Allow access to different rules in code blocks

[jcubic]

Issue type

• Bug Report: no
• Feature Request: yes
• Question: no
• Not an issue: no

Prerequisites

• Can you reproduce the issue?: yes
• Did you search the repository issues?: yes
• Did you check the forums?: yes
• Did you perform a web search (google, yahoo, etc)?: yes

Description

I want to use rules as an array or have one place where I define my rules.

Steps to Reproduce

I have rules:

adapter_async_strings = "get" / "post" / "ask" { return text(); }
adapter_static_strings = "echo" { return text(); }

I would like to use them in my code when I define a function:

function_definition = _ "def" _ name:variable _ "(" args:(variable _ ","? _)* ")" _  body:statement* _ "end" _ {
    const fn_name = name.name.replace(/\$_/, '');
    console.log(adapter_async_strings); // this is undefined 
    // need to hardcode the array of strings  
    if (["echo", "ask", "get", "post"].includes(fn_name)) {
        const error = new Error(`invalid function name, '${fn_name}' is reseved command`);
        error.location = move_location(location(), 4, fn_name.length + 1);
    	throw error;
    }
    var args = args.map(function(arg) { return arg[0]; });
    return {
        "type": "FunctionDeclaration",
        "id": name,
        "params": args,
        "async": true,
        "body": {
            "type": "BlockStatement",
            "body": body
        }
    };
}

It would be nice if possible to not have to use an array with hardcoded strings to validate and show a proper error message.
but use already defined commands.

Software

• PEG.js: 0.10.0
• Node.js: v16.4.2
• NPM or Yarn: 7.18.1
• Browser:
• OS: Fedora GNU/Linux
• Editor:

[Mingun]

If that acceptable for you, you can try to move all strings to the per-parse initializer or global initializer (only in Peggy) section:

{{
let methods = ["echo", "ask", "get", "post"];
}}
adapter_strings = word:$[a-z]+ &{ return methods.includes(word); }
function_definition = ... {
  if (methods.includes(...)) { ... }
}

[jcubic]

Thanks. this is exactly what I needed.