From 6c6da2c66ca356f3ffd08fd22ac3f0d8a948b3fe Mon Sep 17 00:00:00 2001
From: Nic Johnson <nicjohnson145@users.noreply.github.com>
Date: Sun, 2 Oct 2022 17:56:41 -0500
Subject: [PATCH] feat: add TernaryF function (#214)

* feat: add TernaryF function

* docs: update example function to be more concise
---
 README.md         | 17 +++++++++++++++++
 condition.go      |  8 ++++++++
 condition_test.go | 10 ++++++++++
 3 files changed, 35 insertions(+)

diff --git a/README.md b/README.md
index 8fc3272f..0799f8ab 100644
--- a/README.md
+++ b/README.md
@@ -1548,6 +1548,23 @@ result := lo.Ternary[string](false, "a", "b")
 // "b"
 ```
 
+### TernaryF
+
+```go
+result := lo.TernaryF[string](true, func() string { return "a" }, func() string { return "b" })
+// "a"
+
+result := lo.TernaryF[string](false, func() string { return "a" }, func() string { return "b" })
+// "b"
+```
+
+Useful to avoid nil-pointer dereferencing in intializations, or avoid running unnecessary code
+
+```go
+var s *string
+someStr := TernaryF[string](s.Val == nil, func() string { return uuid.New().String() }, func() string { return *s })
+```
+
 ### If / ElseIf / Else
 
 ```go
diff --git a/condition.go b/condition.go
index 6fd31f1e..80de6644 100644
--- a/condition.go
+++ b/condition.go
@@ -9,6 +9,14 @@ func Ternary[T any](condition bool, ifOutput T, elseOutput T) T {
 	return elseOutput
 }
 
+// TernaryF is a 1 line if/else statement whose options are functions
+func TernaryF[T any](condition bool, ifFunc func() T, elseFunc func() T) T {
+	if condition {
+		return ifFunc()
+	}
+	return elseFunc()
+}
+
 type ifElse[T any] struct {
 	result T
 	done   bool
diff --git a/condition_test.go b/condition_test.go
index 85cea19f..ffb1e542 100644
--- a/condition_test.go
+++ b/condition_test.go
@@ -17,6 +17,16 @@ func TestTernary(t *testing.T) {
 	is.Equal(result2, "b")
 }
 
+func TestTernaryF(t *testing.T) {
+	is := assert.New(t)
+
+	result1 := TernaryF(true, func() string { return "a" }, func() string { return "b" })
+	result2 := TernaryF(false, func() string { return "a" }, func() string { return "b" })
+
+	is.Equal(result1, "a")
+	is.Equal(result2, "b")
+}
+
 func TestIfElse(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)