Clojurians Log v2

whats the point of that? requires transpiling before it can be loaded. so might as well emit es6 directly instead and transpile that. I'm pretty sure the closure devs themselves don't recommend using goog.module anymore.

@thheller they updated the Closure wiki 3 weeks ago recommending switching to goog.module - do you have a link that says different?

I also I haven't seen any movement in the Closure Library to switch to ES6 modules, did you see something?

Steve Hicks did mention they were considering it but the plans seem quite unclear (they might do TypeScript)

https://groups.google.com/d/msg/closure-compiler-discuss/Y3pd7X1O3Zo/DuNINoOCCgAJ

thats the last info I saw

goog stuff kinda works when using import Thing from "goog:goog.string"

right that's pretty old

https://github.com/google/closure-library/wiki/goog.module:-an-ES6-module-like-alternative-to-goog.provide/_compare/cba8f42a9f739abd40c1977aeb8feb3bffe6bd22

this was updated 3 weeks ago

> Presently goog.module is recommended over goog.provide for new Closure files.

new closure files ... I think that is meant for the closure library. not sure that applies to 3rd party code

I would say the messaging here is not very clear

and Steve Hicks direct communication simply muddied the waters as to their intentions

but doesn't really matter if goog.module or ESM, right now that just complicates things. especially regarding hot-reload and doesn't really buy anything.

right but like I said earlier

debug loader may go kaput - so we may have to fend for ourselves anyway

hmm yeah I replaced that loader years ago in shadow-cljs so dunno what the state of the goog loader is

but point taken, can probably drag our feet a bit longer and ES6 modules have the benefit of being loadable w/o transpilation

(in browser & Node.js)

thanks for the feedback

@thheller re: ESM how would that complicate hot loading?

I thought just making defs var instead of const was enough for this to work

well real ESM you can't hot load at all since there aren't any global vars to replace

right now we have some.ns.foo = function() ... and just "overwrite" some.ns.foo on the next load

in ESM only the rewritten version allows that since it rewrites to be global again

otherwise you have let foo = function() ... or so in a module but you can't load the replacing code into that module scope

hrm yeah that's what I remembered

that's the problem w/ ESM module export - is that it's really a capture

by the module that uses

yeah I experimented a bit with ESM in the past but interop with the closure lib is annoying and other issues due to no shared global scope

it would be neat if CLJS compiler output could just be consumed as regular ESM by any other tool but that would currently mean getting rid of the closure-library either completely or rewriting the pieces we use to ESM

which isnt' actually a big deal since cljs.core doesn't use that much

but still likely breaks build where people use more

@thheller right ESM has the REPL problem we just talked about

so it doesn't seem like a good target - unless you're talking about a more subtle strategy I don't understand

strict ESM output so all other JS tools work

to keep REPL and hot-reload we just transpile it back down to one shared global scope

that's an interesting project (perhaps very related) - but the second part is the one I'm mostly concerned about now

yeah the transpile mode from closure just rewrites let foo = "thing" based on the filename so var foo$$module$some$file = "thing" or so

so technically thats just a regular global var we can dynamically manipulate or overwrite

in the browser thats no issue at all

though that's treading into pretty yucky territory - since it's relying on the renaming strategy

thats fine IMHO. the names are stable and predictable

there is another transpile mode for compiling ESM->CJS that I haven't tried yet

but that likely is annoying again because no shared global scope

I mean who knows if they'll be stable and predictable

that stuff isn't public far as I know

but rewinding now, another alternative - we don't care what Closure does

since the optimizer works on the lowered global form

i.e. goog.provide(...) is really a triviality - could easily be cljs.namespace(...)

well that wouldn't be recognized by the closure-compiler when going through :advanced

but trivial to preprocess in that case

my point here is break down the problem in some simple options / goals

so just enumerating what "we don't care" look like

well IMHO if changes are made the goal should be ESM output

otherwise goog.provide is fine

replacing the debug loader is easy and can still use those primitives

I'm only saying alternative goog.provide because it may just go away forever

they've started linting it

goog.module imho is bad. still not consumable by other tools and just complicates our story as well

sure I agree w/ that

replacing the debug loader is trivial

yeah I'm not so concerned about the debug loader

I mean it's clear we can proceed as we have for years w/ very few changes

another thing that we would have been better from the start is not adopting the "nested" namespaces in the first place

but dunno if its maybe too later to change that

but cljs.core/assoc could just be var ns$cljs$core = {} for the ns and then ns$cljs$core.assoc = ...

no goog.provide or goog.require needed at all

I mean there's a browser usability issues here

how it is now is plenty inspectable in the browser

dunno if that changes much. the objects are still easily inspectable

it would change a lot

autocomplete becomes way worse

anyways - I'm not saying not a bad idea - but the tradeoffs are definitely there

some tools also rely on the lookups by nested names so they'd all break

but gets rid of a bunch of issues too since there'd be no more clashes for (ns foo.bar) (def thing "x") and (ns foo.bar.thing)

I mean part of this illustrates how bad ESM wrt. REPL based developed

yeah ESM is horrid for anything dynamic

unsurprising since the Racket people worked on it and there's not a good hot-loading narrative there

since they didn't like it in a teaching context

but it is the standard we have and gaining access to all other JS tools would open up many possibilities

transforming it into something usable in a dynamic setting is not so bad either so might be worth

but I don't like ESM myself at all

I'm not personally interested in JS tooling and never think about - what do you have in mind that you think would be useful

or users would find useful in their projects?

things like https://storybook.js.org/ become immediately usable

right now we basically re-invent all the tools because they can't load our code

@thheller instead of starting with ESM, what do you perceive as issues w/ just optionally generating ESM for those use cases?

I feel like if you really want ESM then maybe you don't care about the REPL that much anyway

so one of the issues I ran into when experimenting is with ESM you can't just assume there is a global scope

what I mean is let's consider this as orthogonal thing

so you can't just access stuff which complicates some macros. say a macro generates code using (goog.string/something) but the namespace using that macro didn't have a require for the goog.string

User A wants to use StoryBookJS - they can pass :cljs-es6-module-format or whatever

so tracking references becomes a bit more complicated

@thheller right that's true, the implicitly loaded nses thing is a problem in the wild

yeah lots of code relies on global references since the compiler doesn't really verify those and people like to cheat 😉 https://clojure.atlassian.net/browse/CLJS-712

ESM still feels like a work in progress in many areas though

so might just be best to wait till import maps and stuff become better supported

not familiar w/ import maps (looking a bit now), how would that help?

@thheller isn’t that goog.string problem present in current cljs as well? best practice is to have cljs namespace doing implicit macro requires with all needed requires and document that macros must be used through that cljs namespace only (to force all requires as well), wouldn’t this strategy work with ESM as well?

well currently we don't warn

we used to but it's wasn't Clojure-y

import maps aren't related to CLJS in any way. just make ESM more bearable, otherwise it is too strict and probably the reason it isn't as widely adopted. eg. react still doesn't ship ESM code.

@darwin it isn't present as long as there is a global shared scope and something loaded that namespace before you accessed it

yes, but that is not always the case, e.g. when I use a macro from some library first time and it generates code which uses some namespaces I have no clue about, I only discover it at runtime that those are missing and I have to require them

at least in dev mode, I believe

yes but thats the fault of the library

not the thing I'm talking about

ok, but cure for this via “going through cljs namespace” would work for that goog.string problem with ESM, no? that was my original curiosity

(ns foo.bar ;; cljs
  (:require-macros [foo.bar])
  (:require [goog.string]))

(ns foo.bar) ;; clj
(defmacro thing [& args]
  `(goog.string/foo ~@args))

(ns foo.consumer
  (:require [foo.bar :as bar]))

(bar/thing 1 2 3)

foo.consumer would have no direct import for goog.string yet use it directly

so the code generator would need to detect that and add it

nothing wrong with the macro code at all

can't and shouldn't expect the consumer to add a goog.string require

but its not too hard for the compiler to detect that

ok, good, thanks for your answer

I'm not a fan of ESM at all but it is better than CommonJS etc

I still think the closure approach of namespacing everything into one shared global scope is best

sadly that isn't the way the world is going

but at least with ESM we can transpile to get that world when people follow the spec

considered this trickery to get back global scope with ESM? https://mathiasbynens.be/notes/globalthis https://github.com/ungap/global-this/blob/master/esm/index.js

just did a quick test with node: https://github.com/darwin/esm-trickery

https://github.com/darwin/esm-trickery/blob/master/output.txt

thats horrible ... much better to just use ESM and compile it down. that at least has rules.