Add option to disable pretty printing

[parched]

I was curious if there was any low hanging fruit to speed up the compiler.
I run with the --instrument flag and found that almost all the time is in the pretty printing.

FlatSharp compiler instrumentation: CompileReflectionFbs took 3328.0253ms.
FlatSharp compiler instrumentation: Initialization.WriteCode took 33.4955ms.
FlatSharp compiler instrumentation: PropertyModeling.CodeWriterToString took 0.5624ms.
FlatSharp compiler instrumentation: PropertyModeling.CompilePreviousAssembly took 854.264ms.
FlatSharp compiler instrumentation: PropertyModeling.WriteCode took 14.225ms.
FlatSharp compiler instrumentation: SerializerAndRpcGeneration.CodeWriterToString took 0.1859ms.
FlatSharp compiler instrumentation: SerializerAndRpcGeneration.CompilePreviousAssembly took 793.4003ms.
FlatSharp compiler instrumentation: SerializerAndRpcGeneration.WriteCode took 1523.0881ms.
FlatSharp compiler instrumentation: FinalStep.CodeWriterToString took 9.3971ms.
FlatSharp compiler instrumentation: PostProcessTransforms took 94.4395ms.
FlatSharp compiler instrumentation: PrettyPrint took 20087.2718ms.

Would you be open to me adding a flag to turn off pretty printing? Perhaps even disabling by default.

Do you see any other suspicious numbers above that should be looked at?

[jamescourtney]

I haven't looked at that for awhile, but I do recall that pretty printing was expensive. I agree that adding an option to disable it makes sense. It just never occurred to me because I personally need the code to be prettified to debug it.

Feel free to submit a PR!

[parched]

Would you prefer it on or off by default?

[jamescourtney]

I'm actually more conflicted about this than I expected to be before writing this out.

On one hand, I agree cutting the time in half is a big deal.

On the other, I don't want people to open the output with the default settings and go "wow, this can't possibly be any good".

What do you think?

[parched]

IMO the slowness is a worse look than the unformatted generated code. The code is formatted pretty good anyway---so much so, personally, I'd just strip out the pretty printing altogether.

[jamescourtney]

Ship it as the default then!