utf8s.FormatBinary()

format.go

@@ -0,0 +1,98 @@
+package utf8s
+
+import (
+	"bytes"
+)
+
+// FormatBinary returns a representation of a rune as a sequence of bytes, given in binary format.
+//
+// Example
+//
+//	utf8s.FormatBinary('۵')
+//	
+//	// Outputs:
+//	// <<0b11011011 ; 0b10110101>>
+func FormatBinary(r rune) string {
+
+	var buffer bytes.Buffer
+
+	_, err := WriteRune(&buffer, r)
+	if nil != err {
+		return "<<ERROR>>"
+	}
+
+
+	var output bytes.Buffer
+
+	length := buffer.Len()
+	for i:=0; i<length; i++ {
+		switch i {
+		case 0:
+			output.WriteString("<<0b")
+		default:
+			output.WriteString(" ; 0b")
+		}
+
+
+		b := buffer.Bytes()[i]
+
+		switch {
+		case 0 == (0x80 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x40 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x20 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x10 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x08 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x04 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x02 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+
+		switch {
+		case 0 == (0x01 & b):
+			output.WriteRune('0')
+		default:
+			output.WriteRune('1')
+		}
+	}
+	output.WriteString(">>")
+
+	return output.String()
+}

format_test.go

@@ -0,0 +1,73 @@
+package utf8s
+
+import (
+	"testing"
+)
+
+func TestFormatBinary(t *testing.T) {
+
+	tests := []struct{
+		Rune     rune
+		Expected string
+	}{
+		{
+			Rune:     'A',
+			Expected: "<<0b01000001>>",
+		},
+
+
+
+		{
+			Rune:     'r',
+			Expected: "<<0b01110010>>",
+		},
+
+
+
+		{
+			Rune:     '¡',
+			Expected: "<<0b11000010 ; 0b10100001>>",
+		},
+
+
+
+		{
+			Rune:     '۵',
+			Expected: "<<0b11011011 ; 0b10110101>>",
+		},
+
+
+
+		{
+			Rune:     '‱',
+			Expected: "<<0b11100010 ; 0b10000000 ; 0b10110001>>",
+		},
+
+
+
+		{
+			Rune:     '≡',
+			Expected: "<<0b11100010 ; 0b10001001 ; 0b10100001>>",
+		},
+
+
+
+		{
+			Rune:     '🙂',
+			Expected: "<<0b11110000 ; 0b10011111 ; 0b10011001 ; 0b10000010>>",
+		},
+	}
+
+
+	for testNumber, test := range tests {
+
+		actual := FormatBinary(test.Rune)
+
+		if expected := test.Expected; expected != actual {
+			t.Errorf("For test #%d, expected %q, but actually got %q.", testNumber, expected, actual)
+			t.Errorf("\trune = %q (%X)", test.Rune, test.Rune)
+			continue
+
+		}
+	}
+}