Any language supports this type of syntax?

Richard Deeming

As Pete said, trivial to implement in C#:

public static class SomeExtensions
{
public static bool IsOneOf(this T value, params T[] options)
{
if (options is null || options.Length == 0) return false;
return Array.IndexOf(options, value) != -1;
}

public static bool IsNotOneOf(this T value, params T\[\] options)
{
    if (options is null || options.Length == 0) return true;
    return Array.IndexOf(options, value) == -1;
}

}

...

if (nThatVeryLongVariableYourMateNamed.IsNotOneOf(0, 1, 2))

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

QuantumPlumber

Fortran computed GOTO comes pretty close . . . 11 CONTROL STATEMENTS[^] There - that'll flush out the zealots.

Treading on the toes of giants . . .

Eric Lynch

Not nearly as performant as the original. Though, if avoiding repetition is the OPs goal, a couple of other C# possibilities include: :)

int n = nThatVeryLongVariableYourMateNamed;
if (n == 0 || n == 1 || n == 2)
{
}

switch(nThatVeryLongVariableYourMateNamed)
{
case 0:
case 1
case 2
break;
}

private static readonly HashSet validValues = new HashSet { 0, 1, 2};
.
.
.
if (validValues.Contains(nThatVeryLongVariableYourMateNamed))
{
}

if (new int[] { 0, 1, 2}.Contains(nThatVeryLongVariableYourMateNamed))
{
}

In answer to the original question, I think there are some languages that support syntactic sugar for creating/checking sets. Though, none I commonly use. If I recall, in my hazy memory, I think the largely dead PASCAL language used to have such support :) In general, it's not much of a problem. Almost all languages, have a decently concise syntax for creating/checking sets. They simply do away with the fluff of formalizing it as a separate concept in the language.

PIEBALDconsult

Put the values in a Hashset.

G3Coder

Yes - Delphi does:

Result: Integer;
...
if aPrompt and not (Result in [0, 1, 2, 4]) then
...

Not quite dead BTW - that's production code right there -> but its getting rarer these days. G

David ONeil

C++ equivalent:

bool contains(int var, std::vector ints) {
for (int x :ints) if (var == x) return true;
return false;
}

...

int veryLongVarName = 12;
if (contains(veryLongVarName, { 1, 2, 3 })) {
OutputDebugString(L"Matches! Now we have fire!");
}

The forgotten roots of science | C++ Programming | DWinLib

Dominic Burford

Now that's nice. I'm going to have to borrow that :-D

"There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

Lost User

{
int localVLVYMN = thatVeryLongVariableYourMateNamed;
}

As a single block, so that your temp-int is limited in scope. Also spitting on the hungarian notation - I would not tough that code with a polearm :thumbsup:

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^] "If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Richard Deeming

For extra C#7 goodness:

{
ref int localVLVYMN = ref thatVeryLongVariableYourMateNamed;
...
}

Now any changes to your alias will be reflected in the original. :) An added benefit for large structs: you avoid making a copy of the value. Ref return values and ref locals (C# Guide) | Microsoft Docs[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

Lost User

Richard Deeming wrote:

Now any changes to your alias will be reflected in the original. :)

More ways to obfuscate my code :-D

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^] "If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Richard Deeming

More job security. :-D

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

Lost User

Can't argue with that :)

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^] "If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Joan M

Wasn't the old visual basic capable to use WITH?

www.robotecnik.com[^] - robots, CNC and PLC programming

Eytukan

You remember the syntax? :)

Full Reset

DaveAuld

In Python you can use range(). So, for [0,1,2] you would do either;

if nThatVeryLongVariableYourMateNamed not in [0,1,2]:

or

if nThatVeryLongVariableYourMateNamed not in range(3):

or

if nThatVeryLongVariableYourMateNamed not in range(0,3):

or

if nThatVeryLongVariableYourMateNamed not in range(0,3,1):

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Eytukan

Cool :thumbsup:

Full Reset

Lost User

Copy paste from SOverflow

static class Extensions
{

public static bool In(this T item, params T\[\] items)
{
    if (items == null)
        throw new ArgumentNullException("items");

    return items.Contains(item);
}

}

class Program
{

static void Main()
{


    int myValue = 1;

    if (myValue.In(1, 2, 3))
        // Do Somthing...

    string ds = "Bob";

    if (ds.In("andy", "joel", "matt")) 
    // Do Someting...
}

}