From f16722596cf922db253e040f574a257169203149 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Fri, 2 Dec 2022 15:22:48 +0800
Subject: [PATCH] all: replace generic '<>' with '[]' in error messages and
 comments (#16571)

---
 cmd/tools/vast/vast.v                         |  4 +--
 vlib/datatypes/doubly_linked_list.v           |  6 ++--
 vlib/datatypes/linked_list.v                  |  2 +-
 vlib/datatypes/set.v                          |  4 +--
 vlib/os/os_test.v                             |  2 +-
 vlib/v/ast/table.v                            |  2 +-
 vlib/v/checker/check_types.v                  |  6 ++--
 vlib/v/checker/checker.v                      |  4 +--
 vlib/v/checker/containers.v                   | 16 +++++------
 vlib/v/checker/fn.v                           | 28 +++++++++----------
 vlib/v/checker/interface.v                    |  2 +-
 .../array_of_generic_struct_init_err.out      |  6 ++--
 .../tests/generic_closure_fn_decl_err.out     |  2 +-
 vlib/v/checker/tests/generic_fn_decl_err.out  | 10 +++----
 ...eric_fn_decl_without_generic_names_err.out | 12 ++++----
 ...neric_interface_missing_type_names_err.out |  2 +-
 .../tests/generic_sumtype_decl_err_a.out      |  2 +-
 .../tests/generic_sumtype_decl_err_b.out      |  2 +-
 .../tests/generics_fn_arg_type_err.out        |  2 +-
 .../tests/generics_fn_called_no_arg_err.out   |  2 +-
 .../generics_fn_return_generic_struct_err.out |  2 +-
 .../generics_interface_declaration_err.out    |  2 +-
 .../generics_method_receiver_type_err.out     |  2 +-
 .../tests/map_of_generic_struct_init_err.out  |  6 ++--
 vlib/v/gen/golang/golang.v                    |  2 +-
 vlib/v/parser/fn.v                            |  2 +-
 vlib/v/tests/fn_variadic_test.v               |  2 +-
 vlib/v/tests/generics_test.v                  |  7 ++---
 28 files changed, 70 insertions(+), 71 deletions(-)

diff --git a/cmd/tools/vast/vast.v b/cmd/tools/vast/vast.v
index 588dec94c7..69c8dbd3a9 100644
--- a/cmd/tools/vast/vast.v
+++ b/cmd/tools/vast/vast.v
@@ -1986,7 +1986,7 @@ fn (t Tree) asm_io(node ast.AsmIO) &Node {
 }
 
 // do not support yet by vlang
-// fn (t Tree) array_node1<T>(nodes []T, method_name string) &Node {
+// fn (t Tree) array_node1[T](nodes []T, method_name string) &Node {
 // 	mut arr := new_array()
 
 // 	// call method dynamically, V do not support yet
@@ -2009,7 +2009,7 @@ fn (t Tree) asm_io(node ast.AsmIO) &Node {
 // }
 
 // do not support yet by vlang
-// fn (t Tree) array_node2<T>(nodes []T) &Node {
+// fn (t Tree) array_node2[T](nodes []T) &Node {
 // 	mut arr := new_array()
 
 // 	for node in nodes {
diff --git a/vlib/datatypes/doubly_linked_list.v b/vlib/datatypes/doubly_linked_list.v
index 9ef046bd34..a4d88ba55f 100644
--- a/vlib/datatypes/doubly_linked_list.v
+++ b/vlib/datatypes/doubly_linked_list.v
@@ -7,7 +7,7 @@ mut:
 	prev &DoublyListNode[T] = unsafe { 0 }
 }
 
-// DoublyLinkedList<T> represents a generic doubly linked list of elements, each of type T.
+// DoublyLinkedList[T] represents a generic doubly linked list of elements, each of type T.
 pub struct DoublyLinkedList[T] {
 mut:
 	head &DoublyListNode[T] = unsafe { 0 }
@@ -298,7 +298,7 @@ pub fn (mut list DoublyLinkedList[T]) back_iterator() DoublyListIterBack[T] {
 	}
 }
 
-// DoublyListIter<T> is an iterator for DoublyLinkedList.
+// DoublyListIter[T] is an iterator for DoublyLinkedList.
 // It starts from *the start* and moves forwards to *the end* of the list.
 // It can be used with V's `for x in iter {` construct.
 // One list can have multiple independent iterators, pointing to different positions/places in the list.
@@ -319,7 +319,7 @@ pub fn (mut iter DoublyListIter[T]) next() ?T {
 	return res
 }
 
-// DoublyListIterBack<T> is an iterator for DoublyLinkedList.
+// DoublyListIterBack[T] is an iterator for DoublyLinkedList.
 // It starts from *the end* and moves backwards to *the start* of the list.
 // It can be used with V's `for x in iter {` construct.
 // One list can have multiple independent iterators, pointing to different positions/places in the list.
diff --git a/vlib/datatypes/linked_list.v b/vlib/datatypes/linked_list.v
index e0eb17db17..98673c4aea 100644
--- a/vlib/datatypes/linked_list.v
+++ b/vlib/datatypes/linked_list.v
@@ -192,7 +192,7 @@ pub fn (mut list LinkedList[T]) iterator() ListIter[T] {
 	}
 }
 
-// ListIter<T> is an iterator for LinkedList.
+// ListIter[T] is an iterator for LinkedList.
 // It can be used with V's `for x in iter {` construct.
 // One list can have multiple independent iterators, pointing to different positions/places in the list.
 // An iterator instance always traverses the list from start to finish.
diff --git a/vlib/datatypes/set.v b/vlib/datatypes/set.v
index 9c6db927f4..6c189059d2 100644
--- a/vlib/datatypes/set.v
+++ b/vlib/datatypes/set.v
@@ -47,7 +47,7 @@ pub fn (mut set Set[T]) clear() {
 }
 
 // equal checks whether the two given sets are equal (i.e. contain all and only the same elements).
-[deprecated: 'use set1<T> == set2<T> instead']
+[deprecated: 'use set1[T] == set2[T] instead']
 pub fn (l Set[T]) equal(r Set[T]) bool {
 	return l == r
 }
@@ -115,7 +115,7 @@ pub fn (l Set[T]) intersection(r Set[T]) Set[T] {
 }
 
 // difference returns the difference of sets.
-[deprecated: 'use set1<T> - set2<T> instead']
+[deprecated: 'use set1[T] - set2[T] instead']
 pub fn (l Set[T]) difference(r Set[T]) Set[T] {
 	return l - r
 }
diff --git a/vlib/os/os_test.v b/vlib/os/os_test.v
index 0b3037459b..667d499fc5 100644
--- a/vlib/os/os_test.v
+++ b/vlib/os/os_test.v
@@ -678,7 +678,7 @@ fn test_uname() {
 	assert u.machine.len > 0
 }
 
-// tests for write_file_array and read_file_array<T>:
+// tests for write_file_array and read_file_array[T]:
 const maxn = 3
 
 struct IntPoint {
diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index e481e8cef6..8ddf297c00 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -2005,7 +2005,7 @@ pub fn (mut t Table) unwrap_generic_type(typ Type, generic_names []string, concr
 	return typ
 }
 
-// Foo<U>{ bar: U } to Foo<T>{ bar: T }
+// Foo[U]{ bar: U } to Foo[T]{ bar: T }
 pub fn (mut t Table) replace_generic_type(typ Type, generic_types []Type) {
 	mut ts := t.sym(typ)
 	match mut ts.info {
diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index d5239fdefc..28382251af 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -260,11 +260,11 @@ fn (mut c Checker) check_expected_call_arg(got ast.Type, expected_ ast.Type, lan
 		expected_typ_sym := c.table.sym(expected_)
 
 		// Check on Generics types, there are some case where we have the following case
-		// `&Type<int> == &Type<>`. This is a common case we are implementing a function
-		// with generic parameters like `compare(bst Bst<T> node) {}`
+		// `&Type[int] == &Type[]`. This is a common case we are implementing a function
+		// with generic parameters like `compare(bst Bst[T] node) {}`
 		if got_typ_sym.symbol_name_except_generic() == expected_typ_sym.symbol_name_except_generic() {
 			// Check if we are making a comparison between two different types of
-			// the same type like `Type<int> and &Type<>`
+			// the same type like `Type[int] and &Type[]`
 			if (got.is_ptr() != expected.is_ptr())
 				|| !c.check_same_module(got, expected)
 				|| (!got.is_ptr() && !expected.is_ptr()
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index faa1ae4f40..81534a6848 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -497,11 +497,11 @@ fn (mut c Checker) sum_type_decl(node ast.SumTypeDecl) {
 		} else if mut sym.info is ast.Struct {
 			if sym.info.is_generic {
 				if !variant.typ.has_flag(.generic) {
-					c.error('generic struct `${sym.name}` must specify generic type names, e.g. Foo<T>',
+					c.error('generic struct `${sym.name}` must specify generic type names, e.g. Foo[T]',
 						variant.pos)
 				}
 				if node.generic_types.len == 0 {
-					c.error('generic sumtype `${node.name}` must specify generic type names, e.g. Foo<T>',
+					c.error('generic sumtype `${node.name}` must specify generic type names, e.g. Foo[T]',
 						node.name_pos)
 				} else {
 					for typ in sym.info.generic_types {
diff --git a/vlib/v/checker/containers.v b/vlib/v/checker/containers.v
index bb00d2b34c..5aebb390cb 100644
--- a/vlib/v/checker/containers.v
+++ b/vlib/v/checker/containers.v
@@ -17,10 +17,10 @@ fn (mut c Checker) array_init(mut node ast.ArrayInit) ast.Type {
 				if elem_info.generic_types.len > 0 && elem_info.concrete_types.len == 0
 					&& !node.elem_type.has_flag(.generic) {
 					if c.table.cur_concrete_types.len == 0 {
-						c.error('generic struct must specify type parameter, e.g. Foo<int>',
+						c.error('generic struct must specify type parameter, e.g. Foo[int]',
 							node.elem_type_pos)
 					} else {
-						c.error('generic struct must specify type parameter, e.g. Foo<T>',
+						c.error('generic struct must specify type parameter, e.g. Foo[T]',
 							node.elem_type_pos)
 					}
 				}
@@ -29,10 +29,10 @@ fn (mut c Checker) array_init(mut node ast.ArrayInit) ast.Type {
 				if elem_info.generic_types.len > 0 && elem_info.concrete_types.len == 0
 					&& !node.elem_type.has_flag(.generic) {
 					if c.table.cur_concrete_types.len == 0 {
-						c.error('generic interface must specify type parameter, e.g. Foo<int>',
+						c.error('generic interface must specify type parameter, e.g. Foo[int]',
 							node.elem_type_pos)
 					} else {
-						c.error('generic interface must specify type parameter, e.g. Foo<T>',
+						c.error('generic interface must specify type parameter, e.g. Foo[T]',
 							node.elem_type_pos)
 					}
 				}
@@ -41,10 +41,10 @@ fn (mut c Checker) array_init(mut node ast.ArrayInit) ast.Type {
 				if elem_info.generic_types.len > 0 && elem_info.concrete_types.len == 0
 					&& !node.elem_type.has_flag(.generic) {
 					if c.table.cur_concrete_types.len == 0 {
-						c.error('generic sumtype must specify type parameter, e.g. Foo<int>',
+						c.error('generic sumtype must specify type parameter, e.g. Foo[int]',
 							node.elem_type_pos)
 					} else {
-						c.error('generic sumtype must specify type parameter, e.g. Foo<T>',
+						c.error('generic sumtype must specify type parameter, e.g. Foo[T]',
 							node.elem_type_pos)
 					}
 				}
@@ -307,10 +307,10 @@ fn (mut c Checker) map_init(mut node ast.MapInit) ast.Type {
 				if val_info.generic_types.len > 0 && val_info.concrete_types.len == 0
 					&& !info.value_type.has_flag(.generic) {
 					if c.table.cur_concrete_types.len == 0 {
-						c.error('generic struct `${val_sym.name}` must specify type parameter, e.g. Foo<int>',
+						c.error('generic struct `${val_sym.name}` must specify type parameter, e.g. Foo[int]',
 							node.pos)
 					} else {
-						c.error('generic struct `${val_sym.name}` must specify type parameter, e.g. Foo<T>',
+						c.error('generic struct `${val_sym.name}` must specify type parameter, e.g. Foo[T]',
 							node.pos)
 					}
 				}
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 31e090589a..863a2f752a 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -76,11 +76,11 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 		}
 		if need_generic_names {
 			if node.is_method {
-				c.add_error_detail('use `fn (r SomeType<T>) foo<T>() {`, not just `fn (r SomeType<T>) foo() {`')
+				c.add_error_detail('use `fn (r SomeType[T]) foo[T]() {`, not just `fn (r SomeType[T]) foo() {`')
 				c.error('generic method declaration must specify generic type names',
 					node.pos)
 			} else {
-				c.add_error_detail('use `fn foo<T>(x T) {`, not just `fn foo(x T) {`')
+				c.add_error_detail('use `fn foo[T](x T) {`, not just `fn foo(x T) {`')
 				c.error('generic function declaration must specify generic type names',
 					node.pos)
 			}
@@ -105,7 +105,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			gs := c.table.sym(node.return_type)
 			if gs.info is ast.Struct {
 				if gs.info.is_generic && !node.return_type.has_flag(.generic) {
-					c.error('return generic struct in fn declaration must specify the generic type names, e.g. Foo<T>',
+					c.error('return generic struct in fn declaration must specify the generic type names, e.g. Foo[T]',
 						node.return_type_pos)
 				}
 			}
@@ -136,7 +136,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			for name in generic_names {
 				if name !in node.generic_names {
 					fn_generic_names := node.generic_names.join(', ')
-					c.error('generic type name `${name}` is not mentioned in fn `${node.name}<${fn_generic_names}>`',
+					c.error('generic type name `${name}` is not mentioned in fn `${node.name}[${fn_generic_names}]`',
 						node.return_type_pos)
 				}
 			}
@@ -224,19 +224,19 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 					}
 					if arg_typ_sym.info.generic_types.len > 0 && !param.typ.has_flag(.generic)
 						&& arg_typ_sym.info.concrete_types.len == 0 {
-						c.error('generic struct in fn declaration must specify the generic type names, e.g. Foo<T>',
+						c.error('generic struct in fn declaration must specify the generic type names, e.g. Foo[T]',
 							param.type_pos)
 					}
 				} else if arg_typ_sym.info is ast.Interface {
 					if arg_typ_sym.info.generic_types.len > 0 && !param.typ.has_flag(.generic)
 						&& arg_typ_sym.info.concrete_types.len == 0 {
-						c.error('generic interface in fn declaration must specify the generic type names, e.g. Foo<T>',
+						c.error('generic interface in fn declaration must specify the generic type names, e.g. Foo[T]',
 							param.type_pos)
 					}
 				} else if arg_typ_sym.info is ast.SumType {
 					if arg_typ_sym.info.generic_types.len > 0 && !param.typ.has_flag(.generic)
 						&& arg_typ_sym.info.concrete_types.len == 0 {
-						c.error('generic sumtype in fn declaration must specify the generic type names, e.g. Foo<T>',
+						c.error('generic sumtype in fn declaration must specify the generic type names, e.g. Foo[T]',
 							param.type_pos)
 					}
 				}
@@ -247,7 +247,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 				for name in generic_names {
 					if name !in node.generic_names {
 						fn_generic_names := node.generic_names.join(', ')
-						c.error('generic type name `${name}` is not mentioned in fn `${node.name}<${fn_generic_names}>`',
+						c.error('generic type name `${name}` is not mentioned in fn `${node.name}[${fn_generic_names}]`',
 							param.type_pos)
 					}
 				}
@@ -439,7 +439,7 @@ fn (mut c Checker) anon_fn(mut node ast.AnonFn) ast.Type {
 	c.stmts(node.decl.stmts)
 	c.fn_decl(mut node.decl)
 	if has_generic && node.decl.generic_names.len == 0 {
-		c.error('generic closure fn must specify type parameter, e.g. fn [foo] <T>()',
+		c.error('generic closure fn must specify type parameter, e.g. fn [foo] [T]()',
 			node.decl.pos)
 	}
 	return node.typ
@@ -551,7 +551,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 	if fn_name == 'main' {
 		c.error('the `main` function cannot be called in the program', node.pos)
 	}
-	mut has_generic := false // foo<T>() instead of foo<int>()
+	mut has_generic := false // foo[T]() instead of foo[int]()
 	mut concrete_types := []ast.Type{}
 	node.concrete_types = node.raw_concrete_types
 	for concrete_type in node.concrete_types {
@@ -593,7 +593,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 		typ := c.expr(node.args[0].expr)
 		tsym := c.table.sym(typ)
 
-		if !tsym.name.starts_with('Promise<') {
+		if !tsym.name.starts_with('Promise[') {
 			c.error('JS.await: first argument must be a promise, got `${tsym.name}`',
 				node.pos)
 			return ast.void_type
@@ -918,7 +918,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 		c.ensure_type_exists(concrete_type, node.concrete_list_pos) or {}
 	}
 	if func.generic_names.len > 0 && node.args.len == 0 && node.concrete_types.len == 0 {
-		c.error('no argument generic function must add concrete types, e.g. foo<int>()',
+		c.error('no argument generic function must add concrete types, e.g. foo[int]()',
 			node.pos)
 		return func.return_type
 	}
@@ -1382,7 +1382,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 		}
 	} else if final_left_sym.info is ast.Array && method_name in ['first', 'last', 'pop'] {
 		return c.array_builtin_method_call(mut node, left_type, final_left_sym)
-	} else if c.pref.backend.is_js() && left_sym.name.starts_with('Promise<')
+	} else if c.pref.backend.is_js() && left_sym.name.starts_with('Promise[')
 		&& method_name == 'wait' {
 		info := left_sym.info as ast.Struct
 		if node.args.len > 0 {
@@ -1455,7 +1455,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 		}
 	}
 	if has_method {
-		// x is Bar<T>, x.foo() -> x.foo<T>()
+		// x is Bar[T], x.foo() -> x.foo[T]()
 		rec_sym := c.table.final_sym(node.left_type)
 		rec_is_generic := left_type.has_flag(.generic)
 		mut rec_concrete_types := []ast.Type{}
diff --git a/vlib/v/checker/interface.v b/vlib/v/checker/interface.v
index 4b84a16b47..871c29a93f 100644
--- a/vlib/v/checker/interface.v
+++ b/vlib/v/checker/interface.v
@@ -211,7 +211,7 @@ fn (mut c Checker) interface_decl(mut node ast.InterfaceDecl) {
 			}
 		}
 		if node.generic_types.len == 0 && has_generic_types {
-			c.error('generic interface declaration must specify the generic type names, e.g. Foo<T>',
+			c.error('generic interface declaration must specify the generic type names, e.g. Foo[T]',
 				node.pos)
 		}
 	}
diff --git a/vlib/v/checker/tests/array_of_generic_struct_init_err.out b/vlib/v/checker/tests/array_of_generic_struct_init_err.out
index 83d4c00be4..ed9f2278b9 100644
--- a/vlib/v/checker/tests/array_of_generic_struct_init_err.out
+++ b/vlib/v/checker/tests/array_of_generic_struct_init_err.out
@@ -1,11 +1,11 @@
 vlib/v/checker/tests/array_of_generic_struct_init_err.vv:6:6: warning: unused variable: `arr`
-    4 | 
+    4 |
     5 | fn main() {
     6 |     mut arr := []Item{}
       |         ~~~
     7 | }
-vlib/v/checker/tests/array_of_generic_struct_init_err.vv:6:15: error: generic struct must specify type parameter, e.g. Foo<int>
-    4 | 
+vlib/v/checker/tests/array_of_generic_struct_init_err.vv:6:15: error: generic struct must specify type parameter, e.g. Foo[int]
+    4 |
     5 | fn main() {
     6 |     mut arr := []Item{}
       |                  ~~~~
diff --git a/vlib/v/checker/tests/generic_closure_fn_decl_err.out b/vlib/v/checker/tests/generic_closure_fn_decl_err.out
index 21de87ce62..8252196fb1 100644
--- a/vlib/v/checker/tests/generic_closure_fn_decl_err.out
+++ b/vlib/v/checker/tests/generic_closure_fn_decl_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generic_closure_fn_decl_err.vv:5:2: error: generic closure fn must specify type parameter, e.g. fn [foo] <T>()
+vlib/v/checker/tests/generic_closure_fn_decl_err.vv:5:2: error: generic closure fn must specify type parameter, e.g. fn [foo] [T]()
     3 |
     4 | pub fn (mut app App) register<T>(service T) {
     5 |     fn [service] () {
diff --git a/vlib/v/checker/tests/generic_fn_decl_err.out b/vlib/v/checker/tests/generic_fn_decl_err.out
index d5f40c1347..bd331c0157 100644
--- a/vlib/v/checker/tests/generic_fn_decl_err.out
+++ b/vlib/v/checker/tests/generic_fn_decl_err.out
@@ -1,32 +1,32 @@
-vlib/v/checker/tests/generic_fn_decl_err.vv:19:29: error: generic type name `P` is not mentioned in fn `create1<U>`
+vlib/v/checker/tests/generic_fn_decl_err.vv:19:29: error: generic type name `P` is not mentioned in fn `create1[U]`
    17 | }
    18 |
    19 | fn (r Db) create1<U>(u U, p P) {
       |                             ^
    20 |     println('Yo')
    21 | }
-vlib/v/checker/tests/generic_fn_decl_err.vv:23:29: error: generic type name `P` is not mentioned in fn `create2<U>`
+vlib/v/checker/tests/generic_fn_decl_err.vv:23:29: error: generic type name `P` is not mentioned in fn `create2[U]`
    21 | }
    22 |
    23 | fn (r Db) create2<U>(u U, p &P) {
       |                             ~~
    24 |     println('Yo')
    25 | }
-vlib/v/checker/tests/generic_fn_decl_err.vv:27:29: error: generic type name `P` is not mentioned in fn `create3<U>`
+vlib/v/checker/tests/generic_fn_decl_err.vv:27:29: error: generic type name `P` is not mentioned in fn `create3[U]`
    25 | }
    26 |
    27 | fn (r Db) create3<U>(u U, p []P) {
       |                             ~~~
    28 |     println('Yo')
    29 | }
-vlib/v/checker/tests/generic_fn_decl_err.vv:31:27: error: generic type name `P` is not mentioned in fn `create4<U>`
+vlib/v/checker/tests/generic_fn_decl_err.vv:31:27: error: generic type name `P` is not mentioned in fn `create4[U]`
    29 | }
    30 |
    31 | fn (r Db) create4<U>(u U) P {
       |                           ^
    32 |     return P{}
    33 | }
-vlib/v/checker/tests/generic_fn_decl_err.vv:35:27: error: generic type name `P` is not mentioned in fn `create5<U>`
+vlib/v/checker/tests/generic_fn_decl_err.vv:35:27: error: generic type name `P` is not mentioned in fn `create5[U]`
    33 | }
    34 |
    35 | fn (r Db) create5<U>(u U) []P {
diff --git a/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out b/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out
index 4e5d935b9e..54010333e8 100644
--- a/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out
+++ b/vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.out
@@ -1,24 +1,24 @@
 vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:26:1: error: generic function declaration must specify generic type names
    24 | }
-   25 | 
+   25 |
    26 | fn g_worker(g Generic<T>) {
       | ~~~~~~~~~~~~~~~~~~~~~~~~~
    27 |     t := <-g.ch
    28 |     handle(t)
-Details: use `fn foo<T>(x T) {`, not just `fn foo(x T) {`
+Details: use `fn foo[T](x T) {`, not just `fn foo(x T) {`
 vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:32:1: error: generic function declaration must specify generic type names
    30 | }
-   31 | 
+   31 |
    32 | fn handle(t T) {
       | ~~~~~~~~~~~~~~
    33 |     println('hi')
    34 | }
-Details: use `fn foo<T>(x T) {`, not just `fn foo(x T) {`
+Details: use `fn foo[T](x T) {`, not just `fn foo(x T) {`
 vlib/v/checker/tests/generic_fn_decl_without_generic_names_err.vv:40:1: error: generic method declaration must specify generic type names
    38 | type MayBe<T> = None | T
-   39 | 
+   39 |
    40 | fn (m MayBe<T>) is_some() bool {
       | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    41 |     return m is T
    42 | }
-Details: use `fn (r SomeType<T>) foo<T>() {`, not just `fn (r SomeType<T>) foo() {`
+Details: use `fn (r SomeType[T]) foo[T]() {`, not just `fn (r SomeType[T]) foo() {`
diff --git a/vlib/v/checker/tests/generic_interface_missing_type_names_err.out b/vlib/v/checker/tests/generic_interface_missing_type_names_err.out
index 629053ed41..2e7d169fbe 100644
--- a/vlib/v/checker/tests/generic_interface_missing_type_names_err.out
+++ b/vlib/v/checker/tests/generic_interface_missing_type_names_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generic_interface_missing_type_names_err.vv:16:17: error: generic interface must specify type parameter, e.g. Foo<int>
+vlib/v/checker/tests/generic_interface_missing_type_names_err.vv:16:17: error: generic interface must specify type parameter, e.g. Foo[int]
    14 |
    15 | fn main() {
    16 |   mut outs := []Output{}
diff --git a/vlib/v/checker/tests/generic_sumtype_decl_err_a.out b/vlib/v/checker/tests/generic_sumtype_decl_err_a.out
index 12fac1ed81..27b3d622d1 100644
--- a/vlib/v/checker/tests/generic_sumtype_decl_err_a.out
+++ b/vlib/v/checker/tests/generic_sumtype_decl_err_a.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generic_sumtype_decl_err_a.vv:7:24: error: generic struct `Just` must specify generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generic_sumtype_decl_err_a.vv:7:24: error: generic struct `Just` must specify generic type names, e.g. Foo[T]
     5 | struct Nothing {}
     6 |
     7 | type Maybe = Nothing | Just
diff --git a/vlib/v/checker/tests/generic_sumtype_decl_err_b.out b/vlib/v/checker/tests/generic_sumtype_decl_err_b.out
index 4920a990c7..169f8b1067 100644
--- a/vlib/v/checker/tests/generic_sumtype_decl_err_b.out
+++ b/vlib/v/checker/tests/generic_sumtype_decl_err_b.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generic_sumtype_decl_err_b.vv:7:6: error: generic sumtype `Maybe` must specify generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generic_sumtype_decl_err_b.vv:7:6: error: generic sumtype `Maybe` must specify generic type names, e.g. Foo[T]
     5 | struct Nothing {}
     6 |
     7 | type Maybe = Nothing | Just<T>
diff --git a/vlib/v/checker/tests/generics_fn_arg_type_err.out b/vlib/v/checker/tests/generics_fn_arg_type_err.out
index b12cac6bee..a7d2efff15 100644
--- a/vlib/v/checker/tests/generics_fn_arg_type_err.out
+++ b/vlib/v/checker/tests/generics_fn_arg_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generics_fn_arg_type_err.vv:14:23: error: generic interface in fn declaration must specify the generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generics_fn_arg_type_err.vv:14:23: error: generic interface in fn declaration must specify the generic type names, e.g. Foo[T]
    12 | }
    13 |
    14 | fn do_list_thing(list List) { // <--- Error here
diff --git a/vlib/v/checker/tests/generics_fn_called_no_arg_err.out b/vlib/v/checker/tests/generics_fn_called_no_arg_err.out
index 42128086fc..4a7aa5478f 100644
--- a/vlib/v/checker/tests/generics_fn_called_no_arg_err.out
+++ b/vlib/v/checker/tests/generics_fn_called_no_arg_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generics_fn_called_no_arg_err.vv:13:10: error: no argument generic function must add concrete types, e.g. foo<int>()
+vlib/v/checker/tests/generics_fn_called_no_arg_err.vv:13:10: error: no argument generic function must add concrete types, e.g. foo[int]()
    11 |
    12 | fn main() {
    13 |     q := new_queue()
diff --git a/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out b/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out
index 3fcb8879da..2d1b4f8ed7 100644
--- a/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out
+++ b/vlib/v/checker/tests/generics_fn_return_generic_struct_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:13:32: error: return generic struct in fn declaration must specify the generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generics_fn_return_generic_struct_err.vv:13:32: error: return generic struct in fn declaration must specify the generic type names, e.g. Foo[T]
    11 | }
    12 |
    13 | pub fn new_channel_struct[T]() GenericChannelStruct {
diff --git a/vlib/v/checker/tests/generics_interface_declaration_err.out b/vlib/v/checker/tests/generics_interface_declaration_err.out
index bcf5b5db0c..879277f795 100644
--- a/vlib/v/checker/tests/generics_interface_declaration_err.out
+++ b/vlib/v/checker/tests/generics_interface_declaration_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generics_interface_declaration_err.vv:1:1: error: generic interface declaration must specify the generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generics_interface_declaration_err.vv:1:1: error: generic interface declaration must specify the generic type names, e.g. Foo[T]
     1 | interface Expr {
       | ~~~~~~~~~~~~~~~~
     2 |     accept(v Visitor<R>) R
diff --git a/vlib/v/checker/tests/generics_method_receiver_type_err.out b/vlib/v/checker/tests/generics_method_receiver_type_err.out
index 94d6ec41c1..bd03e25e10 100644
--- a/vlib/v/checker/tests/generics_method_receiver_type_err.out
+++ b/vlib/v/checker/tests/generics_method_receiver_type_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/generics_method_receiver_type_err.vv:6:11: error: generic struct in fn declaration must specify the generic type names, e.g. Foo<T>
+vlib/v/checker/tests/generics_method_receiver_type_err.vv:6:11: error: generic struct in fn declaration must specify the generic type names, e.g. Foo[T]
     4 | }
     5 |
     6 | pub fn (x Node) str() string {
diff --git a/vlib/v/checker/tests/map_of_generic_struct_init_err.out b/vlib/v/checker/tests/map_of_generic_struct_init_err.out
index bbcafb9f46..5ec3cc25ad 100644
--- a/vlib/v/checker/tests/map_of_generic_struct_init_err.out
+++ b/vlib/v/checker/tests/map_of_generic_struct_init_err.out
@@ -1,11 +1,11 @@
 vlib/v/checker/tests/map_of_generic_struct_init_err.vv:6:6: warning: unused variable: `m`
-    4 | 
+    4 |
     5 | fn main() {
     6 |     mut m := map[string]Item{}
       |         ^
     7 | }
-vlib/v/checker/tests/map_of_generic_struct_init_err.vv:6:11: error: generic struct `Item` must specify type parameter, e.g. Foo<int>
-    4 | 
+vlib/v/checker/tests/map_of_generic_struct_init_err.vv:6:11: error: generic struct `Item` must specify type parameter, e.g. Foo[int]
+    4 |
     5 | fn main() {
     6 |     mut m := map[string]Item{}
       |              ~~~~~~~~~~~~~~~~~
diff --git a/vlib/v/gen/golang/golang.v b/vlib/v/gen/golang/golang.v
index a36c4e6621..feaeb59d15 100644
--- a/vlib/v/gen/golang/golang.v
+++ b/vlib/v/gen/golang/golang.v
@@ -251,7 +251,7 @@ pub fn (mut f Gen) mark_types_import_as_used(typ ast.Type) {
 			f.mark_types_import_as_used(concrete_typ)
 		}
 	}
-	name := sym.name.split('<')[0] // take `Type` from `Type<T>`
+	name := sym.name.split('[')[0] // take `Type` from `Type[T]`
 	f.mark_import_as_used(name)
 }
 
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index da7760b5e3..53ba9c2da7 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -333,7 +333,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 			scope: 0
 		}
 	}
-	// <T>
+	// [T]
 	_, mut generic_names := p.parse_generic_types()
 	// generic names can be infer with receiver's generic names
 	if is_method && rec.typ.has_flag(.generic) {
diff --git a/vlib/v/tests/fn_variadic_test.v b/vlib/v/tests/fn_variadic_test.v
index ea95e4f44d..38b0030665 100644
--- a/vlib/v/tests/fn_variadic_test.v
+++ b/vlib/v/tests/fn_variadic_test.v
@@ -22,7 +22,7 @@ fn test_fn_variadic() {
 /*
 // QTODO
 // generic
-fn variadic_test_generic<T>(a int, b ...T) T {
+fn variadic_test_generic[T](a int, b ...T) T {
 	b1 := b[0]
 	b2 := b[1]
 	return '$a $b1 $b2'
diff --git a/vlib/v/tests/generics_test.v b/vlib/v/tests/generics_test.v
index 00b07d5f98..6df92bc4c3 100644
--- a/vlib/v/tests/generics_test.v
+++ b/vlib/v/tests/generics_test.v
@@ -202,7 +202,7 @@ fn map_f[T, U](l []T, f fn (T) U) []U {
 }
 
 /*
-fn foldl<T>(l []T, nil T, f fn(T,T)T) T {
+fn foldl[T](l []T, nil T, f fn(T,T)T) T {
 	mut r := nil
 	for e in l {
 		r = f(r, e)
@@ -302,8 +302,8 @@ pub mut:
 }
 
 // TODO: multiple type generic struct  needs fixing in return for fn
-// fn new_repo<T>(db DB) Repo<T,U> {
-// return Repo<T,Permission>{db: db}
+// fn new_repo[T](db DB) Repo[T,U] {
+// return Repo[T,Permission]{db: db}
 // }
 fn test_generic_struct() {
 	mut a := Repo[User, Permission]{
@@ -474,7 +474,6 @@ fn test_generic_init() {
 }
 
 fn return_one[T](rec int, useless T) T {
-	// foo < bar<T>() should work
 	if rec == 0 || 0 < return_one[T](rec - 1, useless) {
 		return T(1)
 	}