Bin_shape (bin_prot.shape.Bin_shape_lib.Bin

type t

Shape.t are constructed by the bin_shape syntax extension from Ocaml type definitions & expressions.

There is a direct mapping from ocaml type definition syntax to the corresponding Shape.group and from ocaml type expression syntax to the corresponding Shape.t.

include sig ... end

val sexp_of_t : t ‑> Base.Sexp.t

Tid.t & Vid.t are identifiers for type-constructors & type-vars. i.e. Given type 'a t = ...

module Tid : sig ... end

module Vid : sig ... end

module Location : sig ... end

Location.t is required when constructing shapes for which evaluation might fail.

module Uuid : sig ... end

Uuid.t is used by basetype and annotate.

type group

group of mutually recursive type definitions

val group : Location.t ‑> (Tid.t * Vid.t list * t) list ‑> group

This function is generative; repeated calls create distinct groups

val tuple : t list ‑> t

val record : (string * t) list ‑> t

val variant : (string * t list) list ‑> t

type poly_variant_row

val constr : string ‑> t option ‑> poly_variant_row

val inherit_ : Location.t ‑> t ‑> poly_variant_row

val poly_variant : Location.t ‑> poly_variant_row list ‑> t

val rec_app : Tid.t ‑> t list ‑> t

recursive apps within the current group

val top_app : group ‑> Tid.t ‑> t list ‑> t

recursive apps within the current group

apps from outside the group

val var : Location.t ‑> Vid.t ‑> t

val basetype : Uuid.t ‑> t list ‑> t

Built-in types and types with custom serialization: i.e. int,list,... To avoid accidental protocol compatibility, pass a UUID as the string argument

a = annotate s t creates a shape a distinguished, but dependent on shape t. Very much as record [(s,t)] does. But with annotate the ocaml record type does not exist.

val annotate_provisionally : Uuid.t ‑> t ‑> t

Shape.Canonical.t is the result of evaluating a shape to a canonical form, and represents the shape of Ocaml types w.r.t. bin_io serialization.

The idea is that de-serialization is safe if the canonical-shape for the type produced by de-serialization is equivalent to the canonical-shape of the serialized type.

A Canonical.t can be `digested' to a Digest.t, and except for nearly impossible hash collisions, equality of the digests implies equality of canonical-shapes and hence equivalence at the Shape.t level.

Canonical.t may also be constructed with various functions: annotate, basetype, tuple, record, variant, poly_variant, fix, recurse, .. which might be used when setting up unit tests or expected shapes.

module Digest : sig ... end

module Canonical : sig ... end

val eval : t ‑> Canonical.t

eval t returns the canonical-shape for a shape-expression Shape.t. Type aliases are expanded, so that no Tid.t or Vid.t have significance in the resulting canonical-shape. Type-recursion, including non-regular recursion, is translated to the de-bruijn representation used in canonical-shapes.

val eval_to_digest : t ‑> Digest.t

eval_to_digest t returns a hash-value direct from the Shape.t, potentially avoiding the intermediate Canonical.t from being constructed. This is important as the size of a canonical-shape might be exponential in terms of the size of the shape expression. The following holds: Digest.(eval_to_digest exp = Canonical.to_digest (eval exp))

val eval_to_digest_string : t ‑> string

eval_to_digest_string t == Digest.to_hex (eval_to_digest t) Convenience function useful for writing unit tests.