When a macro id is used in an expression position, there is simple bad syntax error. Is there a way to change that message?

yes, your macro can handle that case and produce whatever message you want

Is there a way to change that message for macros that I don’t define?

I don’t understand why this preference follows from the rule “prefer to break at the highest level of syntactic nesting”—or is the example buggy maybe?

This is a nice rule, but how do you reconcile it with not having closing brackets on separated lines?

https://github.com/google/google-java-format/wiki/The-Rectangle-Rule#right-parens\|https://github.com/google/google-java-format/wiki/The-Rectangle-Rule#right-parens

breaking at the outer match clause in addition to the inner match clause

Case covered :)

For symmetry?

Okay now that I’ve actually woken up I can explain what I meant here better

I’m assuming that the pat1, pat2, body1, and body2 forms are complex enough that they can’t all fit on one line

So the rule I follow is basically, jam everything onto one line, then insert linebreaks until I’m under the column limit. When picking where to put a linebreak, I always start with the outermost forms.

(match exp [pat1 (match exp [pat1 body1] [pat2 body2])]) => (match exp [pat1 (match exp [pat1 body1] [pat2 body2])]) => (match exp [pat1 (match exp [pat1 body1] [pat2 body2])]) => (match exp [pat1 (match exp [pat1 body1] [pat2 body2])]) => (match exp [pat1 (match exp [pat1 body1] [pat2 body2])])

and I have some miscellenaeous extra constraints I throw in, like if a match expression needs multiple lines, I never put two pattern-body clauses on the same line

so I wouldn’t write this, for example: (match exp [pat1 body1] [pat2 body2])

I just generalize it to “you can ignore an expression’s “punctuation” when determining its bounding box”

where “punctuation” is a somewhat fuzzy category that I have decided includes parentheses

How does the rectangle rule apply here? Don’t all four of these follow it already?

yes, I forgot that the “prefer to break at the highest level of syntactic nesting” thing is separate from the rectangle rule