Modules and manifests

Modules split a library's source across files. Argon.toml names the library and lists what it depends on.

File modules

Declare a child module with mod:

lib.ar

mod utils;

cell top() {
    let spacing = utils::default_spacing();
}

mod utils; loads utils.ar. A module can also be a directory containing a mod.ar.

Paths start with std:: for the standard library, lib:: for the root of the current library, or a dependency's name for that dependency.

Imports

use brings an item from another module into scope, so it can be named without its path. The item is bound under its last segment, or under the name after as:

lib.ar

mod utils;

use std::layout::{inst, rect};
use utils::default_spacing;
use utils::pad as metal_pad;

cell top() {
    let left = inst(metal_pad(100.), x=0., y=0.);
    let right = inst(metal_pad(100.), x=100. + default_spacing(), y=0.);
    rect("met2", x0=left.x, y0=0., x1=right.x, y1=20.);
}

A group imports several items from one module: use utils::{default_spacing, pad as metal_pad}; is the same as the two separate use lines above. Each entry in the braces is a single name with an optional as, a trailing comma is allowed, and an empty group {} is an error.

• A use applies only to the module that declares it.
• Imports and declarations share one namespace per module, so a module can't import a name it also declares. Use as to import the item under another name.
• A use can't bind the name of a built-in function, such as eq or float.

Standard library

std is available in every library without a manifest entry. It is split into modules:

Module	Contents
std	max, min, Option, and sequence helpers
std::layout	Geometry constructors, inst, bbox, dimension, and rectangle helpers
std::schematic	Signal, connect, device, inst, and DeviceKind

Call a standard library item by its full path, such as std::max(a, b) or std::layout::rect("met1"), or import it with use. Option, Some, and None are in scope in every module without an import.

Library manifest

Argon.toml names the library and points at its technology file, dependencies, and GDS imports:

name = "my-library"
tech = "tech.toml"

[dependencies]
devices = "../devices"

[gds]
"macros::sram" = "gds/sram.gds"

Paths are relative to the manifest. Each GDS import becomes a zero-argument cell at the given module path.

Project layout

my-library/
├── Argon.toml
├── tech.toml
├── lib.ar
├── utils.ar
└── nested/
    └── mod.ar

arc check parses, resolves, and type-checks the whole library.