checker, fmt: check infix_expr with 'and' op (#15466)

vlib/v/checker/infix.v

@@ -20,6 +20,11 @@ pub fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 	if node.op == .key_is {
 		c.inside_x_is_type = false
 	}
+	if node.op == .amp && left_type.is_bool() && right_type.is_bool() && right_type.is_ptr() {
+		pos := node.pos.extend(node.right.pos())
+		c.error('the right expression should be separated from the `&&` by a space', pos)
+		return ast.bool_type
+	}
 	node.right_type = right_type
 	if left_type.is_number() && !left_type.is_ptr()
 		&& right_type in [ast.int_literal_type, ast.float_literal_type] {

vlib/v/checker/tests/infix_and_op_expr_err.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/infix_and_op_expr_err.vv:3:17: error: the right expression should be separated from the `&&` by a space
+    1 | fn main() {
+    2 |     ok1 := true
+    3 |     ok2 := false&&ok1
+      |                 ~~
+    4 |     println(ok2)
+    5 | }

vlib/v/checker/tests/infix_and_op_expr_err.vv

@@ -0,0 +1,5 @@
+fn main() {
+    ok1 := true
+    ok2 := false&&ok1
+    println(ok2)
+}

vlib/v/fmt/fmt.v

@@ -2055,16 +2055,21 @@ pub fn (mut f Fmt) infix_expr(node ast.InfixExpr) {
 	f.expr(node.left)
 	is_one_val_array_init := node.op in [.key_in, .not_in] && node.right is ast.ArrayInit
 		&& (node.right as ast.ArrayInit).exprs.len == 1
+	is_and := node.op == .amp && f.node_str(node.right).starts_with('&')
 	if is_one_val_array_init {
 		// `var in [val]` => `var == val`
 		op := if node.op == .key_in { ' == ' } else { ' != ' }
 		f.write(op)
+	} else if is_and {
+		f.write(' && ')
 	} else {
 		f.write(' $node.op.str() ')
 	}
 	if is_one_val_array_init {
 		// `var in [val]` => `var == val`
 		f.expr((node.right as ast.ArrayInit).exprs[0])
+	} else if is_and {
+		f.write(f.node_str(node.right).trim_string_left('&'))
 	} else {
 		f.expr(node.right)
 	}

vlib/v/fmt/tests/infix_expr_and_op_expected.vv

@@ -0,0 +1,5 @@
+fn main() {
+	ok1 := true
+	ok2 := false && ok1
+	println(ok2)
+}

vlib/v/fmt/tests/infix_expr_and_op_input.vv

@@ -0,0 +1,5 @@
+fn main() {
+    ok1 := true
+    ok2 := false&&ok1
+    println(ok2)
+}