public static Expression OptimizeExpression(ReadOnlyExpressionContext context)
{
Expression expression = context.Expression;
if (context.ScopedExpressions.Count > 1)
{
var body = new List <Expression>();
var variables = new List <ParameterExpression>();
foreach (IGrouping <Type, MethodCallExpression> grouping in context.ScopedExpressions.GroupBy(x => x.Type))
{
if (grouping.Count() > 1)
{
MethodCallExpression methodCallExpression = grouping.First();
ParameterExpression newValue = Expression.Variable(methodCallExpression.Type);
variables.Add(newValue);
var visitor = new ScopedExpressionVisitor(methodCallExpression, newValue);
expression = visitor.Visit(expression);
body.Add(newValue);
body.Add(Expression.Assign(newValue, methodCallExpression));
}
}
if (body.Count > 0)
{
expression = Expression.Block(variables, body.Concat(new[] { expression }));
}
}
return(expression);
}
public ExpressionContext(ReadOnlyExpressionContext context)
{
ScopedExpressions = context.ScopedExpressions.ToList();
Expression = context.Expression;
}
public static Func <Scoped, object> Compile(ReadOnlyExpressionContext context)
{
Expression expression = OptimizeExpression(context);
return((Func <Scoped, object>)Expression.Lambda(expression, ExpressionGenerator.ScopeParameter).CompileFast());
}
internal ExpressionContext(ReadOnlyExpressionContext context)
{
ScopedExpressions = context.ScopedExpressions.ToList();
Expression = context.Expression ?? throw new ArgumentNullException("context.Expression");
}