Standard Library

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Elle's standard library has four layers: Rust primitives, core operators, prelude macros, and stdlib functions.

Libraries (lib/)

Higher-level modules, loaded with import. Each module is a closure: (import "std/NAME") returns it, and calling it returns a struct of the module's exports. Some of them:

libraries.md describes the libraries and how to load them.

Core operators (core.lisp)

Compiled and run before the prelude, from special forms and % intrinsics alone, because prelude macros call them while they expand. They are the sequence operators and the trait layer those operators dispatch through (traits.md):

fold reduce reverse append concat last butlast
trait/elements trait/rebuild

Prelude (prelude.lisp)

Macros loaded before user code:

defn        function definition sugar
let*        alias for let (sequential bindings)
->  ->>     thread-first, thread-last
as-> some-> some->>   threading variants
when        one-armed conditional
unless      negated one-armed conditional
case        equality dispatch
if-let      conditional binding (two arms)
when-let    conditional binding (one arm)
when-ok     run a body when an expression does not error
each        iteration
repeat      run N times
forever     infinite loop
try/catch   error recovery
protect     error capture
defer       guaranteed cleanup
with        resource management
with-temp-dir   a scratch directory, removed afterwards
error       raise an error
assert      check a condition
gate!       run a body, or raise :gated
yield yield*    emit :yield
apply       call with a spread argument list
default     a default for a &named parameter left nil

cond and match are special forms, not macros.

stdlib (stdlib.lisp)

Functions loaded after the prelude, among them:

map filter sum product take drop
sort-by sort-with
compose partial identity

sort, ->array, ->list, freeze, thaw and deep-freeze are VM primitives.

VM primitives

Native functions implemented in Rust. Use (vm/list-primitives) to enumerate, (doc fn-name) for documentation, and (vm/primitive-meta "name") for the full metadata struct:

(assert (> (length (vm/list-primitives)) 500))
(assert (= (get (vm/primitive-meta "length") :arity) "1"))
(assert (nil? (vm/primitive-meta "+")))   # + is a stdlib function, not a primitive

IEEE 754 bitcast

(assert (= (math/f32-bits 1.0) 1065353216))
(assert (= (math/f32-from-bits 1065353216) 1.0))

See also

• plugins.md — native plugin extensions
• modules.md — import system
• functions.md — function reference