From 3066810f92acee2c57287e8aff4c64ea7a681359 Mon Sep 17 00:00:00 2001 From: Andy Long Date: Fri, 2 Sep 2022 00:12:39 +0100 Subject: [PATCH] Adding some new funky functions which I find useful Created a Tuple struct as some of the new functions require you to return a new slice with two fields which is the result of the new functions Created the Join, JoinProjection, Range, SumMap, Zip functions, ecah fuction is documented with how it works and had a unit test or maybe more --- .gitignore | 1 + join.go | 39 +++++++++++++++++++++++++++++++ join_test.go | 30 ++++++++++++++++++++++++ range.go | 16 +++++++++++++ range_test.go | 24 +++++++++++++++++++ sum.go | 10 ++++++++ sum_test.go | 18 ++++++++++++++ tuple.go | 6 +++++ zip.go | 20 ++++++++++++++++ zip_test.go | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++ 10 files changed, 229 insertions(+) create mode 100644 join.go create mode 100644 join_test.go create mode 100644 range.go create mode 100644 range_test.go create mode 100644 tuple.go create mode 100644 zip.go create mode 100644 zip_test.go diff --git a/.gitignore b/.gitignore index 0fd6007..804df32 100644 --- a/.gitignore +++ b/.gitignore @@ -59,3 +59,4 @@ Temporary Items .apdisk docs/public .trivycache/ +.vscode/launch.json diff --git a/join.go b/join.go new file mode 100644 index 0000000..1b2b60b --- /dev/null +++ b/join.go @@ -0,0 +1,39 @@ +package underscore + +// Joins two slices together and returns a Tuple of [T, []P], the selectors allow you to pick the +// keys from your structure you would like to join the sets together with +func Join[T, P any, S comparable]( + left []T, + right []P, + leftSelector func(T) S, + rightSelector func(P) S) []Tuple[T, []P] { + + var results = make([]Tuple[T, []P], 0, len(left)) + for _, l := range left { + var matches = Filter(right, func(r P) bool { return leftSelector(l) == rightSelector(r) }) + var tuple = Tuple[T, []P]{Left: l, Right: matches} + results = append(results, tuple) + } + + return results +} + +// Joins two slices together and returns a []R where R is defined by the output of your projection +// function +// The selectors allow you to pick the keys from your structure you would like to join the sets +// together with. +// While the projection functions allows you to reformat joined datasets contains in the +// Tuple of [T, []P] into your own structure or type +func JoinProject[T, P, R any, S comparable]( + left []T, + right []P, + leftSelector func(T) S, + rightSelector func(P) S, + projection func(Tuple[T, []P]) R) (results []R) { + + for _, x := range Join(left, right, leftSelector, rightSelector) { + results = append(results, projection(x)) + } + + return results +} diff --git a/join_test.go b/join_test.go new file mode 100644 index 0000000..fbf0d4d --- /dev/null +++ b/join_test.go @@ -0,0 +1,30 @@ +package underscore_test + +import ( + "reflect" + "testing" + + u "github.com/rjNemo/underscore" +) + +func Test_Join_Can_Join_Two_Slices_Together(t *testing.T) { + one := u.Tuple[int, string]{Left: 1, Right: "One"} + two := u.Tuple[int, string]{Left: 2, Right: "Two"} + three := u.Tuple[int, string]{Left: 3, Right: "Three"} + + var left = []u.Tuple[int, string]{one, two, three} + var right = []u.Tuple[int, string]{one, three, two, three, two, three} + + selector := func(x u.Tuple[int, string]) int { return x.Left } + + var joined = u.Join(left, right, selector, selector) + var want = []u.Tuple[u.Tuple[int, string], []u.Tuple[int, string]]{ + {Left: one, Right: []u.Tuple[int, string]{one}}, + {Left: two, Right: []u.Tuple[int, string]{two, two}}, + {Left: three, Right: []u.Tuple[int, string]{three, three, three}}, + } + + if !reflect.DeepEqual(joined, want) { + t.Errorf("Expected to get %v but we got %v instead", want, joined) + } +} diff --git a/range.go b/range.go new file mode 100644 index 0000000..204c6b8 --- /dev/null +++ b/range.go @@ -0,0 +1,16 @@ +package underscore + +// Creates a sequence of numbers, i.e. u.Range(0, 3) = [0 1 2 3], while u.Range(3, 0) = [3 2 1 0] +func Range(start int, end int) (result []int) { + if start < end { + for i := start; i <= end; i++ { + result = append(result, i) + } + } else { + for i := start; i >= end; i-- { + result = append(result, i) + } + } + + return result +} diff --git a/range_test.go b/range_test.go new file mode 100644 index 0000000..f59ee5c --- /dev/null +++ b/range_test.go @@ -0,0 +1,24 @@ +package underscore_test + +import ( + "reflect" + "testing" + + u "github.com/rjNemo/underscore" +) + +func Test_Range_Creates_Slices(t *testing.T) { + range1 := u.Range(0, 5) + want1 := []int{0, 1, 2, 3, 4, 5} + + if !reflect.DeepEqual(range1, want1) { + t.Errorf("Expected the result to be %v but we got %v", want1, range1) + } + + range2 := u.Range(5, 0) + want2 := []int{5, 4, 3, 2, 1, 0} + + if !reflect.DeepEqual(range2, want2) { + t.Errorf("Expected the result to be %v but we got %v", want2, range2) + } +} diff --git a/sum.go b/sum.go index 3d2b5db..0cc9652 100644 --- a/sum.go +++ b/sum.go @@ -9,3 +9,13 @@ func Sum[T constraints.Ordered](values []T) (sum T) { } return sum } + +// Sums the values you select from your struct, basically a sort cut instead of +// having to perform a u.Map followed by a u.Sum +func SumMap[T any, R constraints.Ordered](list []T, selector func(T) R) (sum R) { + for _, v := range list { + sum += selector(v) + } + + return sum +} diff --git a/sum_test.go b/sum_test.go index 05a2a8a..4d5556d 100644 --- a/sum_test.go +++ b/sum_test.go @@ -13,3 +13,21 @@ func TestSum(t *testing.T) { assert.Equal(t, want, u.Sum(nums)) } + +func TestSumMap(t *testing.T) { + nums := []u.Tuple[string, int]{ + {"zero", 0}, + {"one", 1}, + {"two", 2}, + {"three", 3}, + {"four", 4}, + {"five", 5}, + {"six", 6}, + {"seven", 7}, + {"eight", 8}, + {"nine", 9}, + } + want := 45 + + assert.Equal(t, want, u.SumMap(nums, func(item u.Tuple[string, int]) int { return item.Right })) +} diff --git a/tuple.go b/tuple.go new file mode 100644 index 0000000..a229f52 --- /dev/null +++ b/tuple.go @@ -0,0 +1,6 @@ +package underscore + +type Tuple[L, R any] struct { + Left L + Right R +} diff --git a/zip.go b/zip.go new file mode 100644 index 0000000..ca53e62 --- /dev/null +++ b/zip.go @@ -0,0 +1,20 @@ +package underscore + +// Zips two slices togther so all the elements of left slice are attached to the corresponding +// elements of the right slice, i.e. [one two three] [1 2 3 4] = [{one, 1} {two, 2} {three, 3}] +// the returned data will be the size of the smallest slice +func Zip[L any, R any](left []L, right []R) []Tuple[L, R] { + shortest := 0 + if len(left) < len(right) { + shortest = len(left) + } else { + shortest = len(right) + } + + results := make([]Tuple[L, R], shortest) + for i := 0; i < shortest; i++ { + results[i] = Tuple[L, R]{Left: left[i], Right: right[i]} + } + + return results +} diff --git a/zip_test.go b/zip_test.go new file mode 100644 index 0000000..66b8ddf --- /dev/null +++ b/zip_test.go @@ -0,0 +1,65 @@ +package underscore_test + +import ( + "reflect" + "testing" + + u "github.com/rjNemo/underscore" +) + +func Test_Zip_Can_Zip_Two_Equal_Sized_Slices(t *testing.T) { + left := []string{"Left 1", "Left 2", "Left 3"} + right := []int{1, 2, 3} + + var zipped = u.Zip(left, right) + + want := []u.Tuple[string, int]{ + {Left: "Left 1", Right: 1}, + {Left: "Left 2", Right: 2}, + {Left: "Left 3", Right: 3}, + } + + if !reflect.DeepEqual(zipped, want) { + t.Errorf("Expected the result to be %v but we got %v", want, zipped) + } +} + +func Test_Zip_Can_Zip_Two_Different_Sized_Slices_Left_Larger(t *testing.T) { + left := []string{"Left 1", "Left 2", "Left 3", "Left 4"} + right := []int{1, 2, 3} + + var zipped = u.Zip(left, right) + if len(zipped) != 3 { + t.Errorf("Expected the result of Zip(left, right) to have a length of 3 but got %v", len(zipped)) + } + + want := []u.Tuple[string, int]{ + {Left: "Left 1", Right: 1}, + {Left: "Left 2", Right: 2}, + {Left: "Left 3", Right: 3}, + } + + if !reflect.DeepEqual(zipped, want) { + t.Errorf("Expected the result to be %v but we got %v", want, zipped) + } +} + +func Test_Zip_Can_Zip_Two_Different_Sized_Slices_Right_Larger(t *testing.T) { + left := []string{"Left 1", "Left 2", "Left 3"} + right := []int{1, 2, 3, 4} + + var zipped = u.Zip(left, right) + if len(zipped) != 3 { + t.Errorf("Expected the result of Zip(left, right) to have a length of 3 but got %v", len(zipped)) + } + + want := []u.Tuple[string, int]{ + {Left: "Left 1", Right: 1}, + {Left: "Left 2", Right: 2}, + {Left: "Left 3", Right: 3}, + } + + if !reflect.DeepEqual(zipped, want) { + t.Errorf("Expected the result to be %v but we got %v", want, zipped) + } +}