S3ctor's S3cret St4sh

require 'scripts.s3.lazy' → lazy; lazy(factory) → callable

Use lazy for something expensive you may never need. The first call builds it; later calls reuse the same value until you reset it.

local lazy = require 'scripts.s3.lazy'
local ui = require 'openmw.ui'
local util = require 'openmw.util'

local getStatusText = lazy(function()
    return ui.create {
        type = ui.TYPE.Text,
        layer = 'HUD',
        props = { text = '', relativeSize = util.vector2(0.4, 0.05) },
    }
end)

local function showStatus(message)
    local statusText = getStatusText()
    statusText.layout.props.text = message
    statusText:update()
end

return {
    eventHandlers = {
        MyModStatusChanged = function(message) showStatus(message) end,
    },
}

Member	Behavior
`getValue()`	Runs the factory once if needed and returns its first value. Factory errors propagate and do not mark the value computed.
`getValue:computed()`	Returns true after a successful computation, even if the result is `nil`.
`getValue:peek()`	Returns the cached value without computing; `nil` is ambiguous.
`getValue:reset()`	Clears the cached value so the next call computes again.

The factory is called with no arguments. Extra factory return values are discarded because the callable represents one value. If the element is destroyed, call getStatusText:reset() before building it again. Recursive factory evaluation and resetting during evaluation raise errors.

Use lazy when construction should happen at most once on demand. For a result that must be refreshed by keys or expiry, use memoize instead; for explicit success/failure, use Result.

Related helpers