2 files changed, 104 insertions, 0 deletions
diff --git a/src/Pure.ml b/src/Pure.ml
new file mode 100644
index 00000000..4201c4b6
--- /dev/null
+++ b/src/Pure.ml
@@ -0,0 +1,103 @@
+open Identifiers
+module T = Types
+module V = Values
+module E = Expressions
+module A = CfimAst
+module TypeVarId = T.TypeVarId
+module RegionId = T.RegionId
+module VariantId = T.VariantId
+module FieldId = T.FieldId
+module SymbolicValueId = V.SymbolicValueId
+
+module SynthPhaseId = IdGen ()
+(** We give an identifier to every phase of the synthesis (forward, backward
+    for group of regions 0, etc.) *)
+
+module BackwardFunId = IdGen ()
+(** Every backward function has its identifier *)
+
+type ty =
+  | Adt of T.type_id * ty list
+      (** [Adt] encodes ADTs, tuples and assumed types.
+       
+          TODO: what about the ended regions?
+       *)
+  | TypeVar of TypeVarId.id
+  | Bool
+  | Char
+  | Never
+  | Integer of T.integer_type
+  | Str
+  | Array of ty (* TODO: there should be a constant with the array *)
+  | Slice of ty
+
+type scalar_value = V.scalar_value
+
+type constant_value = V.constant_value
+
+type symbolic_value = {
+  sv_id : SymbolicValueId.id;
+  sv_ty : ty;
+  sv_rty : T.rty;
+  sv_ended_regions : RegionId.Set.t;
+      (** We need to remember what was the set of ended regions at the time the
+          symbolic value was introduced.
+       *)
+}
+
+type value =
+  | Concrete of constant_value
+  | Adt of adt_value
+  | Symbolic of symbolic_value
+
+and adt_value = {
+  variant_id : (VariantId.id option[@opaque]);
+  field_values : typed_value list;
+}
+
+and typed_value = { value : value; ty : ty }
+
+type projection_elem = { pkind : E.field_proj_kind; field_id : FieldId.id }
+
+type projection = projection_elem list
+
+type operand = typed_value
+
+type assertion = { cond : operand; expected : bool }
+
+type fun_id =
+  | Local of A.FunDefId.id * BackwardFunId.id option
+      (** Backward id: `Some` if the function is a backward function, `None`
+          if it is a forward function *)
+  | Assumed of A.assumed_fun_id
+  | Unop of E.unop
+  | Binop of E.binop
+
+type call = { func : fun_id; type_params : ty list; args : operand list }
+
+type let_bindings = { call : call; bindings : symbolic_value list }
+
+(** **Rk.:** here, [expression] is not at all equivalent to the expressions
+    used in CFIM. They are lambda-calculus expressions, and are thus actually
+    more general than the CFIM statements, in a sense.
+ *)
+type expression =
+  | Let of let_bindings * expression
+      (** Let bindings include the let-bindings introduced because of function calls *)
+  | Assert of assertion
+  | Return of typed_value
+  | Panic of SynthPhaseId.id
+  | Nop
+  | Sequence of expression * expression
+  | Switch of operand * switch_body
+
+and switch_body =
+  | If of expression * expression
+  | SwitchInt of T.integer_type * (scalar_value * expression) list * expression
+  | Match of match_branch list
+
+and match_branch = {
+  variant_id : VariantId.id;
+  vars : symbolic_value list;
+  branch : expression;
+}
diff --git a/src/main.ml b/src/main.ml
index df9134e0..54536503 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -6,6 +6,7 @@ module A = CfimAst
 module I = Interpreter
 module EL = Easy_logging.Logging
 module TA = TypesAnalysis
+module P = Pure
 
 (* This is necessary to have a backtrace when raising exceptions - for some
  * reason, the -g option doesn't work.