Why does List.MatchesAll return true for an empty list?

[blep]

The function documentation says that List.MatchesAll returns true if the condition function is satisfied by all values in the list, otherwise returns false.

Given a value x, I'd expect List.MatchesAll({}, each _ = x) to return false - how can the contents of the list all satisfy the condition of being equal to x if the list does not have any contents against which to test the condition?

For every value of x I've tried:

List.MatchesAll({}, each _ = x) returns true

List.MatchesAny({}, each _ = x) returns false

List.Contains({}, x) returns false

Can anyone explain this behaviour and why it is different for List.MatchesAll than it is for List.MatchesAny and List.Contains?

[mahoneypat]

I wouldn't have guessed that behavior either, but I suspect it starts to iterate through the list with a TRUE condition, and since the list is empty there are no iterations/evaluations.  If you use {null} instead of {} it evaluates as FALSE, as it does do one iteration.

Pat