/// <summary>
/// Parses the string argument as if it was an <see cref="int"/> value and returns the
/// result. Throws <see cref="FormatException"/> if the string does not represent an
/// <see cref="int"/> quantity. The second argument specifies the radix to use when parsing
/// the value.
/// <para/>
/// NOTE: This was parseInt() in Lucene
/// </summary>
/// <param name="chars"> A string representation of an int quantity. </param>
/// <param name="radix"> The base to use for conversion. </param>
/// <returns> The value represented by the argument </returns>
/// <exception cref="FormatException"> If the argument could not be parsed as an int quantity. </exception>
public static int ParseInt32(char[] chars, int offset, int len, int radix)
{
int minRadix = 2, maxRadix = 36;
if (chars is null || radix < minRadix || radix > maxRadix)
{
throw NumberFormatException.Create();
}
int i = 0;
if (len == 0)
{
throw NumberFormatException.Create("chars length is 0");
}
bool negative = chars[offset + i] == '-';
if (negative && ++i == len)
{
throw NumberFormatException.Create("can't convert to an int");
}
if (negative == true)
{
offset++;
len--;
}
return(Parse(chars, offset, len, radix, negative));
}
/// <summary>
/// Converts a hex string at the specified index and length of <paramref name="hex"/>
/// into an <see cref="int"/>.
/// <para/>
/// NOTE: This was hexToInt() in Lucene
/// </summary>
/// <param name="hex">
/// A string in capital or lower case hex, of no more then 16
/// characters.
/// </param>
/// <param name="startIndex">The index of the first character to begin parsing.</param>
/// <param name="length">The number of characters to parse.</param>
/// <exception cref="FormatException">if the string is more than 16 characters long, or if any
/// character is not in the set [0-9a-fA-f]</exception>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="startIndex"/> or <paramref name="length"/> is less than zero.
/// <para/>
/// -or-
/// <para/>
/// <paramref name="startIndex"/> and <paramref name="length"/> refer to a location outside of <paramref name="hex"/>.
/// </exception>
// LUCENENET specific overload
public static int HexToInt32(string hex, int startIndex, int length)
{
if ((length > 16) || !Integer.TryParse(hex, startIndex, length, radix: 16, out int result))
{
throw NumberFormatException.Create();
}
return(result);
}
public static int GetPrefixCodedInt32Shift(BytesRef val)
{
int shift = val.Bytes[val.Offset] - SHIFT_START_INT32;
if (shift > 31 || shift < 0)
{
throw NumberFormatException.Create("Invalid shift value in prefixCoded bytes (is encoded value really an INT?)");
}
return(shift);
}
/// <summary>
/// Returns an <see cref="int"/> from prefixCoded bytes.
/// Rightmost bits will be zero for lower precision codes.
/// This method can be used to decode a term's value.
/// <para/>
/// NOTE: This was prefixCodedToInt() in Lucene
/// </summary>
/// <exception cref="FormatException"> if the supplied <see cref="BytesRef"/> is
/// not correctly prefix encoded. </exception>
/// <seealso cref="Int32ToPrefixCodedBytes(int, int, BytesRef)"/>
public static int PrefixCodedToInt32(BytesRef val)
{
long sortableBits = 0;
for (int i = val.Offset, limit = val.Offset + val.Length; i < limit; i++)
{
sortableBits <<= 7;
var b = val.Bytes[i];
if (b < 0)
{
throw NumberFormatException.Create("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
}
sortableBits |= b;
}
return((int)((sortableBits << GetPrefixCodedInt32Shift(val)) ^ 0x80000000));
}
/// <summary>
/// Returns a <see cref="long"/> from prefixCoded bytes.
/// Rightmost bits will be zero for lower precision codes.
/// This method can be used to decode a term's value.
/// <para/>
/// NOTE: This was prefixCodedToLong() in Lucene
/// </summary>
/// <exception cref="FormatException"> if the supplied <see cref="BytesRef"/> is
/// not correctly prefix encoded. </exception>
/// <seealso cref="Int64ToPrefixCodedBytes(long, int, BytesRef)"/>
public static long PrefixCodedToInt64(BytesRef val)
{
long sortableBits = 0L;
for (int i = val.Offset + 1, limit = val.Offset + val.Length; i < limit; i++)
{
sortableBits <<= 7;
var b = val.Bytes[i];
if (b < 0)
{
throw NumberFormatException.Create("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
}
sortableBits |= (byte)b;
}
return((long)((ulong)(sortableBits << GetPrefixCodedInt64Shift(val)) ^ 0x8000000000000000L)); // LUCENENET TODO: Is the casting here necessary?
}
/// <summary>
/// Converts a hex string into an <see cref="int"/>.
/// <para/>
/// NOTE: This was hexToInt() in Lucene
/// </summary>
/// <param name="hex">
/// A string in capital or lower case hex, of no more then 16
/// characters.
/// </param>
/// <exception cref="FormatException">if the string is more than 16 characters long, or if any
/// character is not in the set [0-9a-fA-f]</exception>
public static int HexToInt32(string hex)
{
int len = hex.Length;
if (len > 16)
{
throw NumberFormatException.Create();
}
try
{
// LUCENENET NOTE: Convert.ToInt32(string, int) throws a
// FormatException if the character does not fall in
// the correct range, which is the behavior we are expecting.
// But throws an ArgumentException if passed a negative number.
// So we need to convert to FormatException to provide the correct behavior.
return(Convert.ToInt32(hex, 16));
}
catch (ArgumentException e)
{
throw NumberFormatException.Create(e);
}
}
private static int Parse(char[] chars, int offset, int len, int radix, bool negative)
{
int max = int.MinValue / radix;
int result = 0;
for (int i = 0; i < len; i++)
{
int digit = (int)char.GetNumericValue(chars[i + offset]);
if (digit == -1)
{
throw NumberFormatException.Create("Unable to parse");
}
if (max > result)
{
throw NumberFormatException.Create("Unable to parse");
}
int next = result * radix - digit;
if (next > result)
{
throw NumberFormatException.Create("Unable to parse");
}
result = next;
}
/*while (offset < len) {
* }*/
if (!negative)
{
result = -result;
if (result < 0)
{
throw NumberFormatException.Create("Unable to parse");
}
}
return(result);
}