gistfile1.txt

grammar Assembly {
    rule TOP { ^ <statement>+ $ }
    rule statement {
        <operator> <operand> $$
    }
    rule operator {
        | lda
        | ldx
        | ldy
    }
    token operand {
        '#' <number> # immediate mode
    }
    token number {
        | 25<[0..5]>
        | 2<[0..4]><[0..9]>
        | 1<[0..9]><[0..9]>
        | <[1..9]><[0..9]>
        | <[0..9]>
    }
}

Assembly.parse("lda #27\nldx #35");