parser: assure explicit `map` init contains no parameters (#8299)

vlib/v/parser/parse_type.v

@@ -90,6 +90,10 @@ pub fn (mut p Parser) parse_map_type() table.Type {
 		// error is reported in parse_type
 		return 0
 	}
+	if value_type.idx() == table.void_type_idx {
+		p.error_with_pos('map value type cannot be void', p.tok.position())
+		return 0
+	}
 	idx := p.table.find_or_register_map(key_type, value_type)
 	return table.new_type(idx)
 }

vlib/v/parser/parser.v

@@ -1140,9 +1140,13 @@ pub fn (mut p Parser) name_expr() ast.Expr {
 	// `map[string]int` initialization
 	if p.tok.lit == 'map' && p.peek_tok.kind == .lsbr {
 		map_type := p.parse_map_type()
-		if p.tok.kind == .lcbr && p.peek_tok.kind == .rcbr {
-			p.next()
+		if p.tok.kind == .lcbr {
 			p.next()
+			if p.tok.kind == .rcbr {
+				p.next()
+			} else {
+				p.error('`}` expected; explicit `map` initialization does not support parameters')
+			}
 		}
 		return ast.MapInit{
 			typ: map_type

vlib/v/parser/tests/map_init.out

@@ -0,0 +1,6 @@
+vlib/v/parser/tests/map_init.vv:3:22: error: `}` expected; explicit `map` initialization does not support parameters
+    1 | fn main() {
+    2 |     a := map[string]int{}
+    3 |     b := map[string]f64{cap: 10}
+      |                         ~~~
+    4 | }

vlib/v/parser/tests/map_init.vv

@@ -0,0 +1,4 @@
+fn main() {
+	a := map[string]int{}
+	b := map[string]f64{cap: 10}
+}

vlib/v/parser/tests/map_init_void.out

@@ -0,0 +1,5 @@
+vlib/v/parser/tests/map_init_void.vv:2:18: error: map value type cannot be void
+    1 | fn main() {
+    2 |     m := map[string]{}
+      |                     ^
+    3 | }

vlib/v/parser/tests/map_init_void.vv

@@ -0,0 +1,3 @@
+fn main() {
+	m := map[string]{}
+}

vlib/v/parser/tests/map_init_void2.out

@@ -0,0 +1,5 @@
+vlib/v/parser/tests/map_init_void2.vv:1:19: error: expecting type declaration
+    1 | fn f(m map[string]) {
+      |                   ^
+    2 |     println('illegal function')
+    3 | }

vlib/v/parser/tests/map_init_void2.vv

@@ -0,0 +1,7 @@
+fn f(m map[string]) {
+	println('illegal function')
+}
+
+fn main() {
+	println('Hello world')
+}