Multiple/combined licence parsing support

[domcleal]

2.0 is in the works, which changes how "+" (or later) licenses are expressed.

http://wiki.spdx.org/view/Legal_Team/Decisions/license_expression_syntax has some information.

It might mean this library has to parse the licence text a little (it probably should already, to support and/or) and validate "GPL-3.0+" as being the "GPL-3.0" licence.

[domcleal]

Maybe I'll change the API to something more supportive of multiple licences, switching "exist" to "valid":

• .valid?("Apache 2.0 or GPL 3.0") => true
• .valid?("GPL 3.0+") => true
• .lookup("GPL 3.0+") => licence
• .lookup("Apache 2.0 or GPL 3.0") => [licence, licence]
• .lookup("Apache 2.0", "GPL 3.0") => [licence, licence]
• .lookup(["Apache 2.0", "GPL 3.0"]) => [licence, licence]

Then perhaps deprecate the single value return value from .lookup for a future version? It would also be nice to be able to parse the and/or in a meaningful way.

[tuxinaut]

👍

[balupton]

@domcleal I wouldn't care about updating lookup to support multiple licenses, but rather that doing the valid proposal

Our use case is over at bevry/staticsitegenerators-list#221