Put a new element after the others.

arrWithAtLeast5Elements
    |> MinArr.push "becomes the last"
--> : Arr (Min Nat6) String

Kick out the element at an index in a direction.

removeLast arrWithAtLeast1Element =
    arrWithAtLeast1Element
        |> MinArr.removeAt nat0 LastToFirst

Put a new element at an index in a direction.

arrWithAtLeast5Elements
    |> MinArr.insertAt nat0 FirstToLast
        "becomes the first"
--> : Arr (Min Nat6) String

Append an Arr (In ...).

Arr.from3 1 2 3
    |> MinArr.extend nat3 arrWithAtLeast3Elements
--> : Arr (Min Nat6) ...

Compare the length to an exact Nat (ArgN ...). Is it greater, less or equal?

min ensures that the Nat (ArgN ...) is bigger than the minimum length.

convertUserArguments :
    String
    -> Result String (Arr (Only Nat3))
convertUserArguments =
    String.words
        >> Array.fromList
        >> Arr.fromArray
        >> MinArr.isLength nat3
            { min = nat0 }
            { equal = Ok
            , less =
                \less ->
                    Err
                        ("I need 3 arguments, but there are only "
                            ++ String.fromInt (val (Arr.length less))
                            ++ "."
                        )
            , greater =
                \more ->
                    Err
                        ("I need exact 3 arguments, so "
                            ++ String.fromInt (val (Arr.length more))
                            ++ " is too much."
                        )
            }

Compare the length to an exact Nat (ArgN ...). Is it equalOrGreater or less?

min ensures that the lower bound is bigger than the minimum length.

convertUserArguments :
    String
    -> Result String (Arr (Min Nat3))
convertUserArguments =
    String.words
        >> Array.fromList
        >> Arr.fromArray
        >> MinArr.isLengthAtLeast nat3
            { min = nat0 }
            { equalOrGreater = Ok
            , less =
                \less ->
                    Err
                        ("I need at least 3 arguments, but there are only "
                            ++ String.fromInt (val (Arr.length less))
                            ++ "."
                        )
            }

Is the length

• equalOrLess than an upper bound or

• greater?

min ensures that the upper bound is greater than the minimum length.

-- only up to 50 tags
tag :
    Arr (In min Nat50 maybeN) String
    -> a
    -> Tagged a


tagIfValidTags : Array String -> a -> Maybe (Tagged a)
tagIfValidTags array value =
    array
        |> Arr.fromArray
        |> MinArr.isLengthAtMost nat50
            { equalOrLess = tag value >> Just
            , greater = \_ -> Nothing
            }

Convert an exact Arr (In min ...) to a Nat (Min min).

between4And10Elements |> MinArr.value
--> : Arr (Min Nat4) ...

There is only 1 situation you should use this.

To make these the same type.

[ atLeast1Element, between1And10Elements ]

Elm complains:

But all the previous elements in the list are Arr (Min Nat1) ...

[ atLeast1Element
, between1And10Elements |> MinArr.value
]

A Codec to serialize Arrs with a minimum amount of elements.

import Serialize




-- we can't start if we have no worlds to choose from!
serializeSaves :
    Serialize.Codec
        String
        (Arr (Min Nat1) World)
serializeSaves =
    MinArr.serialize nat1 serializeWorld


encode :
    Arr (In (Nat1Plus minMinus1) max maybeN) World
    -> Bytes
encode =
    MinArr.value
        >> Serialize.encodeToBytes serializeSaves


decode :
    Bytes
    ->
        Result
            (Serialize.Error String)
            (Arr (Min Nat1) World)
decode =
    Serialize.decodeFromBytes serializeSaves