Support custom MaxNodes property of expr Config

[5idu]

Hi,

I have a batch of rules with a large number of conditions (more than 10,000). When compiling these expressions, I encountered the following error:

compilation failed: expression exceeds maximum allowed nodes

After checking the source code, I found that expr has a default limit of 10,000 nodes during compilation. However, in some scenarios like mine, this limit is not sufficient.

Could you please add a method or option to allow users to customize or increase this maximum node limit when compiling expressions? This would be very helpful for handling complex rules.

Thank you!

[5idu]

@antonmedv any ideas? tks~

[antonmedv]

Sure, I will add it! BTW, could you please share an example of your rules? I'm very interested, and it will help better understand the use case for Expr.

[5idu]

Sure, I will add it! BTW, could you please share an example of your rules? I'm very interested, and it will help better understand the use case for Expr.

Thanks for reply. In my rules, there is a product code field. As long as any of the product codes in the input data matches one in the rule, the rule is considered matched. Usually, we have a very large number of product codes.

[5idu]

Additionally, could you please let me know when this feature is expected to be released? I am eager to experience it as soon as possible, and I would be more than happy to contribute code if needed. Thank you!

[antonmedv]

Done: https://github.com/expr-lang/expr/releases/tag/v1.17.5

[antonmedv]

You can disable max nodes check with 0:

program, err := expr.Compile(code, expr.MaxNodes(0))

[5idu]

Thank you for adding this feature so quickly!