diff --git a/src/java/iced-x86/src/test/java/com/github/icedland/iced/x86/NumberConverter.java b/src/java/iced-x86/src/test/java/com/github/icedland/iced/x86/NumberConverter.java
new file mode 100644
index 000000000..648882cb2
--- /dev/null
+++ b/src/java/iced-x86/src/test/java/com/github/icedland/iced/x86/NumberConverter.java
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: MIT
+// Copyright (C) 2018-present iced project and contributors
+
+package com.github.icedland.iced.x86;
+
+public final class NumberConverter {
+	public static long toUInt64(String value) {
+		int radix = 10;
+		if (value.startsWith("0x")) {
+			value = value.substring(2);
+			radix = 16;
+		}
+		try {
+			return Long.parseUnsignedLong(value, radix);
+		}
+		catch (NumberFormatException ex) {
+			throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value), ex);
+		}
+	}
+
+	public static long toInt64(String value) {
+		String unsigned_value = value;
+		long mult;
+		if (unsigned_value.startsWith("-")) {
+			mult = -1;
+			unsigned_value = unsigned_value.substring(1);
+		}
+		else
+			mult = 1;
+		int radix = 10;
+		if (unsigned_value.startsWith("0x")) {
+			unsigned_value = unsigned_value.substring(2);
+			radix = 16;
+		}
+		try {
+			return Long.parseLong(value, radix) * mult;
+		}
+		catch (NumberFormatException ex) {
+			throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value), ex);
+		}
+	}
+
+	public static int toUInt32(String value) {
+		long v = toUInt64(value);
+		if (Long.compareUnsigned(v, 0xFFFF_FFFF) <= 0)
+			return (int)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static int toInt32(String value) {
+		long v = toInt64(value);
+		if (-0x8000_0000 <= v && v <= 0x7FFF_FFFF)
+			return (int)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static short toUInt16(String value) {
+		long v = toUInt64(value);
+		if (Long.compareUnsigned(v, 0xFFFF) <= 0)
+			return (short)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static short toInt16(String value) {
+		long v = toInt64(value);
+		if (-0x8000 <= v && v <= 0x7FFF)
+			return (short)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static byte toUInt8(String value) {
+		long v = toUInt64(value);
+		if (Long.compareUnsigned(v, 0xFF) <= 0)
+			return (byte)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static byte toInt8(String value) {
+		long v = toInt64(value);
+		if (-0x80 <= v && v <= 0x7F)
+			return (byte)v;
+		throw new UnsupportedOperationException(String.format("Invalid number: '%s'", value));
+	}
+
+	public static boolean toBoolean(String value) {
+		switch (value) {
+		case "true":
+			return true;
+		case "false":
+			return false;
+		default:
+			throw new UnsupportedOperationException(String.format("Invalid boolean: '%s'", value));
+		}
+	}
+}