old star

gistfile1.txt

private[mada] class StarPeg[A](p: Peg[A]) extends Reluctant[A] {
    override def parse(v: Vector[A], start: Int, end: Int): Int = {
        // StarUntil(p, !p) would include unneeded parsing.
        var cur = start
        while (cur != end) {
            val next = p.parse(v, cur, end)
            if (next == Peg.FAILURE) {
                return cur
            }
            // Assert(cur != next) // can't assert dynamic parsers.
            cur = next
        }
        cur
    }

    override def before(that: Peg[A]) = new StarUntilPeg(p, ~that)
    override def until(that: Peg[A]) = new StarUntilPeg(p, that)
}

private[mada] class StarUntilPeg[A](p: Peg[A], q: Peg[A]) extends Peg[A] {
    override def parse(v: Vector[A], start: Int, end: Int): Int = {
        var cur = start
        var next = q.parse(v, cur, end)
        while (next == Peg.FAILURE) {
            next = p.parse(v, cur, end)
            if (next == Peg.FAILURE) {
                return Peg.FAILURE
            }
            cur = next
            next = q.parse(v, cur, end)
        }
        next
    }
}