Batching Values

Batching groups multiple state updates into one update cycle.

Key Point

Batching is useful when one piece of code updates several signals at once.

Why Use Batch?

Many actions change more than one value.

For example, a shop purchase might:

• lower the player's coins
• add bonus gems
• close the shop

With batch, Reheaven waits until the callback finishes, then updates using the final state.

local coins, setCoins = Reheaven.signal(500)
local gems, setGems = Reheaven.signal(25)
local shopOpen, setShopOpen = Reheaven.signal(true)

Reheaven.batch(function()
    setCoins(400)
    setGems(30)
    setShopOpen(false)
end)

All of these updates belong to the same action, so batching keeps them together.

Final Value Wins

If the same signal is set multiple times inside a batch, the last value is the one that matters.

local coins, setCoins = Reheaven.signal(0)

Reheaven.batch(function()
    setCoins(10)
    setCoins(20)
    setCoins(30)
end)

print(coins()) -- 30

Effects Run Once

Batching helps avoid repeated effect runs while several values are changing.

local stop = Reheaven.effect(function()
    print("Coins:", coins())
end)

Reheaven.batch(function()
    setCoins(10)
    setCoins(20)
    setCoins(30)
end)

-- Prints once with 30

Returning Values

batch returns whatever the callback returns.

This is useful when you want to group state updates and still return a result from the action.

local result = Reheaven.batch(function()
    setCoins(100)
    return "done"
end)

print(result) -- done

For most code, you will use batch for the updates, not the return value. But that option is always up :D

When to Use Batch

Use batch when several updates should clearly be treated as one larger change.

Good examples:

• buying an item
• resetting player stats
• applying round rewards
• loading saved data
• updating several UI states at once

Do Not Overuse Batch

You do not need batch for every small update.

For one or two simple setters, the difference is usually negligible. batch becomes more useful when one action updates several pieces of state at once, especially around 4-5 updates or more.

Next Steps

Next, learn how peek lets you read state without subscribing to it.