macwire

![MacWire](https://github.com/softwaremill/macwire/raw/master/banner.png)

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Zero-cost, compile-time, type-safe dependency injection library.

The core of MacWire is a set of macros, that is code which runs at compile-time. The macros generate the `new` instance
creation code automatically, allowing you to avoid a ton of boilerplate code, while maintaining type-safety.

The core library has no dependencies, and incurs no run-time overhead. The main mechanism of defining dependencies of a
class are plain constructors or `apply` methods in companion objects. MacWire doesn't impact the code of your classes 
in any way, there are no annotations that you have to use or conventions to follow.

There's a couple of wiring variants that you can choose from:

* `autowire` create an instance of the given type, using the provided dependencies. Any missing dependencies are created
  using constructors/`apply` methods.
* `wire` create an instance of the given type, using dependencies from the context, within which it is called. 
  Dependencies are looked up in the enclosing trait/class/object and parents (via inheritance).
* `wireRec` is a variant of `wire`, which creates missing dependencies using constructors.
* `wireSet` collect all instances of the given type from the context and return them as a `Set`.
* `wireList` collect all instances of the given type from the context and return them as a `List`, preserving order.

In other words, `autowire` is context-free, while the `wire` family of macros is context-dependent.

MacWire is available for Scala 2.12, 2.13 and 3 on the JVM, JS and Native platforms. Not all functionalities are 
available for each Scala version.

To use, add the following dependency:

```
// sbt
"com.softwaremill.macwire" %% "macros" % "2.6.7" % "provided"

// scala-cli
//> using dep com.softwaremill.macwire::macros:2.6.7
```

# Table of Contents

- [Table of Contents](#table-of-contents)
- [autowire](#autowire)
  - [Providing instantiated dependencies](#providing-instantiated-dependencies)
  - [Using factories](#using-factories)
  - [Specifying implementations to use](#specifying-implementations-to-use)
  - [Using dependencies contained in objects](#using-dependencies-contained-in-objects)
  - [Errors](#errors)
  - [Limitiations of autowire](#limitiations-of-autowire)
- [wire](#wire)
	- [How wiring works](#how-wiring-works)
	- [Factories](#factories)
	- [Factory methods](#factory-methods)
	- [`lazy val` vs. `val`](#lazy-val-vs-val)
	- [Recursive wiring](#recursive-wiring)
	- [Composing modules](#composing-modules)
	- [Scopes](#scopes)
	- [Accessing wired instances dynamically](#accessing-wired-i