I’m glad to see it is helpful to you too! And I really appreciate that you give it a try.
Please be aware that, as discussed here, Formular is not a safe sandbox right now. The design purpose is more about compiling your configuration into runnable code inside the application. So if the code comes from some untrusted user inputs, it could potentially damage the system. Improving is on the way though.
I don’t get code from user input.
So safety is sorted for us.
The big benefit with Formular for us is that since it’s easy to understand, business can modify the rules.
And that way we can keep the logic as Formular rules and away from the codebase.
Thanks a lot for Formular.
Two new versions have been released:
v0.2.2
0.2.xv0.3.0
Formula.used_vars/2 to extract the used variable names in the formula.Highlights:
Performance improvements:
A simple benchmark on a simple formula results in this:
Name ips average deviation median 99th %
compiled_module 947.84 K 1.06 μs ±5536.01% 0.83 μs 1.45 μs
eval 14.53 K 68.82 μs ±8.93% 68.69 μs 87.93 μs
eval_ast 4.86 K 205.58 μs ±18.43% 193.89 μs 333.89 μs
Comparison:
compiled_module 947.84 K
eval 14.53 K - 65.23x slower +67.76 μs
eval_ast 4.86 K - 194.85x slower +204.52 μs
The compilation approach is about 80x faster than the original eval approach in v0.2.2, and 300x faster than versions prior to v0.2.2.
Restricted evaluation:
limited execution time:
Formular.eval(code, timeout: :timer.seconds(5))
limited max heap size by word:
Formular.eval(code, max_heap_size: 15_000)
If limited, the evaluation will be run in a separate process.
Extract used vars API:
This can be helpful if you need to build some UI arround the formula.
iex> Formular.used_vars("a + b - 1")
[:a, :b]