Find the index of first element of a <vector> that satisfies a predicate.
This function finds the index of first element (after start but before end) of a vector which satisfies the given predicate. If no matching element is found, return failure. The defaults for start, end and failure are, respectively, 0, size(vector), and #f. This function is like find-key, but accepts start: and end: rather than skip:.
sealed
| seq | An instance of <vector>. |
| pred? | An instance of <function> that returns #t for a matching condition. |
| start: | An instance of <integer> from which element to start the search. Defaults to 0. |
| end: | An instance of <integer> at which to end the search. Defaults to the size of seq. |
| failure: | An instance of <object>. Returned if no match found. Defaults to #f. |
| key-or-failure | An instance of <integer> or the failure value. |