public override bool Reduce(IVariableMap<Expression> Map, ref Expression Reduced)
{
// Only possible way to reduce a variable is to replace it with its value.
Expression possible = null;
if (Map.Lookup(this.Index, ref possible))
{
VariableExpression ve = possible as VariableExpression;
if (ve != null)
{
if (ve.Index == this.Index)
{
return false;
}
}
Reduced = possible;
return true;
}
return false;
}
/// <summary>
/// Looks up or "dereferences" a variable with the given index in the specified stack.
/// </summary>
public static Expression Lookup(int Index, IVariableMap<Expression> Map)
{
Expression res = null;
if (Map.Lookup(Index, ref res))
{
return res.Substitute(Map);
}
else
{
return Expression.Variable(Index);
}
}