Standard Library

The Crush standard library provides additional capabilities and utilities beyond the core language.

Host-provided, not bundled. The capability framework and a small set of primitives (io.print, io.eprint, io.read) are built into crush-vm. Everything else — fs.*, net.*, sys.*, and the full corecaps suite — must be registered by the embedding host. The bare crush-ast crates ship the interface, not the implementation. When embedding crush-ast, only the capabilities your host explicitly registers are available at runtime.

Importing Modules

import std.io;
import std.fs;
import std.net;
import std.sys;

With Aliases

import std.fs as filesystem;
import std.io as console;

Available Modules

I/O Module (std.io)

Input/output operations:

• io.print(message) - Print to stdout
• io.read() - Read from stdin
• io.eprint(message) - Print to stderr

Filesystem Module (std.fs)

File and directory operations:

• fs.read(path) - Read file
• fs.write(path, content) - Write file
• fs.exists(path) - Check if exists
• fs.delete(path) - Delete file
• fs.list(path) - List directory

System Module (std.sys)

System-level operations:

• sys.exec(command) - Execute command
• sys.env(name) - Get environment variable
• sys.args() - Get command-line arguments
• sys.exit(code) - Exit program

Network Module (std.net)

Network operations:

• net.http(url) - HTTP request
• net.get(url) - HTTP GET
• net.post(url, body) - HTTP POST

Example Usage

import std.io;
import std.fs;
import std.sys;

fn main() {
    // Get command-line arguments
    let args = sys.args();

    if args.length < 2 {
        io.eprint("Usage: program <filename>");
        sys.exit(1);
    }

    let filename = args[1];

    // Check if file exists
    if fs.exists(filename) {
        let content = fs.read(filename);
        io.print(content);
    } else {
        io.eprint("File not found: " + filename);
        sys.exit(1);
    }
}

Next Steps

• Capability System - How capabilities gate stdlib access
• Polyglot Programming - Embed multiple languages