initial commits

ctl/byte.go

@@ -0,0 +1,15 @@
+package ctl
+
+// ByteIsControl returns whether a byte is a control character, as defined by IETF RFC-2616.
+//
+//	CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+func ByteIsControlCharacter(value byte) bool {
+	switch {
+	case 0 <= value && value <= 31:
+		return true
+	case 127 == value:
+		return true
+	default:
+		return false
+	}
+}

ctl/rune.go

@@ -0,0 +1,15 @@
+package ctl
+
+// RuneIsControl returns whether a rune is a control character, as defined by IETF RFC-2616.
+//
+//	CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+func RuneIsControlCharacter(value rune) bool {
+	switch {
+	case 0 <= value && value <= 31:
+		return true
+	case 127 == value:
+		return true
+	default:
+		return false
+	}
+}