An abstract type representing compiled program locations. It is designed to make sampling cheap (see extract), deferring most of the work in the much more expensive lookup function (without guarantee to succeed).

A location that can never be resolved

Sample the location from an arbitrary OCaml function. Cheap, appropriate to use on a fast path.

Turn a location into an actual position. If it succeeds, the position is returned as a triplet (file, line, column). To succeed, debug information must be available for the location.

This call might be quite expensive.

Convenience function composing lookup and extract, to immediately turn a function into a position.