giles
5940b98878
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 19s
69 lines
2.6 KiB
Erlang
69 lines
2.6 KiB
Erlang
-module(define_registry).
|
|
-export([fold/2, fold_fn/0, define_kind/1]).
|
|
|
|
%% Define-registry projection fold — Erlang-fun stand-in for the
|
|
%% genesis `define-registry.sx` body. The intent is identical: a
|
|
%% projection whose state is a registry-shaped property list, fed
|
|
%% by every `Create{Define*{...}}` activity. The SX body would
|
|
%% eventually replace this once an SX-source eval bridge lets the
|
|
%% kernel evaluate the genesis fold directly; until then this
|
|
%% Erlang module proves the meta-projection mechanism wires
|
|
%% through `projection:fold_fn` and `nx_kernel` cleanly.
|
|
%%
|
|
%% State shape mirrors `registry:new()` exactly:
|
|
%% [{Kind, [{Name, Entry}, ...]}, ...]
|
|
%% so callers can use `registry:lookup/3` etc. on the result.
|
|
%%
|
|
%% Type discrimination uses atoms (`define_activity`, …). Real SX
|
|
%% would carry the string forms ("DefineActivity", …); the bridge
|
|
%% will translate. See define_kind/1 for the mapping.
|
|
|
|
fold(Activity, State) ->
|
|
case envelope:get_field(type, Activity) of
|
|
{ok, create} -> fold_create(Activity, State);
|
|
_ -> State
|
|
end.
|
|
|
|
fold_create(Activity, State) ->
|
|
case envelope:get_field(object, Activity) of
|
|
{ok, Obj} ->
|
|
case envelope:get_field(type, Obj) of
|
|
{ok, ObjType} ->
|
|
case define_kind(ObjType) of
|
|
not_a_define -> State;
|
|
Kind -> fold_register(Kind, Obj, State)
|
|
end;
|
|
_ -> State
|
|
end;
|
|
_ -> State
|
|
end.
|
|
|
|
fold_register(Kind, Obj, State) ->
|
|
case envelope:get_field(name, Obj) of
|
|
{ok, Name} ->
|
|
case registry:register(Kind, Name, Obj, State) of
|
|
{ok, NewState} -> NewState;
|
|
{error, unknown_kind} -> State
|
|
end;
|
|
not_found -> State
|
|
end.
|
|
|
|
%% fold_fn/0 — a 2-arity Erlang fun the projection module plants
|
|
%% in its record's :fold slot. Lets `projection:start_link/3`
|
|
%% wire define-registry directly.
|
|
fold_fn() ->
|
|
fun (Activity, State) -> fold(Activity, State) end.
|
|
|
|
%% define_kind/1 — discriminator from the inner Define* object's
|
|
%% :type atom to the registry kind atom. Anything unrecognised
|
|
%% returns not_a_define so the fold treats it as a pass-through.
|
|
|
|
define_kind(define_activity) -> activity_types;
|
|
define_kind(define_object) -> object_types;
|
|
define_kind(define_projection) -> projections;
|
|
define_kind(define_validator) -> validators;
|
|
define_kind(define_codec) -> codecs;
|
|
define_kind(define_sig_suite) -> sig_suites;
|
|
define_kind(define_audience) -> audience;
|
|
define_kind(_) -> not_a_define.
|