# cp.result

Represents the result of an operation which may end in success or failure. If it is a success, a value is typically provided. If it is a failure, a message is typically provided.

Using this type allows for more structured checking when performing an operation which may fail in a number of ways, rather than just calling error and crashing out. For example:

function clamped(value, min, max)
    if value < min then
        return result.failure("expected at least %d but got %d", min, value)
    elseif value > max then
        return result.failure("expected at most %d but got %d", max, value")
    else
        return result.success(value)
    end
end

local outcome = clamped(-1, 0, 100)
if outcome.failure then
    error(outcome.message)
end
local value = outcome.value

Of course, simply checking the result and throwing an error is a common case, so you can achieve the same result like so:

local value = clamped(-1, 0, 100):get()

If you want to perform other tasks, check for .failure or .success and perform the appropriate response.

Functions - API calls offered directly by the extension

• is

Constructors - API calls which return an object, typically one that offers API methods

• failure
• from
• okValue
• success
• valueErr

Methods - API calls which can only be made on an object returned by a constructor

• get
• log