Numeric base convertion in C#, Java and Scala

BaseX.cs

// <copyright file="BaseX.cs" company="http://www.sinbadsoft.com">
// Copyright (c) Chaker Nakhli 2011 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
// License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
// applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
// governing permissions and limitations under the License. 
// </copyright>
// <author>Chaker Nakhli</author>
// <email>Chaker.Nakhli@sinbadsoft.com</email>
// <date>2011/06/04</date>

namespace Javageneration
{
    using System;

    public static class BaseX
    {
        public static int Decode(string str, int baze)
        {
            int result = 0;
            int place = 1;
            int length = str.Length;
            for (int i = 0; i < length; ++i)
            {
                result += Value(str[length - 1 - i]) * place;
                place *= baze;
            }

            return result;
        }

        public static string Encode(int val, int baze)
        {
            var buffer = new char[32];
            int place = 0;
            int q = val;
            do
            {
                buffer[place++] = Symbol(q % baze);
                q /= baze;
            }
            while (q > 0);

            Array.Reverse(buffer, 0, place);
            return new string(buffer, 0, place);
        }

        public static unsafe string UnsafeEncode(int val, int baze)
        {
            char* buffer = stackalloc char[32];
            int place = 0;
            int q = val;
            do
            {
                buffer[place++] = Symbol(q % baze);
                q = q / baze;
            }
            while (q > 0);

            for (int i = 0; i < place / 2; ++i)
            {
                int mirrorIndex = place - 1 - i;
                char tmp = buffer[mirrorIndex];
                buffer[mirrorIndex] = buffer[i];
                buffer[i] = tmp;
            }

            return new string(buffer, 0, place);
        }

        public static int Value(char c)
        {
            if (c == '+') return 62;
            if (c == '/') return 63;
            if (c < '0') throw new ArgumentOutOfRangeException("c");
            if (c < ':') return c - '0';
            if (c < 'A') throw new ArgumentOutOfRangeException("c");
            if (c < '[') return c - 'A' + 10;
            if (c < 'a') throw new ArgumentOutOfRangeException("c");
            if (c < '{') return c - 'a' + 36;
            throw new ArgumentOutOfRangeException("c");
        }

        public static char Symbol(int i)
        {
            if (i < 0) throw new ArgumentOutOfRangeException("i");
            if (i < 10) return (char)('0' + i);
            if (i < 36) return (char)('A' + i - 10);
            if (i < 62) return (char)('a' + i - 36);
            if (i == 62) return '+';
            if (i == 63) return '/';
            throw new ArgumentOutOfRangeException("i");
        }
    }
}

BaseX.java

// <copyright file="BaseX.java" company="http://www.sinbadsoft.com">
// Copyright (c) Chaker Nakhli 2011 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
// License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
// applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
// governing permissions and limitations under the License. 
// </copyright>
// <author>Chaker Nakhli</author>
// <email>Chaker.Nakhli@sinbadsoft.com</email>
// <date>2011/06/04</date>

package com.javageneration;

public final class BaseX {
    public static int decode(String str, int baze) {
        int result = 0;
        int place = 1;
        int length = str.length();
        for (int i = 0; i < length; ++i) {
            result += Value(str.charAt(length - 1 - i)) * place;
            place *= baze;
        }
        return result;
    }

    public static String encode(int val, int baze) {
        char[] buffer = new char[32];
        int place = 0;
        int q = val;
        do {
            buffer[place++] = Symbol(q % baze);
            q /= baze;
        } while (q > 0);

        for (int i = 0; i < place / 2; ++i) {
            int mirrorIndex = place - 1 - i;
            char tmp = buffer[mirrorIndex];
            buffer[mirrorIndex] = buffer[i];
            buffer[i] = tmp;
        }

        return new String(buffer, 0, place);
    }

    public static int Value(char c) {
        if (c == '+') return 62;
        if (c == '/') return 63;
        if (c < '0') throw new IndexOutOfBoundsException("c");
        if (c < ':') return c - '0';
        if (c < 'A') throw new IndexOutOfBoundsException("c");
        if (c < '[') return c - 'A' + 10;
        if (c < 'a') throw new IndexOutOfBoundsException("c");
        if (c < '{') return c - 'a' + 36;
        throw new IndexOutOfBoundsException("c");
    }

    public static char Symbol(int i) {
        if (i < 0) throw new IndexOutOfBoundsException("i");
        if (i < 10) return (char) ('0' + i);
        if (i < 36) return (char) ('A' + i - 10);
        if (i < 62) return (char) ('a' + i - 36);
        if (i == 62) return '+';
        if (i == 63) return '/';
        throw new IndexOutOfBoundsException("i");
    }
}

BaseX.scala

// <copyright file="BaseX.scala" company="http://www.sinbadsoft.com">
// Copyright (c) Chaker Nakhli 2011 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
// License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
// applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
// governing permissions and limitations under the License. 
// </copyright>
// <author>Chaker Nakhli</author>
// <email>Chaker.Nakhli@sinbadsoft.com</email>
// <date>2011/06/04</date>

package com.javageneration

object BaseX extends ValueAndSymbolProvider {
  def encode(value: Int, baze: Int): String = {
    def process(q: Int, place: Int, baze: Int, builder: StringBuilder): StringBuilder = {
      if (q > 0) process(q / baze, place + 1, baze, builder += symbol(q % baze))
      else builder
    }
    if (value == 0) symbol(0).toString
    else process(value, 0, baze, new StringBuilder(32)).reverse.toString
  }
  
  def decode(str: String, baze: Int): Int = {
    def process(acc: Int, place: Int, str: String, index: Int): Int = {
      if (index >= 0) process(acc + value(str.charAt(index)) * place, place * baze, str, index-1)
      else acc
    }
    process(0, 1, str, str.length - 1)
  }
}

object BaseXListBased extends ValueAndSymbolProvider {
  def encode(i: Int, baze: Int): String = {
    def process(q: Int, baze: Int, list: List[Char]): List[Char] = {
      if (q > 0) process(q / baze, baze, symbol(q % baze) :: list)
      else list
    }
    if (i == 0) symbol(0).toString
    else process(i, baze, Nil).mkString
  }
  
  def decode(str: String, baze: Int): Int = {
    def process(acc: Int, place: Int, lst: List[Char]): Int = {
      if (!lst.isEmpty) process(acc + value(lst.head) * place, place * baze, lst.tail) 
      else acc
    }
    process(0, 1, str.reverse.toList)
  }
}

trait ValueAndSymbolProvider {
  def value(c: Char): Int = {
    if (c == '+') 62
    else if (c == '/') 63
    else if (c < '0') throw new IndexOutOfBoundsException("c");
    else if (c < ':') c - '0';
    else if (c < 'A') throw new IndexOutOfBoundsException("c");
    else if (c < '[') c - 'A' + 10;
    else if (c < 'a') throw new IndexOutOfBoundsException("c");
    else if (c < '{') c - 'a' + 36;
    else throw new IndexOutOfBoundsException("c");
  }

  def symbol(i: Int): Char = {
    if (i < 0) throw new IndexOutOfBoundsException("i")
    else if (i < 10) ('0' + i).toChar
    else if (i < 36) ('A' + i - 10).toChar
    else if (i < 62) ('a' + i - 36).toChar
    else if (i == 62) '+'
    else if (i == 63) '/'
    else throw new IndexOutOfBoundsException("i");
  }
}