hasslium v1.0.3

hasslium: A TS/JS preprocessor based on C's

This project is still in development, but it's ready to be used in real projects. Feel free to check it out, feedback is appreciated !

The documentation is under construction, but should be informative enough for now.

A boilerplate is available to see how to use it -> fuka-g/hasslium-boilerplate

Why ?

This preprocessor is mostly useful for:

• Front-end apps
• Commercial apps
• Products you want to make a demo version of

It allows you to include or exclude certain regions of your code (development & debug statements, etc), and to define macros to replace constants you would use all over your project.

It is built around of the C preprocessor's features and syntax to be easy to understand and to provide a steep learning curve.

Installation

$ npm install -D hasslium

Usage

For now, no CLI support has been added yet. The only way to run it is through a js script file.

The main function takes an array of strings as the input, an options object, and a callback

The options object takes a macros array (see examples below) to define macros before processing your file.

You can turn the verbose mode on for debugging purposes, even though the messages are pretty cryptic for now.

export interface processOptions {
	macros?: macroType[];
	verbose?: boolean;
}

Here's an example:

import * as hasslium from "hasslium";
import * as fs from "fs";

const inputArray: string[] = fs
	.readFileSync("yourFilePath.js")
	.toString()
	.split("\n");

// hasslium.process(input: string[], options: processOptions, callback: (error: string, output: string[]))
hasslium.process(
	inputArray,
	{
		macros: [
			["ENV", "dev"],
			["TEST_MACRO", "value"],
		],
		verbose: false,
	},
	(error, output) => {
		if (error) {
			console.error(error);
		} else {
			console.log("Output:", output);
		}
	}
);

Features

• Almost all of the C preprocessor's directives
• Fast
• Tested & strongly typed

GCC's features

See the original preprocessor's features.

Syntax

All directives must start with //# .

• Example: //# define MACRO token

You can either use //# directive or //#directive.

Directives

Defining macros

//# define macro token

//# undef macro

Conditions

Conditional

//# if macro condition

//# elif macro condition

//# else

//# endif

If a macro is defined / undefined

//# ifdef macro

//# ifndef macro

Diagnostics

//# warning message

//# error message

Known bugs

• Issue relating to TypeScript: the last line of a file is not included if it is a comment. It includes hasslium directives

Contributing

Contributions are welcome !