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docs/api/animation.md

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+# Animation API
+
+## spring()
+
+Returns a new state with a dynamically animated value of the source.
+
+- **Type**
+
+    ```lua
+    function spring<T>(
+        source: () -> T & Animatable,
+        period: number = 1,
+        damping_ratio: number = 1
+    ): () -> T
+
+    type Animatable = number | CFrame | Color3 | UDim | UDim2 | Vector2 | Vector3
+    ```
+
+- **Details**
+
+    The output state value is updated every frame based on the source state
+    value.
+
+    The change is physically simulated according to a
+    [spring](https://en.wikipedia.org/wiki/Simple_harmonic_motion).
+
+    `period` is the amount of time in seconds it takes for the spring to
+    complete one full oscillation.
+
+    `damping_ratio` is the amount of resistance applied to the spring.
+
+    - \>1 = Overdamped (not currently supported).
+    - 1 = Critically damped - reaches target without any overshoot.
+    - <1 = Underdamped - reaches target with some overshoot.
+    - 0 = Undamped - never stabilizes, oscillates forever.
+
+    Velocity is conserved between source state updates for smooth animation.

docs/api/creation.md

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+# Element Creation API
+
+<br/>
+
+## create()
+
+Creates a new UI element, applying any given properties.
+
+- ### Type
+
+    ```lua
+    function create(class: string): (Properties) -> Instance
+    function create(instance: Instace): (Properties) -> Instance
+
+    type Properties = Map<string|number, any>
+    ```
+
+- ### Details
+
+    The function can take either a `string` or an `Instance` as its first argument.
+
+    - If given a `string`, a new instance with the same class name will be created.
+    - If given an `Instance`, a new instance that is a clone of the given instance
+    will be created.
+
+    This returns another function that is used to apply any properties to the new
+    instance.
+
+- ### Property setting rules
+
+    - If a table value is another table, that nested table is processed so that
+      any properties inside that table are also applied to the instance just
+      like the outer table.
+    - If a table index is a string:
+      - If its value is a function then it will either bind that property to
+        a state or connect it if the property type is a `RBXScriptSignal`.
+      - If the value is not a function then the property will be set to that
+        value.
+    - If a table index is a number:
+      - If its value is a function then it will parent any instances returned by
+        that function as children.
+      - If its value is an instance then it will be parented to the instance.
+
+- ### Example
+
+    Basic element creation.
+
+    ```lua
+    local frame = create "Frame" {
+        Name = "NewFrame",
+        Position = UDim2.fromScale(1, 0)
+    }
+    ```
+
+    A component using property nesting/grouping.
+
+    ```lua
+    type Layout = {
+        Layout = {
+            Position: UDim2?,
+            Size: UDim2?,
+            AnchorPoint: Vector2?
+        }
+    }
+
+    type Children = {
+        Children = Array<Instance>
+    }
+
+    function Background(props: Layout & Children & {
+        Color: Color3
+    })
+        return create "Frame" {
+            BackgroundColor3 = Color,
+            props.Layout,
+            props.Children
+        }
+    end
+    ```

docs/api/reactivity-core.md

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+# Reactivity API: Core
+
+<br/>
+
+## source()
+
+Creates a new source state with the given value.
+
+- **Type**
+
+    ```lua
+    function source<T>(value: T): (T?) -> T
+    ```
+
+- **Details**
+
+    Calling the returned state with no arguments will return its stored value,
+    calling with arguments will set a new value.
+
+    Reading from the state from within any reactive scope will cause changes
+    to that state to be tracked and anything depending on it to update.
+
+- **Example**
+
+    ```lua
+    local count = source(0)
+
+    count() -- 0
+
+    count(count() + 1) -- 1
+    ```
+
+## watch()
+
+Runs a callback on state change.
+
+- **Type**
+
+    ```lua
+    function watch(callback: () -> ()): Unwatch
+
+    type Unwatch = () -> ()
+    ```
+
+- **Details**
+
+    The callback is ran immediately to determine what states are referenced.
+
+    Any time a state referenced in the callback is changed, the callback will be
+    reran.
+
+    Also returns a function that when called, stops the watcher immediately.
+
+    ::: warning
+    `callback()` cannot yield.
+    :::
+
+- **Example**
+
+    ```lua
+    local state = wrap(1)
+
+    watch(function()
+        print(state.Value)
+    end)
+
+    -- prints 1
+
+    state.Value += 1
+
+    -- prints 2
+    ```
+
+## derive()
+
+Derives a new state from existing states.
+
+- **Type**
+
+    ```lua
+    function derive<T>(source: () -> T): () -> T
+    ```
+
+- **Details**
+
+    The derived state will have its value recalculated when any source state it
+    derives from is updated.
+
+    Anytime its value is recalculated it is also cached, subsequent calls will
+    retun this cached value until it recalculates again.
+
+    Takes a callback that is immediately run to determine what states are being
+    referenced.
+
+    ::: warning
+    `source()` cannot yield.
+    :::
+
+- **Example**
+
+    ```lua
+    local count = wrap(0)
+    local text = derive(function() return `count: {count()}` end)
+
+    text() -- "count: 0"
+
+    count(1)
+
+    text() -- "count: 1"
+    ```
+
+## indexes()
+
+Maps each index in a table to an object.
+
+- **Type**
+
+    ```lua
+    function indexes<KI, VI, VO>(
+        source: () -> Map<KI, VI>,
+        transform: (value: () -> VI, index: KI) -> VO
+    ): Array<VO>
+
+- **Details**
+
+    The transform function is called only ever *once* for each index in the
+    source table. The first argument is a state containing the index's value and
+    the second argument is just the index.
+
+    Anytime a new index is added, the transform function will be called again for
+    that new index.
+
+    Anytime an existing index value changes, the transform function is not rerun,
+    instead the passed state for that index will update, causing anything
+    depending on it to update too.
+
+    Returns a state containing an array of all objects returned by the transform.
+
+    ::: warning
+    `transform()` cannot yield.
+    :::
+
+- **Example**
+
+    The intended purpose of this function is to map each index in a table to
+    a UI element.
+
+    ```lua
+    type Item = {
+        name: string,
+        icon: number
+    }
+
+    local items = source {} :: () -> Array<Item>
+
+    local displays = indexes(numbers, function(item, i)
+        return ItemDisplay {
+            Name = function()
+                return item().name
+            end,
+
+            Image = function()
+                return "rbxassetid://" .. item().icon
+            end,
+
+            LayoutOrder = i
+        }
+    end)
+    ```
+
+## values()
+
+Maps each value in a table to an object.
+
+- **Type**
+
+    ```lua
+    function values<KI, VI, VO>(
+        source: () -> Map<KI, VI>,
+        transform: (value: VI, index: () -> KI) -> VO
+    ): Array<VO>
+
+- **Details**
+
+    The transform function is called only ever *once* for each value in the
+    source table. The first argument is the index's value and
+    the second argument is a state containing the index.
+
+    Anytime a new value is added, the transform function will be called again
+    for that new value.
+
+    Anytime an existing value's index changes, the transform function is not
+    rerun, instead the passed state for that value will update, causing anything
+    depending on it to update too.
+
+    Returns a state containing an array of all objects returned by the transform.
+
+    ::: warning
+    `transform()` cannot yield.
+    :::
+
+- **Example**
+
+    The intended purpose of this function is to map each value in a table to
+    a UI element.
+
+    ```lua
+    type Item = {
+        name: string,
+        icon: number
+    }
+
+    local items = source {} :: () -> Array<Item>
+
+    local displays = values(numbers, function(item, i)
+        return ItemDisplay {
+            Name = item.Name
+
+            Image = "rbxassetid://" .. item.icon,
+
+            LayoutOrder = i
+        }
+    end)
+    ```
+
+- **Extra**
+
+    When should you use `indexes()` and `values()`?
+
+    `values()` should be used when you have a fixed set of objects where the
+    same objects can be re-arranged in the source table. It maps a value to a
+    UI element.
+
+    e.g.
+    - List of all players.
+    - Inventory of items.
+    - Chat message history.
+    - Toast notifications.
+
+    `indexes()` should be used in other cases, especially when your source table
+    has primitive value. It maps an index to a UI element.
+
+    e.g.
+    - List of character or weapon stats.
+
+    In most cases, both functions will appear to have the same behavior.
+    The main difference is performance, picking the right function to use can
+    result in less property updates and less re-renders.
+
+--------------------------------------------------------------------------------

docs/api/reactivity-utility.md

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+# Reactivity API: Utility
+
+## cleanup()
+
+Runs a callback anytime a reactive scope is re-ran.
+
+- **Type**
+
+    ```lua
+    function cleanup(callback: () -> ())
+    ```
+
+- **Example**
+
+    ```lua
+    local data = source(1)
+
+    watch(function()
+        local label = create "TextLabel" { Text = data }
+
+        cleanup(function()
+            label:Destroy()
+        end)
+    end)
+    ```

docs/api/strict-mode.md

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+# Strict Mode
+
+Vide has a special mode called "strict mode" which is used for debugging.
+
+The purpose of strict mode is to help ensure stateful code is *pure*
+(deterministic and free from side effects) or if there are side-effects, that
+they are cleaned up correctly.
+
+Vide is set to strict by doing:
+
+```lua
+local vide = require(path_to_vide)
+vide.strict = true
+```
+
+What strict mode will do:
+
+1. Run derived callbacks twice when re-evaluating.
+2. Run watcher callbacks twice when a state changes.
+3. Throw an error if yields occur where they are not allowed.
+4. Checks for `map()` returning primitive values.
+5. Better error reporting and stack traces.
+
+It is recommend to develop UI with strict mode and to disable it when pushing to
+production.