Seq

Namespace: Deedle.Internal

This module contains additional functions for working with sequences. Deedle.Internals is opened, it extends the standard Seq module.

Functions and values

Function or value	Description
`alignAllOrdered collections comparer` Signature: collections:ReadOnlyCollection<'a> [] -> comparer:IComparer<'a> -> 'a [] * (int64 * int64) [] list Type parameters: 'a	Calls either `alignAllOrderedMany` or `alignAllOrderedFew` depending on the number of sequences to be aligned. Performance measurements suggest that 150 is the limit when the implementation using binomial heap is faster.
`alignAllOrderedFew seqs comparer` Signature: seqs:ReadOnlyCollection<'T> [] -> comparer:IComparer<'T> -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align N ordered sequences of keys (using the specified comparer) This is the same as `alignOrdered` but for larger number of key sequences. Throws ComparisonFailedException when the comparer fails. (This performs union on the specified sequences)
`alignAllOrderedMany seqs comparer` Signature: seqs:ReadOnlyCollection<'T> [] -> comparer:IComparer<'T> -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align N ordered sequences of keys (using the specified comparer) This is the same as `alignOrdered` but for larger number of key sequences. Throws ComparisonFailedException when the comparer fails. (This performs union on the specified sequences)
`alignAllUnordered(seqs)` Signature: seqs:ReadOnlyCollection<'T> [] -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align N unordered sequences of keys (performs union of the keys)
`alignOrdered(...)` Signature: seq1:ReadOnlyCollection<'T> -> seq2:ReadOnlyCollection<'T> -> comparer:IComparer<'T> -> intersectionOnly:bool -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align two ordered sequences of keys (using the specified comparer) The resulting relocations are returned as two-element list for symmetry with other functions Throws ComparisonFailedException when the comparer fails. When `intersectionOnly = true`, the function only adds keys & relocations for keys that appear in both sequences (otherwise, it performs union)
`alignUnordered s1 s2 intersectionOnly` Signature: s1:ReadOnlyCollection<'a> -> s2:ReadOnlyCollection<'a> -> intersectionOnly:bool -> 'a [] * (int64 * int64) [] list Type parameters: 'a	Align two unordered sequences of keys. Calls either `alignUnorderedUnion` or `alignUnorderedIntersection`, based on the `intersectionOnly` parameter.
`alignUnorderedIntersection seq1 seq2` Signature: seq1:ReadOnlyCollection<'T> -> seq2:ReadOnlyCollection<'T> -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align two unordered sequences of keys (performs intersection of the keys) The resulting relocations are returned as two-element list for symmetry with other functions
`alignUnorderedUnion seq1 seq2` Signature: seq1:ReadOnlyCollection<'T> -> seq2:ReadOnlyCollection<'T> -> 'T [] * (int64 * int64) [] list Type parameters: 'T	Align two unordered sequences of keys (performs union of the keys) The resulting relocations are returned as two-element list for symmetry with other functions
`choosel f input` Signature: f:(int64 -> 'a -> 'b option) -> input:seq<'a> -> seq<'b> Type parameters: 'a, 'b	Same as `Seq.choose` but passes 64 bit index (l stands for long) to the function
`chunkedWhile f input` Signature: f:('?692951 -> '?692951 -> bool) -> input:seq<'?692951> -> seq<'?692951 []> Type parameters: '?692951	Generate non-verlapping chunks from the input sequence. A chunk is started at the beginning and then immediately after the end of the previous chunk. To find the end of the chunk, the function calls the provided argument `f` with the first and the last elements of the chunk as arguments. A chunk ends when `f` returns `false`.
`chunkedWithBounds size boundary input` Signature: size:int -> boundary:Boundary -> input:seq<'?692955> -> seq<DataSegment<'?692955 []>> Type parameters: '?692955	Similar to `Seq.windowedWithBounds`, but generates non-overlapping chunks rather than floating windows. See that function for detailed documentation. The function may iterate over the sequence repeatedly.
`chunkRangesWhile f input` Signature: f:('a -> 'a -> bool) -> input:seq<'a> -> seq<int64 * int64> Type parameters: 'a	Generate non-verlapping chunks from the input sequence. A chunk is started at the beginning and then immediately after the end of the previous chunk. To find the end of the chunk, the function calls the provided argument `f` with the first and the last elements of the chunk as arguments. A chunk ends when `f` returns `false`. The function returns the chunks as pairs of their indices.
`chunkRangesWithBounds(...)` Signature: size:int64 -> boundary:Boundary -> length:int64 -> seq<DataSegmentKind * int64 * int64>	Generates addresses of windows in a collection of size 'length'. For example, consider a collection with 7 elements (and indices 0 .. 6) and the requirement to create windows of length 3: 0 1 2 3 4 5 6 When the `AtEnding` flag is set for `boundary`: c c c c c c d The two chunks marked as 'c' are returned always. The incomplete chunk at the end is returned unless the `Skip` flag is set for `boundary`. When the `AtBeginning` flag is set, the incomplete chunk is (when not `Skip`) returned at the beginning: d c c c c c c The chunks are specified by inclusive indices, so, e.g. the first chunk in the second example above is returned as a pair (0, 0).
`getEnumerator(s)` Signature: s:seq<'?692945> -> IEnumerator<'?692945> Type parameters: '?692945	Calls the `GetEnumerator` method. Simple function to guide type inference.
`headOrNone(input)` Signature: input:seq<'a> -> 'a option Type parameters: 'a	If the input is non empty, returns `Some(head)` where `head` is the first value. Otherwise, returns `None`.
`isSorted data comparer` Signature: data:seq<'T> -> comparer:IComparer<'T> -> bool Type parameters: 'T	Returns true if the specified sequence is sorted.
`lastAndLength(input)` Signature: input:seq<'a> -> 'a * int Type parameters: 'a	Returns the last element and the length of a sequence (using just a single iteration over the sequence)
`lastFew count input` Signature: count:int -> input:seq<'?692943> -> seq<'?692943> Type parameters: '?692943	Returns the specified number of elements from the end of the sequence Note that this needs to store the specified number of elements in memory and it needs to iterate over the entire sequence.
`mapl f input` Signature: f:(int64 -> 'a -> 'b) -> input:seq<'a> -> seq<'b> Type parameters: 'a, 'b	Same as `Seq.map` but passes 64 bit index (l stands for long) to the function
`range lo hi` Signature: lo:^T -> hi:^T -> IEnumerable<^T> Type parameters: ^T	A helper function that generates a sequence for the specified range of int or int64 values. This is notably faster than using `lo .. hi`.
`rangeStep lo step hi` Signature: lo:^T -> step:^T -> hi:^T -> IEnumerable<^T> Type parameters: ^T	A helper function that generates a sequence for the specified range of int or int64 values. This is notably faster than using `lo .. step .. hi`.
`skipAtMost count input` Signature: count:int -> input:seq<'b> -> seq<'b> Type parameters: 'b	Skip at most the specified number of elements. This is like `Seq.skip`, but it does not throw when the sequence is shorter.
`startAndEnd startCount endCount input` Signature: startCount:int -> endCount:int -> input:seq<'a> -> seq<Choice<'a,unit,'a>> Type parameters: 'a	Given a sequence, returns `startCount` number of elements at the beginning of the sequence (wrapped in `Choice1Of3`) followed by one `Choice2Of2()` value and then followed by `endCount` number of elements at the end of the sequence wrapped in `Choice3Of3`. If the input is shorter than `startCount + endCount`, then all values are returned and wrapped in `Choice1Of3`.
`structuralEquals s1 s2` Signature: s1:seq<'T> -> s2:seq<'T> -> bool Type parameters: 'T	Comapre two sequences using the `Equals` method. Returns true when all their elements are equal and they have the same size.
`structuralHash(s)` Signature: s:seq<'T> -> int Type parameters: 'T	Calculate hash code of a sequence, based on the values
`tryFirstAndLast(input)` Signature: input:seq<'a> -> ('a * 'a) option Type parameters: 'a	Returns the first and the last element from a sequence or 'None' if the sequence is empty
`uniqueBy f input` Signature: f:('a -> 'b) -> input:seq<'a> -> 'b Type parameters: 'a, 'b	If the projection returns the same value for all elements, then it returns the value. Otherwise it throws an exception.
`unreduce f start` Signature: f:('a -> 'a) -> start:'a -> seq<'a> Type parameters: 'a	Generate infinite sequence using the specified function. The initial state is returned as the first element.
`windowedWhile f input` Signature: f:('T -> 'T -> bool) -> input:seq<'T> -> seq<'T []> Type parameters: 'T	Generate floating windows from the input sequence. New floating window is started for each element. To find the end of the window, the function calls the provided argument `f` with the first and the last elements of the window as arguments. A window ends when `f` returns `false`.
`windowedWithBounds size boundary input` Signature: size:int -> boundary:Boundary -> input:seq<'T> -> seq<DataSegment<'T []>> Type parameters: 'T	A version of `Seq.windowed` that allows specifying more complex boundary behaviour. The `boundary` argument can specify one of the following options: `Boundary.Skip` - only full windows are returned (like `Seq.windowed`) `Boundary.AtBeginning` - incomplete windows (smaller than the required size) are returned at the beginning. `Boundary.AtEnding` - incomplete windows are returned at the end. The result is a sequence of `DataSegnebt<T>` values, which makes it easy to distinguish between complete and incomplete windows.
`windowRangesWhile f input` Signature: f:('T -> 'T -> bool) -> input:seq<'T> -> seq<int64 * int64> Type parameters: 'T	Generate floating windows from the input sequence. New floating window is started for each element. To find the end of the window, the function calls the provided argument `f` with the first and the last elements of the window as arguments. A window ends when `f` returns `false`. The function returns the windows as pairs of their indices.
`windowRangesWithBounds(...)` Signature: size:int64 -> boundary:Boundary -> length:int64 -> seq<DataSegmentKind * int64 * int64>	Generates addresses of chunks in a collection of size 'length'. For example, consider a collection with 7 elements (and indices 0 .. 6) and the requirement to create chunks of length 4: 0 1 2 3 4 5 6 s s s s s s w w w w w w w w w w w w w w w w e e e e e e The windows 's' are returned when `boundary = Boundary.AtBeginning` and the windows 'e' are returned when `boundary = Boundary.AtEnding`. The middle is returned always. The windows are specified by inclusive indices, so, e.g. the first window is returned as a pair (0, 0).