[Bug] broken in sml (Standard ML)

[loreb]

Describe the bug

Not sure if it's your fault or I should blame sml.vim, but your plugin breaks comments in SML; if sml.vim is to blame, sorry to bother you, my vimscript is a bit rusty.

To Reproduce

Steps to reproduce the behavior, Please provide a minimal piece of code to produce this issue, along with it's filename and it's filetype detected by vim (via :set ft?), a piece of text is better than a picture here. For example:

File: wikipediaexample.sml, filetype=sml

datatype shape
    = Circle   of loc * real      (* center and radius *)
    | Square   of loc * real      (* upper-left corner and side length; axis-aligned *)
    | Triangle of loc * loc * loc (* corners *)

Steps:

1. Open file via vim myfile.sml
2. Notice that comment text is NOT commented out; this example is not too bad, but any comment with code snippets...

Expected behavior

Comment text shows as text with no further highlighting other than FIXME/TODO etc.

Screenshots

Additional context

Are you using some third-party syntax plugins? Add any other context about the problem here.
Nothing, only stock sml.vim (and the updated version from https://github.com/mmottl/vim-files which exhibits the same problem).

[luochen1990]

Please try this configuration:

let g:rainbow_conf = {
\  'separately': {
\    'sml': {
\      'parentheses': ['start=/(\ze[^*]/ end=/)/ fold', 'start=/\[/ end=/\]/ fold', 'start=/{/ end=/}/ fold']
\  }}
\}

[loreb]

I tried it on every every sml file I had around and it does the right thing in all cases (nested comments etc), thank you!
Sorry for the late reply.