feat: chain package

This commit is contained in:
Ruidy 2022-01-02 18:51:18 -04:00
parent 2d05b6c518
commit 73ed4021a6
3 changed files with 34 additions and 30 deletions

View file

@ -102,10 +102,10 @@ go test ./...
### Chaining
Calling `NewChain` will cause all future method calls to return wrapped objects. When you've finished the computation,
Calling `chain.Of` will cause all future method calls to return wrapped values. When you've finished the computation,
call `Value` to retrieve the final value.
Methods not returning a slice such as `Reduce`, `Every`, `Some`, will break the chain and return `Value` instantly.
Methods not returning a slice such as `Reduce`, `Every`, `Some`, will break the `Chain` and return `Value` instantly.
## Built With

View file

@ -1,40 +1,44 @@
package underscore
package chain
import "constraints"
import (
"constraints"
u "github.com/rjNemo/underscore"
)
type Chain[T constraints.Ordered] struct {
Value []T
}
// NewChain starts a Chain. All future method calls will return Chain structs. When you've finished the computation,
// Of starts a Chain. All future method calls will return Chain structs. When you've finished the computation,
// call Value to retrieve the final value.
//
// Methods not returning a slice such as Reduce, Every, Some, will break the chain and return Value instantly.
func NewChain[T constraints.Ordered](value []T) Chain[T] {
func Of[T constraints.Ordered](value []T) Chain[T] {
return Chain[T]{Value: value}
}
// Contains returns true if the value is present in the slice and breaks the Chain.
func (c Chain[T]) Contains(value T) bool {
return Contains(c.Value, value)
return u.Contains(c.Value, value)
}
// Each iterates over a slice of elements, yielding each in turn to an action function.
// Breaks the Chain.
func (c Chain[T]) Each(action func(T)) {
Each(c.Value, action)
u.Each(c.Value, action)
}
// Every returns true if all the values in the slice pass the predicate truth test.
// Short-circuits and stops traversing the slice if a false element is found.
// Breaks the Chain.
func (c Chain[T]) Every(predicate func(T) bool) bool {
return Every(c.Value, predicate)
return u.Every(c.Value, predicate)
}
// Filter looks through each value in the slice, returning a slice of all the values that pass a truth test (predicate).
func (c Chain[T]) Filter(predicate func(n T) bool) Chain[T] {
return Chain[T]{Value: Filter(c.Value, predicate)}
return Chain[T]{Value: u.Filter(c.Value, predicate)}
}
// Find looks through each value in the slice, returning the first one that passes a truth test (predicate),
@ -42,7 +46,7 @@ func (c Chain[T]) Filter(predicate func(n T) bool) Chain[T] {
// The function returns as soon as it finds an acceptable element, and doesn't traverse the entire slice.
// Breaks the Chain.
func (c Chain[T]) Find(predicate func(n T) bool) (T, error) {
return Find(c.Value, predicate)
return u.Find(c.Value, predicate)
}
// Map produces a new slice of values by mapping each value in the slice through
@ -50,7 +54,7 @@ func (c Chain[T]) Find(predicate func(n T) bool) (T, error) {
//
// TODO: Move from T to P.
func (c Chain[T]) Map(transform func(n T) T) Chain[T] {
return Chain[T]{Value: Map(c.Value, transform)}
return Chain[T]{Value: u.Map(c.Value, transform)}
}
// Max returns the maximum value in the slice.
@ -58,7 +62,7 @@ func (c Chain[T]) Map(transform func(n T) T) Chain[T] {
// This function uses operator <.
// Breaks the Chain.
func (c Chain[T]) Max() T {
return Max(c.Value)
return u.Max(c.Value)
}
// Min returns the minimum value in the slice.
@ -66,25 +70,25 @@ func (c Chain[T]) Max() T {
// This function uses operator <.
// Breaks the Chain.
func (c Chain[T]) Min() T {
return Min(c.Value)
return u.Min(c.Value)
}
// Partition splits the slice into two slices: one whose elements all satisfy predicate
// and one whose elements all do not satisfy predicate.
// Breaks the Chain.
func (c Chain[T]) Partition(predicate func(T) bool) ([]T, []T) {
return Partition(c.Value, predicate)
return u.Partition(c.Value, predicate)
}
// Reduce combine a list of values into a single value and breaks the Chain.
// acc is the initial state, and each successive step of it should be returned by the reduction function.
func (c Chain[T]) Reduce(reducer func(n, acc T) T, acc T) T {
return Reduce(c.Value, reducer, acc)
return u.Reduce(c.Value, reducer, acc)
}
// Some returns true if any of the values in the slice pass the predicate truth test.
// Short-circuits and stops traversing the slice if a true element is found.
// Breaks the Chain.
func (c Chain[T]) Some(predicate func(T) bool) bool {
return Some(c.Value, predicate)
return u.Some(c.Value, predicate)
}

View file

@ -1,18 +1,18 @@
package underscore_test
package chain_test
import (
"testing"
"github.com/stretchr/testify/assert"
u "github.com/rjNemo/underscore"
"github.com/rjNemo/underscore/chain"
)
func TestChainFilter(t *testing.T) {
want := []int{2, 4, 6, 8}
assert.Equal(t,
want,
u.NewChain(nums).Filter(isEven).Value,
chain.Of(nums).Filter(isEven).Value,
)
}
@ -20,7 +20,7 @@ func TestChainFilterMap(t *testing.T) {
want := []int{4, 16, 36, 64}
assert.Equal(t,
want,
u.NewChain(nums).
chain.Of(nums).
Filter(isEven).
Map(toSquare).
Value)
@ -30,14 +30,14 @@ func TestChainFilterMapReduce(t *testing.T) {
want := 120
assert.Equal(t,
want,
u.NewChain(nums).
chain.Of(nums).
Filter(isEven).
Map(toSquare).
Reduce(sum, 0))
}
func TestChainFilterMapContains(t *testing.T) {
assert.True(t, u.NewChain(nums).
assert.True(t, chain.Of(nums).
Filter(isEven).
Map(toSquare).
Contains(16))
@ -46,7 +46,7 @@ func TestChainFilterMapContains(t *testing.T) {
func TestChainFilterMapEach(t *testing.T) {
want := []int{5, 17, 37, 65}
res := make([]int, 0)
u.NewChain(nums).
chain.Of(nums).
Filter(isEven).
Map(toSquare).
Each(func(n int) { res = append(res, n+1) })
@ -54,14 +54,14 @@ func TestChainFilterMapEach(t *testing.T) {
}
func TestChainFilterMapEvery(t *testing.T) {
assert.True(t, u.NewChain(nums).
assert.True(t, chain.Of(nums).
Filter(isEven).
Map(toSquare).
Every(func(n int) bool { return n%4 == 0 }))
}
func TestChainFilterMapFind(t *testing.T) {
n, err := u.NewChain(nums).
n, err := chain.Of(nums).
Filter(isEven).
Map(toSquare).
Find(func(n int) bool { return n%4 == 0 })
@ -71,7 +71,7 @@ func TestChainFilterMapFind(t *testing.T) {
func TestChainFilterMapMax(t *testing.T) {
want := 64
assert.Equal(t, want, u.NewChain(nums).
assert.Equal(t, want, chain.Of(nums).
Filter(isEven).
Map(toSquare).
Max())
@ -79,7 +79,7 @@ func TestChainFilterMapMax(t *testing.T) {
func TestChainFilterMapMin(t *testing.T) {
w := 4
assert.Equal(t, w, u.NewChain(nums).
assert.Equal(t, w, chain.Of(nums).
Filter(isEven).
Map(toSquare).
Min())
@ -88,7 +88,7 @@ func TestChainFilterMapMin(t *testing.T) {
func TestChainFilterMapPartition(t *testing.T) {
wantLeft := []int{4, 16}
wantRight := []int{36, 64}
left, right := u.NewChain(nums).
left, right := chain.Of(nums).
Filter(isEven).
Map(toSquare).
Partition(func(n int) bool { return n < 20 })
@ -98,7 +98,7 @@ func TestChainFilterMapPartition(t *testing.T) {
}
func TestChainFilterMapSome(t *testing.T) {
assert.True(t, u.NewChain(nums).
assert.True(t, chain.Of(nums).
Filter(isEven).
Map(toSquare).
Some(func(n int) bool { return n%64 == 0 }))