49 lines
1.0 KiB
C#
49 lines
1.0 KiB
C#
using System.Linq.Expressions;
|
|
using Connected.Expressions.Mappings;
|
|
using ExpressionVisitor = Connected.Expressions.Visitors.ExpressionVisitor;
|
|
|
|
namespace Connected.Expressions.Evaluation;
|
|
|
|
internal sealed class ColumnNominator : ExpressionVisitor
|
|
{
|
|
private ColumnNominator()
|
|
{
|
|
Candidates = new HashSet<Expression>();
|
|
}
|
|
|
|
private HashSet<Expression> Candidates { get; set; }
|
|
private bool CannotBeEvaluated { get; set; }
|
|
|
|
public static HashSet<Expression> Nominate(Expression expression)
|
|
{
|
|
var nominator = new ColumnNominator();
|
|
|
|
nominator.Visit(expression);
|
|
|
|
return nominator.Candidates;
|
|
}
|
|
|
|
protected override Expression? Visit(Expression? expression)
|
|
{
|
|
if (expression is not null)
|
|
{
|
|
var saveCannotBeEvaluated = CannotBeEvaluated;
|
|
|
|
CannotBeEvaluated = false;
|
|
|
|
base.Visit(expression);
|
|
|
|
if (!CannotBeEvaluated)
|
|
{
|
|
if (MappingsCache.CanEvaluateLocally(expression))
|
|
Candidates.Add(expression);
|
|
else
|
|
CannotBeEvaluated = true;
|
|
}
|
|
|
|
CannotBeEvaluated |= saveCannotBeEvaluated;
|
|
}
|
|
|
|
return expression;
|
|
}
|
|
} |