Parser doesn't stop when it encounters wrong parenthesis

[shtolfensie]

The parser should stop execution and return an error when it finds invalid syntax. Right now it just logs the error into the console and continues.

Console output

2021/04/28 00:52:06 &{{1 5 5} <nil> <nil>}
2021/04/28 00:52:06 &{{1 2 2} <nil> <nil>}
2021/04/28 00:52:06 &{{1 3 3} <nil> <nil>}
2021/04/28 00:52:06 &{{1 2 2} <nil> <nil>} &{{1 3 3} <nil> <nil>}
2021/04/28 00:52:06 &{{1 5 5} <nil> <nil>}
2021/04/28 00:52:06 &{{0 + 0} 0xc0000a2c30 0xc0000a2c90} &{{1 5 5} <nil> <nil>}
2021/04/28 00:52:06 error at:  (
2021/04/28 00:52:06 &{{1 ( 0} <nil> <nil>}
2021/04/28 00:52:06 &{{0 * 0} 0xc0000a2d50 0xc0000a2d80} &{{1 ( 0} <nil> <nil>}
5 <nil>
PASS
ok      ivs-calculator/pkg/interpreter  0.003s

Code to reproduce

func TestParse(t *testing.T) {
	inStr, _ := toSlice("5%((2 + 3)(*5)")
	post, _ := inToPost(inStr)

	tree := postToTree(post)

	fmt.Println(Interpret(tree))
}

[shtolfensie]

Also with these inputs it doesn't even detect the wrong syntax

inStr, _ := toSlice("5%((2 +3)()*5)")
--- or ---
inStr, _ := toSlice("5%((2 +3)(4)*5)")
--- or ---
inStr, _ := toSlice("5%((2 +3)(4+9)*5)")

Should we consider this correct syntax? I would prefer if it was reported as an error to the user.

The last one is the worst, because it might almost look correct, but the parser completely ignores it.