Rows

Namespace: Polars.FSharp

Module Functions

Rows.choose

Chooses values from the rows of the enumerator that satisfy the predicate.

Rows.choose : chooser: ('T -> 'U option) -> enumerator: RowEnumerator<'T> -> List<'U>

Parameters

Name	Type	Description
chooser	('T -> 'U option)	-
enumerator	RowEnumerator<'T>	-

---

Rows.contains

Tests if the enumerator contains the specified element using default structural equality. Short-circuits upon discovery.

Rows.contains : element: 'T -> enumerator: RowEnumerator<'T> -> bool

Parameters

Name	Type	Description
element	'T	-
enumerator	RowEnumerator<'T>	-

---

Rows.countBy

Applies a key-generating function to each row and returns a dictionary with the frequency of each key.

Rows.countBy : projection: ('T -> 'Key) -> enumerator: RowEnumerator<'T> -> Dictionary<'Key, int64>

Parameters

Name	Type	Description
projection	('T -> 'Key)	-
enumerator	RowEnumerator<'T>	-

---

Rows.exists

Returns whether any row satisfies the predicate.

Rows.exists : predicate: ('T -> bool) -> enumerator: RowEnumerator<'T> -> bool

Parameters

Name	Type	Description
predicate	('T -> bool)	-
enumerator	RowEnumerator<'T>	-

---

Rows.filter

Filters the rows of the enumerator that satisfy the predicate.

Rows.filter : predicate: ('T -> bool) -> enumerator: RowEnumerator<'T> -> List<'T>

Parameters

Name	Type	Description
predicate	('T -> bool)	-
enumerator	RowEnumerator<'T>	-

---

Rows.fold

Folds over the rows of the enumerator, applying the folder function to each row.

Rows.fold : folder: ('State -> ('T -> 'State)) -> initial: 'State -> enumerator: RowEnumerator<'T> -> 'State

Parameters

Name	Type	Description
folder	('State -> ('T -> 'State))	-
initial	'State	-
enumerator	RowEnumerator<'T>	-

---

Rows.foldi

Folds over the rows of the enumerator with index.

Rows.foldi : folder: (int64 -> ('State -> ('T -> 'State))) -> initial: 'State -> enumerator: RowEnumerator<'T> -> 'State

Parameters

Name	Type	Description
folder	(int64 -> ('State -> ('T -> 'State)))	-
initial	'State	-
enumerator	RowEnumerator<'T>	-

---

Rows.forall

Returns whether all rows satisfy the predicate.

Rows.forall : predicate: ('T -> bool) -> enumerator: RowEnumerator<'T> -> bool

Parameters

Name	Type	Description
predicate	('T -> bool)	-
enumerator	RowEnumerator<'T>	-

---

Rows.groupBy

Groups the rows of the enumerator using the key-generating function, returning an idiomatic F# immutable Map of key to row list.

Rows.groupBy : keySelector: ('T -> 'Key) -> enumerator: RowEnumerator<'T> -> Map<'Key, 'T list>

Parameters

Name	Type	Description
keySelector	('T -> 'Key)	-
enumerator	RowEnumerator<'T>	-

---

Rows.head

Returns the first mapped row or raises InvalidOperationException if empty.

Rows.head : enumerator: RowEnumerator<'T> -> 'T

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.iter

Iterates over the rows of the enumerator, applying the action to each row.

Rows.iter : action: ('T -> unit) -> enumerator: RowEnumerator<'T> -> unit

Parameters

Name	Type	Description
action	('T -> unit)	-
enumerator	RowEnumerator<'T>	-

---

Rows.iter2

Iterates simultaneously over two equal-length RowEnumerators, applying the action pairwise.

Rows.iter2 : action: ('T1 -> ('T2 -> unit)) -> enum1: RowEnumerator<'T1> -> enum2: RowEnumerator<'T2> -> unit

Parameters

Name	Type	Description
action	('T1 -> ('T2 -> unit))	-
enum1	RowEnumerator<'T1>	-
enum2	RowEnumerator<'T2>	-

---

Rows.iteri

Iterates over the rows of the enumerator, applying the action with zero-based 64-bit row index.

Rows.iteri : action: (int64 -> ('T -> unit)) -> enumerator: RowEnumerator<'T> -> unit

Parameters

Name	Type	Description
action	(int64 -> ('T -> unit))	-
enumerator	RowEnumerator<'T>	-

---

Rows.iteri2

Iterates simultaneously over two equal-length RowEnumerators with zero-based 64-bit row index.

Rows.iteri2 : action: (int64 -> ('T1 -> ('T2 -> unit))) -> enum1: RowEnumerator<'T1> -> enum2: RowEnumerator<'T2> -> unit

Parameters

Name	Type	Description
action	(int64 -> ('T1 -> ('T2 -> unit)))	-
enum1	RowEnumerator<'T1>	-
enum2	RowEnumerator<'T2>	-

---

Rows.last

Returns the last mapped row or raises InvalidOperationException if empty.

Rows.last : enumerator: RowEnumerator<'T> -> 'T

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.length

Returns the total row count as a 64-bit integer.

Rows.length : enumerator: RowEnumerator<'T> -> int64

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.map

Maps each row of the enumerator to a new value using the mapping function.

Rows.map : mapping: ('T -> 'U) -> enumerator: RowEnumerator<'T> -> seq<'U>

Parameters

Name	Type	Description
mapping	('T -> 'U)	-
enumerator	RowEnumerator<'T>	-

---

Rows.mapToArray

Projects all rows of the enumerator into a strongly-typed array using an inlined mapping function. Eliminates intermediate IEnumerator heap boxing and lambda allocations.

Rows.mapToArray : mapping: ('TIn -> 'TOut) -> enumerator: RowEnumerator<'TIn> -> 'TOut[]

Parameters

Name	Type	Description
mapping	('TIn -> 'TOut)	-
enumerator	RowEnumerator<'TIn>	-

---

Rows.mapi

Maps each row with its zero-based 64-bit row index to a lazy F# sequence.

Rows.mapi : mapping: (int64 -> ('T -> 'U)) -> enumerator: RowEnumerator<'T> -> seq<'U>

Parameters

Name	Type	Description
mapping	(int64 -> ('T -> 'U))	-
enumerator	RowEnumerator<'T>	-

---

Rows.reduce

Applies a function to each row, threading an accumulator argument through the computation. Raises InvalidOperationException if the enumerator has no elements.

Rows.reduce : reduction: ('T -> ('T -> 'T)) -> enumerator: RowEnumerator<'T> -> 'T

Parameters

Name	Type	Description
reduction	('T -> ('T -> 'T))	-
enumerator	RowEnumerator<'T>	-

---

Rows.scan

Like fold, but returns a lazy sequence of intermediate and final results.

Rows.scan : folder: ('State -> ('T -> 'State)) -> initial: 'State -> enumerator: RowEnumerator<'T> -> seq<'State>

Parameters

Name	Type	Description
folder	('State -> ('T -> 'State))	-
initial	'State	-
enumerator	RowEnumerator<'T>	-

---

Rows.sumBy

Sums the values of the rows of the enumerator using the projection function.

Rows.sumBy : projection: ('T -> 'Num) -> enumerator: RowEnumerator<'T> -> 'Num

Parameters

Name	Type	Description
projection	('T -> 'Num)	-
enumerator	RowEnumerator<'T>	-

---

Rows.sumBy$W

Rows.sumBy$W : get_Zero: (unit -> 'Num) -> op_Addition: ('Num -> ('Num -> 'Num)) -> projection: ('T -> 'Num) -> enumerator: RowEnumerator<'T> -> 'Num

Parameters

Name	Type	Description
get_Zero	(unit -> 'Num)	-
op_Addition	('Num -> ('Num -> 'Num))	-
projection	('T -> 'Num)	-
enumerator	RowEnumerator<'T>	-

---

Rows.toArray

Materializes all or remaining mapped rows into an array.

Rows.toArray : enumerator: RowEnumerator<'T> -> 'T[]

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.toList

Materializes all or remaining mapped rows into an F# immutable list.

Rows.toList : enumerator: RowEnumerator<'T> -> 'T list

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.toResizeArray

Materializes all or remaining mapped rows into a ResizeArray.

Rows.toResizeArray : enumerator: RowEnumerator<'T> -> List<'T>

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.tryFind

Tries to find a row that satisfies the predicate.

Rows.tryFind : predicate: ('T -> bool) -> enumerator: RowEnumerator<'T> -> 'T option

Parameters

Name	Type	Description
predicate	('T -> bool)	-
enumerator	RowEnumerator<'T>	-

---

Rows.tryFindValue

Tries to find the first row that satisfies the predicate, returning a ValueOption to eliminate heap boxing.

Rows.tryFindValue : predicate: ('T -> bool) -> enumerator: RowEnumerator<'T> -> 'T voption

Parameters

Name	Type	Description
predicate	('T -> bool)	-
enumerator	RowEnumerator<'T>	-

---

Rows.tryHead

Returns the first mapped row as an option.

Rows.tryHead : enumerator: RowEnumerator<'T> -> 'T option

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.tryHeadValue

Returns the first mapped row as a ValueOption.

Rows.tryHeadValue : enumerator: RowEnumerator<'T> -> 'T voption

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.tryLast

Returns the last mapped row as an option.

Rows.tryLast : enumerator: RowEnumerator<'T> -> 'T option

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.tryLastValue

Returns the last mapped row as a ValueOption.

Rows.tryLastValue : enumerator: RowEnumerator<'T> -> 'T voption

Parameters

Name	Type	Description
enumerator	RowEnumerator<'T>	-

---

Rows.tryPick

Applies the given function to successive elements, returning the first result where the function returns Some. Short-circuits immediately.

Rows.tryPick : chooser: ('T -> 'U option) -> enumerator: RowEnumerator<'T> -> 'U option

Parameters

Name	Type	Description
chooser	('T -> 'U option)	-
enumerator	RowEnumerator<'T>	-

---

Rows.tryPickValue

Applies the given function to successive elements, returning the first result where the function returns ValueSome. Short-circuits with zero heap allocation.

Rows.tryPickValue : chooser: ('T -> 'U voption) -> enumerator: RowEnumerator<'T> -> 'U voption

Parameters

Name	Type	Description
chooser	('T -> 'U voption)	-
enumerator	RowEnumerator<'T>	-

---