Branching and naïve merge strategies

* AGPL license

* branching and merging

* Delete LICENSE in favor of separate PR

Signed-off-by: Marcos Magueta <maguetamarcos@gmail.com>

* add unmonitored tests and docs

---------

Signed-off-by: Marcos Magueta <maguetamarcos@gmail.com>

3 files changed, 82 insertions, 0 deletions

diff --git a/lib/icl/ast.ml b/lib/icl/ast.ml
new file mode 100644
index 0000000..95e0271
--- /dev/null
+++ b/lib/icl/ast.ml
@@ -0,0 +1,23 @@
+open Sexplib.Std
+
+type binding_expr =
+  | Var of string
+  | Const of Drl.Ast.value  (** reuse DRL value for literals *)
+[@@deriving sexp]
+
+type constraint_body =
+  | MemberOf of { target: string; binding: (string * binding_expr) list }
+  | Not of { body: constraint_body; universe: string }
+  | And of constraint_body list
+  | Or of constraint_body list
+  | Exists of { variable: string; quantifier: string; body: constraint_body }
+  | Forall of { variable: string; quantifier: string; body: constraint_body }
+[@@deriving sexp]
+
+type statement =
+  | RegisterConstraint of {
+      constraint_name: string;
+      relation_name: string;
+      body: constraint_body;
+    }
+[@@deriving sexp]
diff --git a/lib/icl/executor.ml b/lib/icl/executor.ml
new file mode 100644
index 0000000..a895135
--- /dev/null
+++ b/lib/icl/executor.ml
@@ -0,0 +1,50 @@
+module Make (Storage : Management.Physical.S) = struct
+  module Ops = Manipulation.Make(Storage)
+
+  type error =
+    | ManipulationError of Manipulation.error
+    | ConversionError of string
+
+  let wrap_manip = Result.map_error (fun e -> ManipulationError e)
+
+  let convert_binding_expr : Ast.binding_expr -> Constraint.binding_expr = function
+    | Ast.Var name -> Constraint.Var name
+    | Ast.Const value -> Constraint.Const (Drl.Ast.value_to_abstract value)
+
+  let convert_binding (pairs : (string * Ast.binding_expr) list) : Constraint.binding =
+    List.fold_left
+      (fun acc (key, expr) ->
+        Constraint.BindingMap.add key (convert_binding_expr expr) acc)
+      Constraint.BindingMap.empty
+      pairs
+
+  let rec convert_body : Ast.constraint_body -> Constraint.t = function
+    | Ast.MemberOf { target; binding } ->
+      Constraint.MemberOf { target; binding = convert_binding binding }
+    | Ast.Not { body; universe } ->
+      Constraint.Not { body = convert_body body; universe }
+    | Ast.And bodies ->
+      Constraint.And (List.map convert_body bodies)
+    | Ast.Or bodies ->
+      Constraint.Or (List.map convert_body bodies)
+    | Ast.Exists { variable; quantifier; body } ->
+      Constraint.Exists { variable; quantifier; body = convert_body body }
+    | Ast.Forall { variable; quantifier; body } ->
+      Constraint.Forall { variable; quantifier; body = convert_body body }
+
+  let execute
+      (storage : Storage.t)
+      (db : Management.Database.t)
+      (stmt : Ast.statement)
+    : (Management.Database.t * string, error) result =
+    match stmt with
+    | Ast.RegisterConstraint { constraint_name; relation_name; body } ->
+      let runtime_body = convert_body body in
+      (match Ops.register_constraint storage db
+               ~constraint_name ~relation_name ~body:runtime_body
+             |> wrap_manip with
+       | Ok new_db -> Ok (new_db, "Constraint registered: " ^ constraint_name)
+       | Error e   -> Error e)
+end
+
+module Memory = Make(Management.Physical.Memory)
diff --git a/lib/icl/parser.ml b/lib/icl/parser.ml
new file mode 100644
index 0000000..a7981c0
--- /dev/null
+++ b/lib/icl/parser.ml
@@ -0,0 +1,9 @@
+type error = ParseError of string
+
+let of_string s =
+  match Sexplib.Sexp.of_string s |> Ast.statement_of_sexp with
+  | stmt          -> Ok stmt
+  | exception exn -> Error (ParseError (Printexc.to_string exn))
+
+let to_string stmt =
+  Ast.sexp_of_statement stmt |> Sexplib.Sexp.to_string_hum