private static LocalScope GetMinimalOuterScope(LocalScope outerScope)
{
while (outerScope != null &&
outerScope._symbols == null &&
outerScope._sharedScope == null)
{
outerScope = outerScope._outerScope;
}
return(outerScope);
}
/// <summary>
/// Makes a copy of this <see cref="LocalScope"/>.
/// </summary>
public LocalScope Copy()
{
// if we have any non-shared symbols, then move them into shared chain of symbols that
// can be shared w/o fear of modification (basically copy-on-fear-of-writing).
if (_symbols != null && _symbols.Count > 0)
{
_sharedScope = new LocalScope(_symbols, null, _sharedScope);
_symbols = null;
}
return(new LocalScope(null, _outerScope, _sharedScope));
}
/// <summary>
/// Create a new instance of a <see cref="LocalScope"/>
/// </summary>
/// <param name="outerScope">An optional outer scope.</param>
public LocalScope(LocalScope outerScope = null)
: this(null, outerScope, null)
{
}
private LocalScope(Dictionary <string, Symbol> symbols, LocalScope outerScope, LocalScope sharedScope)
{
_symbols = symbols;
_outerScope = GetMinimalOuterScope(outerScope);
_sharedScope = sharedScope;
}