public void Repoint(Schema OriginalSchema, Schema NewSchema)
{
if (this._idx >= OriginalSchema.Count)
throw new Exception("Original schema is invalid");
if (OriginalSchema.ColumnAffinity(this._idx) != this._affinity)
throw new Exception("Original schema is invalid");
string name = OriginalSchema.ColumnName(this._idx);
int new_index = NewSchema.ColumnIndex(name);
if (new_index == -1)
throw new Exception("New schema is invalid");
if (NewSchema.ColumnAffinity(new_index) != this._affinity)
throw new Exception("New schema is invalid");
this._idx = new_index;
}
public static FNode Field(Schema Columns, string Name, Register Memory)
{
int idx = Columns.ColumnIndex(Name);
return Field(idx, Columns.ColumnAffinity(idx), Columns.ColumnSize(idx), Memory);
}
/// <summary>
/// Renders a string into a key
/// </summary>
/// <param name="Columns">The schema that will be used in the key generation</param>
/// <param name="Text">The key string to be parsed</param>
/// <returns>A key with defined sort affinities</returns>
public Key Render(Schema Columns, string Text)
{
Columns = Columns ?? new Schema();
string[] tokens = Text.Split(this._FieldDelims.ToArray());
Key k = new Key();
foreach (string t in tokens)
{
string[] temp = t.Split(this._AscDescDelims.ToArray(),StringSplitOptions.RemoveEmptyEntries);
// Get the field name //
string field_or_index = temp[0];
int idx = Columns.ColumnIndex(field_or_index);
if (idx == -1)
{
if (!int.TryParse(field_or_index, out idx))
throw new Exception("Element passed is neither a field or an index: " + field_or_index);
}
// Get the affinity //
string asc_or_desc = (temp.Length < 2) ? "\0" : temp[1];
KeyAffinity sort_type = KeyAffinity.Ascending;
if (this._AscTokens.Contains(asc_or_desc, StringComparer.OrdinalIgnoreCase))
sort_type = KeyAffinity.Ascending;
else if (this._DescTokens.Contains(asc_or_desc, StringComparer.OrdinalIgnoreCase))
sort_type = KeyAffinity.Descending;
k.Add(idx, sort_type);
}
return k;
}
