initial commit

backend/pkg/ptr/ptr.go

@@ -0,0 +1,13 @@
+package ptr
+
+func DerefOrZero[T any](ptrVal *T) T {
+	var zeroT T
+	if ptrVal == nil {
+		return zeroT
+	}
+	return *ptrVal
+}
+
+func Of[T any](v T) *T {
+	return &v
+}

backend/pkg/slices/map.go

@@ -0,0 +1,36 @@
+package slices
+
+// Map consumes []T and a function that returns D
+func Map[T, D any](srcItems []T, mapFunc func(T) D) []D {
+	dstItems := make([]D, len(srcItems))
+	for i, v := range srcItems {
+		dstItems[i] = mapFunc(v)
+	}
+	return dstItems
+}
+
+// First returns the first of a slice
+func First[T any](s []T) (item T, found bool) {
+	if len(s) > 0 {
+		return s[0], true
+	}
+	return item, false
+}
+
+// Last returns the last of a slice
+func Last[T any](s []T) (item T, found bool) {
+	if len(s) > 0 {
+		return s[len(s)-1], true
+	}
+	return item, false
+}
+
+// FindFirst finds the first matching item in s given fn
+func FindFirst[T any](s []T, fn func(T) bool) (item T, found bool) {
+	for _, v := range s {
+		if fn(v) {
+			return v, true
+		}
+	}
+	return item, false
+}

backend/pkg/values/values.go

@@ -0,0 +1,24 @@
+package values
+
+// FirstNonZero will return the first non zero value. If none exists,
+// it returns the zero value.
+func FirstNonZero[T comparable](vals ...T) T {
+	var zeroT T
+	for _, v := range vals {
+		if v != zeroT {
+			return v
+		}
+	}
+	return zeroT
+}
+
+// CountNonZero returns the count of items that are non zero
+func CountNonZero[T comparable](vals ...T) (count int) {
+	var zeroT T
+	for _, v := range vals {
+		if v != zeroT {
+			count++
+		}
+	}
+	return count
+}