ast, parser: fix wrong type name of nested generics (#16749)

vlib/v/ast/types.v

@@ -1154,6 +1154,37 @@ pub fn (t &Table) clean_generics_type_str(typ Type) string {
 	return result.all_before('[')
 }
 
+fn strip_extra_struct_types(name string) string {
+	mut start := 0
+	mut is_start := false
+	mut nested_count := 0
+	mut strips := []string{}
+
+	for i, ch in name {
+		if ch == `<` {
+			if is_start {
+				nested_count++
+			} else {
+				is_start = true
+				start = i
+			}
+		} else if ch == `>` {
+			if nested_count > 0 {
+				nested_count--
+			} else {
+				strips << name.substr(start, i + 1)
+				strips << ''
+				is_start = false
+			}
+		}
+	}
+	if strips.len > 0 {
+		return name.replace_each(strips)
+	} else {
+		return name
+	}
+}
+
 // import_aliases is a map of imported symbol aliases 'module.Type' => 'Type'
 pub fn (t &Table) type_to_str_using_aliases(typ Type, import_aliases map[string]string) string {
 	cache_key := (u64(import_aliases.len) << 32) | u64(typ)
@@ -1280,6 +1311,7 @@ pub fn (t &Table) type_to_str_using_aliases(typ Type, import_aliases map[string]
 					import_aliases))
 				res = '${variant_names.join('|')}'
 			} else {
+				res = strip_extra_struct_types(res)
 				res = t.shorten_user_defined_typenames(res, import_aliases)
 			}
 		}
@@ -1363,6 +1395,7 @@ fn (t Table) shorten_user_defined_typenames(originalname string, import_aliases
 		}
 		// types defined by the user
 		// mod.submod.submod2.Type => submod2.Type
+		if res.count('[') < 2 {
 			mut parts := res.split('.')
 			if parts.len > 1 {
 				ind := parts.len - 2
@@ -1379,6 +1412,7 @@ fn (t Table) shorten_user_defined_typenames(originalname string, import_aliases
 				res = parts[0]
 			}
 		}
+	}
 	return res
 }
 

vlib/v/parser/parse_type.v

@@ -654,14 +654,14 @@ pub fn (mut p Parser) find_type_or_add_placeholder(name string, language ast.Lan
 				if p.struct_init_generic_types.len > 0 && sym.info.generic_types.len > 0
 					&& p.struct_init_generic_types != sym.info.generic_types {
 					generic_names := p.struct_init_generic_types.map(p.table.sym(it).name)
-					mut sym_name := sym.name + '['
+					mut sym_name := sym.name + '<'
 					for i, gt in generic_names {
 						sym_name += gt
 						if i != generic_names.len - 1 {
 							sym_name += ','
 						}
 					}
-					sym_name += ']'
+					sym_name += '>'
 					existing_idx := p.table.type_idxs[sym_name]
 					if existing_idx > 0 {
 						idx = existing_idx

vlib/v/tests/generics_struct_init_with_inconsistent_generic_types_5_test.v

@@ -80,4 +80,15 @@ fn test_generics_struct_init_with_inconsistent_generic_types() {
 	assert ry2[1].b.a.b == 'four'
 	assert ry2[1].b.b.a == 'four'
 	assert ry2[1].b.b.b == 4
+
+	zx1 := []Tuple2[int, Tuple2[string, int]]{}
+	println(typeof(zx1).name)
+	println(typeof(rx1).name)
+	zx2 := []Tuple2[int, Tuple2[Tuple2[string, int], Tuple2[int, string]]]{}
+	println(typeof(zx2).name)
+	println(typeof(rx2).name)
+	assert typeof(zx1).name == '[]Tuple2[int, Tuple2[string, int]]'
+	assert typeof(zx2).name == '[]Tuple2[int, Tuple2[Tuple2[string, int], Tuple2[int, string]]]'
+	assert typeof(zx1).name == typeof(rx1).name
+	assert typeof(zx2).name == typeof(rx2).name
 }