how to add keyword without quotes

[Yokozuna59]

If I have the following langium grammar:

grammar Example

entry Example:
    "example" name=ID
;

hidden terminal WS: /\s+/;
terminal ID: /[\s\S]+/;

Using langium-cli, it'll generate example as a keyword and would be highlighted differently and suggested when typing. But by setting whitespaces as hidden rules, then it would be fine to combine example with ID.

examplewow

That's why I thought of this:

grammar Example

entry Example:
    EXAMPLE name=ID
;

hidden terminal WS: /\s+/;
terminal EXAMPLE: /example(?!\S)/;
terminal ID: /[\s\S]+/;

Which restricts that there shouldn't be a non-whitespace letter after example, but now it's not defined as a keyword.

Is there a way to redefine it as keyword? Or another way to force example to not be combined with ID? Or a better approach?
 

[msujew]

I'm unsure what to recommend here. Mostly due to the question: What constitutes a keyword if not a well-known word that is separated from other words using a non-word character? I.e. either whitespace or other symbols such als brackets, braces or parenthesis.

So, in theory, you can just declare the keyword as normal and override the pattern in the token builder. That would probably accomplish what you're looking for the best.

You could also keep the regex terminal and then add the corresponding parts to the completion provider. Note that there's very little difference between keywords and other terminals during the language server runtime. It's basically only the completion that is provided for keywords. Non cross reference terminals don't get completion support.

[Yokozuna59]

So, in theory, you can just declare the keyword as normal and override the pattern in the token builder. That would probably accomplish what you're looking for the best.

I guess I'll take this approach because:

• It doesn't need much work since I'm familiar with it.
• A bit clearer in grammar.
• Explicitly show that the work is keyword.

But it appears that if it's not a rule, then it won't go to token builder so that I can override the pattern.

[Yokozuna59]

I'm not really sure my question was answered :)

edit: when will the new version be released? I'm thrilled to try out railroad with other features :)

[spoenemann]

Hi, we're planning to release v2.0.0 by end of July.

[Yokozuna59]

But it appears that if it's not a rule, then it won't go to token builder so that I can override the pattern.

Sorry, I overridden the buildTerminalToken by mistake.