3 files changed, 140 insertions, 138 deletions
diff --git a/src/Identifiers.ml b/src/Identifiers.ml
new file mode 100644
index 00000000..b46b00ee
--- /dev/null
+++ b/src/Identifiers.ml
@@ -0,0 +1,42 @@
+exception IntegerOverflow of unit
+
+(** Signature for a module describing an identifier.
+    
+    We often need identifiers (for definitions, variables, etc.) and in
+    order to make sure we don't mix them, we use a generative functor
+    (see [IdGen]).
+*)
+module type Id = sig
+  type id
+
+  type 'a vector
+
+  val zero : id
+
+  val incr : id -> id
+
+  val to_string : id -> string
+end
+
+(** Generative functor for identifiers.
+
+    See [Id].
+*)
+module IdGen () : Id = struct
+  type id = int
+
+  type 'a vector = 'a list (* TODO: use a map *)
+
+  let zero = 0
+
+  let incr x =
+    (* Identifiers should never overflow (because max_int is a really big
+     * value - but we really want to make sure we detect overflows if
+     * they happen *)
+    if x == max_int then raise (IntegerOverflow ()) else x + 1
+
+  let to_string = string_of_int
+end
+
+type name = string list
+(** A name such as: `std::collections::vector` *)
diff --git a/src/Types.ml b/src/Types.ml
new file mode 100644
index 00000000..d435863e
--- /dev/null
+++ b/src/Types.ml
@@ -0,0 +1,97 @@
+open Identifiers
+
+module TypeVarId = IdGen ()
+
+module TypeDefId = IdGen ()
+
+module VariantId = IdGen ()
+
+module FieldId = IdGen ()
+
+module RegionVarId = IdGen ()
+
+type type_var = {
+  index : TypeVarId.id;  (** Unique index identifying the variable *)
+  name : string;  (** Variable name *)
+}
+
+type region_var = {
+  index : RegionVarId.id;  (** Unique index identifying the region *)
+  name : string option;  (** Region name *)
+}
+
+(** A region.
+    
+    Regions are used in function signatures (in which case we use region variable
+    ids) and in symbolic variables and projections (in which case we use region
+    ids).
+ *)
+type 'rid region =
+  | Static  (** Static region *)
+  | Var of 'rid  (** Non-static region *)
+
+(** The type of erased regions.
+    
+    We could use unit, but having a dedicated type makes things more explicit.
+ *)
+type erased_region = Erased
+
+type integer_type =
+  | Isize
+  | I8
+  | I16
+  | I32
+  | I64
+  | I128
+  | Usize
+  | U8
+  | U16
+  | U32
+  | U64
+  | U128
+
+type ref_kind = Mut | Shared
+
+type assumed_ty = Box
+
+type 'r ty =
+  | Adt of TypeDefId.id * 'r list * 'r ty list
+  | TypeVar of TypeVarId.id
+  | Bool
+  | Char
+  | Never
+  | Integer of integer_type
+  | Str
+  | Array of 'r ty (* TODO: there should be a constant with the array *)
+  | Slice of 'r ty
+  | Ref of 'r * 'r ty * ref_kind
+  | Tuple of 'r ty list
+  | Assumed of assumed_ty * 'r list * 'r ty
+
+type rty = RegionVarId.id region ty
+(** Type with *R*egions.
+
+    Used in function signatures and type definitions.
+ *)
+
+type ety = erased_region ty
+(** Type with *E*rased regions.
+    
+    Used in function bodies, "general" value types, etc.
+ *)
+
+type field = { name : string; ty : rty }
+
+type variant = { name : string; fields : field FieldId.vector }
+
+type type_def_kind =
+  | Struct of field FieldId.vector
+  | Enum of variant VariantId.vector
+
+type type_def = {
+  def_id : TypeDefId.id;
+  name : name;
+  region_params : region_var RegionVarId.vector;
+  type_params : type_var TypeVarId.vector;
+  kind : type_def_kind;
+}
diff --git a/src/main.ml b/src/main.ml
index 3b1fc58a..2248506a 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -1,141 +1,4 @@
-exception IntegerOverflow of unit
-
-(** Signature for a module describing an identifier.
-    
-    We often need identifiers (for definitions, variables, etc.) and in
-    order to make sure we don't mix them, we use a generative functor
-    (see [IdGen]).
-*)
-module type Id = sig
-  type id
-
-  type 'a vector
-
-  val zero : id
-
-  val incr : id -> id
-
-  val to_string : id -> string
-end
-
-(** Generative functor for identifiers.
-
-    See [Id].
-*)
-module IdGen () : Id = struct
-  type id = int
-
-  type 'a vector = 'a list (* TODO: use a map *)
-
-  let zero = 0
-
-  let incr x =
-    (* Identifiers should never overflow (because max_int is a really big
-     * value - but we really want to make sure we detect overflows if
-     * they happen *)
-    if x == max_int then raise (IntegerOverflow ()) else x + 1
-
-  let to_string = string_of_int
-end
-
-type name = string list
-(** A name such as: `std::collections::vector` *)
-
-module TypeVarId = IdGen ()
-
-module TypeDefId = IdGen ()
-
-module VariantId = IdGen ()
-
-module FieldId = IdGen ()
-
-module RegionVarId = IdGen ()
-
-type type_var = {
-  index : TypeVarId.id;  (** Unique index identifying the variable *)
-  name : string;  (** Variable name *)
-}
-
-type region_var = {
-  index : RegionVarId.id;  (** Unique index identifying the region *)
-  name : string option;  (** Region name *)
-}
-
-(** A region.
-    
-    Regions are used in function signatures (in which case we use region variable
-    ids) and in symbolic variables and projections (in which case we use region
-    ids).
- *)
-type 'rid region =
-  | Static  (** Static region *)
-  | Var of 'rid  (** Non-static region *)
-
-(** The type of erased regions.
-    
-    We could use unit, but having a dedicated type makes things more explicit.
- *)
-type erased_region = Erased
-
-type integer_type =
-  | Isize
-  | I8
-  | I16
-  | I32
-  | I64
-  | I128
-  | Usize
-  | U8
-  | U16
-  | U32
-  | U64
-  | U128
-
-type ref_kind = Mut | Shared
-
-type assumed_ty = Box
-
-type 'r ty =
-  | Adt of TypeDefId.id * 'r list * 'r ty list
-  | TypeVar of TypeVarId.id
-  | Bool
-  | Char
-  | Never
-  | Integer of integer_type
-  | Str
-  | Array of 'r ty (* TODO: there should be a constant with the array *)
-  | Slice of 'r ty
-  | Ref of 'r * 'r ty * ref_kind
-  | Tuple of 'r ty list
-  | Assumed of assumed_ty * 'r list * 'r ty
-
-type rty = RegionVarId.id region ty
-(** Type with *R*egions.
-
-    Used in function signatures and type definitions.
- *)
-
-type ety = erased_region ty
-(** Type with *E*rased regions.
-    
-    Used in function bodies, "general" value types, etc.
- *)
-
-type field = { name : string; ty : rty }
-
-type variant = { name : string; fields : field FieldId.vector }
-
-type type_def_kind =
-  | Struct of field FieldId.vector
-  | Enum of variant VariantId.vector
-
-type type_def = {
-  def_id : TypeDefId.id;
-  name : name;
-  region_params : region_var RegionVarId.vector;
-  type_params : type_var TypeVarId.vector;
-  kind : type_def_kind;
-}
+open Identifiers
 
 module Id0 = IdGen ()