Parser: Better names for parser util functions

[IvanGoncharov]

Based @OlegIlyenko suggestion:
#1545 (comment)

[IvanGoncharov]

I personally believe that this part of code might benefit from skip + skipOptional + keyword and "expect" alternatives. Purely based on the names, I understood "expect" as something to be used in cases where I'm interested in the token value and "skip" for cases when I just want to jump over the token, but I'm not interested in its value.

@OlegIlyenko I decide to extract it into a separate PR to make review more effective. Can you please review this PR and comment if new names match your suggestion.

[OlegIlyenko]

@IvanGoncharov Thanks a lot for considering my feedback and working this PR!

I think it reads much better now 👍 I like how easy it is to identify which tokens are optional and which are not. I also like how occurrences of skip and expect are unified under the same term.

Just an idea to play around with: I feel that term "expect" (or even more explicit variations expectTerm/expectKeyword) would better communicate the intention. But I'm not sure whether it's just me. So I don't want to emphasize it too much. In a current form it is already a good improvement, I think.

[IvanGoncharov]

Just an idea to play around with: I feel that term "expect" (or even more explicit variations expectTerm/expectKeyword) would better communicate the intention. But I'm not sure whether it's just me. So I don't want to emphasize it too much. In a current form it is already a good improvement, I think.

@OlegIlyenko Not sure I fully understand the proposed naming strategy.
How about we discuss it in term of concrete functions:

• expect - if match token kind then advance and return token else throw
• skip - if match token kind then advance else throw
• skipOptional - if match token kind then advance and return true else return false
• skipKeyword - if match keyword then advance else throw
• skipOptionalKeyword - if match keyword then advance and return true else return false

Can you please copy this list and add/delete funtions or rename them if needed?

[OlegIlyenko]

I mean something like this:

• expectToken - if match token kind then advance and return token else throw
• expectOptionalToken - if match token kind then advance and return token else return null/undefined
• expectKeyword - if match keyword then advance and return token else throw
• expectOptionalKeyword - if match keyword then advance and return token else return null/undefined

So the idea is to boil it down to only expect* functions which can be used in all scenarios. If return value of these functions is not needed, then it can be safely ignored.

[mjmahone]

So I think there's still a little confusion about the proposed terms, especially around "skip" which I usually read as closer to "I think this might be here but it means nothing if it isn't". The original naming scheme was still confusing because of this, I think.

I really like @OlegIlyenko's naming scheme on this, though.

[IvanGoncharov]

I updated PR according @OlegIlyenko last comment.