Lazy compile in lambda

[ealeykin]

Lazy compile delegate in Lambda so the internal Expression can be processed in custom way without default compile overhead.

[ealeykin]

@davideicardi @metoule As a workaround to fix #207 could we merge in this lazy delegate compile, so I can use raw expression without default delegate compile overhead?

[metoule]

That's a good first step, that has minimal impact on the current interface. However, that alone won't fix #207 because the root cause is the UsedParameters vs DeclaredParameters.
Maybe you can also backport the DetectUseParameters option?

I think maybe it should be set to false by default but that is potentially a major change.

PS. I'm currently on holidays, with minimal access to a computer, so I won't be able to push commits for a few days.

[ealeykin]

I won't use Lambda.Invoke. Since the exception highlighted in #207 comes from compile in Lambda constructor you can do the following:

// parameters
var parameters = ...;

// parse
var lambda = interpreter.SetExpression(innerExpression).Parse(expressionText, parameters);

// custom compile and pass all required parameters myself
var delegate = Expression.Lambda(lambda.Expression, parameters).Compile();

// invoke 
var result = delegate.DynamicInvoke(....)

Am I missing something?

[metoule]

In that case, the lazy compilation is enough :)

[metoule]

LGTM!

[davideicardi]

LGTM! Thank you very much @halamah !

I will merge this and release a new version.
But let's keep #211 and related PRs open, because I think that your original idea is the right solution for the future.

[davideicardi]

Published v2.10.0! Thank you again @halamah