`--eval-preload` does not have access to Core anymore

[TimDeve]

It used to be possible to access things from Core in --eval-preload. A useful alias I have is:

carp -x --log-memory --eval-preload '(Debug.sanitize-addresses)' file.carp

but this now produces an error:

Can't find symbol 'Debug.sanitize-addresses' at Preload:1:2.

Using preload without refering to things from Core still works:

$ echo "(defn main [] (IO.println wow))" > main.carp
$ carp -x --eval-preload '(def wow "ok")' main.carp
ok

But anything from Core fails:

$ echo "(defn main [] (IO.println &wow))" > main.carp
$ carp -x --eval-preload '(def wow (String.join "" &[@"ok"]))' main.carp
I couldn’t find the symbol 'String.join' at line 1, column 11 in 'Preload'.

Maybe you forgot to define it? at Preload:1:2.

Traceback:
  (def wow (String.join "" (ref [(copy "ok")]))) at Preload:1:1.

It's possible to work-around that by loading Core manually:

$ echo "(defn main [] (IO.println &wow))" > main.carp
$ carp -x --eval-preload '(load "Core.carp")(def wow (String.join "" &[@"ok"]))' main.carp
ok

[hellerve]

Isn’t this a case for --eval-postload?

[TimDeve]

I guess that would work for (Debug.sanitize-addresses) but not for the other usages.

It's not possible to def a String for example:

$ echo "(defn main [] (IO.println &wow))" > main.carp
$ carp -x --log-memory --eval-preload '(def wow @"string")' main.carp
I can’t find any implementation for the interface `copy` of type (Fn [(Ref String r3)] String) at line 1, column 10 in 'Preload'.

None of the possibilities have the correct signature:
    Array.copy : (Fn [(Ref (Array a) q)] (Array a))
    Pointer.copy : (Fn [(Ref (Ptr p) q)] (Ptr p))
    Box.copy : (Fn [(Ref (Box t) q)] (Box t))
    Function.Arity0.copy : (Fn [(Ref (Fn [] z) q)] a)
    Function.Arity1.copy : (Fn [(Ref (Fn [d] z) q)] a)
    Function.Arity2.copy : (Fn [(Ref (Fn [d, e] z) q)] a)
    Function.Arity3.copy : (Fn [(Ref (Fn [d, e, f] z) q)] a)
    Function.Arity4.copy : (Fn [(Ref (Fn [d, e, f, g] z) q)] a)
    Function.Arity5.copy : (Fn [(Ref (Fn [d, e, f, g, h] z) q)] a)
    Function.Arity6.copy : (Fn [(Ref (Fn [d, e, f, g, h, i] z) q)] a)
    Function.Arity7.copy : (Fn [(Ref (Fn [d, e, f, g, h, i, j] z) q)] a)
    Function.Arity8.copy : (Fn [(Ref (Fn [d, e, f, g, h, i, j, k] z) q)] a)
    Function.Arity9.copy : (Fn [(Ref (Fn [d, e, f, g, h, i, j, k, l] z) q)] a) at Preload:1:2.

Traceback:
  (def wow (copy "string")) at Preload:1:1.

[scolsen]

huh, whatever changed the behavior is not obvious. the actual pre/post impl haven't changed at all since they were first implemented, as far as I can tell

might need to do a git bisect and check the behavior at each stage. presumably we can use the commit that introduced the feature as the good commit: 6bce3b1

[hellerve]

What has changed is the order in which things are ran:

it used to be:

loadFilesOnce startingContext coreModulesToLoad
            >>= load [carpProfile | hasProfile]
            >>= execStrs "Preload" preloads
            >>= load argFilesToLoad
            >>= execStrs "Postload" postloads

And now is

pure startingContext
          >>= load [carpProfile | hasProfile && profile]
          >>= execStrs "Preload" preloads
          >>= loadOnce coreModulesToLoad
          >>= load argFilesToLoad
          >>= execStrs "Postload" postloads

But I also can’t remember why.

As for It's not possible to def a String for example:, in your example you use --eval-preload. Shouldn’t it be postload instead?

[TimDeve]

Postload runs after the user files so you can't inject things to be used by these files.

But I also can’t remember why.

Git blame says the last changes were two years ago and that's a formatting commit, clearly I haven't used preload in a while then.

[TimDeve]

I'm just gonna close this, it seems that preload use to behave differently but if that was two years ago then it doesn't feel that that this is a useful.