[FEEDBACK] incorrect syntax error test case?

[janishorsts]

The syntax looks good to me in the following test case.

message-format-wg/test/tests/syntax-errors.json

Line 126 in 57740d8

"src": "bad {:placeholder @attribute=$foo}"

Why is it a syntax error?

[aphillips]

It only looks good because you're used to assignments taking variable values. The actual syntax is:

attribute = "@" identifier [o "=" o literal]

The reason only literals can be used is that attributes are not permitted to have any impact on formatting. Evaluating a variable might have such impact, so the WG decided to forbid them. We might need to add some explanation here.

[janishorsts]

Thanks for the clarification, @aphillips!

I relied on the ABNF syntax that currently allows a variable.

message-format-wg/spec/message.abnf

Line 38 in daf7e0b

attribute = "@" identifier [o "=" o (literal / variable)]

[aphillips]

Looks like we have a merge error! Gold star for finding the bug!