internal static Expression <Func <TResult> > ApplyParameters <TParameter0, TParameter1, TResult>(this Expression <Func <TParameter0, TParameter1, TResult> > func, TParameter0 parameter0Value, TParameter1 parameter1Value)
{
Expression body = new ReplaceParameterVisitor(new Dictionary <ParameterExpression, Expression>()
{
{ func.Parameters[0], Expression.Constant(parameter0Value, func.Parameters[0].Type) }, { func.Parameters[1], Expression.Constant(parameter1Value, func.Parameters[1].Type) }
}).Visit(func.Body);
// ReSharper disable once AssignNullToNotNullAttribute
return(Expression.Lambda <Func <TResult> >(body));
}
internal static LambdaExpression ApplyParameters(this LambdaExpression lambdaExpression, object[] parameterValues)
{
Dictionary <ParameterExpression, Expression> replacements = new Dictionary <ParameterExpression, Expression>();
for (int index = 0; index < parameterValues.Length; index++)
{
replacements.Add(lambdaExpression.Parameters[index], Expression.Constant(parameterValues[index], lambdaExpression.Parameters[index].Type));
}
Expression body = new ReplaceParameterVisitor(replacements).Visit(lambdaExpression.Body);
return(Expression.Lambda(body));
}
private static Expression <Func <ZipPair <int, TSourceItem>, bool> > getZipPairPredicateExpression(Expression <Func <TSourceItem, bool> > predicateExpression)
{
ParameterExpression zipPairParameterExpression
= Expression.Parameter(typeof(ZipPair <int, TSourceItem>), "zipPair");
Expression zipPairItem2Expression
= Expression.PropertyOrField(
zipPairParameterExpression,
nameof(ZipPair <int, TSourceItem> .RightItem));
ReplaceParameterVisitor replaceParameterVisitor
= new ReplaceParameterVisitor(
predicateExpression.Parameters[0],
zipPairItem2Expression);
Expression <Func <ZipPair <int, TSourceItem>, bool> > zipPairPredicateExpression
= Expression.Lambda <Func <ZipPair <int, TSourceItem>, bool> >(
replaceParameterVisitor.Visit(predicateExpression.Body),
zipPairParameterExpression);
return(zipPairPredicateExpression);
}
private static Expression <Func <ZipPair <int, TSourceItem>, bool> > getZipPairNotPredicateExpression(Expression <Func <TSourceItem, int, bool> > predicateExpression)
{
ParameterExpression zipPairParameterExpression
= Expression.Parameter(typeof(ZipPair <int, TSourceItem>), "zipPair");
Expression zipPairIndexExpression
= Expression.PropertyOrField(
zipPairParameterExpression,
nameof(ZipPair <int, TSourceItem> .LeftItem));
Expression zipPairItemExpression
= Expression.PropertyOrField(
zipPairParameterExpression,
nameof(ZipPair <int, TSourceItem> .RightItem));
ReplaceParameterVisitor replaceParameterVisitor
= new ReplaceParameterVisitor(
predicateExpression.Parameters,
new[] { zipPairItemExpression, zipPairIndexExpression });
Expression <Func <ZipPair <int, TSourceItem>, bool> > zipPairNotPredicateExpression
= Expression.Lambda <Func <ZipPair <int, TSourceItem>, bool> >(
// ReSharper disable once AssignNullToNotNullAttribute
Expression.Not(replaceParameterVisitor.Visit(predicateExpression.Body)),
zipPairParameterExpression);
return(zipPairNotPredicateExpression);
}
private static Expression <Func <ZipPair <int, TSourceItem>, INotifyCollectionChanged> > getZipPairSelectorExpression(Expression <Func <TSourceItem, int, INotifyCollectionChanged> > selectorExpression)
{
ParameterExpression zipPairParameterExpression
= Expression.Parameter(typeof(ZipPair <int, TSourceItem>), "zipPair");
Expression zipPairIndexExpression
= Expression.PropertyOrField(
zipPairParameterExpression,
nameof(ZipPair <int, TSourceItem> .LeftItem));
Expression zipPairItemExpression
= Expression.PropertyOrField(
zipPairParameterExpression,
nameof(ZipPair <int, TSourceItem> .RightItem));
ReplaceParameterVisitor replaceParameterVisitor
= new ReplaceParameterVisitor(
selectorExpression.Parameters,
new[] { zipPairItemExpression, zipPairIndexExpression });
Expression <Func <ZipPair <int, TSourceItem>, INotifyCollectionChanged> > zipPairSelectorExpression
= Expression.Lambda <Func <ZipPair <int, TSourceItem>, INotifyCollectionChanged> >(
// ReSharper disable once AssignNullToNotNullAttribute
replaceParameterVisitor.Visit(selectorExpression.Body),
zipPairParameterExpression);
return(zipPairSelectorExpression);
}
private static Expression <Func <JoinPair <TOuterSourceItem, TInnerSourceItem>, bool> > getJoinPairPredicateExpression(Expression <Func <TOuterSourceItem, TInnerSourceItem, bool> > joinPredicateExpression)
{
ParameterExpression joinPairParameterExpression
= Expression.Parameter(typeof(JoinPair <TOuterSourceItem, TInnerSourceItem>), "joinPair");
Expression joinPairOuterItemExpression
= Expression.PropertyOrField(
joinPairParameterExpression,
nameof(JoinPair <TOuterSourceItem, TInnerSourceItem> .OuterItem));
Expression joinPairInnerItemExpression
= Expression.PropertyOrField(
joinPairParameterExpression,
nameof(JoinPair <TOuterSourceItem, TInnerSourceItem> .InnerItem));
ReplaceParameterVisitor replaceParameterVisitor
= new ReplaceParameterVisitor(
joinPredicateExpression.Parameters,
new[] { joinPairOuterItemExpression, joinPairInnerItemExpression });
Expression <Func <JoinPair <TOuterSourceItem, TInnerSourceItem>, bool> > joinPairPredicateExpression
= Expression.Lambda <Func <JoinPair <TOuterSourceItem, TInnerSourceItem>, bool> >(
// ReSharper disable once AssignNullToNotNullAttribute
replaceParameterVisitor.Visit(joinPredicateExpression.Body),
joinPairParameterExpression);
return(joinPairPredicateExpression);
}