parse list { } as list{}

[bobzhang]

For beginners, it is confusing that list{1,2}works while list {1,2} does not work, it is a whitespace sensitive language now.
I propose that we lex list\ws+{ as a token, so that we can parse both
cc @IwanKaramazow let me know what you think?

cc @butterunderflow

[butterunderflow]

After some tries, simply lexing list\ws+{ as a token will make some regression. Expression like

switch list {
| true => 1
| false => 0
}

will not be successfully parsed anymore.

Actually, I think the current behavior of

switch list {
| true => 1
| false => 0
}

parsed with no issue but

switch list{
| true => 0
| false => 1
}

triggering a syntax error is also a little bit confusing.

[IwanKaramazow]

Yes, this is not possible. There are too many nuances and error messages that would regress.

[bobzhang]

indeed, we have to document list{ as a gotcha some where, I regert that I did not stand firm to use #{ as list instead, but now let's move on and accept it as is