mkSProxies generates a LOT of boilerplate code

[dariooddenino]

Environment

• purescript-halogen 6.1.0
• purescript-halogen-formless 2.0.1

Hi!
While doing some profiling for one of my purescript webapps, I found out that one single formless component was generating a 180kb js file on its own. A ~300LOC ps component was generating almost 3k LOC of javascript code.

I found out that the main culprit was mkSProxies. Every time one of the proxies is used, a huge block of code is generated.
For example by just using prx.maxUsages the js code would result in:

new Data_Symbol.IsSymbol(function () {
            return "maxUsages";
        }))()()((Components_Coupon_Types.prx()()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "active";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "code";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "description";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "individualUse";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "isAuto";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "maxUsages";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "minAmount";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "minQty";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "platforms";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "productsIn";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "productsOut";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "regionsIn";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "regionsOut";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "travelFrom";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "travelTo";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "type";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "typesIn";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "typesOut";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "validFrom";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "validTo";
        }))()(Formless_Transform_Row.makeSProxiesCons(new Data_Symbol.IsSymbol(function () {
            return "value";
        }))()(Formless_Transform_Row.makeSProxiesNil))))))))))))))))))))))).maxUsages

By replacing mkSproxies with a manually written record of proxies the file size went down from ~180K to ~90K.

Similar things happen in other places (for example when defining render, handleAction and handleEvent) but I guess that's a consequence of how this library was designed and are probably not as easily solvable as this one.

For now I'm replacing all of mkSproxies usages, but I was wondering if I'm doing anything wrong on my end.

Thanks!

[JordanMartinez]

I'm pretty sure this large amount of code is expected. It's the major drawback of using that function. I believe it's provided for convenience, not for performance, because doing it by hand is tedious.

[dariooddenino]

I thought that maybe this one flew under the radar. It's not a big deal, maybe just worth explaining this in the docs since the impact of using it is so big

[thomashoneyman]

Sorry for such a late response -- I'm probably going to remove this function altogether because it really is terrible. At the time I wrote it (while learning PureScript) I didn't understand the ridiculous code bloat that came along with it, and just enjoyed the reduced boilerplate, but it's really not worth it and I wouldn't advise anyone use it outside of a toy situation.

[thomashoneyman]

@dariooddenino What do you think of #77?

[dariooddenino]

@thomashoneyman I think that it's a good solution!