Create a 'crs' crate?

[frewsxcv]

It would be a crate for looking up CRS information. Something like Crs::from_str("EPSG:4326").proj_string().

We would need to populate the crate with CRS information, potentially from:

• https://epsg.io/
• https://raw.githubusercontent.com/jjimenezshaw/crs-explorer/master/crslist.json
• https://spatialreference.org/ref/

[urschrei]

Is there a specific reason you need the proj string, when libproj (as of v5? I think) can create transforms using EPSG codes (see e.g. https://github.com/georust/proj#convert-from-nad-83-us-survey-feet-to-nad-83-meters-using-epsg-codes) or is this intended to be a totally separate concern from proj functionality?

[urschrei]

That aside, it could be built using a build script and a phf hashmap populated from either a JSON or SQLite source. We'd also have to ensure that the source matched the current libproj version in use by the proj crate, as I believe there is a little bit of EPSG code churn between versions.