Odd behaviour of Sequence.all and Sequence.any

[clsource]

There is something odd in Sequence.all and Sequence.any.

wren/src/vm/wren_core.wren

Line 12 in 3d5e68f

if (!result) return result

The docs says https://wren.io/modules/core/sequence.html

Iterates over the sequence, passing each element to the function predicate. If it returns something false, stops iterating and returns the value. Otherwise, returns true.

  all(f) {
    var result = true
    for (element in this) {
      result = f.call(element)
      if (!result) return result
    }
    return result
  }

By "If it returns something false, stops iterating and returns the value" should be if (!result) return element instead of result?

[mhermier]

The documentation is lying. `all` or `any` are tests and we expect to return a truthy or falsy value. `element` obviously doesn't match its criteria.

[clsource]

So the behaviour is correct, but the docs need improvement

[mhermier]

Yes. The behavior you describe is most likely related to something like a find method (which does not exist and would need a PR) that would return an iterator on the Sequence.

[clsource]

@ruby0x1 told that PR #803 is related.

Would be this wording more inline with the actual behaviour?

all(predicate)

Tests whether all the elements in the sequence pass the predicate.

Iterates over the sequence, passing each element to the function predicate. If it returns something false, stops iterating and returns false. Otherwise, returns true.

any(predicate)

Tests whether any element in the sequence passes the predicate.

Iterates over the sequence, passing each element to the function predicate. If it returns something true, stops iterating and returns true. Otherwise, returns false.

find

Maybe the find method would be similar to

find(predicate) { WhereSequence.new(this, predicate).take(1) }

[mhermier]

Even if more more valid than before, the statement is technically wrong, the predicate only needs to return truthy/falsy values. This was made so that predicate could also act as/work with a map function.

Don't add find documentation, I handled it in the push request I issued.