diff --git a/digit/byte.go b/digit/byte.go
new file mode 100644
index 0000000..289b907
--- /dev/null
+++ b/digit/byte.go
@@ -0,0 +1,5 @@
+package digit
+
+func ByteIs(value byte) bool {
+	return '0' <= value && value <= '9'
+}
diff --git a/digit/byte_test.go b/digit/byte_test.go
new file mode 100644
index 0000000..d9ef1d3
--- /dev/null
+++ b/digit/byte_test.go
@@ -0,0 +1,1055 @@
+package digit_test
+
+import (
+	"testing"
+
+	"sourcecode.social/reiver/go-rfc2396/digit"
+)
+
+func TestByteIs(t *testing.T) {
+
+	tests := []struct{
+		Value byte
+		Expected bool
+	}{
+		{
+			Value: 0x00,
+			Expected: false,
+		},
+		{
+			Value: 0x01,
+			Expected: false,
+		},
+		{
+			Value: 0x02,
+			Expected: false,
+		},
+		{
+			Value: 0x03,
+			Expected: false,
+		},
+		{
+			Value: 0x04,
+			Expected: false,
+		},
+		{
+			Value: 0x05,
+			Expected: false,
+		},
+		{
+			Value: 0x06,
+			Expected: false,
+		},
+		{
+			Value: 0x07,
+			Expected: false,
+		},
+		{
+			Value: 0x08,
+			Expected: false,
+		},
+		{
+			Value: 0x09,
+			Expected: false,
+		},
+		{
+			Value: 0x0A,
+			Expected: false,
+		},
+		{
+			Value: 0x0B,
+			Expected: false,
+		},
+		{
+			Value: 0x0C,
+			Expected: false,
+		},
+		{
+			Value: 0x0D,
+			Expected: false,
+		},
+		{
+			Value: 0x0E,
+			Expected: false,
+		},
+		{
+			Value: 0x0F,
+			Expected: false,
+		},
+		{
+			Value: 0x10,
+			Expected: false,
+		},
+		{
+			Value: 0x11,
+			Expected: false,
+		},
+		{
+			Value: 0x12,
+			Expected: false,
+		},
+		{
+			Value: 0x13,
+			Expected: false,
+		},
+		{
+			Value: 0x14,
+			Expected: false,
+		},
+		{
+			Value: 0x15,
+			Expected: false,
+		},
+		{
+			Value: 0x16,
+			Expected: false,
+		},
+		{
+			Value: 0x17,
+			Expected: false,
+		},
+		{
+			Value: 0x18,
+			Expected: false,
+		},
+		{
+			Value: 0x19,
+			Expected: false,
+		},
+		{
+			Value: 0x1A,
+			Expected: false,
+		},
+		{
+			Value: 0x1B,
+			Expected: false,
+		},
+		{
+			Value: 0x1C,
+			Expected: false,
+		},
+		{
+			Value: 0x1D,
+			Expected: false,
+		},
+		{
+			Value: 0x1E,
+			Expected: false,
+		},
+		{
+			Value: 0x1F,
+			Expected: false,
+		},
+		{
+			Value: 0x20,
+			Expected: false,
+		},
+		{
+			Value: 0x21,
+			Expected: false,
+		},
+		{
+			Value: 0x22,
+			Expected: false,
+		},
+		{
+			Value: 0x23,
+			Expected: false,
+		},
+		{
+			Value: 0x24,
+			Expected: false,
+		},
+		{
+			Value: 0x25,
+			Expected: false,
+		},
+		{
+			Value: 0x26,
+			Expected: false,
+		},
+		{
+			Value: 0x27,
+			Expected: false,
+		},
+		{
+			Value: 0x28,
+			Expected: false,
+		},
+		{
+			Value: 0x29,
+			Expected: false,
+		},
+		{
+			Value: 0x2A,
+			Expected: false,
+		},
+		{
+			Value: 0x2B,
+			Expected: false,
+		},
+		{
+			Value: 0x2C,
+			Expected: false,
+		},
+		{
+			Value: 0x2D,
+			Expected: false,
+		},
+		{
+			Value: 0x2E,
+			Expected: false,
+		},
+		{
+			Value: 0x2F,
+			Expected: false,
+		},
+		{
+			Value: 0x30, // == '0'
+			Expected: true,
+		},
+		{
+			Value: 0x31, // == '1'
+			Expected: true,
+		},
+		{
+			Value: 0x32, // == '2'
+			Expected: true,
+		},
+		{
+			Value: 0x33, // == '3'
+			Expected: true,
+		},
+		{
+			Value: 0x34, // == '4'
+			Expected: true,
+		},
+		{
+			Value: 0x35, // == '5'
+			Expected: true,
+		},
+		{
+			Value: 0x36, // == '6'
+			Expected: true,
+		},
+		{
+			Value: 0x37, // == '7'
+			Expected: true,
+		},
+		{
+			Value: 0x38, // == '8'
+			Expected: true,
+		},
+		{
+			Value: 0x39, // == '9'
+			Expected: true,
+		},
+		{
+			Value: 0x3A,
+			Expected: false,
+		},
+		{
+			Value: 0x3B,
+			Expected: false,
+		},
+		{
+			Value: 0x3C,
+			Expected: false,
+		},
+		{
+			Value: 0x3D,
+			Expected: false,
+		},
+		{
+			Value: 0x3E,
+			Expected: false,
+		},
+		{
+			Value: 0x3F,
+			Expected: false,
+		},
+		{
+			Value: 0x40,
+			Expected: false,
+		},
+		{
+			Value: 0x41,
+			Expected: false,
+		},
+		{
+			Value: 0x42,
+			Expected: false,
+		},
+		{
+			Value: 0x43,
+			Expected: false,
+		},
+		{
+			Value: 0x44,
+			Expected: false,
+		},
+		{
+			Value: 0x45,
+			Expected: false,
+		},
+		{
+			Value: 0x46,
+			Expected: false,
+		},
+		{
+			Value: 0x47,
+			Expected: false,
+		},
+		{
+			Value: 0x48,
+			Expected: false,
+		},
+		{
+			Value: 0x49,
+			Expected: false,
+		},
+		{
+			Value: 0x4A,
+			Expected: false,
+		},
+		{
+			Value: 0x4B,
+			Expected: false,
+		},
+		{
+			Value: 0x4C,
+			Expected: false,
+		},
+		{
+			Value: 0x4D,
+			Expected: false,
+		},
+		{
+			Value: 0x4E,
+			Expected: false,
+		},
+		{
+			Value: 0x4F,
+			Expected: false,
+		},
+		{
+			Value: 0x50,
+			Expected: false,
+		},
+		{
+			Value: 0x51,
+			Expected: false,
+		},
+		{
+			Value: 0x52,
+			Expected: false,
+		},
+		{
+			Value: 0x53,
+			Expected: false,
+		},
+		{
+			Value: 0x54,
+			Expected: false,
+		},
+		{
+			Value: 0x55,
+			Expected: false,
+		},
+		{
+			Value: 0x56,
+			Expected: false,
+		},
+		{
+			Value: 0x57,
+			Expected: false,
+		},
+		{
+			Value: 0x58,
+			Expected: false,
+		},
+		{
+			Value: 0x59,
+			Expected: false,
+		},
+		{
+			Value: 0x5A,
+			Expected: false,
+		},
+		{
+			Value: 0x5B,
+			Expected: false,
+		},
+		{
+			Value: 0x5C,
+			Expected: false,
+		},
+		{
+			Value: 0x5D,
+			Expected: false,
+		},
+		{
+			Value: 0x5E,
+			Expected: false,
+		},
+		{
+			Value: 0x5F,
+			Expected: false,
+		},
+		{
+			Value: 0x60,
+			Expected: false,
+		},
+		{
+			Value: 0x61,
+			Expected: false,
+		},
+		{
+			Value: 0x62,
+			Expected: false,
+		},
+		{
+			Value: 0x63,
+			Expected: false,
+		},
+		{
+			Value: 0x64,
+			Expected: false,
+		},
+		{
+			Value: 0x65,
+			Expected: false,
+		},
+		{
+			Value: 0x66,
+			Expected: false,
+		},
+		{
+			Value: 0x67,
+			Expected: false,
+		},
+		{
+			Value: 0x68,
+			Expected: false,
+		},
+		{
+			Value: 0x69,
+			Expected: false,
+		},
+		{
+			Value: 0x6A,
+			Expected: false,
+		},
+		{
+			Value: 0x6B,
+			Expected: false,
+		},
+		{
+			Value: 0x6C,
+			Expected: false,
+		},
+		{
+			Value: 0x6D,
+			Expected: false,
+		},
+		{
+			Value: 0x6E,
+			Expected: false,
+		},
+		{
+			Value: 0x6F,
+			Expected: false,
+		},
+		{
+			Value: 0x70,
+			Expected: false,
+		},
+		{
+			Value: 0x71,
+			Expected: false,
+		},
+		{
+			Value: 0x72,
+			Expected: false,
+		},
+		{
+			Value: 0x73,
+			Expected: false,
+		},
+		{
+			Value: 0x74,
+			Expected: false,
+		},
+		{
+			Value: 0x75,
+			Expected: false,
+		},
+		{
+			Value: 0x76,
+			Expected: false,
+		},
+		{
+			Value: 0x77,
+			Expected: false,
+		},
+		{
+			Value: 0x78,
+			Expected: false,
+		},
+		{
+			Value: 0x79,
+			Expected: false,
+		},
+		{
+			Value: 0x7A,
+			Expected: false,
+		},
+		{
+			Value: 0x7B,
+			Expected: false,
+		},
+		{
+			Value: 0x7C,
+			Expected: false,
+		},
+		{
+			Value: 0x7D,
+			Expected: false,
+		},
+		{
+			Value: 0x7E,
+			Expected: false,
+		},
+		{
+			Value: 0x7F,
+			Expected: false,
+		},
+		{
+			Value: 0x80,
+			Expected: false,
+		},
+		{
+			Value: 0x81,
+			Expected: false,
+		},
+		{
+			Value: 0x82,
+			Expected: false,
+		},
+		{
+			Value: 0x83,
+			Expected: false,
+		},
+		{
+			Value: 0x84,
+			Expected: false,
+		},
+		{
+			Value: 0x85,
+			Expected: false,
+		},
+		{
+			Value: 0x86,
+			Expected: false,
+		},
+		{
+			Value: 0x87,
+			Expected: false,
+		},
+		{
+			Value: 0x88,
+			Expected: false,
+		},
+		{
+			Value: 0x89,
+			Expected: false,
+		},
+		{
+			Value: 0x8A,
+			Expected: false,
+		},
+		{
+			Value: 0x8B,
+			Expected: false,
+		},
+		{
+			Value: 0x8C,
+			Expected: false,
+		},
+		{
+			Value: 0x8D,
+			Expected: false,
+		},
+		{
+			Value: 0x8E,
+			Expected: false,
+		},
+		{
+			Value: 0x8F,
+			Expected: false,
+		},
+		{
+			Value: 0x90,
+			Expected: false,
+		},
+		{
+			Value: 0x91,
+			Expected: false,
+		},
+		{
+			Value: 0x92,
+			Expected: false,
+		},
+		{
+			Value: 0x93,
+			Expected: false,
+		},
+		{
+			Value: 0x94,
+			Expected: false,
+		},
+		{
+			Value: 0x95,
+			Expected: false,
+		},
+		{
+			Value: 0x96,
+			Expected: false,
+		},
+		{
+			Value: 0x97,
+			Expected: false,
+		},
+		{
+			Value: 0x98,
+			Expected: false,
+		},
+		{
+			Value: 0x99,
+			Expected: false,
+		},
+		{
+			Value: 0x9A,
+			Expected: false,
+		},
+		{
+			Value: 0x9B,
+			Expected: false,
+		},
+		{
+			Value: 0x9C,
+			Expected: false,
+		},
+		{
+			Value: 0x9D,
+			Expected: false,
+		},
+		{
+			Value: 0x9E,
+			Expected: false,
+		},
+		{
+			Value: 0x9F,
+			Expected: false,
+		},
+		{
+			Value: 0xA0,
+			Expected: false,
+		},
+		{
+			Value: 0xA1,
+			Expected: false,
+		},
+		{
+			Value: 0xA2,
+			Expected: false,
+		},
+		{
+			Value: 0xA3,
+			Expected: false,
+		},
+		{
+			Value: 0xA4,
+			Expected: false,
+		},
+		{
+			Value: 0xA5,
+			Expected: false,
+		},
+		{
+			Value: 0xA6,
+			Expected: false,
+		},
+		{
+			Value: 0xA7,
+			Expected: false,
+		},
+		{
+			Value: 0xA8,
+			Expected: false,
+		},
+		{
+			Value: 0xA9,
+			Expected: false,
+		},
+		{
+			Value: 0xAA,
+			Expected: false,
+		},
+		{
+			Value: 0xAB,
+			Expected: false,
+		},
+		{
+			Value: 0xAC,
+			Expected: false,
+		},
+		{
+			Value: 0xAD,
+			Expected: false,
+		},
+		{
+			Value: 0xAE,
+			Expected: false,
+		},
+		{
+			Value: 0xAF,
+			Expected: false,
+		},
+		{
+			Value: 0xB0,
+			Expected: false,
+		},
+		{
+			Value: 0xB1,
+			Expected: false,
+		},
+		{
+			Value: 0xB2,
+			Expected: false,
+		},
+		{
+			Value: 0xB3,
+			Expected: false,
+		},
+		{
+			Value: 0xB4,
+			Expected: false,
+		},
+		{
+			Value: 0xB5,
+			Expected: false,
+		},
+		{
+			Value: 0xB6,
+			Expected: false,
+		},
+		{
+			Value: 0xB7,
+			Expected: false,
+		},
+		{
+			Value: 0xB8,
+			Expected: false,
+		},
+		{
+			Value: 0xB9,
+			Expected: false,
+		},
+		{
+			Value: 0xBA,
+			Expected: false,
+		},
+		{
+			Value: 0xBB,
+			Expected: false,
+		},
+		{
+			Value: 0xBC,
+			Expected: false,
+		},
+		{
+			Value: 0xBD,
+			Expected: false,
+		},
+		{
+			Value: 0xBE,
+			Expected: false,
+		},
+		{
+			Value: 0xBF,
+			Expected: false,
+		},
+		{
+			Value: 0xC0,
+			Expected: false,
+		},
+		{
+			Value: 0xC1,
+			Expected: false,
+		},
+		{
+			Value: 0xC2,
+			Expected: false,
+		},
+		{
+			Value: 0xC3,
+			Expected: false,
+		},
+		{
+			Value: 0xC4,
+			Expected: false,
+		},
+		{
+			Value: 0xC5,
+			Expected: false,
+		},
+		{
+			Value: 0xC6,
+			Expected: false,
+		},
+		{
+			Value: 0xC7,
+			Expected: false,
+		},
+		{
+			Value: 0xC8,
+			Expected: false,
+		},
+		{
+			Value: 0xC9,
+			Expected: false,
+		},
+		{
+			Value: 0xCA,
+			Expected: false,
+		},
+		{
+			Value: 0xCB,
+			Expected: false,
+		},
+		{
+			Value: 0xCC,
+			Expected: false,
+		},
+		{
+			Value: 0xCD,
+			Expected: false,
+		},
+		{
+			Value: 0xCE,
+			Expected: false,
+		},
+		{
+			Value: 0xCF,
+			Expected: false,
+		},
+		{
+			Value: 0xD0,
+			Expected: false,
+		},
+		{
+			Value: 0xD1,
+			Expected: false,
+		},
+		{
+			Value: 0xD2,
+			Expected: false,
+		},
+		{
+			Value: 0xD3,
+			Expected: false,
+		},
+		{
+			Value: 0xD4,
+			Expected: false,
+		},
+		{
+			Value: 0xD5,
+			Expected: false,
+		},
+		{
+			Value: 0xD6,
+			Expected: false,
+		},
+		{
+			Value: 0xD7,
+			Expected: false,
+		},
+		{
+			Value: 0xD8,
+			Expected: false,
+		},
+		{
+			Value: 0xD9,
+			Expected: false,
+		},
+		{
+			Value: 0xDA,
+			Expected: false,
+		},
+		{
+			Value: 0xDB,
+			Expected: false,
+		},
+		{
+			Value: 0xDC,
+			Expected: false,
+		},
+		{
+			Value: 0xDD,
+			Expected: false,
+		},
+		{
+			Value: 0xDE,
+			Expected: false,
+		},
+		{
+			Value: 0xDF,
+			Expected: false,
+		},
+		{
+			Value: 0xE0,
+			Expected: false,
+		},
+		{
+			Value: 0xE1,
+			Expected: false,
+		},
+		{
+			Value: 0xE2,
+			Expected: false,
+		},
+		{
+			Value: 0xE3,
+			Expected: false,
+		},
+		{
+			Value: 0xE4,
+			Expected: false,
+		},
+		{
+			Value: 0xE5,
+			Expected: false,
+		},
+		{
+			Value: 0xE6,
+			Expected: false,
+		},
+		{
+			Value: 0xE7,
+			Expected: false,
+		},
+		{
+			Value: 0xE8,
+			Expected: false,
+		},
+		{
+			Value: 0xE9,
+			Expected: false,
+		},
+		{
+			Value: 0xEA,
+			Expected: false,
+		},
+		{
+			Value: 0xEB,
+			Expected: false,
+		},
+		{
+			Value: 0xEC,
+			Expected: false,
+		},
+		{
+			Value: 0xED,
+			Expected: false,
+		},
+		{
+			Value: 0xEE,
+			Expected: false,
+		},
+		{
+			Value: 0xEF,
+			Expected: false,
+		},
+		{
+			Value: 0xF0,
+			Expected: false,
+		},
+		{
+			Value: 0xF1,
+			Expected: false,
+		},
+		{
+			Value: 0xF2,
+			Expected: false,
+		},
+		{
+			Value: 0xF3,
+			Expected: false,
+		},
+		{
+			Value: 0xF4,
+			Expected: false,
+		},
+		{
+			Value: 0xF5,
+			Expected: false,
+		},
+		{
+			Value: 0xF6,
+			Expected: false,
+		},
+		{
+			Value: 0xF7,
+			Expected: false,
+		},
+		{
+			Value: 0xF8,
+			Expected: false,
+		},
+		{
+			Value: 0xF9,
+			Expected: false,
+		},
+		{
+			Value: 0xFA,
+			Expected: false,
+		},
+		{
+			Value: 0xFB,
+			Expected: false,
+		},
+		{
+			Value: 0xFC,
+			Expected: false,
+		},
+		{
+			Value: 0xFD,
+			Expected: false,
+		},
+		{
+			Value: 0xFE,
+			Expected: false,
+		},
+		{
+			Value: 0xFF,
+			Expected: false,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := digit.ByteIs(test.Value)
+
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %t", expected)
+			t.Logf("ACTUAL:   %t", actual)
+			t.Logf("VALUE: %q (0x%02X)", test.Value, test.Value)
+			continue
+		}
+	}
+}
diff --git a/digit/rune.go b/digit/rune.go
new file mode 100644
index 0000000..925b3f7
--- /dev/null
+++ b/digit/rune.go
@@ -0,0 +1,5 @@
+package digit
+
+func RuneIs(value rune) bool {
+	return '0' <= value && value <= '9'
+}
diff --git a/digit/rune_test.go b/digit/rune_test.go
new file mode 100644
index 0000000..1162d73
--- /dev/null
+++ b/digit/rune_test.go
@@ -0,0 +1,1055 @@
+package digit_test
+
+import (
+	"testing"
+
+	"sourcecode.social/reiver/go-rfc2396/digit"
+)
+
+func TestRuneIs(t *testing.T) {
+
+	tests := []struct{
+		Value rune
+		Expected bool
+	}{
+		{
+			Value: 0x00,
+			Expected: false,
+		},
+		{
+			Value: 0x01,
+			Expected: false,
+		},
+		{
+			Value: 0x02,
+			Expected: false,
+		},
+		{
+			Value: 0x03,
+			Expected: false,
+		},
+		{
+			Value: 0x04,
+			Expected: false,
+		},
+		{
+			Value: 0x05,
+			Expected: false,
+		},
+		{
+			Value: 0x06,
+			Expected: false,
+		},
+		{
+			Value: 0x07,
+			Expected: false,
+		},
+		{
+			Value: 0x08,
+			Expected: false,
+		},
+		{
+			Value: 0x09,
+			Expected: false,
+		},
+		{
+			Value: 0x0A,
+			Expected: false,
+		},
+		{
+			Value: 0x0B,
+			Expected: false,
+		},
+		{
+			Value: 0x0C,
+			Expected: false,
+		},
+		{
+			Value: 0x0D,
+			Expected: false,
+		},
+		{
+			Value: 0x0E,
+			Expected: false,
+		},
+		{
+			Value: 0x0F,
+			Expected: false,
+		},
+		{
+			Value: 0x10,
+			Expected: false,
+		},
+		{
+			Value: 0x11,
+			Expected: false,
+		},
+		{
+			Value: 0x12,
+			Expected: false,
+		},
+		{
+			Value: 0x13,
+			Expected: false,
+		},
+		{
+			Value: 0x14,
+			Expected: false,
+		},
+		{
+			Value: 0x15,
+			Expected: false,
+		},
+		{
+			Value: 0x16,
+			Expected: false,
+		},
+		{
+			Value: 0x17,
+			Expected: false,
+		},
+		{
+			Value: 0x18,
+			Expected: false,
+		},
+		{
+			Value: 0x19,
+			Expected: false,
+		},
+		{
+			Value: 0x1A,
+			Expected: false,
+		},
+		{
+			Value: 0x1B,
+			Expected: false,
+		},
+		{
+			Value: 0x1C,
+			Expected: false,
+		},
+		{
+			Value: 0x1D,
+			Expected: false,
+		},
+		{
+			Value: 0x1E,
+			Expected: false,
+		},
+		{
+			Value: 0x1F,
+			Expected: false,
+		},
+		{
+			Value: 0x20,
+			Expected: false,
+		},
+		{
+			Value: 0x21,
+			Expected: false,
+		},
+		{
+			Value: 0x22,
+			Expected: false,
+		},
+		{
+			Value: 0x23,
+			Expected: false,
+		},
+		{
+			Value: 0x24,
+			Expected: false,
+		},
+		{
+			Value: 0x25,
+			Expected: false,
+		},
+		{
+			Value: 0x26,
+			Expected: false,
+		},
+		{
+			Value: 0x27,
+			Expected: false,
+		},
+		{
+			Value: 0x28,
+			Expected: false,
+		},
+		{
+			Value: 0x29,
+			Expected: false,
+		},
+		{
+			Value: 0x2A,
+			Expected: false,
+		},
+		{
+			Value: 0x2B,
+			Expected: false,
+		},
+		{
+			Value: 0x2C,
+			Expected: false,
+		},
+		{
+			Value: 0x2D,
+			Expected: false,
+		},
+		{
+			Value: 0x2E,
+			Expected: false,
+		},
+		{
+			Value: 0x2F,
+			Expected: false,
+		},
+		{
+			Value: 0x30, // == '0'
+			Expected: true,
+		},
+		{
+			Value: 0x31, // == '1'
+			Expected: true,
+		},
+		{
+			Value: 0x32, // == '2'
+			Expected: true,
+		},
+		{
+			Value: 0x33, // == '3'
+			Expected: true,
+		},
+		{
+			Value: 0x34, // == '4'
+			Expected: true,
+		},
+		{
+			Value: 0x35, // == '5'
+			Expected: true,
+		},
+		{
+			Value: 0x36, // == '6'
+			Expected: true,
+		},
+		{
+			Value: 0x37, // == '7'
+			Expected: true,
+		},
+		{
+			Value: 0x38, // == '8'
+			Expected: true,
+		},
+		{
+			Value: 0x39, // == '9'
+			Expected: true,
+		},
+		{
+			Value: 0x3A,
+			Expected: false,
+		},
+		{
+			Value: 0x3B,
+			Expected: false,
+		},
+		{
+			Value: 0x3C,
+			Expected: false,
+		},
+		{
+			Value: 0x3D,
+			Expected: false,
+		},
+		{
+			Value: 0x3E,
+			Expected: false,
+		},
+		{
+			Value: 0x3F,
+			Expected: false,
+		},
+		{
+			Value: 0x40,
+			Expected: false,
+		},
+		{
+			Value: 0x41,
+			Expected: false,
+		},
+		{
+			Value: 0x42,
+			Expected: false,
+		},
+		{
+			Value: 0x43,
+			Expected: false,
+		},
+		{
+			Value: 0x44,
+			Expected: false,
+		},
+		{
+			Value: 0x45,
+			Expected: false,
+		},
+		{
+			Value: 0x46,
+			Expected: false,
+		},
+		{
+			Value: 0x47,
+			Expected: false,
+		},
+		{
+			Value: 0x48,
+			Expected: false,
+		},
+		{
+			Value: 0x49,
+			Expected: false,
+		},
+		{
+			Value: 0x4A,
+			Expected: false,
+		},
+		{
+			Value: 0x4B,
+			Expected: false,
+		},
+		{
+			Value: 0x4C,
+			Expected: false,
+		},
+		{
+			Value: 0x4D,
+			Expected: false,
+		},
+		{
+			Value: 0x4E,
+			Expected: false,
+		},
+		{
+			Value: 0x4F,
+			Expected: false,
+		},
+		{
+			Value: 0x50,
+			Expected: false,
+		},
+		{
+			Value: 0x51,
+			Expected: false,
+		},
+		{
+			Value: 0x52,
+			Expected: false,
+		},
+		{
+			Value: 0x53,
+			Expected: false,
+		},
+		{
+			Value: 0x54,
+			Expected: false,
+		},
+		{
+			Value: 0x55,
+			Expected: false,
+		},
+		{
+			Value: 0x56,
+			Expected: false,
+		},
+		{
+			Value: 0x57,
+			Expected: false,
+		},
+		{
+			Value: 0x58,
+			Expected: false,
+		},
+		{
+			Value: 0x59,
+			Expected: false,
+		},
+		{
+			Value: 0x5A,
+			Expected: false,
+		},
+		{
+			Value: 0x5B,
+			Expected: false,
+		},
+		{
+			Value: 0x5C,
+			Expected: false,
+		},
+		{
+			Value: 0x5D,
+			Expected: false,
+		},
+		{
+			Value: 0x5E,
+			Expected: false,
+		},
+		{
+			Value: 0x5F,
+			Expected: false,
+		},
+		{
+			Value: 0x60,
+			Expected: false,
+		},
+		{
+			Value: 0x61,
+			Expected: false,
+		},
+		{
+			Value: 0x62,
+			Expected: false,
+		},
+		{
+			Value: 0x63,
+			Expected: false,
+		},
+		{
+			Value: 0x64,
+			Expected: false,
+		},
+		{
+			Value: 0x65,
+			Expected: false,
+		},
+		{
+			Value: 0x66,
+			Expected: false,
+		},
+		{
+			Value: 0x67,
+			Expected: false,
+		},
+		{
+			Value: 0x68,
+			Expected: false,
+		},
+		{
+			Value: 0x69,
+			Expected: false,
+		},
+		{
+			Value: 0x6A,
+			Expected: false,
+		},
+		{
+			Value: 0x6B,
+			Expected: false,
+		},
+		{
+			Value: 0x6C,
+			Expected: false,
+		},
+		{
+			Value: 0x6D,
+			Expected: false,
+		},
+		{
+			Value: 0x6E,
+			Expected: false,
+		},
+		{
+			Value: 0x6F,
+			Expected: false,
+		},
+		{
+			Value: 0x70,
+			Expected: false,
+		},
+		{
+			Value: 0x71,
+			Expected: false,
+		},
+		{
+			Value: 0x72,
+			Expected: false,
+		},
+		{
+			Value: 0x73,
+			Expected: false,
+		},
+		{
+			Value: 0x74,
+			Expected: false,
+		},
+		{
+			Value: 0x75,
+			Expected: false,
+		},
+		{
+			Value: 0x76,
+			Expected: false,
+		},
+		{
+			Value: 0x77,
+			Expected: false,
+		},
+		{
+			Value: 0x78,
+			Expected: false,
+		},
+		{
+			Value: 0x79,
+			Expected: false,
+		},
+		{
+			Value: 0x7A,
+			Expected: false,
+		},
+		{
+			Value: 0x7B,
+			Expected: false,
+		},
+		{
+			Value: 0x7C,
+			Expected: false,
+		},
+		{
+			Value: 0x7D,
+			Expected: false,
+		},
+		{
+			Value: 0x7E,
+			Expected: false,
+		},
+		{
+			Value: 0x7F,
+			Expected: false,
+		},
+		{
+			Value: 0x80,
+			Expected: false,
+		},
+		{
+			Value: 0x81,
+			Expected: false,
+		},
+		{
+			Value: 0x82,
+			Expected: false,
+		},
+		{
+			Value: 0x83,
+			Expected: false,
+		},
+		{
+			Value: 0x84,
+			Expected: false,
+		},
+		{
+			Value: 0x85,
+			Expected: false,
+		},
+		{
+			Value: 0x86,
+			Expected: false,
+		},
+		{
+			Value: 0x87,
+			Expected: false,
+		},
+		{
+			Value: 0x88,
+			Expected: false,
+		},
+		{
+			Value: 0x89,
+			Expected: false,
+		},
+		{
+			Value: 0x8A,
+			Expected: false,
+		},
+		{
+			Value: 0x8B,
+			Expected: false,
+		},
+		{
+			Value: 0x8C,
+			Expected: false,
+		},
+		{
+			Value: 0x8D,
+			Expected: false,
+		},
+		{
+			Value: 0x8E,
+			Expected: false,
+		},
+		{
+			Value: 0x8F,
+			Expected: false,
+		},
+		{
+			Value: 0x90,
+			Expected: false,
+		},
+		{
+			Value: 0x91,
+			Expected: false,
+		},
+		{
+			Value: 0x92,
+			Expected: false,
+		},
+		{
+			Value: 0x93,
+			Expected: false,
+		},
+		{
+			Value: 0x94,
+			Expected: false,
+		},
+		{
+			Value: 0x95,
+			Expected: false,
+		},
+		{
+			Value: 0x96,
+			Expected: false,
+		},
+		{
+			Value: 0x97,
+			Expected: false,
+		},
+		{
+			Value: 0x98,
+			Expected: false,
+		},
+		{
+			Value: 0x99,
+			Expected: false,
+		},
+		{
+			Value: 0x9A,
+			Expected: false,
+		},
+		{
+			Value: 0x9B,
+			Expected: false,
+		},
+		{
+			Value: 0x9C,
+			Expected: false,
+		},
+		{
+			Value: 0x9D,
+			Expected: false,
+		},
+		{
+			Value: 0x9E,
+			Expected: false,
+		},
+		{
+			Value: 0x9F,
+			Expected: false,
+		},
+		{
+			Value: 0xA0,
+			Expected: false,
+		},
+		{
+			Value: 0xA1,
+			Expected: false,
+		},
+		{
+			Value: 0xA2,
+			Expected: false,
+		},
+		{
+			Value: 0xA3,
+			Expected: false,
+		},
+		{
+			Value: 0xA4,
+			Expected: false,
+		},
+		{
+			Value: 0xA5,
+			Expected: false,
+		},
+		{
+			Value: 0xA6,
+			Expected: false,
+		},
+		{
+			Value: 0xA7,
+			Expected: false,
+		},
+		{
+			Value: 0xA8,
+			Expected: false,
+		},
+		{
+			Value: 0xA9,
+			Expected: false,
+		},
+		{
+			Value: 0xAA,
+			Expected: false,
+		},
+		{
+			Value: 0xAB,
+			Expected: false,
+		},
+		{
+			Value: 0xAC,
+			Expected: false,
+		},
+		{
+			Value: 0xAD,
+			Expected: false,
+		},
+		{
+			Value: 0xAE,
+			Expected: false,
+		},
+		{
+			Value: 0xAF,
+			Expected: false,
+		},
+		{
+			Value: 0xB0,
+			Expected: false,
+		},
+		{
+			Value: 0xB1,
+			Expected: false,
+		},
+		{
+			Value: 0xB2,
+			Expected: false,
+		},
+		{
+			Value: 0xB3,
+			Expected: false,
+		},
+		{
+			Value: 0xB4,
+			Expected: false,
+		},
+		{
+			Value: 0xB5,
+			Expected: false,
+		},
+		{
+			Value: 0xB6,
+			Expected: false,
+		},
+		{
+			Value: 0xB7,
+			Expected: false,
+		},
+		{
+			Value: 0xB8,
+			Expected: false,
+		},
+		{
+			Value: 0xB9,
+			Expected: false,
+		},
+		{
+			Value: 0xBA,
+			Expected: false,
+		},
+		{
+			Value: 0xBB,
+			Expected: false,
+		},
+		{
+			Value: 0xBC,
+			Expected: false,
+		},
+		{
+			Value: 0xBD,
+			Expected: false,
+		},
+		{
+			Value: 0xBE,
+			Expected: false,
+		},
+		{
+			Value: 0xBF,
+			Expected: false,
+		},
+		{
+			Value: 0xC0,
+			Expected: false,
+		},
+		{
+			Value: 0xC1,
+			Expected: false,
+		},
+		{
+			Value: 0xC2,
+			Expected: false,
+		},
+		{
+			Value: 0xC3,
+			Expected: false,
+		},
+		{
+			Value: 0xC4,
+			Expected: false,
+		},
+		{
+			Value: 0xC5,
+			Expected: false,
+		},
+		{
+			Value: 0xC6,
+			Expected: false,
+		},
+		{
+			Value: 0xC7,
+			Expected: false,
+		},
+		{
+			Value: 0xC8,
+			Expected: false,
+		},
+		{
+			Value: 0xC9,
+			Expected: false,
+		},
+		{
+			Value: 0xCA,
+			Expected: false,
+		},
+		{
+			Value: 0xCB,
+			Expected: false,
+		},
+		{
+			Value: 0xCC,
+			Expected: false,
+		},
+		{
+			Value: 0xCD,
+			Expected: false,
+		},
+		{
+			Value: 0xCE,
+			Expected: false,
+		},
+		{
+			Value: 0xCF,
+			Expected: false,
+		},
+		{
+			Value: 0xD0,
+			Expected: false,
+		},
+		{
+			Value: 0xD1,
+			Expected: false,
+		},
+		{
+			Value: 0xD2,
+			Expected: false,
+		},
+		{
+			Value: 0xD3,
+			Expected: false,
+		},
+		{
+			Value: 0xD4,
+			Expected: false,
+		},
+		{
+			Value: 0xD5,
+			Expected: false,
+		},
+		{
+			Value: 0xD6,
+			Expected: false,
+		},
+		{
+			Value: 0xD7,
+			Expected: false,
+		},
+		{
+			Value: 0xD8,
+			Expected: false,
+		},
+		{
+			Value: 0xD9,
+			Expected: false,
+		},
+		{
+			Value: 0xDA,
+			Expected: false,
+		},
+		{
+			Value: 0xDB,
+			Expected: false,
+		},
+		{
+			Value: 0xDC,
+			Expected: false,
+		},
+		{
+			Value: 0xDD,
+			Expected: false,
+		},
+		{
+			Value: 0xDE,
+			Expected: false,
+		},
+		{
+			Value: 0xDF,
+			Expected: false,
+		},
+		{
+			Value: 0xE0,
+			Expected: false,
+		},
+		{
+			Value: 0xE1,
+			Expected: false,
+		},
+		{
+			Value: 0xE2,
+			Expected: false,
+		},
+		{
+			Value: 0xE3,
+			Expected: false,
+		},
+		{
+			Value: 0xE4,
+			Expected: false,
+		},
+		{
+			Value: 0xE5,
+			Expected: false,
+		},
+		{
+			Value: 0xE6,
+			Expected: false,
+		},
+		{
+			Value: 0xE7,
+			Expected: false,
+		},
+		{
+			Value: 0xE8,
+			Expected: false,
+		},
+		{
+			Value: 0xE9,
+			Expected: false,
+		},
+		{
+			Value: 0xEA,
+			Expected: false,
+		},
+		{
+			Value: 0xEB,
+			Expected: false,
+		},
+		{
+			Value: 0xEC,
+			Expected: false,
+		},
+		{
+			Value: 0xED,
+			Expected: false,
+		},
+		{
+			Value: 0xEE,
+			Expected: false,
+		},
+		{
+			Value: 0xEF,
+			Expected: false,
+		},
+		{
+			Value: 0xF0,
+			Expected: false,
+		},
+		{
+			Value: 0xF1,
+			Expected: false,
+		},
+		{
+			Value: 0xF2,
+			Expected: false,
+		},
+		{
+			Value: 0xF3,
+			Expected: false,
+		},
+		{
+			Value: 0xF4,
+			Expected: false,
+		},
+		{
+			Value: 0xF5,
+			Expected: false,
+		},
+		{
+			Value: 0xF6,
+			Expected: false,
+		},
+		{
+			Value: 0xF7,
+			Expected: false,
+		},
+		{
+			Value: 0xF8,
+			Expected: false,
+		},
+		{
+			Value: 0xF9,
+			Expected: false,
+		},
+		{
+			Value: 0xFA,
+			Expected: false,
+		},
+		{
+			Value: 0xFB,
+			Expected: false,
+		},
+		{
+			Value: 0xFC,
+			Expected: false,
+		},
+		{
+			Value: 0xFD,
+			Expected: false,
+		},
+		{
+			Value: 0xFE,
+			Expected: false,
+		},
+		{
+			Value: 0xFF,
+			Expected: false,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := digit.RuneIs(test.Value)
+
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %t", expected)
+			t.Logf("ACTUAL:   %t", actual)
+			t.Logf("VALUE: %q (0x%02X)", test.Value, test.Value)
+			continue
+		}
+	}
+}