Variable token order for rule

[setht...@gmail.com]

Hello all,

I am making a basic JS-like programming language as a side project, with the exception being that it is statically typed (rather similar to TypeScript). I am currently implementing classes and OOP inheritance; however, I have come across an mild issue as far as specifying attributes for member methods and properties. For example, say I want to have a method talk() as part of a basic class, and I want to make it const, abstract, and one of either private or public. If I were to implement these three keywords with the slash operator for public/private, like so:

const:'const'? _ abs:'abstract'? _ acc:('public' / 'private')?

Then it is all well and good, with the exception being that one would have to specify the keywords in exactly that order. The only way I can think of as of yet to make the order irrelevant would be to create separate subrules for each placement of the keywords... Obviously less than optimal.

Is there a PEGjs feature I'm missing here, or is there any other way of making dynamic keyword placement work that I'm just not thinking of? Thanks in advance!

[Samuel Crow]

Have you considered a more general modifier rule that uses a star operation for multiple keywords? Otherwise you may just have to slash operation for each permutation of the keywords, placing each keyword parser into a separate rule.

[Seth Traman]

Using a star operator actually would work, combined with a quick JS check to make sure no keyword is stated more than once... Certainly a step up from the rule permutation option :P Thank you!