/// <summary>
/// Changes the extension of a string.
/// </summary>
/// <param name="id">The string to affect.</param>
/// <param name="extension">The new extension with a leading period.</param>
/// <returns>The id of a string with the new extension.</returns>
public StringId ChangeExtension(StringId id, StringId extension)
{
Contract.Requires(IsValid());
Contract.Requires(id.IsValid);
Contract.Requires(extension.IsValid);
Contract.Ensures(Contract.Result <StringId>().IsValid);
int originalLength = GetLength(id);
int extLength = GetLength(extension);
using (var wrapper = Pools.GetCharArray(originalLength + extLength))
{
char[] name = wrapper.Instance;
CopyString(id, name, 0);
int newLength = originalLength;
for (int i = originalLength; --i >= 0;)
{
char ch = name[i];
if (ch == '.')
{
newLength = i;
break;
}
}
CopyString(extension, name, newLength);
var s = new CharArraySegment(name, 0, newLength + extLength);
return(AddString(s));
}
}
/// <summary>
/// Concatenates two strings together.
/// </summary>
public StringId Concat(StringId id1, StringId id2)
{
Contract.Requires(id1.IsValid);
Contract.Requires(id2.IsValid);
Contract.Ensures(Contract.Result <StringId>().IsValid);
int len1 = GetLength(id1);
int len2 = GetLength(id2);
using (var wrapper = Pools.GetCharArray(len1 + len2))
{
char[] buffer = wrapper.Instance;
CopyString(id1, buffer, 0);
CopyString(id2, buffer, len1);
var s = new CharArraySegment(buffer, 0, len1 + len2);
return(AddString(s));
}
}
/// <summary>
/// Gets a string from this table.
/// </summary>
public string GetString(StringId id)
{
Contract.Requires(id.IsValid);
Contract.Requires(IsValid());
if (!m_expansionCache.TryGetValue(id, out string result))
{
int len = GetLength(id);
using (var wrapper = Pools.GetCharArray(len))
{
char[] buffer = wrapper.Instance;
CopyString(id, buffer, 0);
result = new string(buffer, 0, len);
m_expansionCache.AddItem(id, result);
}
}
return(result);
}
/// <summary>
/// Remove the extension of a path.
/// </summary>
/// <param name="id">The string affect.</param>
/// <returns>The id of a path without its last extension.</returns>
public StringId RemoveExtension(StringId id)
{
Contract.Requires(IsValid());
Contract.Requires(id.IsValid);
Contract.Ensures(Contract.Result <StringId>().IsValid);
int originalLength = GetLength(id);
using (var wrapper = Pools.GetCharArray(originalLength))
{
char[] name = wrapper.Instance;
CopyString(id, name, 0);
int newLength = originalLength;
for (int i = originalLength; --i >= 0;)
{
char ch = name[i];
if (ch == '.')
{
newLength = i;
break;
}
}
if (newLength == 0)
{
// if we'd end up with an empty string just return the original
return(id);
}
if (newLength == originalLength)
{
// no . found, return original string
return(id);
}
var s = new CharArraySegment(name, 0, newLength);
return(AddString(s));
}
}
/// <summary>
/// Gets the extension of a string.
/// </summary>
/// <param name="id">The string of which to extract the extension.</param>
/// <returns>The extension.</returns>
public StringId GetExtension(StringId id)
{
Contract.Requires(id.IsValid);
int length = GetLength(id);
using (var wrapper = Pools.GetCharArray(length))
{
char[] name = wrapper.Instance;
CopyString(id, name, 0);
for (int i = length; --i >= 0;)
{
char ch = name[i];
if (ch == '.')
{
var s = new CharArraySegment(name, i, length - i);
return(AddString(s));
}
}
return(StringId.Invalid);
}
}