/// <summary>
/// Returns whether or not an <see cref="Expression"/> inside the given <paramref name="tree"/>
/// matches the given <paramref name="predicate"/>.
/// </summary>
public static bool Exists(this Expression tree, Predicate <Expression> predicate)
{
bool doesExist = false;
ExpressionPipeline visitor = Expressive.Pipeline();
visitor.Pipeline += expr =>
{
if (predicate(expr))
{
doesExist = true;
visitor.Stop();
}
return(expr);
};
visitor.Visit(tree);
return(doesExist);
}
/// <summary>
/// Returns whether or not the given expression <paramref name="tree"/>
/// contains the specified <paramref name="expression"/>.
/// </summary>
public static bool Contains(this Expression tree, Expression expression)
{
bool doesContain = false;
ExpressionPipeline visitor = Expressive.Pipeline();
visitor.Pipeline += expr =>
{
if (expr == expression)
{
doesContain = true;
visitor.Stop();
}
return(expr);
};
visitor.Visit(tree);
return(doesContain);
}
/// <summary>
/// Returns all <see cref="Expression"/>s that matches
/// the given <paramref name="predicate"/>.
/// </summary>
public static List <Expression> FindAll(this Expression tree, Predicate <Expression> predicate)
{
List <Expression> result = new List <Expression>();
ExpressionPipeline visitor = Expressive.Pipeline();
visitor.Pipeline += expr =>
{
if (predicate(expr))
{
result.Add(expr);
visitor.Stop();
}
return(expr);
};
visitor.Visit(tree);
return(result);
}
/// <summary>
/// Returns the first <see cref="Expression"/> that matches
/// the given <paramref name="predicate"/>.
/// </summary>
public static Expression Find(this Expression tree, Predicate <Expression> predicate)
{
Expression result = null;
ExpressionPipeline visitor = Expressive.Pipeline();
visitor.Pipeline += expr =>
{
if (predicate(expr))
{
result = expr;
visitor.Stop();
}
return(expr);
};
visitor.Visit(tree);
return(result);
}
/// <summary>
/// Returns the given expression <paramref name="tree"/>, replacing
/// one expression by another.
/// </summary>
public static Expression Replace(this Expression tree, Expression replacee, Expression replacer)
{
return(Expressive.Pipeline(expr => expr == replacee ? replacer : expr).Visit(tree));
}
