From cdb1cf3e03aa5a208a30a3cf180fc272c32b1437 Mon Sep 17 00:00:00 2001
From: Timon Ringwald <timon.ringwald@mequen.de>
Date: Tue, 6 Sep 2022 01:58:19 +0200
Subject: [PATCH] more helper functions

---
 slices.go => contains.go | 18 -----------------
 each.go                  | 11 +++++++++++
 flat.go                  |  9 +++++++++
 map.go                   |  9 +++++++++
 of.go                    | 16 +++++++++++++++
 to.go                    | 42 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 87 insertions(+), 18 deletions(-)
 rename slices.go => contains.go (61%)
 create mode 100644 each.go
 create mode 100644 flat.go
 create mode 100644 map.go
 create mode 100644 of.go
 create mode 100644 to.go

diff --git a/slices.go b/contains.go
similarity index 61%
rename from slices.go
rename to contains.go
index 0d413e0..8a4d4ab 100644
--- a/slices.go
+++ b/contains.go
@@ -20,21 +20,3 @@ func Contains[T comparable](slice []T, value T) bool {
 func ContainsCmp[T comparable](slice []T, value T, cmp EqualityComparator[T]) bool {
 	return IndexOfCmp(slice, value, cmp) != -1
 }
-
-func Map[I, O any](slice []I, mapper func(I) O) []O {
-	ret := make([]O, 0, len(slice))
-	for _, v := range slice {
-		ret = append(ret, mapper(v))
-	}
-	return ret
-}
-
-func Each[T any](slice []T, f func(T)) {
-	EachIndex(slice, func(_ int, v T) { f(v) })
-}
-
-func EachIndex[T any](slice []T, f func(int, T)) {
-	for i, v := range slice {
-		f(i, v)
-	}
-}
diff --git a/each.go b/each.go
new file mode 100644
index 0000000..fced363
--- /dev/null
+++ b/each.go
@@ -0,0 +1,11 @@
+package slices
+
+func Each[T any](slice []T, f func(T)) {
+	EachIndex(slice, func(_ int, v T) { f(v) })
+}
+
+func EachIndex[T any](slice []T, f func(int, T)) {
+	for i, v := range slice {
+		f(i, v)
+	}
+}
diff --git a/flat.go b/flat.go
new file mode 100644
index 0000000..17a5fbd
--- /dev/null
+++ b/flat.go
@@ -0,0 +1,9 @@
+package slices
+
+func Flat[T any](s ...[]T) []T {
+	out := make([]T, 0)
+	for _, v := range s {
+		out = append(out, v...)
+	}
+	return out
+}
diff --git a/map.go b/map.go
new file mode 100644
index 0000000..a364ec1
--- /dev/null
+++ b/map.go
@@ -0,0 +1,9 @@
+package slices
+
+func Map[I, O any](slice []I, mapper func(I) O) []O {
+	ret := make([]O, 0, len(slice))
+	for _, v := range slice {
+		ret = append(ret, mapper(v))
+	}
+	return ret
+}
diff --git a/of.go b/of.go
new file mode 100644
index 0000000..d8f12cf
--- /dev/null
+++ b/of.go
@@ -0,0 +1,16 @@
+package slices
+
+func Of[T any](values ...T) []T {
+	return values
+}
+
+// OfMap returns a slice containing the return values of the unmapper function
+// applied to any key-value pair in m
+// The order is random
+func OfMap[K comparable, V, T any](m map[K]V, unmapper func(K, V) T) []T {
+	out := make([]T, 0, len(m))
+	for k, v := range m {
+		out = append(out, unmapper(k, v))
+	}
+	return out
+}
diff --git a/to.go b/to.go
new file mode 100644
index 0000000..855e0d2
--- /dev/null
+++ b/to.go
@@ -0,0 +1,42 @@
+package slices
+
+import (
+	"container/list"
+)
+
+// Deref returns a slice containing all dereferenced values of s.
+// The returned slice will be a dereferenced and continuous block of memory.
+// Nil pointers are ignored.
+func Deref[T any](s []*T) []T {
+	out := make([]T, 0, len(s))
+	Each(s, func(v *T) {
+		if v != nil {
+			out = append(out, *v)
+		}
+	})
+	return out
+}
+
+// ToList returns a list.List containing all values of s
+func ToList[T any](s []T) *list.List {
+	l := list.New()
+	Each(s, func(value T) { l.PushBack(value) })
+	return l
+}
+
+// ToMap returns a map containing all values of s.
+// The map key-value pairs are determined by mapper
+func ToMap[T any, K comparable, V any](s []T, mapper func(T) (K, V)) map[K]V {
+	m := map[K]V{}
+	Each(s, func(value T) {
+		k, v := mapper(value)
+		m[k] = v
+	})
+	return m
+}
+
+// ToStructMap returns a struct{} map containing all values of s as keys.
+// It is a shorthand for ToMap(s, func(value T) (T, struct{}) { return value, struct{}{} })
+func ToStructMap[T comparable](s []T) map[T]struct{} {
+	return ToMap(s, func(value T) (T, struct{}) { return value, struct{}{} })
+}