Library
Module
Module type
Parameter
Class
Class type
Functions for manipulating tuples of length two
Functions for manipulating pairs of values
Create a two-tuple with the given values.
The values do not have to be of the same type.
Examples
Tuple2.make 3 "Clementine" = (3, "Clementine")
Create a tuple from the first two elements of an Array
.
If the array is longer than two elements, the extra elements are ignored.
If the array is less than two elements, returns None
Examples
Tuple2.fromArray [|1; 2|] = Some (1, 2)
Tuple2.fromArray [|1|] = None
Tuple2.fromArray [|4; 5; 6|] = Some (4, 5)
Create a tuple from the first two elements of a List
.
If the list is longer than two elements, the extra elements are ignored.
If the list is less than two elements, returns None
Examples
Tuple2.fromList [1; 2] = Some (1, 2)
Tuple2.fromList [1] = None
Tuple2.fromList [4; 5; 6] = Some (4, 5)
Extract the first value from a tuple.
Examples
Tuple2.first (3, 4) = 3
Tuple2.first ("john", "doe") = "john"
Extract the second value from a tuple.
Examples
Tuple2.second (3, 4) = 4
Tuple2.second ("john", "doe") = "doe"
Transform the first
value in a tuple.
Examples
Tuple2.mapFirst ~f:String.reverse ("stressed", 16) = ("desserts", 16)
Tuple2.mapFirst ~f:String.length ("stressed", 16) = (8, 16)
Transform the second value in a tuple.
Examples
Tuple2.mapSecond ~f:Float.squareRoot ("stressed", 16.) = ("stressed", 4.)
Tuple2.mapSecond ~f:(~-) ("stressed", 16) = ("stressed", -16)
Transform both values of a tuple, using f
for the first value and g
for the second.
Examples
Tuple2.mapEach ~f:String.reverse ~g:Float.squareRoot ("stressed", 16.) = ("desserts", 4.)
Tuple2.mapEach ~f:String.length ~g:(~-) ("stressed", 16) = (8, -16)
Transform both of the values of a tuple using the same function.
mapAll
can only be used on tuples which have the same type for each value.
Examples
Tuple2.mapAll ~f:(Int.add 1) (3, 4, 5) = (4, 5, 6)
Tuple2.mapAll ~f:String.length ("was", "stressed") = (3, 8)
Switches the first and second values of a tuple.
Examples
Tuple2.swap (3, 4) = (4, 3)
Tuple2.swap ("stressed", 16) = (16, "stressed")
Turns a tuple into an Array
of length two.
This function can only be used on tuples which have the same type for each value.
Examples
Tuple2.toArray (3, 4) = [|3; 4|]
Tuple2.toArray ("was", "stressed") = [|"was"; "stressed"|]
Turns a tuple into a list of length two. This function can only be used on tuples which have the same type for each value.
Examples
Tuple2.toList (3, 4) = [3; 4]
Tuple2.toList ("was", "stressed") = ["was"; "stressed"]
Test two Tuple2
s for equality, using the provided functions to test the first and second components.
Examples
Tuple2.equal Int.equal String.equal (1, "Fox") (1, "Fox") = true
Tuple2.equal Int.equal String.equal (1, "Fox") (2, "Hen") = false
Compare two Tuple2
s, using the provided functions to compare the first components then, if the first components are equal, the second components.
Examples
Tuple2.compare Int.compare String.compare (1, "Fox") (1, "Fox") = 0
Tuple2.compare Int.compare String.compare (1, "Fox") (1, "Eel") = 1
Tuple2.compare Int.compare String.compare (1, "Fox") (2, "Hen") = -1