ExpressionVisitorUtils.cs

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using System.Linq.Expressions;
 
namespace System.Dynamic.Utils;
 
internal static class ExpressionVisitorUtils
{
    public static Expression[] VisitBlockExpressions(ExpressionVisitor visitor, BlockExpression block)
    {
        Expression[] array = null;
        int i = 0;
        for (int expressionCount = block.ExpressionCount; i < expressionCount; i++)
        {
            Expression expression = block.GetExpression(i);
            Expression expression2 = visitor.Visit(expression);
            if (array != null)
            {
                array[i] = expression2;
            }
            else if (expression2 != expression)
            {
                array = new Expression[expressionCount];
                for (int j = 0; j < i; j++)
                {
                    array[j] = block.GetExpression(j);
                }
                array[i] = expression2;
            }
        }
        return array;
    }
 
    public static ParameterExpression[] VisitParameters(ExpressionVisitor visitor, IParameterProvider nodes, string callerName)
    {
        ParameterExpression[] array = null;
        int i = 0;
        for (int parameterCount = nodes.ParameterCount; i < parameterCount; i++)
        {
            ParameterExpression parameter = nodes.GetParameter(i);
            ParameterExpression parameterExpression = visitor.VisitAndConvert(parameter, callerName);
            if (array != null)
            {
                array[i] = parameterExpression;
            }
            else if (parameterExpression != parameter)
            {
                array = new ParameterExpression[parameterCount];
                for (int j = 0; j < i; j++)
                {
                    array[j] = nodes.GetParameter(j);
                }
                array[i] = parameterExpression;
            }
        }
        return array;
    }
 
    public static Expression[] VisitArguments(ExpressionVisitor visitor, IArgumentProvider nodes)
    {
        Expression[] array = null;
        int i = 0;
        for (int argumentCount = nodes.ArgumentCount; i < argumentCount; i++)
        {
            Expression argument = nodes.GetArgument(i);
            Expression expression = visitor.Visit(argument);
            if (array != null)
            {
                array[i] = expression;
            }
            else if (expression != argument)
            {
                array = new Expression[argumentCount];
                for (int j = 0; j < i; j++)
                {
                    array[j] = nodes.GetArgument(j);
                }
                array[i] = expression;
            }
        }
        return array;
    }
}