# `RustQ.Meta.Lower.Paths`
[🔗](https://github.com/elixir-crab/rustq/blob/v1.0.0-rc.19/lib/rustq/meta/lower/paths.ex#L1)

The Rust paths Elixir aliases name, and the callables a path or a receiver's type reaches.

An alias a `defrustmod` maps is that Rust module, with what follows it; an alias ending in a
plural, as `Atoms`, is a Rust module in snake case; any other is a Rust type or module as
written. A call through a path or on a receiver finds its signature among the callables
RustQ knows, trying the targets the path may name.

# `alias_ast?`

Whether `ast` is an alias.

# `alias_parts`

The Rust path an alias names; see the module docs.

# `alias_path_ast?`

Whether `ast` is an alias or a field path through one, as `Kinds.FANCY`.

# `alias_path_parts`

The Rust path an alias or field path through one names.

# `alias_prefixes`

The ways to split alias `parts` into a prefix and the rest, longest prefix first.

# `callable_argument_types`

The argument types of the callable `function/arity` on `target` (nil for a function), from the callables RustQ knows.

# `callable_return_type`

```elixir
@spec callable_return_type(
  Macro.t(),
  keyword()
) :: RustQ.Meta.Type.t() | nil
```

The return type of a local or remote call, from the callable metadata the `:callables` option
supplies, which tells lowering when a call returning `Result`, `Option`, or `NifResult`
lowers with Rust `?`.

# `callable_target_from_type`

The callable target, as a Rust type name, a receiver of `type` calls methods on.

# `constant_alias?`

Whether alias `parts` end in an upper-case segment, as a constant such as `Kind.PLAIN`.

# `mapped_alias_parts`

The Rust path alias `parts` name, through the longest `defrustmod` mapping of a prefix.

# `parent_module_callable_argument_types`

The argument types of a function `Super.function` names, in the module's parent.

# `path_callable_argument_types`

The argument types of a function a Rust path names, trying each target the path may mean.

# `path_callable_argument_types`

# `rust_constructor_alias?`

Whether `ast` is an alias RustQ reserves for building Rust AST, as `Stmt`.

# `super_alias_ast?`

Whether `ast` is `Super`, the Rust parent module.

# `type_for_callable_target`

The type a callable target names.

---

*Consult [api-reference.md](api-reference.md) for complete listing*