chore(kernel/error_msgs): change type mismatch error messages, closes #33

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/kernel/error_msgs.cpp

@@ -55,10 +55,10 @@ format pp_app_type_mismatch(formatter const & fmt, expr const & app, expr const
     r += pp_indent_expr(fmt, app);
     r += compose(line(), format("term"));
     r += pp_indent_expr(fmt, arg);
-    r += compose(line(), format("is expected of type"));
-    r += expected_fmt;
-    r += compose(line(), format("but is given type"));
+    r += compose(line(), format("has type"));
     r += given_fmt;
+    r += compose(line(), format("but is expected to have type"));
+    r += expected_fmt;
     return r;
 }
 
@@ -67,10 +67,10 @@ format pp_def_type_mismatch(formatter const & fmt, name const & n, expr const &
     std::tie(expected_fmt, given_fmt) = pp_until_different(fmt, expected_type, given_type);
     format r("type mismatch at definition '");
     r += format(n);
-    r += format("', it is expected of type");
-    r += expected_fmt;
-    r += compose(line(), format("but is given type"));
+    r += format("', has type");
     r += given_fmt;
+    r += compose(line(), format("but is expected to have type"));
+    r += expected_fmt;
     return r;
 }
 

src/library/unifier.cpp

@@ -496,10 +496,10 @@ struct unifier_fn {
                 }
                 format expected_fmt, given_fmt;
                 std::tie(expected_fmt, given_fmt) = pp_until_different(fmt, m_type, v_type);
-                r += compose(line(), format("placeholder is expected of type"));
-                r += expected_fmt;
-                r += compose(line(), format("but is given type"));
+                r += compose(line(), format("placeholder has type"));
                 r += given_fmt;
+                r += compose(line(), format("but is expected to have type"));
+                r += expected_fmt;
                 r += compose(line(), format("the assignment was attempted when trying to solve"));
                 r += nest(2*get_pp_indent(fmt.get_options()), compose(line(), j.pp(fmt, nullptr, subst)));
                 return r;

tests/lean/bug1.lean.expected.out

@@ -1,19 +1,19 @@
-bug1.lean:9:7: error: type mismatch at definition 'and_intro', it is expected of type
+bug1.lean:9:7: error: type mismatch at definition 'and_intro', has type
+  ∀ (p q : bool),
+    p → q → (∀ (c : bool), (p → q → c) → c)
+but is expected to have type
   ∀ (p q : bool),
     p → q → a
-but is given type
+bug1.lean:13:7: error: type mismatch at definition 'and_intro', has type
   ∀ (p q : bool),
     p → q → (∀ (c : bool), (p → q → c) → c)
-bug1.lean:13:7: error: type mismatch at definition 'and_intro', it is expected of type
+but is expected to have type
   ∀ (p q : bool),
     p → q → and p p
-but is given type
+bug1.lean:17:7: error: type mismatch at definition 'and_intro', has type
   ∀ (p q : bool),
     p → q → (∀ (c : bool), (p → q → c) → c)
-bug1.lean:17:7: error: type mismatch at definition 'and_intro', it is expected of type
+but is expected to have type
   ∀ (p q : bool),
     p → q → and q p
-but is given type
-  ∀ (p q : bool),
-    p → q → (∀ (c : bool), (p → q → c) → c)
 and_intro : ∀ (p q : bool), p → q → and p q

tests/lean/crash.lean.expected.out

@@ -3,7 +3,7 @@ crash.lean:8:12: error: type mismatch at application
   ?M_1
 term
   H
-is expected of type
-  not P
-but is given type
+has type
   P
+but is expected to have type
+  not P

tests/lean/empty.lean.expected.out

@@ -1,9 +1,9 @@
 empty.lean:5:25: error: type error in placeholder assigned to
   inhabited_Prop
-placeholder is expected of type
-  inhabited ?M_1
-but is given type
+placeholder has type
   inhabited Prop
+but is expected to have type
+  inhabited ?M_1
 the assignment was attempted when trying to solve
     failed to synthesize placeholder
      ⊢ inhabited Empty

tests/lean/let1.lean.expected.out

@@ -30,9 +30,9 @@ let1.lean:16:10: error: type mismatch at application
 term
   λ (p q : Prop) (H1 : p) (H2 : q) (c : Prop) (H : p → q → c),
     H H1 H2
-is expected of type
-  ∀ (p q : Prop),
-    p → q → (λ (p q : Prop), ∀ (c : Prop), (p → q → c) → c) q p
-but is given type
+has type
   ∀ (p q : Prop),
     p → q → (∀ (c : Prop), (p → q → c) → c)
+but is expected to have type
+  ∀ (p q : Prop),
+    p → q → (λ (p q : Prop), ∀ (c : Prop), (p → q → c) → c) q p

tests/lean/t10.lean.expected.out

@@ -3,10 +3,10 @@ t10.lean:14:6: error: type mismatch at application
   ite (and p q) q
 term
   q
-is expected of type
-  N
-but is given type
+has type
   B
+but is expected to have type
+  N
 cons x (cons y (cons z (cons x (cons y (cons y nil))))) : list
 cons x nil : list
 nil : list