Built-ins & Project Modules

The current Prady CLI provides built-in functions and data structures, and loads project .pr files through import declarations. It does not currently ship the std::io, std::fs, std::math, std::sys, or std::time source modules shown in older drafts of this page. Importing those names does not make their APIs available.

Built-in functions and data structures

Common built-ins include print, println, input, assert, and len. input() reads one line from standard input and returns it as a string; pass an optional string prompt to display before waiting. The runtime also provides collection/string operations and the data structures listed in the data-structure reference. The exact supported functions and methods are those implemented by the current compiler/runtime.

fn main() {
    let values = [1, 2, 3];
    let name = input("Name: ");
    println("Count: " + len(values));
    println("Hello " + name);
    assert(len(values) == 3, "the list should contain three values");
}

Project imports

import models.user;

fn main() {
    let user = User("Prady");
    println(user.name);
}

The import path models.user resolves to models/user.pr relative to the importing source file (or the project’s src directory). The imported file must define the symbols used by the program. The CLI currently discovers local project .pr files; it does not download or resolve third-party packages just because an import path is written.

The browser playground cannot access local files, so it reports project imports as warnings. Use the CLI or VS Code extension for multi-file projects. See Errors & Troubleshooting if an import cannot be resolved.