Add promoter expression

src/analysis_and_optimization/Mir_utils.ml

@@ -243,6 +243,7 @@ let rec expr_var_set Expr.Fixed.{pattern; meta} =
   | TernaryIf (expr1, expr2, expr3) -> union_recur [expr1; expr2; expr3]
   | Indexed (expr, ix) ->
       Set.Poly.union_list (expr_var_set expr :: List.map ix ~f:index_var_set)
+  | Promotion (expr, _) -> expr_var_set expr
   | EAnd (expr1, expr2) | EOr (expr1, expr2) -> union_recur [expr1; expr2]
 
 and index_var_set ix =
@@ -361,6 +362,7 @@ let rec expr_depth Expr.Fixed.{pattern; _} =
       + max (expr_depth e)
           (Option.value ~default:0
              (List.max_elt ~compare:compare_int (List.map ~f:idx_depth l)) )
+  | Promotion (expr, _) -> 1 + expr_depth expr
   | EAnd (e1, e2) | EOr (e1, e2) ->
       1
       + Option.value ~default:0
@@ -405,6 +407,10 @@ let rec update_expr_ad_levels autodiffable_variables
       let e1 = update_expr_ad_levels autodiffable_variables e1 in
       let e2 = update_expr_ad_levels autodiffable_variables e2 in
       {pattern= EOr (e1, e2); meta= {e.meta with adlevel= ad_level_sup [e1; e2]}}
+  | Promotion (expr, ut) ->
+      let expr' = update_expr_ad_levels autodiffable_variables expr in
+      { pattern= Promotion (expr', ut)
+      ; meta= {e.meta with adlevel= ad_level_sup [expr']} }
   | Indexed (ixed, i_list) ->
       let ixed = update_expr_ad_levels autodiffable_variables ixed in
       let i_list =

src/analysis_and_optimization/Monotone_framework.ml

@@ -24,6 +24,7 @@ let print_mfp to_string (mfp : (int, 'a entry_exit) Map.Poly.t)
 let rec free_vars_expr (e : Expr.Typed.t) =
   match e.pattern with
   | Var x -> Set.Poly.singleton x
+  | Promotion (expr, _) -> free_vars_expr expr
   | Lit (_, _) -> Set.Poly.empty
   | FunApp (kind, l) -> free_vars_fnapp kind l
   | TernaryIf (e1, e2, e3) ->
@@ -544,6 +545,7 @@ let rec used_subexpressions_expr (e : Expr.Typed.t) =
     (Expr.Typed.Set.singleton e)
     ( match e.pattern with
     | Var _ | Lit (_, _) -> Expr.Typed.Set.empty
+    | Promotion (expr, _) -> used_subexpressions_expr expr
     | FunApp (k, l) ->
         Expr.Typed.Set.union_list
           (List.map ~f:used_subexpressions_expr (l @ Fun_kind.collect_exprs k))

src/analysis_and_optimization/Optimize.ml

@@ -224,6 +224,9 @@ let rec inline_function_expression propto adt fim (Expr.Fixed.{pattern; _} as e)
   match pattern with
   | Var _ -> ([], [], e)
   | Lit (_, _) -> ([], [], e)
+  | Promotion (expr, ut) ->
+      let d, sl, expr' = inline_function_expression propto adt fim expr in
+      (d, sl, {e with pattern= Promotion (expr', ut)})
   | FunApp (kind, es) -> (
       let d_list, s_list, es =
         inline_list (inline_function_expression propto adt fim) es in
@@ -1024,8 +1027,8 @@ let block_fixing mir =
 (* TODO: add tests *)
 (* TODO: add pass to get rid of redundant declarations? *)
 
-(** 
- * A generic optimization pass for finding a minimal set of variables that 
+(**
+ * A generic optimization pass for finding a minimal set of variables that
  * are generated by some circumstance, and then updating the MIR with that set.
  * @param gen_variables: the variables that must be added to the set at
  *  the given statement

src/analysis_and_optimization/Partial_evaluator.ml

@@ -93,6 +93,7 @@ let rec eval_expr ?(preserve_stability = false) (e : Expr.Typed.t) =
     pattern=
       ( match e.pattern with
       | Var _ | Lit (_, _) -> e.pattern
+      | Promotion (expr, ut) -> Promotion (eval_expr expr, ut)
       | FunApp (kind, l) -> (
           let l = List.map ~f:(eval_expr ~preserve_stability) l in
           match kind with

src/frontend/Ast.ml

@@ -44,6 +44,7 @@ type ('e, 'f) expression =
   | ImagNumeral of string
   | FunApp of 'f * identifier * 'e list
   | CondDistApp of 'f * identifier * 'e list
+  | Promotion of 'e * UnsizedType.t
   (* GetLP is deprecated *)
   | GetLP
   | GetTarget
@@ -250,9 +251,14 @@ type typed_program = typed_statement program [@@deriving sexp, compare, map]
 (** Forgetful function from typed to untyped expressions *)
 let rec untyped_expression_of_typed_expression ({expr; emeta} : typed_expression)
     : untyped_expression =
-  { expr=
-      map_expression untyped_expression_of_typed_expression (fun _ -> ()) expr
-  ; emeta= {loc= emeta.loc} }
+  match expr with
+  | Promotion (e, _) -> untyped_expression_of_typed_expression e
+  | _ ->
+      { expr=
+          map_expression untyped_expression_of_typed_expression
+            (fun _ -> ())
+            expr
+      ; emeta= {loc= emeta.loc} }
 
 let rec untyped_lvalue_of_typed_lvalue ({lval; lmeta} : typed_lval) :
     untyped_lval =
@@ -304,7 +310,11 @@ let rec id_of_lvalue {lval; _} =
 
 let rec get_loc_expr (e : untyped_expression) =
   match e.expr with
-  | TernaryIf (e, _, _) | BinOp (e, _, _) | PostfixOp (e, _) | Indexed (e, _) ->
+  | TernaryIf (e, _, _)
+   |BinOp (e, _, _)
+   |PostfixOp (e, _)
+   |Indexed (e, _)
+   |Promotion (e, _) ->
       get_loc_expr e
   | PrefixOp (_, e) | ArrayExpr (e :: _) | RowVectorExpr (e :: _) | Paren e ->
       e.emeta.loc.begin_loc

src/frontend/Ast_to_Mir.ml

@@ -81,6 +81,7 @@ and trans_expr {Ast.expr; Ast.emeta} =
       FunApp (CompilerInternal FnMakeRowVec, trans_exprs eles) |> ewrap
   | Indexed (lhs, indices) ->
       Indexed (trans_expr lhs, List.map ~f:trans_idx indices) |> ewrap
+  | Promotion (e, ty) -> Promotion (trans_expr e, ty) |> ewrap
 
 and trans_idx = function
   | Ast.All -> All

src/frontend/Canonicalize.ml

@@ -142,7 +142,7 @@ let rec no_parens {expr; emeta} =
                   | i -> map_index keep_parens i )
                 l )
       ; emeta }
-  | ArrayExpr _ | RowVectorExpr _ | FunApp _ | CondDistApp _ ->
+  | ArrayExpr _ | RowVectorExpr _ | FunApp _ | CondDistApp _ | Promotion _ ->
       {expr= map_expression no_parens ident expr; emeta}
 
 and keep_parens {expr; emeta} =

src/frontend/Pretty_printing.ml

@@ -272,6 +272,7 @@ and pp_expression ppf ({expr= e_content; emeta= {loc; _}} : untyped_expression)
   | ArrayExpr es -> pf ppf "{@[%a}@]" pp_list_of_expression (es, loc)
   | RowVectorExpr es -> pf ppf "[@[%a]@]" pp_list_of_expression (es, loc)
   | Paren e -> pf ppf "(%a)" pp_expression e
+  | Promotion (e, _) -> pp_expression ppf e
   | Indexed (e, l) -> (
     match l with
     | [] -> pf ppf "%a" pp_expression e

src/frontend/SignatureMismatch.ml

@@ -110,37 +110,50 @@ let rec compare_errors e1 e2 =
       | SuffixMismatch _, _ | _, InputMismatch _ -> -1
       | InputMismatch _, _ | _, SuffixMismatch _ -> 1 ) )
 
+type promotions = None | RealPromotion | ComplexPromotion
+
 let rec check_same_type depth t1 t2 =
-  let wrap_func = Option.map ~f:(fun e -> TypeMismatch (t1, t2, Some e)) in
+  let wrap_func = Result.map_error ~f:(fun e -> TypeMismatch (t1, t2, Some e)) in
   match (t1, t2) with
-  | t1, t2 when t1 = t2 -> None
-  | UnsizedType.(UReal, UInt) when depth < 1 -> None
+  | t1, t2 when t1 = t2 -> Ok None
+  | UnsizedType.(UReal, UInt) when depth < 1 -> Ok RealPromotion
+  | UnsizedType.(UComplex, UInt) when depth < 1 -> Ok ComplexPromotion
+  | UnsizedType.(UComplex, UReal) when depth < 1 -> Ok ComplexPromotion
+  (* Arrays: Try to recursively promote, but make sure the error is for these types,
+     not the recursive call *)
+  | UArray nt1, UArray nt2 ->
+      check_same_type depth nt1 nt2
+      |> Result.map_error ~f:(function
+           | TypeMismatch _ -> TypeMismatch (t1, t2, None)
+           | e -> e )
   | UFun (_, _, s1, _), UFun (_, _, s2, _)
     when Fun_kind.without_propto s1 <> Fun_kind.without_propto s2 ->
-      Some
+      Error
         (SuffixMismatch (Fun_kind.without_propto s1, Fun_kind.without_propto s2))
       |> wrap_func
   | UFun (_, rt1, _, _), UFun (_, rt2, _, _) when rt1 <> rt2 ->
-      Some (ReturnTypeMismatch (rt1, rt2)) |> wrap_func
-  | UFun (l1, _, _, _), UFun (l2, _, _, _) ->
-      check_compatible_arguments (depth + 1) l2 l1
-      |> Option.map ~f:(fun e -> InputMismatch e)
-      |> wrap_func
-  | t1, t2 -> Some (TypeMismatch (t1, t2, None))
+      Error (ReturnTypeMismatch (rt1, rt2)) |> wrap_func
+  | UFun (l1, _, _, _), UFun (l2, _, _, _) -> (
+    match check_compatible_arguments (depth + 1) l2 l1 with
+    | Ok _ -> Ok None
+    | Error e -> Error (InputMismatch e) |> wrap_func )
+  | t1, t2 -> Error (TypeMismatch (t1, t2, None))
 
-and check_compatible_arguments depth args1 args2 =
-  match List.zip args1 args2 with
+and check_compatible_arguments depth typs args2 :
+    (promotions list, function_mismatch) result =
+  match List.zip typs args2 with
   | List.Or_unequal_lengths.Unequal_lengths ->
-      Some (ArgNumMismatch (List.length args1, List.length args2))
+      Error (ArgNumMismatch (List.length typs, List.length args2))
   | Ok l ->
-      List.find_mapi l ~f:(fun i ((ad1, ut1), (ad2, ut2)) ->
+      List.mapi l ~f:(fun i ((ad1, ut1), (ad2, ut2)) ->
           match check_same_type depth ut1 ut2 with
-          | Some e -> Some (ArgError (i + 1, e))
-          | None ->
-              if ad1 = ad2 then None
+          | Error e -> Error (ArgError (i + 1, e))
+          | Ok p ->
+              if ad1 = ad2 then Ok p
               else if depth < 2 && UnsizedType.autodifftype_can_convert ad1 ad2
-              then None
-              else Some (ArgError (i + 1, DataOnlyError)) )
+              then Ok p
+              else Error (ArgError (i + 1, DataOnlyError)) )
+      |> Result.all
 
 let check_compatible_arguments_mod_conv = check_compatible_arguments 0
 let max_n_errors = 5
@@ -153,6 +166,16 @@ let extract_function_types f =
       Some (return, args, (fun x -> UserDefined x), mem)
   | _ -> None
 
+let promote es promotions =
+  List.map2_exn es promotions ~f:(fun (exp : Ast.typed_expression) prom ->
+      let emeta = exp.emeta in
+      match prom with
+      | RealPromotion when emeta.type_ <> UReal ->
+          Ast.{expr= Ast.Promotion (exp, UReal); emeta}
+      | ComplexPromotion when emeta.type_ <> UComplex ->
+          {expr= Promotion (exp, UComplex); emeta}
+      | _ -> exp )
+
 let returntype env name args =
   (* NB: Variadic arguments are special-cased in the typechecker and not handled here *)
   let name = Utils.stdlib_distribution_name name in
@@ -164,8 +187,8 @@ let returntype env name args =
   |> List.fold_until ~init:[]
        ~f:(fun errors (rt, tys, funkind_constructor, _) ->
          match check_compatible_arguments 0 tys args with
-         | None -> Stop (Ok (rt, funkind_constructor))
-         | Some e -> Continue (((rt, tys), e) :: errors) )
+         | Ok p -> Stop (Ok (rt, funkind_constructor, p))
+         | Error e -> Continue (((rt, tys), e) :: errors) )
        ~finish:(fun errors ->
          let errors =
            List.sort errors ~compare:(fun (_, e1) (_, e2) ->
@@ -180,7 +203,7 @@ let check_variadic_args allow_lpdf mandatory_arg_tys mandatory_fun_arg_tys
   in
   let minimal_args =
     (UnsizedType.AutoDiffable, minimal_func_type) :: mandatory_arg_tys in
-  let wrap_err x = Some (minimal_args, ArgError (1, x)) in
+  let wrap_err x = Error (minimal_args, ArgError (1, x)) in
   match args with
   | ( _
     , ( UnsizedType.UFun (fun_args, ReturnType return_type, suffix, _) as
@@ -193,22 +216,22 @@ let check_variadic_args allow_lpdf mandatory_arg_tys mandatory_fun_arg_tys
       let suffix = Fun_kind.without_propto suffix in
       if suffix = FnPlain || (allow_lpdf && suffix = FnLpdf ()) then
         match check_compatible_arguments 1 mandatory mandatory_fun_arg_tys with
-        | Some x -> wrap_func_error (InputMismatch x)
-        | None -> (
+        | Error x -> wrap_func_error (InputMismatch x)
+        | Ok _ -> (
           match check_same_type 1 return_type fun_return with
-          | Some _ ->
+          | Error _ ->
               wrap_func_error
                 (ReturnTypeMismatch
                    (ReturnType fun_return, ReturnType return_type) )
-          | None ->
+          | Ok _ ->
               let expected_args =
                 ((UnsizedType.AutoDiffable, func_type) :: mandatory_arg_tys)
                 @ variadic_arg_tys in
               check_compatible_arguments 0 expected_args args
-              |> Option.map ~f:(fun x -> (expected_args, x)) )
+              |> Result.map_error ~f:(fun x -> (expected_args, x)) )
       else wrap_func_error (SuffixMismatch (FnPlain, suffix))
   | (_, x) :: _ -> TypeMismatch (minimal_func_type, x, None) |> wrap_err
-  | [] -> Some ([], ArgNumMismatch (List.length mandatory_arg_tys, 0))
+  | [] -> Error ([], ArgNumMismatch (List.length mandatory_arg_tys, 0))
 
 let pp_signature_mismatch ppf (name, arg_tys, (sigs, omitted)) =
   let open Fmt in

src/frontend/SignatureMismatch.mli

@@ -19,16 +19,27 @@ type signature_error =
   (UnsizedType.returntype * (UnsizedType.autodifftype * UnsizedType.t) list)
   * function_mismatch
 
+(** Indicate a promotion by the resulting type *)
+type promotions = private None | RealPromotion | ComplexPromotion
+
 val check_compatible_arguments_mod_conv :
      (UnsizedType.autodifftype * UnsizedType.t) list
   -> (UnsizedType.autodifftype * UnsizedType.t) list
-  -> function_mismatch option
+  -> (promotions list, function_mismatch) result
+
+val promote :
+  Ast.typed_expression list -> promotions list -> Ast.typed_expression list
+(** Given a list of expressions (arguments) and a list of [promotions],
+  return a list of expressions which include the
+  [Promotion] expression as appropiate *)
 
 val returntype :
      Environment.t
   -> string
   -> (UnsizedType.autodifftype * UnsizedType.t) list
-  -> ( UnsizedType.returntype * (bool Middle.Fun_kind.suffix -> Ast.fun_kind)
+  -> ( UnsizedType.returntype
+       * (bool Middle.Fun_kind.suffix -> Ast.fun_kind)
+       * promotions list
      , signature_error list * bool )
      result
 
@@ -38,8 +49,9 @@ val check_variadic_args :
   -> (UnsizedType.autodifftype * UnsizedType.t) list
   -> UnsizedType.t
   -> (UnsizedType.autodifftype * UnsizedType.t) list
-  -> ((UnsizedType.autodifftype * UnsizedType.t) list * function_mismatch)
-     option
+  -> ( promotions list
+     , (UnsizedType.autodifftype * UnsizedType.t) list * function_mismatch )
+     result
 
 val pp_signature_mismatch :
      Format.formatter

src/frontend/Typechecker.ml

@@ -425,14 +425,16 @@ let check_fn ~is_cond_dist loc tenv id es =
       |> error
   | _ (* a function *) -> (
     match SignatureMismatch.returntype tenv id.name (get_arg_types es) with
-    | Ok (Void, _) ->
+    | Ok (Void, _, _) ->
         Semantic_error.returning_fn_expected_nonreturning_found loc id.name
         |> error
-    | Ok (ReturnType ut, fnk) ->
+    | Ok (ReturnType ut, fnk, promotions) ->
         mk_typed_expression
           ~expr:
             (mk_fun_app ~is_cond_dist
-               (fnk (Fun_kind.suffix_from_name id.name), id, es) )
+               ( fnk (Fun_kind.suffix_from_name id.name)
+               , id
+               , SignatureMismatch.promote es promotions ) )
           ~ad_level:(expr_ad_lub es) ~type_:ut ~loc
     | Error x ->
         es
@@ -458,11 +460,13 @@ let check_reduce_sum ~is_cond_dist loc id es =
         SignatureMismatch.check_variadic_args true mandatory_args
           mandatory_fun_args UReal (get_arg_types es)
       with
-      | None ->
+      | Ok promotions ->
           mk_typed_expression
-            ~expr:(mk_fun_app ~is_cond_dist (StanLib FnPlain, id, es))
+            ~expr:
+              (mk_fun_app ~is_cond_dist
+                 (StanLib FnPlain, id, SignatureMismatch.promote es promotions) )
             ~ad_level:(expr_ad_lub es) ~type_:UnsizedType.UReal ~loc
-      | Some (expected_args, err) ->
+      | Error (expected_args, err) ->
           Semantic_error.illtyped_reduce_sum loc id.name
             (List.map ~f:type_of_expr_typed es)
             expected_args err
@@ -477,7 +481,7 @@ let check_reduce_sum ~is_cond_dist loc id es =
       let expected_args, err =
         SignatureMismatch.check_variadic_args true mandatory_args
           mandatory_fun_args UReal (get_arg_types es)
-        |> Option.value_exn in
+        |> Result.error |> Option.value_exn in
       Semantic_error.illtyped_reduce_sum_generic loc id.name
         (List.map ~f:type_of_expr_typed es)
         expected_args err
@@ -498,12 +502,14 @@ let check_variadic_ode ~is_cond_dist loc id es =
       Stan_math_signatures.variadic_ode_mandatory_fun_args
       Stan_math_signatures.variadic_ode_fun_return_type (get_arg_types es)
   with
-  | None ->
+  | Ok promotions ->
       mk_typed_expression
-        ~expr:(mk_fun_app ~is_cond_dist (StanLib FnPlain, id, es))
+        ~expr:
+          (mk_fun_app ~is_cond_dist
+             (StanLib FnPlain, id, SignatureMismatch.promote es promotions) )
         ~ad_level:(expr_ad_lub es)
         ~type_:Stan_math_signatures.variadic_ode_return_type ~loc
-  | Some (expected_args, err) ->
+  | Error (expected_args, err) ->
       Semantic_error.illtyped_variadic_ode loc id.name
         (List.map ~f:type_of_expr_typed es)
         expected_args err
@@ -657,6 +663,10 @@ and check_expression cf tenv ({emeta; expr} : Ast.untyped_expression) :
       es |> List.map ~f:ce |> check_funapp loc cf tenv ~is_cond_dist:false id
   | CondDistApp ((), id, es) ->
       es |> List.map ~f:ce |> check_funapp loc cf tenv ~is_cond_dist:true id
+  | Promotion (e, _) ->
+      (* Should never happen: promotions are produced during typechecking *)
+      Common.FatalError.fatal_error_msg
+        [%message "Promotion in untyped AST" (e : Ast.untyped_expression)]
 
 and check_expression_of_int_type cf tenv e name =
   let te = check_expression cf tenv e in
@@ -699,11 +709,15 @@ let check_nrfn loc tenv id es =
       |> error
   | _ (* a function *) -> (
     match SignatureMismatch.returntype tenv id.name (get_arg_types es) with
-    | Ok (Void, fnk) ->
+    | Ok (Void, fnk, promotions) ->
         mk_typed_statement
-          ~stmt:(NRFunApp (fnk (Fun_kind.suffix_from_name id.name), id, es))
+          ~stmt:
+            (NRFunApp
+               ( fnk (Fun_kind.suffix_from_name id.name)
+               , id
+               , SignatureMismatch.promote es promotions ) )
           ~return_type:NoReturnType ~loc
-    | Ok (ReturnType _, _) ->
+    | Ok (ReturnType _, _, _) ->
         Semantic_error.nonreturning_fn_expected_returning_found loc id.name
         |> error
     | Error x ->

src/middle/Expr.ml

@@ -17,6 +17,7 @@ module Fixed = struct
       | EAnd of 'a * 'a
       | EOr of 'a * 'a
       | Indexed of 'a * 'a Index.t list
+      | Promotion of 'a * UnsizedType.t
     [@@deriving sexp, hash, map, compare, fold]
 
     let pp pp_e ppf = function
@@ -42,6 +43,8 @@ module Fixed = struct
             indices
       | EAnd (l, r) -> Fmt.pf ppf "%a && %a" pp_e l pp_e r
       | EOr (l, r) -> Fmt.pf ppf "%a || %a" pp_e l pp_e r
+      | Promotion (from, ut) ->
+          Fmt.pf ppf "%a -> %a" pp_e from UnsizedType.pp ut
 
     include Foldable.Make (struct
       type nonrec 'a t = 'a t
@@ -146,6 +149,8 @@ module Labelled = struct
         associate ~init:(associate ~init:(associate ~init:assocs e3) e2) e1
     | Indexed (e, idxs) ->
         List.fold idxs ~init:(associate ~init:assocs e) ~f:associate_index
+    (* Not sure?*)
+    | Promotion (e1, _) -> associate ~init:assocs e1
 
   and associate_index assocs = function
     | All -> assocs

src/middle/Expr.mli

@@ -15,6 +15,7 @@ module Fixed : sig
       | EAnd of 'a * 'a
       | EOr of 'a * 'a
       | Indexed of 'a * 'a Index.t list
+      | Promotion of 'a * UnsizedType.t
     [@@deriving sexp, hash, compare]
 
     include Pattern.S with type 'a t := 'a t

src/middle/Stan_math_signatures.ml

@@ -339,6 +339,7 @@ let fst2 (a, _, _) = a
 let thrd (_, _, c) = c
 
 (* -- Querying stan_math_signatures -- *)
+(* TODO: Remove/prefer to use SignatureMismatch instead of UnsizedType *)
 let stan_math_returntype (name : string) (args : fun_arg list) =
   let name = Utils.stdlib_distribution_name name in
   let namematches = Hashtbl.find_multi stan_math_signatures name in
@@ -351,13 +352,12 @@ let stan_math_returntype (name : string) (args : fun_arg list) =
   | x when is_reduce_sum_fn x -> Some (UnsizedType.ReturnType UReal)
   | x when is_variadic_ode_fn x -> Some (UnsizedType.ReturnType (UArray UVector))
   | _ ->
-      if List.length filteredmatches = 0 then None
-        (* Return the least return type in case there are multiple options (due to implicit UInt-UReal conversion), where UInt<UReal *)
-      else
-        Some
-          (List.hd_exn
-             (List.sort ~compare:UnsizedType.compare_returntype
-                (List.map ~f:fst2 filteredmatches) ) )
+      (* Return the least return type in case there are multiple options
+         (due to implicit UInt-UReal conversion), where UInt<UReal
+      *)
+      List.hd
+        (List.sort ~compare:UnsizedType.compare_returntype
+           (List.map ~f:fst2 filteredmatches) )
 
 let is_stan_math_function_name name =
   let name = Utils.stdlib_distribution_name name in

src/stan_math_backend/Expression_gen.ml

@@ -497,6 +497,11 @@ and pp_expr ppf Expr.Fixed.({pattern; meta} as e) =
   | Lit (Str, s) -> pf ppf "\"%s\"" (Cpp_str.escaped s)
   | Lit (Imaginary, s) -> pf ppf "stan::math::to_complex(0, %s)" s
   | Lit ((Real | Int), s) -> pf ppf "%s" s
+  | Promotion (expr, ut) ->
+      if is_scalar expr && ut = UReal then pp_expr ppf expr
+      else
+        pf ppf "stan::math::promote_scalar<%a>(%a)" pp_unsizedtype_local
+          (meta.adlevel, ut) pp_expr expr
   | FunApp
       ( StanLib (op, _, _)
       , [ { meta= {type_= URowVector; _}

test/integration/bad/algebra_solver/stanc.expected

@@ -125,48 +125,6 @@ Available signatures:
  data real, data real) => vector
 where F2 = (vector, vector, data array[] real, data array[] int) => vector
   The 5th argument must be array[] int but got array[] real
-(<F2>, vector, vector, data array[] real, data array[] int) => vector
-  Expected 5 arguments but found 8 arguments.
-  $ ../../../../../install/default/bin/stanc bad_newton_x_r_type.stan
-Semantic error in 'bad_newton_x_r_type.stan', line 31, column 10 to column 69:
-   -------------------------------------------------
-    29:  transformed parameters {
-    30:    vector[2] y_s_p;
-    31:    y_s_p = algebra_solver_newton(algebra_system, y, theta_p, x_r, x_i);
-                   ^
-    32:  }
-    33:  
-   -------------------------------------------------
-
-Ill-typed arguments supplied to function 'algebra_solver_newton':
-(<F1>, vector, vector, array[] int, array[] int)
-where F1 = (vector, vector, array[] real, array[] int) => vector
-Available signatures:
-(<F2>, vector, vector, data array[] real, data array[] int) => vector
-where F2 = (vector, vector, data array[] real, data array[] int) => vector
-  The fourth argument must be array[] real but got array[] int
-(<F2>, vector, vector, data array[] real, data array[] int, data real,
- data real, data real) => vector
-  Expected 8 arguments but found 5 arguments.
-  $ ../../../../../install/default/bin/stanc bad_newton_x_r_type_control.stan
-Semantic error in 'bad_newton_x_r_type_control.stan', line 31, column 10 to column 85:
-   -------------------------------------------------
-    29:  transformed parameters {
-    30:    vector[2] y_s_p;
-    31:    y_s_p = algebra_solver_newton(algebra_system, y, theta_p, x_r, x_i, 0.01, 0.01, 10);
-                   ^
-    32:  }
-    33:  
-   -------------------------------------------------
-
-Ill-typed arguments supplied to function 'algebra_solver_newton':
-(<F1>, vector, vector, array[] int, array[] int, real, real, int)
-where F1 = (vector, vector, array[] real, array[] int) => vector
-Available signatures:
-(<F2>, vector, vector, data array[] real, data array[] int, data real,
- data real, data real) => vector
-where F2 = (vector, vector, data array[] real, data array[] int) => vector
-  The fourth argument must be array[] real but got array[] int
 (<F2>, vector, vector, data array[] real, data array[] int) => vector
   Expected 5 arguments but found 8 arguments.
   $ ../../../../../install/default/bin/stanc bad_newton_x_r_var_type.stan
@@ -371,48 +329,6 @@ Available signatures:
  data real, data real) => vector
 where F2 = (vector, vector, data array[] real, data array[] int) => vector
   The 5th argument must be array[] int but got array[] real
-(<F2>, vector, vector, data array[] real, data array[] int) => vector
-  Expected 5 arguments but found 8 arguments.
-  $ ../../../../../install/default/bin/stanc bad_x_r_type.stan
-Semantic error in 'bad_x_r_type.stan', line 31, column 10 to column 62:
-   -------------------------------------------------
-    29:  transformed parameters {
-    30:    vector[2] y_s_p;
-    31:    y_s_p = algebra_solver(algebra_system, y, theta_p, x_r, x_i);
-                   ^
-    32:  }
-    33:  
-   -------------------------------------------------
-
-Ill-typed arguments supplied to function 'algebra_solver':
-(<F1>, vector, vector, array[] int, array[] int)
-where F1 = (vector, vector, array[] real, array[] int) => vector
-Available signatures:
-(<F2>, vector, vector, data array[] real, data array[] int) => vector
-where F2 = (vector, vector, data array[] real, data array[] int) => vector
-  The fourth argument must be array[] real but got array[] int
-(<F2>, vector, vector, data array[] real, data array[] int, data real,
- data real, data real) => vector
-  Expected 8 arguments but found 5 arguments.
-  $ ../../../../../install/default/bin/stanc bad_x_r_type_control.stan
-Semantic error in 'bad_x_r_type_control.stan', line 31, column 10 to column 78:
-   -------------------------------------------------
-    29:  transformed parameters {
-    30:    vector[2] y_s_p;
-    31:    y_s_p = algebra_solver(algebra_system, y, theta_p, x_r, x_i, 0.01, 0.01, 10);
-                   ^
-    32:  }
-    33:  
-   -------------------------------------------------
-
-Ill-typed arguments supplied to function 'algebra_solver':
-(<F1>, vector, vector, array[] int, array[] int, real, real, int)
-where F1 = (vector, vector, array[] real, array[] int) => vector
-Available signatures:
-(<F2>, vector, vector, data array[] real, data array[] int, data real,
- data real, data real) => vector
-where F2 = (vector, vector, data array[] real, data array[] int) => vector
-  The fourth argument must be array[] real but got array[] int
 (<F2>, vector, vector, data array[] real, data array[] int) => vector
   Expected 5 arguments but found 8 arguments.
   $ ../../../../../install/default/bin/stanc bad_x_r_var_type.stan

test/integration/bad/stanc.expected

@@ -1779,29 +1779,6 @@ Semantic error in 'prob-poisson_log-trunc-low.stan', line 11, column 2 to column
    -------------------------------------------------
 
 Truncation is only defined if distribution has _lcdf and _lccdf functions implemented with appropriate signature.
-  $ ../../../../install/default/bin/stanc propto-bad1.stan
-Semantic error in 'propto-bad1.stan', line 2, column 14 to column 37:
-   -------------------------------------------------
-     1:  model {
-     2:      target += normal_lupdf(1| {0}, 1);
-                       ^
-     3:  }
-   -------------------------------------------------
-
-Ill-typed arguments supplied to function 'normal_lupdf':
-(int, array[] int, int)
-Available signatures:
-(real, real, real) => real
-  The second argument must be real but got array[] int
-(real, real, array[] real) => real
-  The second argument must be real but got array[] int
-(real, real, vector) => real
-  The second argument must be real but got array[] int
-(real, real, row_vector) => real
-  The second argument must be real but got array[] int
-(real, vector, real) => real
-  The second argument must be vector but got array[] int
-(Additional signatures omitted)
   $ ../../../../install/default/bin/stanc real-pdf.stan
 Semantic error in 'real-pdf.stan', line 2, column 2 to line 4, column 3:
    -------------------------------------------------

test/integration/good/code-gen/mir.expected

@@ -251,9 +251,17 @@
                 (((pattern (Var u))
                   (meta
                    ((type_ UReal) (loc <opaque>) (adlevel AutoDiffable))))
-                 ((pattern (Lit Int 0))
+                 ((pattern
+                   (Promotion
+                    ((pattern (Lit Int 0))
+                     (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                    UReal))
                   (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
-                 ((pattern (Lit Int 1))
+                 ((pattern
+                   (Promotion
+                    ((pattern (Lit Int 1))
+                     (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                    UReal))
                   (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
               (meta ((type_ UReal) (loc <opaque>) (adlevel AutoDiffable))))))
            (meta <opaque>))
@@ -4827,7 +4835,11 @@
         (FunApp (StanLib diag_matrix FnPlain AoS)
          (((pattern
             (FunApp (StanLib rep_vector FnPlain AoS)
-             (((pattern (Lit Int 1))
+             (((pattern
+                (Promotion
+                 ((pattern (Lit Int 1))
+                  (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                 UReal))
                (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
               ((pattern
                 (FunApp (StanLib rows FnPlain AoS)
@@ -4843,7 +4855,11 @@
         (FunApp (StanLib diag_matrix FnPlain AoS)
          (((pattern
             (FunApp (StanLib rep_vector FnPlain AoS)
-             (((pattern (Lit Int 1))
+             (((pattern
+                (Promotion
+                 ((pattern (Lit Int 1))
+                  (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                 UReal))
                (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
               ((pattern
                 (FunApp (StanLib rows FnPlain AoS)
@@ -8735,7 +8751,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -8763,7 +8783,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -8813,7 +8837,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -8863,7 +8891,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -10969,7 +11001,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -10997,7 +11033,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -11047,7 +11087,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -11097,7 +11141,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))

test/integration/good/code-gen/promotion.stan

@@ -0,0 +1,16 @@
+functions {
+   complex ident (complex x){
+     return x;
+   }
+
+   real foo(array[] real zs){
+     return zs[0];
+   }
+}
+
+generated quantities {
+   real z = 1;
+   complex zi = ident(z);
+   array[4] int zs = {1,2,3,4};
+   real x = foo(zs);
+}

test/integration/good/code-gen/transformed_mir.expected

@@ -254,9 +254,17 @@
                 (((pattern (Var u))
                   (meta
                    ((type_ UReal) (loc <opaque>) (adlevel AutoDiffable))))
-                 ((pattern (Lit Int 0))
+                 ((pattern
+                   (Promotion
+                    ((pattern (Lit Int 0))
+                     (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                    UReal))
                   (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
-                 ((pattern (Lit Int 1))
+                 ((pattern
+                   (Promotion
+                    ((pattern (Lit Int 1))
+                     (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                    UReal))
                   (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
               (meta ((type_ UReal) (loc <opaque>) (adlevel AutoDiffable))))))
            (meta <opaque>))
@@ -8234,7 +8242,11 @@
         (FunApp (StanLib diag_matrix FnPlain AoS)
          (((pattern
             (FunApp (StanLib rep_vector FnPlain AoS)
-             (((pattern (Lit Int 1))
+             (((pattern
+                (Promotion
+                 ((pattern (Lit Int 1))
+                  (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                 UReal))
                (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
               ((pattern
                 (FunApp (StanLib rows FnPlain AoS)
@@ -8250,7 +8262,11 @@
         (FunApp (StanLib diag_matrix FnPlain AoS)
          (((pattern
             (FunApp (StanLib rep_vector FnPlain AoS)
-             (((pattern (Lit Int 1))
+             (((pattern
+                (Promotion
+                 ((pattern (Lit Int 1))
+                  (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+                 UReal))
                (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
               ((pattern
                 (FunApp (StanLib rows FnPlain AoS)
@@ -12542,7 +12558,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -12570,7 +12590,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -12620,7 +12644,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -12670,7 +12698,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -16218,7 +16250,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -16246,7 +16282,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -16296,7 +16336,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))
@@ -16346,7 +16390,11 @@
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
           ((pattern (Lit Real 0.01))
            (meta ((type_ UReal) (loc <opaque>) (adlevel DataOnly))))
-          ((pattern (Lit Int 10))
+          ((pattern
+            (Promotion
+             ((pattern (Lit Int 10))
+              (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly))))
+             UReal))
            (meta ((type_ UInt) (loc <opaque>) (adlevel DataOnly)))))))
        (meta ((type_ UVector) (loc <opaque>) (adlevel AutoDiffable))))))
     (meta <opaque>))

test/integration/good/parser-generator/complex_scalar.stan → test/integration/good/lang/good_complex.stan

@@ -91,11 +91,10 @@ generated quantities {
   gq_r = foo5(gq_complex_array);
   gq_complex_array = foo6(gq_r);
   gq_complex_array = foo7(gq_complex_array);
-  
+
   // test imaginary literal
   complex zi = 1 + 3.14i;
   zi = zi * 0i;
   complex yi = to_complex(0, 1.1) + to_complex(0.0, 2.2) + to_complex();
   real x = get_real(3i - 40e-3i);
 }
-

test/integration/good/lang/pretty.expected

@@ -1,3 +1,105 @@
+  $ ../../../../../install/default/bin/stanc --auto-format good_complex.stan
+functions {
+  complex foo() {
+    return to_complex();
+  }
+  real foo1(complex z) {
+    return 1.0;
+  }
+  complex foo2(real r) {
+    return to_complex(r);
+  }
+  complex foo3(complex z) {
+    return z;
+  }
+  array[] complex foo4() {
+    return {to_complex(), to_complex()};
+  }
+  real foo5(array[] complex z) {
+    return 1.0;
+  }
+  array[] complex foo6(real r) {
+    return {to_complex(r), to_complex(r, r)};
+  }
+  array[] complex foo7(array[] complex z) {
+    return z;
+  }
+}
+data {
+  int<lower=0> N;
+  complex d_complex;
+  array[N] complex d_complex_array;
+  array[N, 2] complex d_complex_array_2d;
+  array[N, 2, 3] complex d_complex_array_3d;
+}
+transformed data {
+  complex td_complex = d_complex;
+  td_complex = 1;
+  td_complex = to_complex(1, 2);
+  array[N] complex td_complex_array = d_complex_array;
+  array[2, 3] complex td_complex_array_2d;
+  array[2, 3, 4] complex td_complex_array_3d;
+  for (td_i in 1 : 2) {
+    for (td_j in 1 : 3) {
+      for (td_k in 1 : 4) {
+        td_complex_array_3d[td_i, td_j, td_k] = to_complex(1, 2.2);
+      }
+    }
+  }
+  real td_r = get_real(td_complex);
+  real td_i = get_imag(td_complex);
+}
+parameters {
+  complex p_complex;
+  array[N] complex p_complex_array;
+  array[N, 2] complex p_complex_array_2d;
+  array[N, 2, 3] complex p_complex_array_3d;
+}
+transformed parameters {
+  complex tp_complex = p_complex;
+  tp_complex = 1;
+  tp_complex = to_complex(1, 2);
+  array[N] complex tp_complex_array = p_complex_array;
+  array[2, 3] complex tp_complex_array_2d;
+  array[2, 3, 4] complex tp_complex_array_3d;
+  for (tp_i in 1 : 2) {
+    for (tp_j in 1 : 3) {
+      for (tp_k in 1 : 4) {
+        tp_complex_array_3d[tp_i, tp_j, tp_k] = to_complex(1, 2.2);
+      }
+    }
+  }
+  real tp_r = get_real(tp_complex);
+  real tp_i = get_imag(tp_complex);
+}
+model {
+  abs(p_complex) ~ normal(0, 1);
+}
+generated quantities {
+  complex gq_complex;
+  array[2] complex gq_complex_array;
+  array[2, 3] complex gq_complex_array_2d = {{1, 2, 3},
+                                             {to_complex(), to_complex(
+                                              1.1), to_complex(1, 2.1)}};
+  array[2, 3, 4] complex gq_complex_array_3d;
+  gq_complex = 3;
+  gq_complex_array[1] = to_complex(5.1, 6);
+  gq_complex = foo();
+  real gq_r = foo1(gq_complex);
+  gq_complex = foo2(gq_r);
+  gq_complex = foo3(gq_complex);
+  gq_complex_array = foo4();
+  gq_r = foo5(gq_complex_array);
+  gq_complex_array = foo6(gq_r);
+  gq_complex_array = foo7(gq_complex_array);
+
+  // test imaginary literal
+  complex zi = 1 + 3.14i;
+  zi = zi * 0i;
+  complex yi = to_complex(0, 1.1) + to_complex(0.0, 2.2) + to_complex();
+  real x = get_real(3i - 40e-3i);
+}
+
   $ ../../../../../install/default/bin/stanc --auto-format good_const.stan
 transformed data {
   real y;

test/integration/good/parser-generator/pretty.expected

@@ -60,108 +60,6 @@ transformed parameters {
   cholesky_factor_cov[3] cfcov_33;
 }
 
-  $ ../../../../../install/default/bin/stanc --auto-format complex_scalar.stan
-functions {
-  complex foo() {
-    return to_complex();
-  }
-  real foo1(complex z) {
-    return 1.0;
-  }
-  complex foo2(real r) {
-    return to_complex(r);
-  }
-  complex foo3(complex z) {
-    return z;
-  }
-  array[] complex foo4() {
-    return {to_complex(), to_complex()};
-  }
-  real foo5(array[] complex z) {
-    return 1.0;
-  }
-  array[] complex foo6(real r) {
-    return {to_complex(r), to_complex(r, r)};
-  }
-  array[] complex foo7(array[] complex z) {
-    return z;
-  }
-}
-data {
-  int<lower=0> N;
-  complex d_complex;
-  array[N] complex d_complex_array;
-  array[N, 2] complex d_complex_array_2d;
-  array[N, 2, 3] complex d_complex_array_3d;
-}
-transformed data {
-  complex td_complex = d_complex;
-  td_complex = 1;
-  td_complex = to_complex(1, 2);
-  array[N] complex td_complex_array = d_complex_array;
-  array[2, 3] complex td_complex_array_2d;
-  array[2, 3, 4] complex td_complex_array_3d;
-  for (td_i in 1 : 2) {
-    for (td_j in 1 : 3) {
-      for (td_k in 1 : 4) {
-        td_complex_array_3d[td_i, td_j, td_k] = to_complex(1, 2.2);
-      }
-    }
-  }
-  real td_r = get_real(td_complex);
-  real td_i = get_imag(td_complex);
-}
-parameters {
-  complex p_complex;
-  array[N] complex p_complex_array;
-  array[N, 2] complex p_complex_array_2d;
-  array[N, 2, 3] complex p_complex_array_3d;
-}
-transformed parameters {
-  complex tp_complex = p_complex;
-  tp_complex = 1;
-  tp_complex = to_complex(1, 2);
-  array[N] complex tp_complex_array = p_complex_array;
-  array[2, 3] complex tp_complex_array_2d;
-  array[2, 3, 4] complex tp_complex_array_3d;
-  for (tp_i in 1 : 2) {
-    for (tp_j in 1 : 3) {
-      for (tp_k in 1 : 4) {
-        tp_complex_array_3d[tp_i, tp_j, tp_k] = to_complex(1, 2.2);
-      }
-    }
-  }
-  real tp_r = get_real(tp_complex);
-  real tp_i = get_imag(tp_complex);
-}
-model {
-  abs(p_complex) ~ normal(0, 1);
-}
-generated quantities {
-  complex gq_complex;
-  array[2] complex gq_complex_array;
-  array[2, 3] complex gq_complex_array_2d = {{1, 2, 3},
-                                             {to_complex(), to_complex(
-                                              1.1), to_complex(1, 2.1)}};
-  array[2, 3, 4] complex gq_complex_array_3d;
-  gq_complex = 3;
-  gq_complex_array[1] = to_complex(5.1, 6);
-  gq_complex = foo();
-  real gq_r = foo1(gq_complex);
-  gq_complex = foo2(gq_r);
-  gq_complex = foo3(gq_complex);
-  gq_complex_array = foo4();
-  gq_r = foo5(gq_complex_array);
-  gq_complex_array = foo6(gq_r);
-  gq_complex_array = foo7(gq_complex_array);
-
-  // test imaginary literal
-  complex zi = 1 + 3.14i;
-  zi = zi * 0i;
-  complex yi = to_complex(0, 1.1) + to_complex(0.0, 2.2) + to_complex();
-  real x = get_real(3i - 40e-3i);
-}
-
   $ ../../../../../install/default/bin/stanc --auto-format data_qualifier_scope_xformed_data.stan
 functions {
   vector target_(vector y, vector theta, array[] real x_r, array[] int x_i) {

test/integration/good/promotion/array_promotion.stan

@@ -0,0 +1,10 @@
+functions {
+   void printer(array[] real x){
+     print(x);
+   }
+}
+
+model {
+  array[3] int d = {1,2,3};
+  printer(d);
+}

test/integration/good/promotion/complex_functions.stan

@@ -0,0 +1,32 @@
+functions {
+   void promote_complex_array(array[] complex zs){
+      print(zs[0]);
+   }
+}
+
+generated quantities {
+   real x = norm(1);
+   x = norm(1.5);
+   x = norm(3i);
+
+   real y = abs(4+3i);
+   y = arg(4+1i);
+   y = arg(2.5);
+   y = arg(1);
+
+   complex z;
+   z = conj(4.1+7i);
+   z = conj(4.1);
+   z = conj(0);
+
+   z = proj(4.1+7i);
+   z = proj(4.1);
+   z = proj(0);
+
+   z = polar(1.5,0.5);
+   z = polar(2,3);
+
+   array[3] int xs = {1,2,3};
+   promote_complex_array(xs);
+
+}

test/integration/good/promotion/dune

@@ -0,0 +1 @@
+(include ../dune)

test/integration/good/promotion/pretty.expected

@@ -0,0 +1,170 @@
+  $ ../../../../../install/default/bin/stanc --auto-format array_promotion.stan
+functions {
+  void printer(array[] real x) {
+    print(x);
+  }
+}
+model {
+  array[3] int d = {1, 2, 3};
+  printer(d);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format bad_newton_x_r_type.stan
+functions {
+  vector algebra_system(vector y, vector theta, array[] real x_r,
+                        array[] int x_i) {
+    vector[2] f_y;
+    f_y[1] = y[1] - theta[1];
+    f_y[2] = y[2] - theta[2];
+    return f_y;
+  }
+}
+data {
+
+}
+transformed data {
+  vector[2] y;
+  array[0] int x_r;
+  array[0] int x_i;
+}
+parameters {
+  vector[2] theta_p;
+  real dummy_parameter;
+}
+transformed parameters {
+  vector[2] y_s_p;
+  y_s_p = algebra_solver_newton(algebra_system, y, theta_p, x_r, x_i);
+}
+model {
+  dummy_parameter ~ normal(0, 1);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format bad_newton_x_r_type_control.stan
+functions {
+  vector algebra_system(vector y, vector theta, array[] real x_r,
+                        array[] int x_i) {
+    vector[2] f_y;
+    f_y[1] = y[1] - theta[1];
+    f_y[2] = y[2] - theta[2];
+    return f_y;
+  }
+}
+data {
+
+}
+transformed data {
+  vector[2] y;
+  array[0] int x_r;
+  array[0] int x_i;
+}
+parameters {
+  vector[2] theta_p;
+  real dummy_parameter;
+}
+transformed parameters {
+  vector[2] y_s_p;
+  y_s_p = algebra_solver_newton(algebra_system, y, theta_p, x_r, x_i, 0.01,
+                                0.01, 10);
+}
+model {
+  dummy_parameter ~ normal(0, 1);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format bad_x_r_type.stan
+functions {
+  vector algebra_system(vector y, vector theta, array[] real x_r,
+                        array[] int x_i) {
+    vector[2] f_y;
+    f_y[1] = y[1] - theta[1];
+    f_y[2] = y[2] - theta[2];
+    return f_y;
+  }
+}
+data {
+
+}
+transformed data {
+  vector[2] y;
+  array[0] int x_r;
+  array[0] int x_i;
+}
+parameters {
+  vector[2] theta_p;
+  real dummy_parameter;
+}
+transformed parameters {
+  vector[2] y_s_p;
+  y_s_p = algebra_solver(algebra_system, y, theta_p, x_r, x_i);
+}
+model {
+  dummy_parameter ~ normal(0, 1);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format bad_x_r_type_control.stan
+functions {
+  vector algebra_system(vector y, vector theta, array[] real x_r,
+                        array[] int x_i) {
+    vector[2] f_y;
+    f_y[1] = y[1] - theta[1];
+    f_y[2] = y[2] - theta[2];
+    return f_y;
+  }
+}
+data {
+
+}
+transformed data {
+  vector[2] y;
+  array[0] int x_r;
+  array[0] int x_i;
+}
+parameters {
+  vector[2] theta_p;
+  real dummy_parameter;
+}
+transformed parameters {
+  vector[2] y_s_p;
+  y_s_p = algebra_solver(algebra_system, y, theta_p, x_r, x_i, 0.01, 0.01,
+                         10);
+}
+model {
+  dummy_parameter ~ normal(0, 1);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format complex_functions.stan
+functions {
+  void promote_complex_array(array[] complex zs) {
+    print(zs[0]);
+  }
+}
+generated quantities {
+  real x = norm(1);
+  x = norm(1.5);
+  x = norm(3i);
+
+  real y = abs(4 + 3i);
+  y = arg(4 + 1i);
+  y = arg(2.5);
+  y = arg(1);
+
+  complex z;
+  z = conj(4.1 + 7i);
+  z = conj(4.1);
+  z = conj(0);
+
+  z = proj(4.1 + 7i);
+  z = proj(4.1);
+  z = proj(0);
+
+  z = polar(1.5, 0.5);
+  z = polar(2, 3);
+
+  array[3] int xs = {1, 2, 3};
+  promote_complex_array(xs);
+}
+
+  $ ../../../../../install/default/bin/stanc --auto-format propto-bad1.stan
+model {
+  target += normal_lupdf(1 | {0}, 1);
+}
+

test/unit/Optimize.ml

@@ -1964,7 +1964,7 @@ let%expect_test "partial evaluation" =
             int i;
             FnPrint__(3);
             FnPrint__((i + 3));
-            FnPrint__(log1m(i));
+            FnPrint__(log((1 - i) -> real));
           }
         }
       }
@@ -2360,7 +2360,7 @@ model {
           target += sqrt(34.);
           target += sqrt(34.);
           target += variance(x_vector);
-          target += sqrt2();
+          target += sqrt(2 -> real);
           target += squared_distance(x_vector, y_vector);
           target += trace(x_matrix);
           target += trace_gen_quad_form(x_matrix, z_matrix, y_matrix);