use crate::parser::parse_test;

parse_test! {
name: arith
syntax: r#"
    rule _ = [' ']*;

    rule num = #str(['0'-'9']+);

    rule start = e <- _ e:expr _;
    

    rule expr {
        Add(l, r) <- l:expr2 _ "+" _ r:expr;
        Sub(l, r) <- l:expr2 _ "-" _ r:expr;
        expr2;
    }
    

    rule expr2 {
        Mul(l, r) <- l:expr3 _ "*" _ r:expr2;
        Div(l, r) <- l:expr3 _ "/" _ r:expr2;
        expr3;
    }

    rule expr3 {
        Pow(l, r) <- l:expr3 _ "^" _ r:expr4;
        expr4;
    }

    rule expr4 {
        Neg(e) <- "-" _ e:expr4;
        Num(e) <- e:num;
    }
    
    "#
passing tests:
    "123" => "Num('123')"
    "5 * 4 + 20 * 4 - 50" => "Add(Mul(Num('5'), Num('4')), Sub(Mul(Num('20'), Num('4')), Num('50')))"
    "5 * 4 - 20 * 4 + 50" => "Sub(Mul(Num('5'), Num('4')), Add(Mul(Num('20'), Num('4')), Num('50')))"
    "-5 * -4 - -20 * -4 + -50" => "Sub(Mul(Neg(Num('5')), Neg(Num('4'))), Add(Mul(Neg(Num('20')), Neg(Num('4'))), Neg(Num('50'))))"
    "1 + 2 * 3" => "Add(Num('1'), Mul(Num('2'), Num('3')))"
    "1 * 2 + 3" => "Add(Mul(Num('1'), Num('2')), Num('3'))"
    "1 - 2 / 3" => "Sub(Num('1'), Div(Num('2'), Num('3')))"
    "1 / 2 - 3" => "Sub(Div(Num('1'), Num('2')), Num('3'))"
    "-8" => "Neg(Num('8'))"

failing tests:
    ""
    "1+"
    "+1"
}