Not all methods using ExpressionCompiler in RuleExpressionCompiler?

[snikolayev]

Discussed in #326

^{Originally posted by lustoro April 21, 2023}
I've started to use NRules and I'm facing performance issues when Compiling rules by using RuleCompiler.Compile(). I've seen that one of the ways to do some performance improvements is using FastExpressionCompiler suggested here https://github.com/NRules/NRules/wiki/Expression-Compiler. But after doing some performance profiling I've seen that it still works slow for CompileLhsFactExpression in RuleExpressionCompiler.cs. And I've seen that CompileLhsFactExpression do not uses ExpressionCompiler for compilation and only that method do not uses ExpressionCompiler, other methods are using ExpressionCompiler

NRules/src/NRules/NRules/Utilities/RuleExpressionCompiler.cs

Lines 40 to 48 in f84f59d

	public ILhsFactExpression<TResult> CompileLhsFactExpression<TResult>(ExpressionElement element)
	{
	var optimizedExpression = ExpressionOptimizer.Optimize<Func<Fact, TResult>>(
	element.Expression, IndexMap.Unit, tupleInput: false, factInput: true);
	var @delegate = optimizedExpression.Compile();
	var argumentMap = new ArgumentMap(IndexMap.Unit, 1);
	var expression = new LhsFactExpression<TResult>(element.Expression, @delegate, argumentMap);
	return expression;
	}

to have perfromance improvement is it possible to use ExpressionCompiler for CompileLhsFactExpression as well ? And have that change in future version ?

[snikolayev]

Fixed in commit b8c44a3