$#include "StringHash.h"

/// 32-bit hash value for a string.
class StringHash
{
public:
    /// Construct with zero value.
    StringHash() :
        value_(0)
    {
    }
    
    /// Copy-construct from another hash.
    StringHash(const StringHash& rhs) :
        value_(rhs.value_)
    {
    }
    
    /// Construct with an initial value.
    explicit StringHash(unsigned value) :
        value_(value)
    {
    }
    
    /// Construct from a C string case-insensitively.
    StringHash(const char* str);
    /// Construct from a string case-insensitively.
    StringHash(const String& str);
    
    /// Add a hash.
    StringHash operator + (const StringHash& rhs) const
    {
        StringHash ret;
        ret.value_ = value_ + rhs.value_;
        return ret;
    }
    
    // Test for equality with another hash.
    bool operator == (const StringHash& rhs) const { return value_ == rhs.value_; }
    /// Test if less than another hash.
    bool operator < (const StringHash& rhs) const { return value_ < rhs.value_; }
    /// Return true if nonzero hash value.
    operator bool () const { return value_ != 0; }
    /// Return hash value.
    unsigned Value() const { return value_; }
    /// Return as string.
    String ToString() const;
    /// Return hash value for HashSet & HashMap.
    unsigned ToHash() const { return value_; }
    
    /// Calculate hash value case-insensitively from a C string.
    static unsigned Calculate(const char* str);
    
    /// Zero hash.
    static const StringHash ZERO;
};

/// 16-bit hash value for a string.
class ShortStringHash
{
public:
    /// Construct with zero hash value.
    ShortStringHash();
    
    /// Copy-construct from another hash value.
    ShortStringHash(const ShortStringHash& rhs);
    
    /// Copy-construct from another 32-bit hash value (ignore the high bits.)
    explicit ShortStringHash(const StringHash& rhs);
    
    /// Construct with an initial value.
    explicit ShortStringHash(unsigned short value);

    /// Construct from a C string case-insensitively.
    ShortStringHash(const char* str);
    
    /// Construct from a string case-insensitively.
    ShortStringHash(const String& str);
    
    /// Add a hash.
    ShortStringHash operator + (const ShortStringHash& rhs) const;
    
    /// Test for equality with another hash.
    bool operator == (const ShortStringHash& rhs) const;
    
    /// Test if less than another hash.
    bool operator < (const ShortStringHash& rhs) const;
    
    /// Return hash value.
    unsigned short Value() const { return value_; }
    
    /// Calculate hash value case-insensitively from a C string.
    static unsigned short Calculate(const char* str);
    
    /// Zero hash.
    static const ShortStringHash ZERO;
};