prog8/compiler/test/helpers/mapCombinations.kt

68 lines
2.0 KiB
Kotlin

package prog8tests.helpers
object Combinations {
fun <T, U> cartesianProduct(c1: Collection<T>, c2: Collection<U>): Sequence<Pair<T, U>> {
return c1.flatMap { lhsElem -> c2.map { rhsElem -> lhsElem to rhsElem } }.asSequence()
}
fun <T, U, V> cartesianProduct(c1: Collection<T>, c2: Collection<U>, c3: Collection<V>): Sequence<Triple<T, U, V>> {
return sequence {
for (a in c1)
for (b in c2)
for (c in c3)
yield(Triple(a, b, c))
}
}
data class Product<out T, out U, out V, out W>(val first: T, val second: U, val third: V, val fourth: W)
fun <T, U, V, W> cartesianProduct(
c1: Collection<T>,
c2: Collection<U>,
c3: Collection<V>,
c4: Collection<W>
): Sequence<Product<T, U, V, W>> {
return sequence {
for (a in c1)
for (b in c2)
for (c in c3)
for (d in c4)
yield(Product(a, b, c, d))
}
}
fun <A, B, R> mapCombinations(dim1: Iterable<A>, dim2: Iterable<B>, combine2: (A, B) -> R) =
sequence {
for (a in dim1)
for (b in dim2)
yield(combine2(a, b))
}.toList()
fun <A, B, C, R> mapCombinations(
dim1: Iterable<A>,
dim2: Iterable<B>,
dim3: Iterable<C>,
combine3: (A, B, C) -> R
) =
sequence {
for (a in dim1)
for (b in dim2)
for (c in dim3)
yield(combine3(a, b, c))
}.toList()
fun <A, B, C, D, R> mapCombinations(
dim1: Iterable<A>,
dim2: Iterable<B>,
dim3: Iterable<C>,
dim4: Iterable<D>,
combine4: (A, B, C, D) -> R
) =
sequence {
for (a in dim1)
for (b in dim2)
for (c in dim3)
for (d in dim4)
yield(combine4(a, b, c, d))
}.toList()
}