Be much more careful about parsing * in import and export statements

[GeoffreyBooth]

While writing the documentation for modules, I stumbled across a bug. Yes, I broke it already.

I was writing this as an example:

export square = (x) -> x * x

Which choked on the *, because our check for whether * should be treated as EXPORT_ALL was whether we’ve seen an EXPORT token and that the indent was 0. I knew that indent check was going to be trouble; but I gave it a lot more thought this time, and noticed two things:

• In import statements, an * always precedes an as.
• In export statements, the only time * can appear is in a statement like export * from 'lib'

So I made the check for converting * to IMPORT_ALL or EXPORT_ALL much narrower, based on these two rules. This made my example compile properly, and broke no other tests. I added two new tests like this example, where * is used on the same line (and indentation level) as an export keyword. I also re-ran the Meteor todos test.

@lydell you were wondering why we can’t just put * in the grammar? It’s because the lexer converts * to tag MATH, and I don’t want to write grammar like EXPORT MATH FROM String. That doesn’t make much sense, and then in ExportAllDeclaration I would need to filter whether MATH was an * and throw an error otherwise. Better to intercept * in the lexer and convert it to IMPORT_ALL or EXPORT_ALL there rather than MATH.

[lydell]

Nice catch!