std.foldr documentation does not match behavior

[zapster]

The documentation says

std.foldr(func, arr, init)

Classic foldr function. Calls the function on the result of the previous function call and each array element, or init in the case of the initial element. Traverses the array from right to left.

but the behaviour is "Calls the function on each array element and the result of the previous function call."

Example (adopted from #788):

[
  std.foldr(function(x, y) x + y, ["a", "b", "c"], "I")
]

returns

[
  "abcI"
]

although according to the documentation it would be

[
  "lcba"
]

[sbarzowski]

You're correct. In this case we should fix the documentation, because it makes more sense this way (rationale) and people depend on this behavior already.

I put some context below for posterity.

Here's what it does: Step 1: res = "I" Step 2: res = f("c", "I") = "cI" Step 3: res = f("b", "cI") = "bcI" Step 4: res = f("a", "bcI") = "abcI"

Here's the code (you can see the inverted arguments): https://github.com/google/jsonnet/blob/v0.17.0/stdlib/std.jsonnet#L788 https://github.com/google/jsonnet/blob/v0.17.0/stdlib/std.jsonnet#L796