Style and form in generated code

[honey the codewitch]

I almost as a matter of course involve code generation in my larger projects. So that means I'm dealing with a lot of generated code. Typically, I don't design my generated code for manual modification. I design the tool that generates it to be customizable. Ergo, the tool will make the code do what you want. Change the tool parameters to change the code but leave the code alone. The reason being is it's almost always stupid to try to support generated code that a user has modified and for extremely complicated code, like parse tables, dfa tables, or business rule tables that have a lot of conditionals and branching. So the code is a black box. And because of *that* I throw a lot of traditional design assumptions out the window, or go meta with them. Comments are an example: Commenting the generated code is pointless. Commenting the code that generates the code is project-critical Constants are another example. It doesn't matter if you use hard coded values in your generated code if the values are const in the code that generates *it*. Generating private constants just adds to code size with not much upside. The exception is long constant strings. And gotos are totally acceptable, especially in state machine code, and in the absence of cross language CodeDom loop break statements. (CodeDom only supports for() and no while() nor do while(), no break, no continue. How many of you hate me for this, and who agrees with me here? :cool: I'm just curious.

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[Maximilien]

kinda agree.

I'd rather be phishing!

[PIEBALDconsult]

I agree. I insert a comment at the top: /* This is a generated file, any modifications may be lost. */

[honey the codewitch]

absolutely. typically the CodeDomProvider framework will even generate one for you =)

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[CodeWraith]

So it's you who torments the rest of the world with half baked, unorthodox rule engines. Has any one of these ever worked to begin with or sucessfully survived all attempts to derail it by clueless bosses with ever crazier new rules? The next step then would be a half baked rule engine with also half baked modifications to the (unorthodox and uncommented) generated code, which of course may never be generated again. Excellent. What a joy to see how the will to live is drained from those who have to maintain that thing, once Dr. Frankenfurter was done half baking his rule engine has left in search for new gullible victims. :-)

I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

[honey the codewitch]

In my defense I've only ever made a rule engine that generated code once, and it was used for years, and it worked. You maintained the damn thing by maintaining the rule specs, not the code. The code generation could alter all three tiers (SQL schema, middleware XSD and code, and front end admin UI stuff (non admin pages were not generated because that's stupid in practice, but it *did* expose functionality to the front-end that the front end could use in the form of rule aware javascript and html widgets) I generate mostly state machine code and things like parse tables. Those will always be incomprehensible and if you try to manually modify the state machine you deserve to be chased with a ball peen hammer.

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[Forogar]

I concur - do what you like in generated code - it's generated, not for reading or modifying! Just don't forget the big "Keep your stinking paws of this code you dirty ape!" notice at the top!

- I would love to change the world, but they won’t give me the source code.

[Daniel Pfeffer]

No one claimed that she's a good witch :)

Freedom is the freedom to say that two plus two make four. If that is granted, all else follows. -- 6079 Smith W.

[Dan Neely]

As long as the generation tool is capable enough that I never have to hand edit its results I really don't care what all is inside the sausage factory. When the generation falls short and I need to hand-edit the results or worse write a fix tool, the nastier the generated output is the more I'll hate the guilty party. The flip side is when it is simultaneously simple enough in scope and capable enough in function to ingest my modifications without problem for round trip modifications (*cough*WinForm Designer*cough*) that I'll fall in love and still be mourning not having anything equivalent in newer projects (web, wpf, uwp, android, ios) years later.

Did you ever see history portrayed as an old man with a wise brow and pulseless heart, weighing all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt

[honey the codewitch]

Round tripping was cool even if it wasn't perfect. It was the (almost) perfect solution to providing VB6 style designer functionality without making it opaque like VB6 did.

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[honey the codewitch]

I'm certainly not. =D

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[Kornfeld Eliyahu Peter]

I'm too do a lot of generated code (mostly JS as today)... The only comment I add is a warning about the changes one thinks to make - futile (especially when I minimize the generated code :-))... I try to generate optimized code, so I will use variables for constants I reuse in the code, others will be in-place...

"The only place where Success comes before Work is in the dictionary." Vidal Sassoon, 1928 - 2012

[honey the codewitch]

I try to generate somewhat "portable", optimized code in that order. By portable in .NET i mean code dom constructs that work for most if not all languages. Sometimes that means trading against optimization but it's usually worthwhile if you're making a tool for general purpose use like a parser generator, as long as the hit isn't that big, or somewhere time critical.

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[Jorgen Andersson]

But sharing is caring. ;-)

Wrong is evil and must be defeated. - Jeff Ello

[honey the codewitch]

I've just developed a little class to greatly abbreviate building CodeDOM trees. I'll probably publish a Tip & Trick on it once I've used it for what I'm using it for. I like to dogfood things before I post them if possible.

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[Jorgen Andersson]

You see, that's what I mean.:)

Wrong is evil and must be defeated. - Jeff Ello

[realJSOP]

I have an app that generates models and (optionally) viewmodels from stored procs in the seleted database. In both entity types, I give the user the opportunity to specify namespaces, and base classes (that the generator does not create). All generated model and viewmodel entities are generated as public partial, and all properties are virtual, with a comment that reminds the coder that the model/viewmodel in question is generated, and that any changes to the generated file(s) will be lost if they regenerate the entity, and further, and changes should be made to either a partial extension file, or inside an deriving class. For the record, my app does it better than the ado.net project template, and is SIGNIFICANTLY less buggy or finicky. Beyond that, once you click the generate button, it creates all of the entities in less than 5 seconds in a database with over 200 stored procs.

".45 ACP - because shooting twice is just silly" - JSOP, 2010
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You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
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When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

[honey the codewitch]

Nice. I used to write tools like that back when i was doing this professionally. Part of me misses it. Part of me is glad i don't have to deal with that crap anymore. :laugh:

When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.

[dywanex192]

.

[Sander Rossel]

Just make sure to add some attributes so designers know not to check the code for style issues. I think the GeneratedCodeAttribute does that in .NET. Nothing is worse than having some blue information and yellow warning icons for stuff you can't change X|

Best, Sander sanderrossel.com Continuous Integration, Delivery, and Deployment arrgh.js - Bringing LINQ to JavaScript Object-Oriented Programming in C# Succinctly