Module B0_store

Lazy immutable stores.

These stores provide access to immutable, lazily determined, typed key-value bindings.

The value of a key in a store is defined either:

Once determined the value of a key in the store never changes.


type 'a key

The type for keys binding values of type 'a.

type binding =
  1. | B : 'a key * 'a B0_std.Fut.t -> binding

The type for store bindings. A key and its value.

type t

The type for stores.

val make : B0_memo.t -> dir:B0_std.Fpath.t -> binding list -> t

make memo ~dir bs is a store with predefined bindings bs. If a key is mentioned more than once in bs the last binding takes over. The store uses memo to determine other keys as needed. dir is a scratch directory used by key determination functions to write memoized file outputs.

val memo : t -> B0_memo.t

memo s is s's memo as given on make.

val dir : t -> B0_std.Fpath.t

dir s is the scratch directory of s. Key determination functions using this directory to write files should do so using nice file name prefixes (e.g. lowercased module or lib names) to avoid name clashes.

val key : ?mark:string -> (t -> B0_memo.t -> 'a B0_std.Fut.t) -> 'a key

key ~mark det is a new key whose value is determined on access by the future:

det s (Memo.with_mark mark (B0_store.memo s))

mark defaults to "".

val get : t -> 'a key -> 'a B0_std.Fut.t

get s k is a future that dermines with the value of k in s.