# IRangeKeyOperations<'TKey>

Namespace: Deedle.Ranges

A set of operations on keys that you need to implement in order to use the Ranges<'TKey> type. The 'TKey type is typically the key of a BigDeedle series. It can represent different things, such as:

• int64 - if you have ordinally indexed series
• Date (of some sort) - if you have daily time series
• DateTimeOffset - if you have time series with DTO keys

The operations need to implement the right thing based on the logic of the keys. So for example if you have one data point every hour, IncrementBy should add the appropriate number of hours. Or if you have keys as business days, the IncrementBy operation should add a number of business days (that is, the operations may be simple numerical addition, but may contain more logic).

### Instance members

 Instance member Description  x.Compare(arg1, arg2)  Signature: ('TKey * 'TKey) -> int Modifiers: abstract Compare two keys. Return +1 if first is larger, -1 if second is larger, 0 otherwise  x.Distance(arg1, arg2)  Signature: ('TKey * 'TKey) -> int64 Modifiers: abstract Return distance between two keys - return 0 if the keys are the same (the second key is always larger than the first)  x.IncrementBy(arg1, arg2)  Signature: ('TKey * int64) -> 'TKey Modifiers: abstract Get the n-th next key after the specified key (n is always non-negative)  x.Range(arg1, arg2)  Signature: ('TKey * 'TKey) -> seq<'TKey> Modifiers: abstract Generate keys within the specific range (inclusively). Here, the second key can be smaller (in which case the range should be from larger to smaller)  x.ValidateKey(arg1, arg2)  Signature: ('TKey * Lookup) -> OptionalValue<'TKey> Modifiers: abstract Find the first valid key around the specified 'TKey value. This is used when not all 'TKey values can appear as keys of the series. If lookup is Exact, it should just check validity; for other lookups, this should either find first smaller or first larger valid key (but not skip any keys). This is only called with lookup = Lookup.Exact, unless you are also using Ranges.lookup function inside IVirtualVectorSource<'T>.LookupValue.