internal: more focused tests for const arguments

Author: matklad

crates/parser/src/grammar/generic_args.rs

@@ -23,25 +23,29 @@ pub(super) fn opt_generic_arg_list(p: &mut Parser, colon_colon_required: bool) {
     m.complete(p, GENERIC_ARG_LIST);
 }
 
-// test type_arg
-// type A = B<'static, i32, 1, { 2 }, Item=u64, true, false>;
+// test generic_arg
+// type T = S<i32>;
 fn generic_arg(p: &mut Parser) {
     match p.current() {
         LIFETIME_IDENT => lifetime_arg(p),
+        T!['{'] | T![true] | T![false] | T![-] => const_arg(p),
+        k if k.is_literal() => const_arg(p),
         // test associated_type_bounds
         // fn print_all<T: Iterator<Item, Item::Item, Item::<true>, Item: Display, Item<'a> = Item>>(printables: T) {}
         IDENT if [T![<], T![=], T![:]].contains(&p.nth(1)) => {
             let m = p.start();
             name_ref(p);
             opt_generic_arg_list(p, false);
             match p.current() {
-                // NameRef<...> =
+                // test assoc_type_eq
+                // type T = StreamingIterator<Item<'a> = &'a T>;
                 T![=] => {
                     p.bump_any();
                     types::type_(p);
                     m.complete(p, ASSOC_TYPE_ARG);
                 }
-                // NameRef<...>:
+                // test assoc_type_bound
+                // type T = StreamingIterator<Item<'a>: Clone>;
                 T![:] if !p.at(T![::]) => {
                     generic_params::bounds(p);
                     m.complete(p, ASSOC_TYPE_ARG);
@@ -53,42 +57,52 @@ fn generic_arg(p: &mut Parser) {
                 }
             }
         }
-        // test const_generic_negated_literal
-        // fn f() { S::<-1> }
-        T!['{'] | T![true] | T![false] | T![-] => const_arg(p),
-        k if k.is_literal() => const_arg(p),
         _ => type_arg(p),
     }
 }
 
+// test lifetime_arg
+// type T = S<'static>;
 fn lifetime_arg(p: &mut Parser) {
     let m = p.start();
     lifetime(p);
     m.complete(p, LIFETIME_ARG);
 }
 
+// test const_arg
+// type T = S<92>;
 pub(super) fn const_arg(p: &mut Parser) {
     let m = p.start();
     match p.current() {
+        // test const_arg_block
+        // type T = S<{90 + 2}>;
         T!['{'] => {
             expressions::block_expr(p);
             m.complete(p, CONST_ARG);
         }
+        // test const_arg_literal
+        // type T = S<"hello", 0xdeadbeef>;
         k if k.is_literal() => {
             expressions::literal(p);
             m.complete(p, CONST_ARG);
         }
+        // test const_arg_bool_literal
+        // type T = S<true>;
         T![true] | T![false] => {
             expressions::literal(p);
             m.complete(p, CONST_ARG);
         }
+        // test const_arg_negative_number
+        // type T = S<-92>;
         T![-] => {
             let lm = p.start();
             p.bump(T![-]);
             expressions::literal(p);
             lm.complete(p, PREFIX_EXPR);
             m.complete(p, CONST_ARG);
         }
+        // test const_arg_path
+        // struct S<const N: u32 = u32::MAX>;
         _ => {
             let lm = p.start();
             paths::use_path(p);

crates/parser/src/grammar/generic_params.rs

@@ -81,8 +81,6 @@ fn const_param(p: &mut Parser, m: Marker) {
     if p.at(T![=]) {
         // test const_param_defaults
         // struct A<const N: i32 = -1>;
-        // struct B<const N: i32 = {}>;
-        // struct C<const N: i32 = some::CONST>;
         p.bump(T![=]);
         generic_args::const_arg(p);
     }

crates/syntax/test_data/parser/inline/ok/0039_type_arg.rast

@@ -1,4 +1,4 @@
-SOURCE_FILE@0..96
+SOURCE_FILE@0..29
   [email protected]
     [email protected] "struct"
     [email protected] " "
@@ -29,68 +29,3 @@ [email protected]
       [email protected] ">"
     [email protected] ";"
   [email protected] "\n"
-  [email protected]
-    [email protected] "struct"
-    [email protected] " "
-    [email protected]
-      [email protected] "B"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected] "const"
-        [email protected] " "
-        [email protected]
-          [email protected] "N"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected] "i32"
-        [email protected] " "
-        [email protected] "="
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected] "{"
-            [email protected] "}"
-      [email protected] ">"
-    [email protected] ";"
-  [email protected] "\n"
-  [email protected]
-    [email protected] "struct"
-    [email protected] " "
-    [email protected]
-      [email protected] "C"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected] "const"
-        [email protected] " "
-        [email protected]
-          [email protected] "N"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected] "i32"
-        [email protected] " "
-        [email protected] "="
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "some"
-              [email protected] "::"
-              [email protected]
-                [email protected]
-                  [email protected] "CONST"
-      [email protected] ">"
-    [email protected] ";"
-  [email protected] "\n"

crates/syntax/test_data/parser/inline/ok/0039_type_arg.rs

@@ -1,3 +1 @@
 struct A<const N: i32 = -1>;
-struct B<const N: i32 = {}>;
-struct C<const N: i32 = some::CONST>;

crates/syntax/test_data/parser/inline/ok/0164_const_generic_negated_literal.rast

@@ -0,0 +1,31 @@
+[email protected]
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "T"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "S"
+          [email protected]
+            [email protected] "<"
+            [email protected]
+              [email protected]
+                [email protected] "{"
+                [email protected]
+                  [email protected]
+                    [email protected] "90"
+                  [email protected] " "
+                  [email protected] "+"
+                  [email protected] " "
+                  [email protected]
+                    [email protected] "2"
+                [email protected] "}"
+            [email protected] ">"
+    [email protected] ";"
+  [email protected] "\n"

crates/syntax/test_data/parser/inline/ok/0164_const_generic_negated_literal.rs

@@ -0,0 +1 @@
+type T = S<{90 + 2}>;