[swift-evolution] [Discussion]: Renaming #line, the line control statement

[Chris Lattner]

> On Feb 3, 2016, at 7:29 PM, Brent Royal-Gordon via swift-evolution <swift-evolution at swift.org> wrote:
> 
>> line-control-statement → #line­
>> line-control-statement → #line­line-number­file-name­
>> line-number → A decimal integer greater than zero
>> file-name → static-string-literal­
>> 
>> The accepted implementation of SE-0028 disambiguates the two by requiring #line (the control statement) to appear at the first column for the time being. This is a stop-gap solution best remedied by renaming #line. 
>> 
>> Chris Lattner writes, "The core team isn’t thrilled with the magic “first token on a line” whitespace behavior that #line will be getting, and would like someone to start a discussion about renaming the old #line directive to something more specific and tailored to its purpose.   Once that name and syntax is settled, we can rename the directive and remove the whitespace rule."
>> 
>> I'd recommend #setline or #linenumber. Starting this thread to solicit other suggestions.
> 
> I don't love the way the current format has two unlabeled parameters in an arbitrary order. Maybe something more like this?
> 
> 	#reset line=50, file="foo.swift"
> 
> (I have a soft preference for "reset" over "set" because these are things the compiler changes automatically, but that might be a silly reason.)
> 
> Perhaps this could even let you set any combination of the #whatever parameters, so if, for instance, you were writing a parser generator, you could set #function to the name of the rule a particular piece of code came from.

Using something like this as the grammar structure makes sense to me, but I’d suggest something more specific (and longer) for this, perhaps:

#setsyntacticsourcelocation

or something. :-)

-Chris