Modules¶

Importing other Candela files¶

You can import other Candela files with the import keyword at the top-level.

Imports can be nested, and circular imports are detected and produce an error.

import "fibonacci_lib.cdl"; // all functions/structs are available under fibonacci_lib::
import "other_lib.cdl" as mylib; // all functions/structs are available under mylib::

fn main() {print(mylib::my_func(42));}

Importing libraries¶

Import a library by its namespaced name. import std::string binds the module's functions under string::, and the resolver finds the shipped module for you, so this works from any working directory with nothing to configure.

import std::math;
import std::string;
import std::list;

fn main() {
    print(math::cos(3.14159265359));
    print(string::capitalize("hello"));
    print(list::sum([1, 2, 3, 4]));
}

Add as to choose a different namespace: import std::string as s; makes the functions available under s::.

How a namespaced import resolves¶

A namespaced import maps to a .cdl file in the shipped library directory: std::string resolves to std/string.cdl under that directory. The library directory is libs/ next to the Candela executable, which is where the installer places it, so a normal install needs nothing set. Set CANDELA_LIB_PATH to point the lookup at a different libs/ directory (the one holding std/ and, for the C-backed libraries, std_src/); this is an escape hatch for source checkouts and custom builds, not part of normal use.

Resolution happens at compile time, so a program built to a .cdlb artifact has the imported module bytecode inlined and runs under candela-vm with no library files present.

Standard library¶

The standard library lives in the shipped std/ directory. The math, time, and random libraries are backed by a C library loaded across Candela's dynamic-library FFI. The string, list, convert, and assert libraries are written in Candela and use no dynamic library.