Caching behaviour attached to a Liquex.Context.

Used internally to memoize parsed partial templates. Custom filters can also opt in to per-render memoization via memoize/3 — useful for wrapping calls to external systems (DB, HTTP, etc.) that are referentially transparent within a single render.

Plug an implementation in via Liquex.Context.new(env, cache: MyCache). Two implementations ship with Liquex:

• Liquex.Cache.DisabledCache — default; never memoizes.
• Liquex.Cache.SimpleCache — ETS-backed; call init/0 before use.

Example: a memoizing custom filter

defmodule MyFilters do
  use Liquex.Filter

  def lookup(value, context) do
    Liquex.Cache.memoize(context, {__MODULE__, :lookup, value}, fn ->
      ExpensiveSystem.fetch(value)
    end)
  end
end

ctx =
  Liquex.Context.new(%{},
    cache: Liquex.Cache.SimpleCache,
    cache_prefix: tenant_id,
    filter_module: MyFilters
  )

Drops cannot reach the context from Access.fetch/2, and custom Liquex.FileSystem modules see only a template name. Both have to hold their own cache reference if they need memoization. The built-in partial-template cache in Liquex.Tag.RenderTag already covers the read+parse path.