Better error messages for incomplete probability calls

src/frontend/Semantic_check.ml

@@ -290,9 +290,45 @@ let semantic_check_fn_normal ~is_cond_dist ~loc id es =
     | Some _ ->
         (* Check that Funaps are actually functions *)
         Semantic_error.returning_fn_expected_nonfn_found loc id.name |> error
-    | None ->
-        Semantic_error.returning_fn_expected_undeclaredident_found loc id.name
-        |> error)
+    | None -> (
+        let gen_prefix l = String.concat ~sep:"_" (List.rev l) in
+        match List.rev (String.split id.name ~on:'_') with
+        | (("lpmf" | "lupmf") as suffix) :: tl
+          when Utils.is_distribution_name
+                 (String.concat ~sep:"_" (List.rev tl @ ["lpdf"])) ->
+            Semantic_error.returning_fn_expected_wrong_dist_suffix_found loc
+              (gen_prefix tl, suffix)
+            |> error
+        | (("lpdf" | "lupdf") as suffix) :: tl
+          when Utils.is_distribution_name
+                 (String.concat ~sep:"_" (List.rev tl @ ["lpmf"])) ->
+            Semantic_error.returning_fn_expected_wrong_dist_suffix_found loc
+              (gen_prefix tl, suffix)
+            |> error
+        | suffix :: tl
+          when List.mem Utils.cumulative_distribution_suffices_w_rng suffix
+                 ~equal:String.equal ->
+            let prefix = gen_prefix tl in
+            let known_families =
+              List.map
+                ~f:(fun (_, y, _, _) -> y)
+                Stan_math_signatures.distributions
+            in
+            let is_known_family s =
+              List.mem known_families s ~equal:String.equal
+            in
+            if is_known_family prefix then
+              Semantic_error.returning_fn_expected_undeclared_dist_suffix_found
+                loc (prefix, suffix)
+              |> error
+            else
+              Semantic_error.returning_fn_expected_undeclaredident_found loc
+                id.name
+              |> error
+        | _ ->
+            Semantic_error.returning_fn_expected_undeclaredident_found loc
+              id.name
+            |> error ))
 
 (* Stan-Math function application *)
 let semantic_check_fn_stan_math ~is_cond_dist ~loc id es =

src/middle/Semantic_error.ml

@@ -33,6 +33,8 @@ module TypeError = struct
     | ReturningFnExpectedNonReturningFound of string
     | ReturningFnExpectedNonFnFound of string
     | ReturningFnExpectedUndeclaredIdentFound of string
+    | ReturningFnExpectedUndeclaredDistSuffixFound of string * string
+    | ReturningFnExpectedWrongDistSuffixFound of string * string
     | NonReturningFnExpectedReturningFound of string
     | NonReturningFnExpectedNonFnFound of string
     | NonReturningFnExpectedUndeclaredIdentFound of string
@@ -168,6 +170,22 @@ module TypeError = struct
           "A returning function was expected but an undeclared identifier \
            '%s' was supplied."
           fn_name
+    | ReturningFnExpectedUndeclaredDistSuffixFound (prefix, suffix) ->
+        Fmt.pf ppf "Function '%s_%s' is not implemented for distribution '%s'."
+          prefix suffix prefix
+    | ReturningFnExpectedWrongDistSuffixFound (prefix, suffix) ->
+        let newsuffix =
+          match suffix with
+          | "lpdf" -> "lpmf"
+          | "lupdf" -> "lupmf"
+          | "lpmf" -> "lpdf"
+          | "lupmf" -> "lupdf"
+          | _ -> raise_s [%message "This should never happen."]
+        in
+        Fmt.pf ppf
+          "Function '%s_%s' is not implemented for distribution '%s', use \
+           '%s_%s' instead."
+          prefix suffix prefix prefix newsuffix
     | NonReturningFnExpectedUndeclaredIdentFound fn_name ->
         Fmt.pf ppf
           "A non-returning function was expected but an undeclared identifier \
@@ -496,6 +514,16 @@ let returning_fn_expected_nonfn_found loc name =
 let returning_fn_expected_undeclaredident_found loc name =
   TypeError (loc, TypeError.ReturningFnExpectedUndeclaredIdentFound name)
 
+let returning_fn_expected_undeclared_dist_suffix_found loc (prefix, suffix) =
+  TypeError
+    ( loc
+    , TypeError.ReturningFnExpectedUndeclaredDistSuffixFound (prefix, suffix)
+    )
+
+let returning_fn_expected_wrong_dist_suffix_found loc (prefix, suffix) =
+  TypeError
+    (loc, TypeError.ReturningFnExpectedWrongDistSuffixFound (prefix, suffix))
+
 let nonreturning_fn_expected_returning_found loc name =
   TypeError (loc, TypeError.NonReturningFnExpectedReturningFound name)
 

src/middle/Semantic_error.mli

@@ -34,6 +34,12 @@ val returning_fn_expected_nonfn_found : Location_span.t -> string -> t
 val returning_fn_expected_undeclaredident_found :
   Location_span.t -> string -> t
 
+val returning_fn_expected_undeclared_dist_suffix_found :
+  Location_span.t -> string * string -> t
+
+val returning_fn_expected_wrong_dist_suffix_found :
+  Location_span.t -> string * string -> t
+
 val illtyped_reduce_sum :
      Location_span.t
   -> string

src/middle/Utils.ml

@@ -12,6 +12,11 @@ let conditioning_suffices =
   ["_lpdf"; "_lupdf"; "_lupmf"; "_lpmf"; "_cdf"; "_lcdf"; "_lccdf"]
 
 let conditioning_suffices_w_log = conditioning_suffices @ ["_log"]
+let cumulative_distribution_suffices = ["cdf"; "lcdf"; "lccdf"]
+
+let cumulative_distribution_suffices_w_rng =
+  cumulative_distribution_suffices @ ["rng"]
+
 let is_user_ident = Fn.non (String.is_suffix ~suffix:"__")
 
 let unnormalized_suffix = function

test/integration/bad/missing_dist_suffix/deprecated_suffix.stan

@@ -0,0 +1,5 @@
+data {
+}
+model {
+    target += von_mises_ccdf_log(1, 0,1);
+}

test/integration/bad/missing_dist_suffix/dune

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

test/integration/bad/missing_dist_suffix/lpmf_lpdf_replacement1.stan

@@ -0,0 +1,6 @@
+data { 
+}
+model {  
+    // known family, known suffix, not implemented  
+    target += binomial_lpdf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/lpmf_lpdf_replacement2.stan

@@ -0,0 +1,6 @@
+data { 
+}
+model {  
+    // known family, known suffix, not implemented  
+    target += normal_lpmf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/no_rng_suffix.stan

@@ -0,0 +1,3 @@
+generated quantities {
+   real x = multi_gp_cholesky_rng([[0,0],[0,0]], [1,0]);
+}

test/integration/bad/missing_dist_suffix/non_existing_distribution_suffix1.stan

@@ -0,0 +1,5 @@
+data { 
+}
+model {  
+    target += von_mises_cdf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/non_existing_distribution_suffix2.stan

@@ -0,0 +1,5 @@
+data { 
+}
+model {  
+    target += von_mises_lcdf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/non_existing_distribution_suffix3.stan

@@ -0,0 +1,5 @@
+data { 
+}
+model {  
+    target += von_mises_lccdf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/non_existing_distribution_suffix4.stan

@@ -0,0 +1,5 @@
+data { 
+}
+model {  
+    target += von_mises_notasuffix(1,0,1);
+}

test/integration/bad/missing_dist_suffix/stanc.expected

@@ -0,0 +1,120 @@
+  $ ../../../../../install/default/bin/stanc deprecated_suffix.stan
+Semantic error in 'deprecated_suffix.stan', line 4, column 14 to column 40:
+   -------------------------------------------------
+     2:  }
+     3:  model {
+     4:      target += von_mises_ccdf_log(1, 0,1);
+                       ^
+     5:  }
+   -------------------------------------------------
+
+A returning function was expected but an undeclared identifier 'von_mises_ccdf_log' was supplied.
+  $ ../../../../../install/default/bin/stanc lpmf_lpdf_replacement1.stan
+Semantic error in 'lpmf_lpdf_replacement1.stan', line 5, column 14 to column 34:
+   -------------------------------------------------
+     3:  model {  
+     4:      // known family, known suffix, not implemented  
+     5:      target += binomial_lpdf(1|0,1);
+                       ^
+     6:  }
+   -------------------------------------------------
+
+Function 'binomial_lpdf' is not implemented for distribution 'binomial', use 'binomial_lpmf' instead.
+  $ ../../../../../install/default/bin/stanc lpmf_lpdf_replacement2.stan
+Semantic error in 'lpmf_lpdf_replacement2.stan', line 5, column 14 to column 32:
+   -------------------------------------------------
+     3:  model {  
+     4:      // known family, known suffix, not implemented  
+     5:      target += normal_lpmf(1|0,1);
+                       ^
+     6:  }
+   -------------------------------------------------
+
+Function 'normal_lpmf' is not implemented for distribution 'normal', use 'normal_lpdf' instead.
+  $ ../../../../../install/default/bin/stanc no_rng_suffix.stan
+Semantic error in 'no_rng_suffix.stan', line 2, column 12 to column 55:
+   -------------------------------------------------
+     1:  generated quantities {
+     2:     real x = multi_gp_cholesky_rng([[0,0],[0,0]], [1,0]);
+                     ^
+     3:  }
+   -------------------------------------------------
+
+Function 'multi_gp_cholesky_rng' is not implemented for distribution 'multi_gp_cholesky'.
+  $ ../../../../../install/default/bin/stanc non_existing_distribution_suffix1.stan
+Semantic error in 'non_existing_distribution_suffix1.stan', line 4, column 14 to column 34:
+   -------------------------------------------------
+     2:  }
+     3:  model {  
+     4:      target += von_mises_cdf(1|0,1);
+                       ^
+     5:  }
+   -------------------------------------------------
+
+Function 'von_mises_cdf' is not implemented for distribution 'von_mises'.
+  $ ../../../../../install/default/bin/stanc non_existing_distribution_suffix2.stan
+Semantic error in 'non_existing_distribution_suffix2.stan', line 4, column 14 to column 35:
+   -------------------------------------------------
+     2:  }
+     3:  model {  
+     4:      target += von_mises_lcdf(1|0,1);
+                       ^
+     5:  }
+   -------------------------------------------------
+
+Function 'von_mises_lcdf' is not implemented for distribution 'von_mises'.
+  $ ../../../../../install/default/bin/stanc non_existing_distribution_suffix3.stan
+Semantic error in 'non_existing_distribution_suffix3.stan', line 4, column 14 to column 36:
+   -------------------------------------------------
+     2:  }
+     3:  model {  
+     4:      target += von_mises_lccdf(1|0,1);
+                       ^
+     5:  }
+   -------------------------------------------------
+
+Function 'von_mises_lccdf' is not implemented for distribution 'von_mises'.
+  $ ../../../../../install/default/bin/stanc non_existing_distribution_suffix4.stan
+Semantic error in 'non_existing_distribution_suffix4.stan', line 4, column 14 to column 41:
+   -------------------------------------------------
+     2:  }
+     3:  model {  
+     4:      target += von_mises_notasuffix(1,0,1);
+                       ^
+     5:  }
+   -------------------------------------------------
+
+A returning function was expected but an undeclared identifier 'von_mises_notasuffix' was supplied.
+  $ ../../../../../install/default/bin/stanc user_defined.stan
+Semantic error in 'user_defined.stan', line 7, column 13 to column 27:
+   -------------------------------------------------
+     5:  }
+     6:  model {
+     7:     target += bar_lpmf(19.2);
+                      ^
+     8:  }
+   -------------------------------------------------
+
+Function 'bar_lpmf' is not implemented for distribution 'bar', use 'bar_lpdf' instead.
+  $ ../../../../../install/default/bin/stanc user_defined_no_cdf.stan
+Semantic error in 'user_defined_no_cdf.stan', line 7, column 14 to column 29:
+   -------------------------------------------------
+     5:  }
+     6:  model {
+     7:      target += bar_lcdf(1|0,1);
+                       ^
+     8:  }
+   -------------------------------------------------
+
+A returning function was expected but an undeclared identifier 'bar_lcdf' was supplied.
+  $ ../../../../../install/default/bin/stanc user_defined_no_rng.stan
+Semantic error in 'user_defined_no_rng.stan', line 7, column 12 to column 23:
+   -------------------------------------------------
+     5:  }
+     6:  generated quantities {
+     7:     real x = bar_rng(10);
+                     ^
+     8:  }
+   -------------------------------------------------
+
+A returning function was expected but an undeclared identifier 'bar_rng' was supplied.

test/integration/bad/missing_dist_suffix/user_defined.stan

@@ -0,0 +1,8 @@
+functions {
+   real bar_lpdf(real x){
+     return 1.0;
+   }
+}
+model {
+   target += bar_lpmf(19.2);
+}

test/integration/bad/missing_dist_suffix/user_defined_no_cdf.stan

@@ -0,0 +1,8 @@
+functions {
+   real bar_lpdf(real x){
+     return 1.0;
+   }
+}
+model {
+    target += bar_lcdf(1|0,1);
+}

test/integration/bad/missing_dist_suffix/user_defined_no_rng.stan

@@ -0,0 +1,8 @@
+functions {
+   real bar_lpdf(real x){
+     return 1.0;
+   }
+}
+generated quantities {
+   real x = bar_rng(10);
+}

test/integration/tfp/stan_models/test_mat_corr.stan

@@ -0,0 +1,9 @@
+data {
+  int K;
+}
+parameters {
+  cholesky_factor_corr[K] L;
+}
+model {
+   target += lkj_corr_cholesky_lpdf(L|2.5);
+}