checker: check generic struct init without type parameter (#13404)

vlib/datatypes/doubly_linked_list.v

@@ -46,7 +46,7 @@ pub fn (list DoublyLinkedList<T>) last() ?T {
 
 // push_back adds an element to the end of the linked list
 pub fn (mut list DoublyLinkedList<T>) push_back(item T) {
-	mut new_node := &DoublyListNode{
+	mut new_node := &DoublyListNode<T>{
 		data: item
 	}
 	if list.is_empty() {
@@ -63,7 +63,7 @@ pub fn (mut list DoublyLinkedList<T>) push_back(item T) {
 
 // push_front adds an element to the beginning of the linked list
 pub fn (mut list DoublyLinkedList<T>) push_front(item T) {
-	mut new_node := &DoublyListNode{
+	mut new_node := &DoublyListNode<T>{
 		data: item
 	}
 	if list.is_empty() {
@@ -149,7 +149,7 @@ fn (mut list DoublyLinkedList<T>) insert_back(idx int, item T) {
 	//  |next|---->|next|
 	//  |prev|<----|prev|
 	//  ------     ------
-	new := &DoublyListNode{
+	new := &DoublyListNode<T>{
 		data: item
 		next: node
 		prev: prev
@@ -176,7 +176,7 @@ fn (mut list DoublyLinkedList<T>) insert_front(idx int, item T) {
 	//  |next|---->|next|
 	//  |prev|<----|prev|
 	//  ------     ------
-	new := &DoublyListNode{
+	new := &DoublyListNode<T>{
 		data: item
 		next: next
 		prev: node

vlib/datatypes/linked_list.v

@@ -61,7 +61,7 @@ pub fn (list LinkedList<T>) index(idx int) ?T {
 
 // push adds an element to the end of the linked list
 pub fn (mut list LinkedList<T>) push(item T) {
-	new_node := &ListNode{
+	new_node := &ListNode<T>{
 		data: item
 	}
 	if list.head == 0 {
@@ -124,7 +124,7 @@ pub fn (mut list LinkedList<T>) insert(idx int, item T) ? {
 
 		if idx == 0 {
 			// first node case
-			list.head = &ListNode{
+			list.head = &ListNode<T>{
 				data: item
 				next: node
 			}
@@ -132,7 +132,7 @@ pub fn (mut list LinkedList<T>) insert(idx int, item T) ? {
 			for i := 0; i < idx - 1; i++ {
 				node = node.next
 			}
-			node.next = &ListNode{
+			node.next = &ListNode<T>{
 				data: item
 				next: node.next
 			}

vlib/v/ast/ast.v

@@ -397,9 +397,10 @@ pub mut:
 
 pub struct StructInit {
 pub:
-	pos      token.Pos
+	pos             token.Pos
-	name_pos token.Pos
+	name_pos        token.Pos
-	is_short bool
+	is_short        bool
+	is_short_syntax bool
 pub mut:
 	unresolved           bool
 	pre_comments         []Comment

vlib/v/checker/struct.v

@@ -131,9 +131,14 @@ pub fn (mut c Checker) struct_init(mut node ast.StructInit) ast.Type {
 	struct_sym := c.table.sym(node.typ)
 	if struct_sym.info is ast.Struct {
 		if struct_sym.info.generic_types.len > 0 && struct_sym.info.concrete_types.len == 0
-			&& c.table.cur_concrete_types.len == 0 {
+			&& !node.is_short_syntax {
-			c.error('generic struct init must specify type parameter, e.g. Foo<int>',
+			if c.table.cur_concrete_types.len == 0 {
-				node.pos)
+				c.error('generic struct init must specify type parameter, e.g. Foo<int>',
+					node.pos)
+			} else if node.generic_types.len == 0 {
+				c.error('generic struct init must specify type parameter, e.g. Foo<T>',
+					node.pos)
+			}
 		}
 		if node.generic_types.len > 0 && struct_sym.info.generic_types != node.generic_types {
 			c.table.replace_generic_type(node.typ, node.generic_types)

vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out

@@ -12,10 +12,4 @@ vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:32:1: error: g
       | ~~~~~~~~~~~~~~
    33 |     println("hi")
    34 | }
-vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:23:9: error: cannot use `Generic` as type `Generic<Concrete>` in return argument
+
-   21 |     go g_worker(g)
-   22 |
-   23 |     return g
-      |            ^
-   24 | }
-   25 |

vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv

@@ -14,7 +14,7 @@ fn main() {
 }
 
 fn create_generic_t<T>() Generic<T> {
-	g := Generic{
+	g := Generic<T>{
 		ch: chan T{}
 	}
 

vlib/v/checker/tests/generics_fn_return_generic_struct_err.out

@@ -5,3 +5,10 @@ vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:13:32: error: retu
       |                                ~~~~~~~~~~~~~~~~~~~~
    14 |     d := GenericChannelStruct{
    15 |         ch: chan T{}
+vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:14:7: error: generic struct init must specify type parameter, e.g. Foo<T>
+   12 |
+   13 | pub fn new_channel_struct<T>() GenericChannelStruct {
+   14 |     d := GenericChannelStruct{
+      |          ~~~~~~~~~~~~~~~~~~~~~
+   15 |         ch: chan T{}
+   16 |     }

vlib/v/checker/tests/generics_struct_init_err.out

@@ -12,3 +12,45 @@ vlib/v/checker/tests/generics_struct_init_err.vv:67:8: error: generic struct ini
       |           ~~~~~~~~~~~~~~
    68 |     assert ret == -6
    69 | }
+vlib/v/checker/tests/generics_struct_init_err.vv:22:7: error: generic struct init must specify type parameter, e.g. Foo<T>
+   20 |
+   21 | fn holder_call_1<T>(func T, a int) int {
+   22 |     h := FnHolder1{func}
+      |          ~~~~~~~~~~~~~~~
+   23 |     return h.call(a)
+   24 | }
+vlib/v/checker/tests/generics_struct_init_err.vv:27:7: error: generic struct init must specify type parameter, e.g. Foo<T>
+   25 |
+   26 | fn holder_call_2<T>(func T, a int) int {
+   27 |     h := FnHolder2{func}
+      |          ~~~~~~~~~~~~~~~
+   28 |     return h.call(a)
+   29 | }
+vlib/v/checker/tests/generics_struct_init_err.vv:33:7: error: generic struct init must specify type parameter, e.g. Foo<T>
+   31 | fn holder_call_11<T>(func T, a int) int {
+   32 |     f := func
+   33 |     h := FnHolder1{f}
+      |          ~~~~~~~~~~~~
+   34 |     return h.call(a)
+   35 | }
+vlib/v/checker/tests/generics_struct_init_err.vv:39:7: error: generic struct init must specify type parameter, e.g. Foo<T>
+   37 | fn holder_call_21<T>(func T, a int) int {
+   38 |     f := func
+   39 |     h := FnHolder2{f}
+      |          ~~~~~~~~~~~~
+   40 |     return h.call(a)
+   41 | }
+vlib/v/checker/tests/generics_struct_init_err.vv:44:9: error: generic struct init must specify type parameter, e.g. Foo<T>
+   42 |
+   43 | fn holder_call_12<T>(func T, a int) int {
+   44 |     return FnHolder1{func}.call(a)
+      |            ~~~~~~~~~~~~~~~
+   45 | }
+   46 |
+vlib/v/checker/tests/generics_struct_init_err.vv:48:9: error: generic struct init must specify type parameter, e.g. Foo<T>
+   46 |
+   47 | fn holder_call_22<T>(func T, a int) int {
+   48 |     return FnHolder2{func}.call(a)
+      |            ~~~~~~~~~~~~~~~
+   49 | }
+   50 |

vlib/v/parser/struct.v

@@ -426,6 +426,7 @@ fn (mut p Parser) struct_init(typ_str string, short_syntax bool) ast.StructInit
 		name_pos: first_pos
 		pos: first_pos.extend(if short_syntax { p.tok.pos() } else { p.prev_tok.pos() })
 		is_short: no_keys
+		is_short_syntax: short_syntax
 		pre_comments: pre_comments
 		generic_types: p.struct_init_generic_types
 	}

vlib/v/tests/generics_struct_anon_fn_type_test.v

@@ -19,33 +19,33 @@ fn (self FnHolder2<T>) call(a int) int {
 }
 
 fn holder_call_1<T>(func T, a int) int {
-	h := FnHolder1{func}
+	h := FnHolder1<T>{func}
 	return h.call(a)
 }
 
 fn holder_call_2<T>(func T, a int) int {
-	h := FnHolder2{func}
+	h := FnHolder2<T>{func}
 	return h.call(a)
 }
 
 fn holder_call_11<T>(func T, a int) int {
 	f := func
-	h := FnHolder1{f}
+	h := FnHolder1<T>{f}
 	return h.call(a)
 }
 
 fn holder_call_21<T>(func T, a int) int {
 	f := func
-	h := FnHolder2{f}
+	h := FnHolder2<T>{f}
 	return h.call(a)
 }
 
 fn holder_call_12<T>(func T, a int) int {
-	return FnHolder1{func}.call(a)
+	return FnHolder1<T>{func}.call(a)
 }
 
 fn holder_call_22<T>(func T, a int) int {
-	return FnHolder2{func}.call(a)
+	return FnHolder2<T>{func}.call(a)
 }
 
 fn test_generic_struct_with_anon_fn_parameter() {