fix(frontends/lean/scanner): fixes #626

src/frontends/lean/scanner.cpp

@@ -61,9 +61,12 @@ bool is_letter_like_unicode(unsigned u) {
 }
 bool is_super_sub_script_alnum_unicode(unsigned u) {
     return
-        (0x2070 <= u && u <= 0x2079) ||
-        (0x207f <= u && u <= 0x2089) ||
-        (0x2090 <= u && u <= 0x209c);
+        (0x2070 <= u && u <= 0x2079) || // most (numeric) superscripts
+        (0x207f <= u && u <= 0x2089) || // n superscript and numberic subscripts
+        (0x2090 <= u && u <= 0x209c) || // letter-like subscripts
+        u == 0x00B2 ||  // 2 superscript
+        u == 0x00B3 ||  // 3 superscript
+        u == 0x00B9;    // 1 superscript
 }
 
 void scanner::next() {

tests/lean/626a.lean

@@ -0,0 +1,9 @@
+namespace foo
+  definition C¹ := nat
+  definition foo (c : C¹) := nat.rec_on c _ _
+end foo
+
+namespace boo
+  notation `C¹` := nat
+  definition foo (c : C¹) := nat.rec_on c _ _
+end boo

tests/lean/626a.lean.expected.out

@@ -0,0 +1,28 @@
+626a.lean:3:29: error: don't know how to synthesize placeholder
+c : C¹
+⊢ nat → Type
+626a.lean:3:42: error: don't know how to synthesize placeholder
+c : C¹
+⊢ ?M_1
+626a.lean:3:44: error: don't know how to synthesize placeholder
+c : C¹
+⊢ Π (a : nat),
+    ?M_1 → ?M_1
+626a.lean:3:29: error: failed to add declaration 'foo.foo' to environment, value has metavariables
+remark: set 'formatter.hide_full_terms' to false to see the complete term
+  λ (c : C¹),
+    nat.rec_on c ?M_2 ?M_3
+626a.lean:8:29: error: don't know how to synthesize placeholder
+c : C¹
+⊢ C¹ → Type
+626a.lean:8:42: error: don't know how to synthesize placeholder
+c : C¹
+⊢ ?M_1
+626a.lean:8:44: error: don't know how to synthesize placeholder
+c : C¹
+⊢ Π (a : C¹),
+    ?M_1 → ?M_1
+626a.lean:8:29: error: failed to add declaration 'boo.foo' to environment, value has metavariables
+remark: set 'formatter.hide_full_terms' to false to see the complete term
+  λ (c : C¹),
+    nat.rec_on c ?M_2 ?M_3

tests/lean/626b.hlean

@@ -0,0 +1,4 @@
+import hit.circle
+open circle
+
+definition f (x : S¹) : bool := circle.rec_on x _ _

tests/lean/626b.hlean.expected.out

@@ -0,0 +1,10 @@
+626b.hlean:4:48: error: don't know how to synthesize placeholder
+x : S¹
+⊢ bool
+626b.hlean:4:50: error: don't know how to synthesize placeholder
+x : S¹
+⊢ eq.transport (λ (a : S¹), bool) loop ?M_1 = ?M_1
+626b.hlean:4:32: error: failed to add declaration 'f' to environment, value has metavariables
+remark: set 'formatter.hide_full_terms' to false to see the complete term
+  λ (x : S¹),
+    circle.rec_on x ?M_1 ?M_2