p+0002
4.1   +ULP             4.1000000000000005        4.1000000000000005e+000           0x1.0666666666667p+2       +0x1.0666666666667p+0002    +0d1.0250000000000001p+0002

##</code><code>##

...
10.0  -ULP             9.9999999999999982        9.9999999999999982e+000           0x1.3ffffffffffffp+3       +0x1.3ffffffffffffp+0003    +0d1.2499999999999998p+0003
10.0                  10.0000000000000000        1.0000000000000000e+001           0x1.4000000000000p+3       +0x1.4000000000000p+0003    +0d1.2500000000000000p+0003
10.0  +ULP            10.0000000000000020        1.0000000000000002e+001           0x1.4000000000001p+3       +0x1.4000000000001p+0003    +0d1.2500000000000002p+0003

128.0 -ULP           127.9999999999999900        1.2799999999999999e+002           0x1.fffffffffffffp+6       +0x1.fffffffffffffp+0006    +0d1.9999999999999998p+0006
128.0                128.0000000000000000        1.2800000000000000e+002           0x1.0000000000000p+7       +0x1.0000000000000p+0007    +0d1.0000000000000000p+0007
128.0 +ULP           128.0000000000000300        1.2800000000000003e+002           0x1.0000000000001p+7       +0x1.0000000000001p+0007    +0d1.0000000000000002p+0007

1024.0-ULP          1023.9999999999999000        1.0239999999999999e+003           0x1.fffffffffffffp+9       +0x1.fffffffffffffp+0009    +0d1.9999999999999998p+0009
1024.0              1024.0000000000000000        1.0240000000000000e+003          0x1.0000000000000p+10       +0x1.0000000000000p+0010    +0d1.0000000000000000p+0010
1024.0+ULP          1024.0000000000002000        1.0240000000000002e+003          0x1.0000000000001p+10       +0x1.0000000000001p+0010    +0d1.0000000000000002p+0010

approx                            %30.16f                        %30.16e                             %a         to_hex_floatingpoint()         to_dec_floatingpoint()