/// <summary>
/// Check for equivalent array initializers.
/// </summary>
/// <remarks>
/// To be true, type must be equivalent and expressions must be similar.
/// </remarks>
/// <param name="source">The source <see cref="NewArrayExpression"/>.</param>
/// <param name="target">The target <see cref="NewArrayExpression"/>.</param>
/// <returns>A flag indicating whether the array initializers are equivalent.</returns>
private bool NewArraysAreSimilar(
NewArrayExpression source,
NewArrayExpression target)
{
if (source.Type != target.Type)
{
return(false);
}
return(ExpressionSimilarity.AreSimilar(source.Expressions, target.Expressions));
}
/// <summary>
/// Method to compare two <seealso cref="ConstantExpression"/>
/// instances.
/// </summary>
/// <remarks>
/// If the constant is an expression, similarity is recursed. If it is a value type,
/// the source and target must be equal. Otherwise, similar is based on types.
/// </remarks>
/// <param name="source">The source <see cref="ConstantExpression"/>.</param>
/// <param name="target">The target <see cref="ConstantExpression"/>.</param>
/// <returns>A flag indicating whether the two are similar.</returns>
private bool ConstantsAreSimilar(
ConstantExpression source,
ConstantExpression target)
{
if (!ExpressionSimilarity.TypesAreSimilar(source.Type, typeof(Expression)) &&
!ExpressionSimilarity.TypesAreSimilar(source.Type, target.Type))
{
return(false);
}
if (source.Value == null)
{
return(target.Value == null);
}
if (source.Value is Expression expression)
{
return(ExpressionSimilarity.AreSimilar(
expression,
target.Value as Expression));
}
// lists
if (typeof(Array).IsAssignableFrom(source.Type) ||
typeof(System.Collections.ICollection).IsAssignableFrom(source.Type))
{
return(true);
}
// string
if (source.Type == typeof(string))
{
return(source.Value == target.Value);
}
// typed collections
if (source.Type.GetInterfaces()
.Any(i => i.IsGenericType &&
i.GetGenericTypeDefinition() == typeof(IEnumerable <>)))
{
return(true);
}
// "primitives"
return(eq.ValuesAreEquivalent(
source.Value,
target.Value));
}
/// <summary>
/// Check for similar member initialization.
/// </summary>
/// <remarks>
/// The expression must be similar, the types similar, and every binding must be equivalent.
/// </remarks>
/// <param name="source">The source <see cref="MemberInitExpression"/>.</param>
/// <param name="target">The target <see cref="MemberInitExpression"/>.</param>
/// <returns>A flag indicating whether the member initializations are similar.</returns>
private bool MemberInitAreSimilar(
MemberInitExpression source,
MemberInitExpression target)
{
if (!ExpressionSimilarity.TypesAreSimilar(source.Type, target.Type))
{
return(false);
}
if (!ExpressionSimilarity.AreSimilar(source.NewExpression, target.NewExpression))
{
return(false);
}
return(ExpressionSimilarity.MemberBindingsAreSimilar(source.Bindings, target.Bindings));
}
/// <summary>
/// Check for similar object initializer.
/// </summary>
/// <remarks>
/// To be true, type must be similar,
/// parameters are similar and arguments are similar.
/// </remarks>
/// <param name="source">The source <see cref="NewExpression"/>.</param>
/// <param name="target">The target <see cref="NewExpression"/>.</param>
/// <returns>A flag indicating whether the object initializers are equivalent.</returns>
private bool NewAreSimilar(
NewExpression source,
NewExpression target)
{
if (!ExpressionSimilarity.TypesAreSimilar(source.Type, target.Type))
{
return(false);
}
if (!ExpressionSimilarity.ParameterInfosAreSimilar(
source.Constructor.GetParameters(),
target.Constructor.GetParameters()))
{
return(false);
}
return(ExpressionSimilarity.AreSimilar(source.Arguments, target.Arguments));
}
/// <summary>
/// Method to compare two <see cref="InvocationExpression"/> for similarty.
/// </summary>
/// <remarks>
/// To be similar, types must be assignable, arguments must be similar,
/// and the source expression must be part of the target expression.
/// </remarks>
/// <param name="source">The source <see cref="InvocationExpression"/>.</param>
/// <param name="target">The target <see cref="InvocationExpression"/>.</param>
/// <returns>A value that indicates whether they are similar.</returns>
private bool InvocationsAreSimilar(
InvocationExpression source,
InvocationExpression target)
{
if (!ExpressionSimilarity.TypesAreSimilar(source.Type, target.Type))
{
return(false);
}
if (source.Arguments.Count != target.Arguments.Count)
{
return(false);
}
if (!ExpressionSimilarity.AreSimilar(source.Arguments, target.Arguments))
{
return(false);
}
return(ExpressionSimilarity.IsPartOf(source.Expression, target.Expression));
}
/// <summary>
/// Determine whether two lambdas are similar.
/// </summary>
/// <remarks>
/// Two lambda expressions are similar when they share the same name,
/// similar parameters, and when both body and parameters are similar.
/// </remarks>
/// <param name="source">The source <see cref="LambdaExpression"/>.</param>
/// <param name="target">The target <see cref="LambdaExpression"/>.</param>
/// <returns>A flag indicating whether the two expressions are similar.</returns>
private bool LambdasAreSimilar(
LambdaExpression source,
LambdaExpression target)
{
if (source.Name != target.Name)
{
return(false);
}
if (source.Parameters.Count != target.Parameters.Count)
{
return(false);
}
if (!ExpressionSimilarity.AreSimilar(source.Parameters, target.Parameters))
{
return(false);
}
return(ExpressionSimilarity.IsPartOf(source.Body, target.Body));
}
/// <summary>
/// Comparison of multiple expressions. Similar
/// only when all elements match, in order, and
/// pass the similarity test. It's fine if the
/// source does not have the same number of entities
/// as the target.
/// </summary>
/// <param name="source">The source expressions.</param>
/// <param name="target">The target expressions.</param>
/// <returns>A flag indicating whether the two sets of
/// expressions are Similar.</returns>
public bool AreSimilar(
IEnumerable <Expression> source,
IEnumerable <Expression> target) =>
ExpressionSimilarity.AreSimilar(source, target);
/// <summary>
/// Entry for similarity comparisons. Will cast to
/// known types and compare.
/// </summary>
/// <typeparam name="T">The <see cref="Type"/> of entity.</typeparam>
/// <param name="source">The source <see cref="IQueryable{T}"/>.</param>
/// <param name="target">The target <see cref="IQueryable{T}"/> to compare to.</param>
/// <returns>A flag indicating whether the source and target are similar.</returns>
public bool AreSimilar <T>(IQueryable <T> source, IQueryable <T> target) =>
ExpressionSimilarity.AreSimilar(source?.Expression, target?.Expression);
/// <summary> /// Entry for similarity comparisons. Will cast to /// known types and compare. /// </summary> /// <param name="source">The source <see cref="Expression"/>.</param> /// <param name="target">The target <see cref="Expression"/> to compare to.</param> /// <returns>A flag indicating whether the source and target are similar.</returns> public bool AreSimilar(Expression source, Expression target) => ExpressionSimilarity.AreSimilar(source, target);
