Types and Values

AetherShell is a typed shell where every expression produces a structured Value. Unlike traditional shells that pipe raw text, AetherShell pipelines carry rich, typed data.

Core Types

Integers and Floats

let x = 42       # Int
let y = 3.14     # Float
let z = x + y    # Float (auto-promoted)

Integer division always produces a Float:

10 / 3   # => 3.3333...

Strings

Strings support ${expr} interpolation:

let name = "world"
let greeting = "Hello, ${name}!"    # => "Hello, world!"
let math = "2 + 2 = ${2 + 2}"      # => "2 + 2 = 4"

String concatenation works with + and auto-converts the other operand:

"count: " + 42        # => "count: 42"
100 + " items"         # => "100 items"

URIs

URIs identify resources with a scheme prefix, commonly used for AI model references:

let model = openai:gpt-4o-mini
let local = ollama:llama3

Arrays

Arrays hold any mix of types:

let nums = [1, 2, 3]
let mixed = [1, "two", true, [4, 5]]

Records

Records are key-value maps with sorted keys:

let person = {name: "Ada", age: 36, langs: ["Rust", "Python"]}
person.name    # => "Ada"
person.langs   # => ["Rust", "Python"]

Tables

Tables are structured arrays of records with a defined schema. Many builtins return tables:

ls "."    # => Table with columns: name, path, ext, is_dir, size, modified

Tables get special pretty-printed column-aligned output in the terminal.

Type Conversion

AetherShell performs automatic numeric promotion in arithmetic:

Equality comparison between Int and Float works via casting.

Truthiness

All values have a boolean interpretation:

JSON Interop

Values convert bidirectionally with JSON:

let data = from_json '{"name": "test", "count": 42}'
data.name    # => "test"

let json_str = to_json {name: "test", count: 42}
# => '{"count":42,"name":"test"}'

Type Inspection

describe 42          # => "Int"
describe "hello"     # => "String"
describe [1, 2, 3]   # => "Array(3 elements)"