Is there a standard name for this function?

Question

What would you name a function that takes a list and a function, and returns True if applying the function to all elements gives the same result?

def identical_results(l, func):
    if len(l) <= 1: return True
    result = func(l[0])
    for el in l[1:]:
        if func(el) != result:
            return False
    return True

Is there a nice generally accepted name for this thing? Bonus if you can implement in a less clunky fashion.

Answer 1

In .NET, the closest is Array.TrueForAll.

Maybe SameForAll would be more appropriate for this function?

Answer 2

Havn't heard about a special name for this yet (somewhat similar to Forall, but not exactly). IdenticalResults seems okay so (Jon Seigel proposed SameForAll, also quite nice)

Additionally: That's the way one could implement this in Haskell using the all function (TrueForall under .NET)

ident [] = True
ident (x:xs) = all (== x) xs

sameForAll f = ident . map f

And Python:

def idents(f, list):
    if len(list) <= 1:
        return True
    else:
        let fx0 = f(list[0])
        return all(( f(x) == fx0 for x in list[1:] ))

Answer 3

Can't think of a good name so far, but this one does the same:

def identical_results(l, func):
    return len(set(map(func, l))) <= 1

Answer 4

identical_results sounds like a reasonable name to me.

Answer 5

I posted this in a comment above, but the formatting got messed up, so here it is again for clarity:

def identical_results(l, func):
    return reduce(lamdba x,y: x and y, map(func, l))