gistfile1.txt

#Constructor 1.
proc newSketcher*[T](): Sketcher[T] {.inline, forceCheck: [].} =
    @[]

#Constructor 2.
proc newSketcher*[T](
    elements: seq[T] = @[]
): Sketcher[T] {.forceCheck: [].} =
    result = @[]
    for element in elements:
        result.add(SketchElement[T](
            element: element,
            significance: 0
        ))

#Add an element.
proc add*[T](
    sketcher: Sketcher[T],
    elem: T,
    significance: int
) {.forceCheck: [].} =
    sketcher.add(SketchElement(
        element: elem,
        significance: significance
    ))

#Convert a Sketcher to a Sketch.
proc toSketch[T](
    sketcher: Sketcher[T],
    capacity: int,
    significant: int,
    salt: string
): tuple[
    sketch: Sketch,
    hashes: Table[uint64, int]
] {.forceCheck: [
    ValueError
].} =
    #Create the sketch.
    result.sketch = newSketch(64, 0, capacity)
    result.hashes = initTable[uint64, int]()

    var hash: uint64
    for e in 0 ..< sketcher.len:
        #If it's significant, use it.
        if sketcher[e].significance >= significant:
            #Hash the element.
            hash = sketcher[e].element.sketchHash(salt)
            #If there's a collision, throw.
            if result.hashes.hasKey(hash):
                raise newException(ValueError, "Collision found while sketching values.")

            result.sketch.add(hash)
            result.hashes[hash] = e