switch to env.mem

Author: adamhaber

src/frontend/Typechecker.ml

@@ -405,12 +405,10 @@ let check_fn ~is_cond_dist loc tenv id es =
             List.mem known_families s ~equal:String.equal
           in
           match suffix with
-          | ("lpmf" | "lumpf")
-            when Utils.is_distribution_name (prefix ^ "_lpdf") ->
+          | ("lpmf" | "lumpf") when Env.mem tenv (prefix ^ "_lpdf") ->
               Semantic_error.returning_fn_expected_wrong_dist_suffix_found loc
                 (prefix, suffix)
-          | ("lpdf" | "lumdf")
-            when Utils.is_distribution_name (prefix ^ "_lpmf") ->
+          | ("lpdf" | "lumdf") when Env.mem tenv (prefix ^ "_lpmf") ->
               Semantic_error.returning_fn_expected_wrong_dist_suffix_found loc
                 (prefix, suffix)
           | _ ->

test/integration/bad/missing_dist_suffix/completely_undefined1.stan

@@ -0,0 +1,3 @@
+model {
+  target += foo_lpdf(1);
+}

test/integration/bad/missing_dist_suffix/completely_undefined2.stan

@@ -0,0 +1,6 @@
+data {
+   int foo_lpmf;
+}
+model {
+  target += foo_lpdf(1);
+}

test/integration/bad/missing_dist_suffix/stanc.expected

@@ -1,3 +1,24 @@
+  $ ../../../../../install/default/bin/stanc completely_undefined1.stan
+Semantic error in 'completely_undefined1.stan', line 2, column 12 to column 23:
+   -------------------------------------------------
+     1:  model {
+     2:    target += foo_lpdf(1);
+                     ^
+     3:  }
+   -------------------------------------------------
+
+A returning function was expected but an undeclared identifier 'foo_lpdf' was supplied.
+  $ ../../../../../install/default/bin/stanc completely_undefined2.stan
+Semantic error in 'completely_undefined2.stan', line 5, column 12 to column 23:
+   -------------------------------------------------
+     3:  }
+     4:  model {
+     5:    target += foo_lpdf(1);
+                     ^
+     6:  }
+   -------------------------------------------------
+
+Function 'foo_lpdf' is not implemented for distribution 'foo', use 'foo_lpmf' instead.
   $ ../../../../../install/default/bin/stanc deprecated_suffix.stan
 Semantic error in 'deprecated_suffix.stan', line 4, column 14 to column 40:
    -------------------------------------------------