On Fri, 23 Sep 2022 16:48:40 GMT, Alexey Ivanov <[email protected]> wrote:
>> With this change, the code is more concise but we double the number of tests
>> ?
>
>> With this change, the code is more concise but we double the number of tests
>> ?
>
> For a rather rare case. I don't think it's a critical path which affects
> performance.
>
> If you like, you can create a variable to store the result of `n == 4` to
> avoid testing once again. I still don't think it's worth it.
Could we reach a conciliation with this version. ? All cases are treated in 2
or 3 tests.
It incorporates all your suggestions and my single comment about the number of
tests.
if (n < 5) {
if (n < 3) {
return null;
} else {
final char r = digits.charAt(0);
final char g = digits.charAt(1);
final char b = digits.charAt(2);
final char a = n == 4 ? digits.charAt(3) : 'f';
digits = String.format("%1$s%1$s%2$s%2$s%3$s%3$s%4$s%4$s", r,
g, b, a);
}
} else if (n < 7) {
if (n == 5) {
return null;
} else {
digits = String.format("%sff", digits);
}
} else if (n != 8 ) {
return null;
}
try {
int i = Integer.parseUnsignedInt(digits, 16);
return new Color((i >> 24) & 0xFF, (i >> 16) & 0xFF, (i >> 8) &
0xFF, i & 0xFF);
} catch (NumberFormatException nfe) {
return null;
}
Some articles suggest to avoid using exceptions as flow controls. I never
tested this point. That's why I introduced Patterns in this method. May I run
tests in this case ? With the code below :
if (n < 5) {
if (n < 3 || !hex.matcher(digits).matches()) {
return null;
} else {
final char r = digits.charAt(0);
final char g = digits.charAt(1);
final char b = digits.charAt(2);
final char a = n == 4 ? digits.charAt(3) : 'f';
digits = String.format("%1$s%1$s%2$s%2$s%3$s%3$s%4$s%4$s", r,
g, b, a);
}
} else if (n < 7) {
if (n == 5 || !hex.matcher(digits).matches()) {
return null;
} else {
digits = String.format("%sff", digits);
}
} else if (n != 8 || !hex.matcher(digits).matches()) {
return null;
}
try {
int i = Integer.parseUnsignedInt(digits, 16);
return new Color((i >> 24) & 0xFF, (i >> 16) & 0xFF, (i >> 8) &
0xFF, i & 0xFF);
} catch (NumberFormatException nfe) {
return null;
}
I also wish to test the version with bit rotation too :
if (n < 5) {
if (n < 3 || !hex.matcher(digits).matches()) {
return null;
} else {
final char r = digits.charAt(0);
final char g = digits.charAt(1);
final char b = digits.charAt(2);
final char a = n == 4 ? digits.charAt(3) : 'f';
digits = String.format("%1$s%1$s%2$s%2$s%3$s%3$s%4$s%4$s", r,
g, b, a);
}
} else if (n < 7) {
if (n == 5 || !hex.matcher(digits).matches()) {
return null;
} else {
digits = String.format("%sff", digits);
}
} else if (n != 8 || !hex.matcher(digits).matches()) {
return null;
}
try {
return new
Color(Integer.rotateRight(Integer.parseUnsignedInt(digits, 16),8),
true);
} catch (NumberFormatException nfe) {
return null;
}
-------------
PR: https://git.openjdk.org/jdk/pull/10317
