From ac10a7a79cb09b51c3171c3a7c22ff114b2b5737 Mon Sep 17 00:00:00 2001
From: Charles Iliya Krempeaux <iamreiver@gmail.com>
Date: Sun, 5 Nov 2023 01:20:57 -0700
Subject: [PATCH] .GetElse()

---
 optional.go              |  23 +++++
 optional_getelse_test.go | 213 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 236 insertions(+)
 create mode 100644 optional_getelse_test.go

diff --git a/optional.go b/optional.go
index 1638d4c..53e5d75 100644
--- a/optional.go
+++ b/optional.go
@@ -141,6 +141,29 @@ func (receiver Optional[T]) Get() (T, bool) {
 	return receiver.value, receiver.something
 }
 
+// GetElse returns the value inside of the optional-type if it is holding something.
+// Else it returns the alternstive value passed as a parameter.
+// Example usage:
+//
+//	var op opt.Optional[string]
+//	
+//	// ...
+//	
+//	value := op.GetElse(alternative)
+//	
+//	if found {
+//		fmt.Println("VALUE:", value)
+//	} else {
+//		fmt.Println("nothing")
+//	}
+func (receiver Optional[T]) GetElse(alternative T) T {
+	if receiver.isnothing() {
+		return alternative
+	}
+
+	return receiver.value
+}
+
 // GoString makes it that when the fmt.Fprintf(), fmt.Printf(), and fmt.Sprintf() family of functions
 // renders this type with the %#v verb, that it will be easier to understand.
 //
diff --git a/optional_getelse_test.go b/optional_getelse_test.go
new file mode 100644
index 0000000..cc4bf61
--- /dev/null
+++ b/optional_getelse_test.go
@@ -0,0 +1,213 @@
+package opt_test
+
+import (
+	"sourcecode.social/reiver/go-opt"
+
+	"testing"
+)
+
+func TestOptional_GetElse_string(t *testing.T) {
+
+	tests := []struct{
+		Optional opt.Optional[string]
+		Alternative string
+		Expected string
+	}{
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "alternative",
+			Expected:    "alternative",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "",
+			Expected:    "",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "apple",
+			Expected:    "apple",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "banana",
+			Expected:    "banana",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "cherry",
+			Expected:    "cherry",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "ONCE TWICE THRICE FOURCE",
+			Expected:    "ONCE TWICE THRICE FOURCE",
+		},
+		{
+			Optional: opt.Nothing[string](),
+			Alternative: "😈",
+			Expected:    "😈",
+		},
+
+
+
+		{
+			Optional: opt.Something("ONCE TWICE THRICE FOURCE"),
+			Alternative: "😈",
+			Expected:                "ONCE TWICE THRICE FOURCE",
+		},
+
+
+
+		{
+			Optional: opt.Something("۰۱۲۳۴۵۶۷۸۹"),
+			Alternative: "😈",
+			Expected:               "۰۱۲۳۴۵۶۷۸۹",
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := test.Optional.GetElse(test.Alternative)
+
+		{
+			expected := test.Expected
+
+			if expected != actual {
+				t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+				t.Logf("EXPECTED VALUE: %q", expected)
+				t.Logf("ACTUAL   VALUE: %q", actual)
+				t.Logf("OPTIONAL: %#v", test.Optional)
+	/////////////////////// CONTINUE
+				continue
+			}
+		}
+	}
+}
+
+func TestOptional_GetElse_int8(t *testing.T) {
+
+	tests := []struct{
+		Optional opt.Optional[int8]
+		Alternative int8
+		Expected int8
+	}{
+		{
+			Optional: opt.Nothing[int8](),
+			Alternative: -2,
+			Expected:    -2,
+		},
+		{
+			Optional: opt.Nothing[int8](),
+			Alternative: -1,
+			Expected:    -1,
+		},
+		{
+			Optional: opt.Nothing[int8](),
+			Alternative: 0,
+			Expected:    0,
+		},
+		{
+			Optional: opt.Nothing[int8](),
+			Alternative: 1,
+			Expected:    1,
+		},
+		{
+			Optional: opt.Nothing[int8](),
+			Alternative: 2,
+			Expected:    2,
+		},
+
+
+
+		{
+			Optional: opt.Something[int8](-127),
+			Alternative: 42,
+			Expected:                     -127,
+		},
+		{
+			Optional: opt.Something[int8](0),
+			Alternative: 42,
+			Expected:                     0,
+		},
+		{
+			Optional: opt.Something[int8](127),
+			Alternative: 42,
+			Expected:                     127,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := test.Optional.GetElse(test.Alternative)
+
+		{
+			expected := test.Expected
+
+			if expected != actual {
+				t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+				t.Logf("EXPECTED VALUE: %q", expected)
+				t.Logf("ACTUAL   VALUE: %q", actual)
+				t.Logf("OPTIONAL: %#v", test.Optional)
+	/////////////////////// CONTINUE
+				continue
+			}
+		}
+	}
+}
+
+func TestOptional_GetElse_uint8(t *testing.T) {
+
+	tests := []struct{
+		Optional opt.Optional[uint8]
+		Alternative uint8
+		Expected uint8
+	}{
+		{
+			Optional: opt.Nothing[uint8](),
+			Alternative: 0,
+			Expected:    0,
+		},
+		{
+			Optional: opt.Nothing[uint8](),
+			Alternative: 1,
+			Expected:    1,
+		},
+		{
+			Optional: opt.Nothing[uint8](),
+			Alternative: 2,
+			Expected:    2,
+		},
+
+
+
+		{
+			Optional: opt.Something[uint8](0),
+			Alternative: 42,
+			Expected:                     0,
+		},
+		{
+			Optional: opt.Something[uint8](127),
+			Alternative: 42,
+			Expected:                     127,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := test.Optional.GetElse(test.Alternative)
+
+		{
+			expected := test.Expected
+
+			if expected != actual {
+				t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+				t.Logf("EXPECTED VALUE: %q", expected)
+				t.Logf("ACTUAL   VALUE: %q", actual)
+				t.Logf("OPTIONAL: %#v", test.Optional)
+	/////////////////////// CONTINUE
+				continue
+			}
+		}
+	}
+}