rust platform · beginners · Zulip Chat Archive

Hi, I'm new here and started playing around with the example rust-platform. I am getting a compiler error now. I know that I broke the platform by changing the rust-platform/main.roc file. Is it expected that I get

Luke Boswell (May 20 2024 at 21:44):

It's hard to answer your question without more context. Are you able to share the error message? It may already be a known issue.

Max (May 20 2024 at 21:55):

Basically I just played with the requires of the platform, changed main to mai, then did not provide it and changed types. Here is the output of RUST_BACKTRACE=full roc rocLovesRust.roc inside the platform-switching directory:

mxw@MacBook-Pro platform-switching % RUST_BACKTRACE=full roc rocLovesRust.roc
An internal compiler expectation was broken.
This is definitely a compiler bug.
Please file an issue here: https://github.com/roc-lang/roc/issues/new/choose
thread 'main' panicked at crates/compiler/module/src/symbol.rs:153:13:
ident_string's IdentIds did not contain an entry for 1 in module 17
stack backtrace:
   0:        0x104f4c54c - __mh_execute_header
   1:        0x10439d4cc - __mh_execute_header
   2:        0x104f48530 - __mh_execute_header
   3:        0x104f4c344 - __mh_execute_header
   4:        0x104f4da60 - __mh_execute_header
   5:        0x104f4d75c - __mh_execute_header
   6:        0x104f4e064 - __mh_execute_header
   7:        0x104f4de40 - __mh_execute_header
   8:        0x104f4c9e4 - __mh_execute_header
   9:        0x104f4dbd4 - __mh_execute_header
  10:        0x1066297dc - __ZN4llvm15SmallVectorBaseIyE8grow_podEPvmm
  11:        0x104a8dde4 - __mh_execute_header
  12:        0x104d914a4 - __mh_execute_header
  13:        0x104d55914 - __mh_execute_header
  14:        0x10459ea7c - __mh_execute_header
  15:        0x10468f608 - __mh_execute_header
  16:        0x1045573c0 - __mh_execute_header
  17:        0x1045356c4 - __mh_execute_header
  18:        0x1045356e8 - __mh_execute_header
  19:        0x104f405e8 - __mh_execute_header
  20:        0x10455a52c - __mh_execute_header

Luke Boswell (May 20 2024 at 23:13):

Ideally roc should give a nice error instead of crashing. Though this is a more advanced use case because you are doing platform development.

There's not a lot of documentation, so it's harder to get started developing platforms.

Luke Boswell (May 20 2024 at 23:16):

If you change the type on mainForHost back to Str I think it should work for you

Luke Boswell (May 20 2024 at 23:18):

The host is still expecting a RocStr from roc. If you want to change that you will need to change the API in lib.rs

Max (May 21 2024 at 07:15):

My long/midterm goal would be that I can compile code at runtime as some kind of service. Say I expect the User to give me a string that compiles as a roc program. I would want to define a type Html and require the Users program to provide ahtml: Html. Here I feel like I have to decide whether I want to deal with the Html type in the platform I'm writing (I haven't looked into this) or if this is possible from roc. I hoped for the latter, so my naive idea would be that I still require html: Html. But in order that my platform just has to deal with a String, I would write a function htmlToString: Html -> String und have mainForHost: String and mainForHost = htmlToString html.

Brendan Hansknecht (May 23 2024 at 10:51):

Brendan Hansknecht (May 23 2024 at 10:53):

mainForHost : Bool

Max (May 24 2024 at 20:09):

You are right, I just compiled with main: Bool and mainToHost: Str and it worked! I was sure I already tried that without success, but I must have just done a mistake there =)

I still filed the issue in case we don't want that compiler error. But very happy to know I will be able to do what I was hoping to =)

Stream: beginners

Topic: rust platform

Max (May 20 2024 at 20:23):