Define the environments (for types and values)

diff --git a/compiler/src/lib/tiger/tiger_env.ml b/compiler/src/lib/tiger/tiger_env.ml
new file mode 100644 (file)
index 0000000..f698f89
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env.ml
@@ -0,0 +1,25 @@
+module Map   = Tiger_map
+module Type  = Tiger_env_type
+module Value = Tiger_env_value
+
+type t =
+  { typs : Type.env
+  ; vals : Value.env
+  }
+
+let base =
+  { typs = Type.built_in
+  ; vals = Value.built_in
+  }
+
+let get_typ {typs; _} k =
+  Map.get typs ~k
+
+let get_val {vals; _} k =
+  Map.get vals ~k
+
+let set_typ t k v =
+  {t with typs = Map.set t.typs ~k ~v}
+
+let set_val t k v =
+  {t with vals = Map.set t.vals ~k ~v}

diff --git a/compiler/src/lib/tiger/tiger_env.mli b/compiler/src/lib/tiger/tiger_env.mli
new file mode 100644 (file)
index 0000000..91747e5
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env.mli
@@ -0,0 +1,9 @@
+type t
+
+val base : t
+
+val get_typ : t -> Tiger_symbol.t -> Tiger_env_type.t option
+val get_val : t -> Tiger_symbol.t -> Tiger_env_value.t option
+
+val set_typ : t -> Tiger_symbol.t -> Tiger_env_type.t -> t
+val set_val : t -> Tiger_symbol.t -> Tiger_env_value.t -> t

diff --git a/compiler/src/lib/tiger/tiger_env_type.ml b/compiler/src/lib/tiger/tiger_env_type.ml
new file mode 100644 (file)
index 0000000..041d421
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env_type.ml
@@ -0,0 +1,96 @@
+open Printf
+
+module List    = ListLabels
+
+module Map    = Tiger_map
+module Symbol = Tiger_symbol
+
+type unique =
+  unit ref
+
+type t =
+  | Unit
+  | Nil
+  | Int
+  | String
+  | Record of
+      { unique : unique
+      ; fields : (Symbol.t * t) list
+      }
+  | Array of
+      { unique : unique
+      ; ty     : t
+      }
+  | Name of Symbol.t * t option ref
+
+type env =
+  (Symbol.t, t ) Map.t
+
+let new_unique () =
+  ref ()
+
+let new_record fields =
+  Record
+    { fields
+    ; unique = new_unique ()
+    }
+
+let new_array ty =
+  Array
+    { ty
+    ; unique = new_unique ()
+    }
+
+let is_equal t1 t2 =
+  match t1, t2 with
+  | Record {unique=u1; _},  Record {unique=u2; _} -> u1 == u2
+  | Array  {unique=u1; _},  Array  {unique=u2; _} -> u1 == u2
+  | t1                   , t2                     -> t1 =  t2
+  (* The above pattern matching is "fragile" and I'm OK with it.
+   * TODO: Can we ignore the warning locally?
+   * *)
+
+let is_record = function
+  | Unit
+  | Int
+  | String
+  | Name _
+  | Array  _ -> false
+  | Nil  (* nil belongs to ANY record *)
+  | Record _ -> true
+
+let is_int = function
+  | Unit
+  | Nil
+  | String
+  | Name _
+  | Record _
+  | Array  _ -> false
+  | Int      -> true
+
+let is_name = function
+  | Unit
+  | Nil
+  | String
+  | Int
+  | Record _
+  | Array  _ -> false
+  | Name _   -> true
+
+let to_string = function
+  | Unit               -> "unit"
+  | Nil                -> "nil"
+  | String             -> "string"
+  | Record {unique; _} -> sprintf "record(%d)" (Obj.magic unique)
+  | Array  {unique; _} -> sprintf "array(%d)"  (Obj.magic unique)
+  | Int                -> "int"
+  | Name (name, _)     -> Symbol.to_string name
+
+let built_in =
+  [ ("unit"   , Unit)
+  ; ("nil"    , Nil)
+  ; ("int"    , Int)
+  ; ("string" , String)
+  ]
+  |> List.map ~f:(fun (k, v) -> (Symbol.of_string k, v))
+  |> Map.of_list

diff --git a/compiler/src/lib/tiger/tiger_env_type.mli b/compiler/src/lib/tiger/tiger_env_type.mli
new file mode 100644 (file)
index 0000000..825750c
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env_type.mli
@@ -0,0 +1,31 @@
+type unique
+
+type t =
+  | Unit
+  | Nil
+  | Int
+  | String
+  | Record of
+      { unique : unique
+      ; fields : (Tiger_symbol.t * t) list
+      }
+  | Array of
+      { unique : unique
+      ; ty     : t
+      }
+  | Name of Tiger_symbol.t * t option ref
+
+type env =
+  (Tiger_symbol.t, t ) Tiger_map.t
+
+val built_in : env
+
+val is_equal  : t -> t -> bool
+val is_record : t -> bool
+val is_int    : t -> bool
+val is_name   : t -> bool
+
+val new_record : (Tiger_symbol.t * t) list -> t
+val new_array  : t -> t
+
+val to_string : t -> string

diff --git a/compiler/src/lib/tiger/tiger_env_value.ml b/compiler/src/lib/tiger/tiger_env_value.ml
new file mode 100644 (file)
index 0000000..80f145e
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env_value.ml
@@ -0,0 +1,35 @@
+module List    = ListLabels
+
+module Map    = Tiger_map
+module Symbol = Tiger_symbol
+module Type   = Tiger_env_type
+
+type t =
+  | Var of
+      {ty : Type.t}
+  | Fun of
+      { formals : Type.t list
+      ; result  : Type.t
+      }
+
+type env =
+  (Symbol.t, t ) Map.t
+
+let built_in =
+  [ ("print"     , [Type.String]                     , Type.Unit   )
+  ; ("flush"     , []                                , Type.Unit   )
+  ; ("getchar"   , []                                , Type.String )
+  ; ("ord"       , [Type.String]                     , Type.Int    )
+  ; ("chr"       , [Type.Int]                        , Type.String )
+  ; ("size"      , [Type.String]                     , Type.Int    )
+  ; ("substring" , [Type.String; Type.Int; Type.Int] , Type.String )
+  ; ("concat"    , [Type.String; Type.String]        , Type.String )
+  ; ("not"       , [Type.Int]                        , Type.Int    )
+  ; ("exit"      , [Type.Int]                        , Type.Unit   )
+  ]
+  |> List.map ~f:(fun (name, formals, result) ->
+      let key   = Symbol.of_string name in
+      let value = Fun {formals; result} in
+      (key, value)
+    )
+  |> Map.of_list

diff --git a/compiler/src/lib/tiger/tiger_env_value.mli b/compiler/src/lib/tiger/tiger_env_value.mli
new file mode 100644 (file)
index 0000000..71209eb
--- /dev/null
+++ b/compiler/src/lib/tiger/tiger_env_value.mli
@@ -0,0 +1,12 @@
+type t =
+  | Var of
+      {ty : Tiger_env_type.t}
+  | Fun of
+      { formals : Tiger_env_type.t list
+      ; result  : Tiger_env_type.t
+      }
+
+type env =
+  (Tiger_symbol.t, t ) Tiger_map.t
+
+val built_in : env