Moved everything out of internal

utils/string_collections.go

@@ -0,0 +1,34 @@
+package utils
+
+// https://gobyexample.com/collection-functions
+
+func StrIndex(vs []string, t string) int {
+	for i, v := range vs {
+		if v == t {
+			return i
+		}
+	}
+	return -1
+}
+
+func StrInclude(vs []string, t string) bool {
+	return StrIndex(vs, t) >= 0
+}
+
+func StrFilter(vs []string, f func(string) bool) []string {
+	vsf := make([]string, 0)
+	for _, v := range vs {
+		if f(v) {
+			vsf = append(vsf, v)
+		}
+	}
+	return vsf
+}
+
+func StrMap(vs []string, f func(string) string) []string {
+	vsm := make([]string, len(vs))
+	for i, v := range vs {
+		vsm[i] = f(v)
+	}
+	return vsm
+}