Get line causing error in catch?

Using Swift
3

Is this for debugging during development or at runtime (e.g. to print to some log)?

For the former, you should be able to break on swift_willThrow in lldb.

For the latter, you use a wrapper error type and a helper function to wrap errors thrown from the functions you call:

struct SourceLocationError<T: Error>: Error {
    let file: String, line: Int, error: T
}

func annotateError<T>(_ proc: @autoclosure () throws -> T, file: String = #file, line: Int = #line) throws -> T {
    do {
        return try proc()
    } catch {
        throw SourceLocationError(file: file, line: line, error: error)
    }
}

And then use it like this:

do {
    try annotateError(someFunction())
} catch {
    print(error)
}

Sadly, from what I tried, pre-/postfix operators cant have extra arguments, even when they have default values. That would have made it a bit less visually obtrusive, but if that is an issue a shorter wrapper function name should go a long way.

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