Example Basics

Example: Basics

This example defines a minimal Crodox grammar that parses simple .txt files written in pseudo-code. It is designed as a starting point to learn the core concepts before moving to real-world use cases.

Work in progress: This grammar is not complete. It is a starting point meant to be extended and adapted to your needs.

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Full Definition

<~"FROM".txt~>

    <:import:>
        import <| <<name:up>> <||> { <<name:up>> } |> from <<"FROM".txt>> <| ; <||> \n |>
    <:>

    <:class:>
        class <<NAME:up>> ( <? <| , <||> <<NAME:down>> |> ?> ) { <-function, class, refference, variable-> }
    <:>

    <:function:>
        function <<NAME:up>> ( <? <| , <||> <<NAME:down>> |> ?> ) { <-function_-> }
    <:>

    <:variable:>
        let <<NAME>> <? = <<'name'>> ?> ;
    <:>

    <:refference:>
        <<'name'>> . <<![class|function]name!>> ( <? <| , <||> |> <<'name'>> ?> ) ;
    <:>

<~>

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Breakdown

File Definition

Element	Description
<~"FROM".txt~>	Matches all .txt files. "FROM" is the path variable for cross-file linking.

Objects

Object	Description
import	Imports a name or destructured name from another file. Uses :up scope so the imported name is visible to all siblings. <<"FROM".txt>> creates a path dependency to the referenced file.
class	Class with an uppercase variable <<NAME:up>> (overwrites, no dependency). Parameters use <<NAME:down>> to pass names into the class body. Body allows nested functions, classes, references, and variables.
function	Function with <<NAME:up>>. Parameters with <<NAME:down>>. Body uses <-function_-> - the underscore means it accepts any object type as children (wildcard sub-body).
variable	let declaration. Optional initializer = <<'name'>> uses a reference variable - creates a dependency without overwriting.
refference	Method call on an object. <<![class|function]name!>> uses dependency selection - only links to objects of type class or function. Parameters repeat with <<'name'>> references.

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Concepts Demonstrated

Concept	Where	What it does
Path variable <<"FROM".txt>>	import	Links files to each other
:up scope	import, class, function	Makes names visible to parent and older siblings
:down scope	class, function	Passes names into child objects (parameters)
Uppercase variable <<NAME>>	class, function, variable	Overwrites the value, does not create a dependency
Reference variable <<'name'>>	variable, refference	Creates a dependency, does not overwrite
Dependency selection <<![class|function]name!>>	refference	Limits which object types the reference can link to
Or statement <| ... <||> ... |>	import, class, function	Alternative patterns (e.g., direct import vs destructured)
Repeat <? ?>	class, function, refference	Repeats parameters separated by commas
Sub-body <-...->	class	Named sub-body - only listed object types allowed as children
Wildcard sub-body <-name_->	function	Underscore suffix - accepts any object type

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Test Repository

A matching test repository is available at Test_Repo with the following structure:

testFile.txt          - imports, class C1 with functions F1/F2, references
bridgeTest2.txt       - class C2 with functions F3/F4
refFile.txt           - class C3 (minimal)
folder/
  bridgeTest.txt      - imports C3, function F5

testFile.txt

import { C2 } from './bridgeTest2.txt';
import { F5 } from './folder/bridgeTest.txt';

let aaa ;
let bbb ;
let ccc ;

class C1 (a , b , c ) {

    let hhh ;
    let zzz ;

    function F1 ( V1 ) {
        let xxx = zzz;
        let yyy;
    }

    function F2 ( V2 ) {
        let zzz = bbb;
        let yyy = hhh;
    }

}

C1.F1(aaa);
C1.F2(ccc);
C2.F3();
C2.F4();

bridgeTest2.txt

class C2 () {
    let ddd ;
    let eee ;

    function F3 ( Q3 ) {
        let ccc ;
        let ddd ;
    }

    function F4 ( eee, aaa, bbb ) {
        let xxx = ddd;
        let yyy = eee;
    }

    F2();
}

folder/bridgeTest.txt

import { C3 } from '../refFile.txt';

function F5 ( ) {
    let ccc ;
    let ddd ;
}

refFile.txt

class C3 () {
  // hello world
  // dfkjljf K
}

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See also: Angular Example - C# Example - Python Example - Syntax Overview