parser: treat f<mod.Type> as generic call not `<` operator (#8938)

vlib/v/parser/parser.v

@@ -1121,15 +1121,20 @@ fn (p &Parser) is_generic_call() bool {
 	} else {
 		false
 	}
+	tok2 := p.peek_token(2)
+	tok3 := p.peek_token(3)
+	tok4 := p.peek_token(4)
+	tok5 := p.peek_token(5)
 	// use heuristics to detect `func<T>()` from `var < expr`
-	return !lit0_is_capital && p.peek_tok.kind == .lt && (match p.peek_token(2).kind {
+	return !lit0_is_capital && p.peek_tok.kind == .lt && (match tok2.kind {
 		.name {
-			// maybe `f<int>`, `f<map[`, f<string,
+			// (`f<int>`, `f<string,`) || (`f<mod.Type>`, `<mod.Type,`) || `f<map[`,
-			(p.peek_token(2).kind == .name && p.peek_token(3).kind in [.gt, .comma]) || (p.peek_token(2).lit == 'map' && p.peek_token(3).kind == .lsbr)
+
+			tok3.kind in [.gt, .comma] || (tok3.kind == .dot && tok4.kind == .name && tok5.kind in [.gt, .comma]) || (tok2.lit == 'map' && tok3.kind == .lsbr)
 		}
 		.lsbr {
 			// maybe `f<[]T>`, assume `var < []` is invalid
-			p.peek_token(3).kind == .rsbr
+			tok3.kind == .rsbr
 		}
 		else {
 			false

vlib/v/tests/generics_test.v

@@ -23,6 +23,8 @@ fn test_identity() {
 
 	assert simple<[]int>([1])[0] == 1
 	assert simple<map[string]string>({'a':'b'})['a'] == 'b'
+
+	assert simple<simplemodule.Data>(simplemodule.Data{value: 0}).value == 0
 }
 
 fn test_plus() {

vlib/v/tests/modules/simplemodule/simplemodule.v

@@ -11,3 +11,8 @@ pub fn imul(x int, y int) int {
 pub struct ThisIsGeneric<T> {
 	msg T
 }
+
+pub struct Data {
+pub:
+	value int
+}