private IEnumerable <Expression> ReplaceVar(Dictionary <Expression, List <Expression> > vars, ExpressionTree expression)
{
if (expression == null)
{
yield break;
}
if (expression.Root == null)
{
expression.SetRoot();
}
if (expression.IsLeaf())
{
foreach (var kvp in vars)
{
if (SingletonEquality(expression.Data, kvp.Key))
{
foreach (var var in kvp.Value)
{
// safeguard against infinite loop
if (SingletonEquality(kvp.Key, var))
{
continue;
}
ExpressionTree newVal = RewriteExpression(expression, kvp.Key, var);
if (newVal == null)
{
break;
}
var copy = expression.Root.Copy();
var newTree = ExpressionTree.FindAndReplaceNode(copy, newVal, expression.Copy());
yield return(newTree.Root.TreeToExpression());
foreach (var item in ReplaceVar(vars, newTree.Root))
{
yield return(item);
}
}
}
}
}
else
{
foreach (var item in ReplaceVar(vars, expression.LChild))
{
yield return(item);
}
foreach (var item in ReplaceVar(vars, expression.RChild))
{
yield return(item);
}
}
}
private IEnumerable <Expression> ReplaceConstants(ExpressionTree expression, List <Expression> constants, List <IVariable> vars)
{
if (expression == null)
{
yield break;
}
if (expression.Root == null)
{
expression.SetRoot();
}
if (expression.IsLeaf())
{
if (HasConstant(expression.Data, constants))
{
foreach (var var in vars)
{
if (!ValidateType(var, expression.Parent.TreeToExpression() as BinaryExpr))
{
continue;
}
var newVal = ExpressionTree.ExpressionToTree(VariableToExpression(var));
var copy = expression.Root.Copy();
var newTree = ExpressionTree.FindAndReplaceNode(copy, newVal, expression.Copy());
yield return(newTree.Root.TreeToExpression());
foreach (var item in ReplaceConstants(newTree.Root, constants, vars))
{
yield return(item);
}
}
}
}
else
{
foreach (var item in ReplaceConstants(expression.LChild, constants, vars))
{
yield return(item);
}
foreach (var item in ReplaceConstants(expression.RChild, constants, vars))
{
yield return(item);
}
}
}