raco-sloc: filter search by #lang

[bennn]

Add --lang <PREGEXP> command line option to limit search to files whose #lang matches the regular expression.

"Works", but:

• manually parses the #lang line from a path string
• uses pregexp because I think most users will be through posix-compliant terminals
• no tests; should we make a repo syntax-sloc-test with static files to count lines for?
• looks for exact matches (so "racket" doesn't capture "racket/base" files)

Will write docs once we agree on a design.

Examples:

bash-3.2$ raco sloc .
SLOC    Source
  399   .
bash-3.2$ raco sloc --lang racket .
SLOC    Source
   0    .
bash-3.2$ raco sloc --lang racket/base .
SLOC    Source
 169    .
bash-3.2$ raco sloc --lang "scribble.*" *
SLOC    Source
 N/A    README.md
   0    compiled
   0    info.rkt
   0    scribblings
  93    syntax-sloc
   0    typed

[bennn]

Can I commit test files to a new folder in this repo?

[AlexKnauth]

The way DrRacket gets the #lang line is in drracket/private/module-language-tools.rkt. It gets an input port (L176), calls read-language on that port (L199), gets the current line, column, and position after the read (L213). After that it gets the text up to that point (L215).

That can't be the whole story though, otherwise #|#lang scribble/manual|# #!racket would throw it off, and it doesn't.

[AlexKnauth]

Re: test files in a separate folder: Yes that's a good idea.

[bennn]

Current strategy:

1. call read-language, get the end position (like Dr. Racket)
2. read-string up to the end position
3. regexp-match-positions* to get the end of the last #lang or #!
4. return everything between (3) and (2) as a string

[AlexKnauth]

If I were a user, I would expect raco sloc --lang racket . to only report #lang racket files, and not #lang typed/racket or #lang racket/base. I might expect raco sloc --lang .*racket.* ., or maybe raco sloc --lang #px".*racket.*" . to do that, but not raco sloc --lang racket ..

[bennn]

I can put the ^ and $ back. But then --lang racket won't capture things like #lang sweet-exp racket.

(We could add a second option that enables the old behavior. "old" = current = the pregexp on the command line is matched as-is against the string following #lang or #!)

[AlexKnauth]

You wouldn't have to use ^ and $, you could use regexp-match-exact? instead, and it would make more sense for a short string like a #lang line.

[bennn]

Ok.

Are you alright with --lang racket not matching #lang sweet-exp racket ?

[AlexKnauth]

Yes. If someone wants to use this feature, then they probably would be expecting this and they would be ready to write "racket|sweet-exp racket".

[bennn]

• Added docs
• Using regexp-match-exact
• lang-file-sloc/filter returns 0 on failure

[AlexKnauth]

What's .raco-sloc.rkt.swp?

[bennn]

argh I did git add .

It's a vim-generated swapfile. Can I add *.swp and *.swo to the .gitignore?

[AlexKnauth]

Yes you can add those to the .gitignore.

[bennn]

Removed the unnecessary macro & unused imports.

[AlexKnauth]

Did you address this: https://github.com/AlexKnauth/syntax-sloc/pull/3#discussion_r64140555 ? Otherwise it will report the SLOC as 0 instead of N/A.

[bennn]

I hadn't. That's fixed now.

[AlexKnauth]

I just moved most of the #lang-file-related stuff, incliding your read-#lang function, to this repository: https://github.com/AlexKnauth/lang-file