feat: support lpeg 1.1

[jokajak]

This changeset adds support for lpeg 1.1 which updated the lpeg.version from a function to a string.

Therefore we have to check the type of the value.

Refs: #47

[Neph-Oo]

Hi @jokajak,

There is a problem with the patch:
local DecimalLpegVersion = lpeg.version and tonumber((type(lpeg.version) == "string" and lpeg.version or lpeg.version()):match("^(%d+%.%d+)")) or 0.7

lpeg.version contain the string "LPeg 1.1.0", not just a version number. So tonumber("LPeg 1.1.0") return nil and DecimalLpegVersion always take the default value of 0.7.

The fix should be something like:
local DecimalLpegVersion = lpeg.version and tonumber((type(lpeg.version) == "string" and lpeg.version:match("(%d+%.%d+)") or lpeg.version()):match("^(%d+%.%d+)")) or 0.7

This correction gives the expected result of 1.1.

Do you want me to create a new Pull Request for this fix or can you do it @jokajak ?

Furthermore, this change is not applied for luarocks users because the Rockspec file refers to the 1.3.4 tag which is several commits behind this one and must be updated to the last commit on the master branch of the repository. Can you do something about this @harningt ?

[jokajak]

@Neph-Oo thanks for fixing my fix! I submitted a new PR at #49.

I don't quite understand why my original fix didn't work though because the tonumber function is only ever called against something that is :match()

[Neph-Oo]

My bad, you're right @jokajak. I hadn't seen that tonumber function is only called against something thas is :match().

This is in fact a pattern matching error in the call to match("^(%d+%.%d+)").
The ^ will only match if the string in the variable lpeg.version starts with 1.x.x. which is not the case in the new version. So, removing the caret should have worked perfectly without calling match twice.

See here

A pattern is a sequence of pattern items. A caret '^' at the beginning of a pattern anchors the match at the beginning of the subject string. A '$' at the end of a pattern anchors the match at the end of the subject string. At other positions, '^' and '$' have no special meaning and represent themselves.

[jokajak]

Ah, yep, great catch. I updated my PR to be more like my first change just fixed the pattern matching to support the numbers being not at the start.

[Neph-Oo]

Great ! Thanks a lot for your PR.

I'll probably open another issue for the luarocks package, which is really obsolete. But I don't know if harningt will have time to update or add a new tag.