ephemeral relations as outputs of FOL and program overhaul

2 files changed, 94 insertions, 164 deletions

diff --git a/test/unit/evaluators/FOL.ml b/test/unit/evaluators/FOL.ml
index 404e7a4..046fa3f 100644
--- a/test/unit/evaluators/FOL.ml
+++ b/test/unit/evaluators/FOL.ml
@@ -3,7 +3,6 @@ open Rnt
 module Make (S : Abstract.Storage.STORAGE) (C : Helpers.Storage.CONFIGURATOR) = struct
   open Alcotest
   module H = Helpers.Storage.Make (S) (C)
-  module SR = Rnt.Kernel.SubstantialRelation.Make (S)
 
   let alaric =
     { Concepts.Tuple.type_= "employee";
@@ -14,20 +13,31 @@ module Make (S : Abstract.Storage.STORAGE) (C : Helpers.Storage.CONFIGURATOR) =
     Concepts.Condition.condition "not-a-directory"
       "A handle was expected to carry the directory protocol and did not" Concepts.Condition.empty
 
-  let not_a_program () =
-    Concepts.Condition.condition "not-a-program"
-      "A handle was expected to carry the program protocol and did not" Concepts.Condition.empty
+  let missing name =
+    Concepts.Condition.condition "missing" "A name was expected in the directory and was absent"
+      Concepts.Condition.("name" |=| Concepts.Value.String name)
+
+  let employee name age =
+    { Concepts.Tuple.type_= "employee";
+      attributes=
+        BatMap.String.of_list ["name", Concepts.Value.String name; "age", Concepts.Value.Integer age]
+    }
+
+  let drain result =
+    let open Utilities.Result in
+    let* enumerable = Protocols.Enumerable.require result in
+    let* cursor = Protocols.Enumerable.enumerate enumerable in
+    let* scan = Protocols.Cursor.require cursor in
+    let* tuples = Protocols.Cursor.drain scan () in
+    Protocols.Handle.release cursor;
+    Protocols.Handle.release result;
+    Ok (BatFingerTree.to_list tuples)
 
   let scan_a_base_relation conn =
     let scanned =
       begin
         let open Utilities.Result in
-        let* tx = S.start conn in
-        let* schematics = H.store_schema tx ["name"] in
-        let* relation = SR.empty tx ~schematics () in
-        let* relation = SR.assert_tuple tx relation alaric in
-        let* () = S.commit tx in
-        let* employee = SR.wrap conn relation in
+        let* employee = H.relation conn ["name"] [alaric] in
         let root =
           Kernel.Prototype.mixture
             [ Kernel.Prototype.Directory.of_properties
@@ -37,17 +47,12 @@ module Make (S : Abstract.Storage.STORAGE) (C : Helpers.Storage.CONFIGURATOR) =
           Protocols.Directory.from root |> Option.to_result ~none:(not_a_directory ())
         in
         let* found = Protocols.Directory.find directory "fol" in
-        let* evaluator = Option.to_result ~none:(not_a_program ()) found in
-        let* interpreter =
-          Rnt.Evaluators.FOL.Program.from evaluator |> Option.to_result ~none:(not_a_program ())
+        let* evaluator = Option.to_result ~none:(missing "fol") found in
+        let* evaluator = Protocols.Evaluator.require evaluator in
+        let* result =
+          Rnt.Evaluators.FOL.(program (Base employee)) |> Protocols.Evaluator.invoke evaluator
         in
-        let* cursor =
-          Rnt.Evaluators.FOL.Program.invoke interpreter (Rnt.Evaluators.FOL.Base employee)
-        in
-        let* scan = Protocols.Cursor.require cursor in
-        let* tuples = Protocols.Cursor.drain scan () in
-        Protocols.Handle.release cursor;
-        Ok (BatFingerTree.to_list tuples)
+        drain result
       end
       |> Helpers.condition_as_failure
     in
@@ -58,12 +63,76 @@ module Make (S : Abstract.Storage.STORAGE) (C : Helpers.Storage.CONFIGURATOR) =
            Concepts.Hash.hash_equals (Concepts.Tuple.hash tuple) (Concepts.Tuple.hash alaric) )
          scanned )
 
-  let suite prefix =
-    ( "fol/" ^ prefix,
-      [test_case "scan-a-base-relation" `Quick (H.with_connection scan_a_base_relation "fol-test")]
-    )
+  let project_away_an_attribute conn =
+    let projected =
+      begin
+        let open Utilities.Result in
+        let* employees =
+          H.relation conn ["name"; "age"]
+            [employee "Alaric" 42; employee "Alaric" 30; employee "Brunhild" 42]
+        in
+        let* evaluator = Protocols.Evaluator.require (Rnt.Evaluators.FOL.make ()) in
+        let* result =
+          Rnt.Evaluators.FOL.(program (Project (Base employees, BatFingerTree.singleton "name")))
+          |> Protocols.Evaluator.invoke evaluator
+        in
+        drain result
+      end
+      |> Helpers.condition_as_failure
+    in
+    check
+      (list (list (pair string Helpers.value)))
+      "each name once, and nothing else"
+      [["name", Concepts.Value.String "Alaric"]; ["name", Concepts.Value.String "Brunhild"]]
+      ( projected
+      |> List.map (fun tuple -> BatMap.String.bindings tuple.Concepts.Tuple.attributes)
+      |> List.sort compare )
+
+  let pull_one_tuple_at_a_time () =
+    let produced = ref 0 and closed = ref false in
+    let description =
+      BatMap.String.singleton "value" {Protocols.Schematics.domain= "integer"; provenance= []}
+    in
+    let rec count ~yield n =
+      incr produced;
+      yield
+        { Concepts.Tuple.type_= "counter";
+          attributes= BatMap.String.singleton "value" (Concepts.Value.Integer n) };
+      count ~yield (n + 1)
+    in
+    let source =
+      Kernel.EphemeralRelation.instantiate description
+        {Kernel.EphemeralRelation.schematics= `Temporary description}
+        (fun () -> Ok (Kernel.Generator.cursor_of ~finally:(fun () -> closed := true) (count 0)))
+    in
+    let first =
+      begin
+        let open Utilities.Result in
+        let* evaluator = Protocols.Evaluator.require (Rnt.Evaluators.FOL.make ()) in
+        let* result =
+          Rnt.Evaluators.FOL.(program (Project (Base source, BatFingerTree.singleton "value")))
+          |> Protocols.Evaluator.invoke evaluator
+        in
+        let* enumerable = Protocols.Enumerable.require result in
+        let* cursor = Protocols.Enumerable.enumerate enumerable in
+        let* scan = Protocols.Cursor.require cursor in
+        let* first = Protocols.Cursor.next scan in
+        Protocols.Handle.release cursor; Protocols.Handle.release result; Ok first
+      end
+      |> Helpers.condition_as_failure
+    in
+    check bool "a tuple came through" true (Option.is_some first);
+    check int "the source produced only that tuple" 1 !produced;
+    check bool "and was closed with its consumer" true !closed
+
+  let suite =
+    ( "evaluators/fol",
+      [ test_case "scan-a-base-relation" `Quick (H.with_connection scan_a_base_relation "fol-test");
+        test_case "project-away-an-attribute" `Quick
+          (H.with_connection project_away_an_attribute "fol-test");
+        test_case "pull-one-tuple-at-a-time" `Quick pull_one_tuple_at_a_time ] )
 end
 
 module LMDB = Make (Rnt.Backend.Storage.LMDB) (Helpers.Storage.LMDB_Configurator)
 
-let suites () = [LMDB.suite "lmdb"]
+let suites () = [LMDB.suite]
diff --git a/test/unit/evaluators/Lambda.ml b/test/unit/evaluators/Lambda.ml
deleted file mode 100644
index ee15c16..0000000
--- a/test/unit/evaluators/Lambda.ml
+++ /dev/null
@@ -1,139 +0,0 @@
-open Rnt
-
-module Make (S : Abstract.Storage.STORAGE) (C : Helpers.Storage.CONFIGURATOR) = struct
-  open Alcotest
-  module H = Helpers.Storage.Make (S) (C)
-  module SR = Rnt.Kernel.SubstantialRelation.Make (S)
-
-  let datum =
-    { Concepts.Tuple.type_= "noun";
-      attributes= BatMap.String.empty |> BatMap.String.add "lemma" (Concepts.Value.String "datum")
-    }
-
-  let reticulare =
-    { Concepts.Tuple.type_= "verb";
-      attributes=
-        BatMap.String.empty |> BatMap.String.add "lemma" (Concepts.Value.String "rēticulāre") }
-
-  let not_a_directory () =
-    Concepts.Condition.condition "not-a-directory"
-      "A handle was expected to carry the directory protocol and did not" Concepts.Condition.empty
-
-  let not_a_program () =
-    Concepts.Condition.condition "not-a-program"
-      "A handle was expected to carry the program protocol and did not" Concepts.Condition.empty
-
-  (* Sets up the relations "noun" and "verb", each holding one Latin
-     lemma, hands [term] to the lambda evaluator, and drains the cursor
-     it returns. Change [term] in the cases below to play with the
-     calculus *)
-  let evaluate conn term =
-    let open Utilities.Result in
-    let* tx = S.start conn in
-    let* schematics = H.store_schema tx ["lemma"] in
-    let singleton tuple =
-      let* relation = SR.empty tx ~schematics () in
-      SR.assert_tuple tx relation tuple
-    in
-    let* noun = singleton datum in
-    let* verb = singleton reticulare in
-    let* () = S.commit tx in
-    let* noun = SR.wrap conn noun in
-    let* verb = SR.wrap conn verb in
-    let root =
-      Kernel.Prototype.mixture
-        [ Kernel.Prototype.Directory.of_properties
-            ["noun", noun; "verb", verb; "lambda", Rnt.Evaluators.Lambda.make ()] ]
-    in
-    let* directory = Protocols.Directory.from root |> Option.to_result ~none:(not_a_directory ()) in
-    let* found = Protocols.Directory.find directory "lambda" in
-    let* evaluator = Option.to_result ~none:(not_a_program ()) found in
-    let* interpreter =
-      Rnt.Evaluators.Lambda.Program.from evaluator |> Option.to_result ~none:(not_a_program ())
-    in
-    let* cursor = Rnt.Evaluators.Lambda.(Program.invoke interpreter (Program (term, directory))) in
-    let* scan = Protocols.Cursor.require cursor in
-    let* tuples = Protocols.Cursor.drain scan () in
-    Protocols.Handle.release cursor;
-    Ok (BatFingerTree.to_list tuples)
-
-  let is lemma tuple =
-    Concepts.Hash.hash_equals (Concepts.Tuple.hash tuple) (Concepts.Tuple.hash lemma)
-
-  (* A bare name resolves through the directory, so the relations it
-     holds are the outer environment *)
-  let a_name_is_a_relation conn =
-    let scanned =
-      evaluate conn (Rnt.Evaluators.Lambda.Name "noun") |> Helpers.condition_as_failure
-    in
-    check int "one tuple scanned" 1 (List.length scanned);
-    check bool "the tuple that was asserted" true (List.for_all (is datum) scanned)
-
-  (* (\x. x) noun *)
-  let identity_applied_to_a_relation conn =
-    let open Rnt.Evaluators.Lambda in
-    let scanned =
-      evaluate conn (Apply (Abstract ("x", Name "x"), Name "noun")) |> Helpers.condition_as_failure
-    in
-    check int "one tuple scanned" 1 (List.length scanned);
-    check bool "the tuple that was asserted" true (List.for_all (is datum) scanned)
-
-  (* (\x. \y. x) noun (\z. z), so the argument that wins is the one
-     the closure kept *)
-  let a_closure_keeps_its_binding conn =
-    let open Rnt.Evaluators.Lambda in
-    let scanned =
-      evaluate conn
-        (Apply
-           (Apply (Abstract ("x", Abstract ("y", Name "x")), Name "noun"), Abstract ("z", Name "z"))
-        )
-      |> Helpers.condition_as_failure
-    in
-    check int "one tuple scanned" 1 (List.length scanned);
-    check bool "the tuple that was asserted" true (List.for_all (is datum) scanned)
-
-  (* The classic conditional, with no conditional in the calculus. A
-     boolean is the choice it makes, so [if] is application and both
-     branches are relations *)
-  let church_conditional conn =
-    let open Rnt.Evaluators.Lambda in
-    let true_ = Abstract ("then", Abstract ("else", Name "then")) in
-    let false_ = Abstract ("then", Abstract ("else", Name "else")) in
-    let if_ condition then_ else_ = Apply (Apply (condition, then_), else_) in
-    let declining = if_ true_ (Name "noun") (Name "verb") in
-    let conjugating = if_ false_ (Name "noun") (Name "verb") in
-    let declined = evaluate conn declining |> Helpers.condition_as_failure in
-    let conjugated = evaluate conn conjugating |> Helpers.condition_as_failure in
-    check int "one tuple on the then branch" 1 (List.length declined);
-    check bool "the then branch is the noun" true (List.for_all (is datum) declined);
-    check int "one tuple on the else branch" 1 (List.length conjugated);
-    check bool "the else branch is the verb" true (List.for_all (is reticulare) conjugated)
-
-  (* A program reducing to an abstraction names nothing to
-     enumerate *)
-  let an_abstraction_is_not_a_result conn =
-    let open Rnt.Evaluators.Lambda in
-    match evaluate conn (Abstract ("x", Name "x")) with
-    | Error condition ->
-        check bool "unapplied abstraction" true
-          (String.starts_with ~prefix:"unapplied-abstraction"
-             (Concepts.Condition.to_string_hum condition) )
-    | Ok _ -> fail "an abstraction was enumerated"
-
-  let suite prefix =
-    ( "lambda/" ^ prefix,
-      [ test_case "a-name-is-a-relation" `Quick
-          (H.with_connection a_name_is_a_relation "lambda-name");
-        test_case "identity-applied-to-a-relation" `Quick
-          (H.with_connection identity_applied_to_a_relation "lambda-identity");
-        test_case "a-closure-keeps-its-binding" `Quick
-          (H.with_connection a_closure_keeps_its_binding "lambda-closure");
-        test_case "church-conditional" `Quick
-          (H.with_connection church_conditional "lambda-conditional");
-        test_case "an-abstraction-is-not-a-result" `Quick
-          (H.with_connection an_abstraction_is_not_a_result "lambda-abstraction") ] )
-end
-
-module LMDB = Make (Rnt.Backend.Storage.LMDB) (Helpers.Storage.LMDB_Configurator)
-
-let suites () = [LMDB.suite "lmdb"]