How do I call an Elixir function from Elchemy?

Use the ffi call syntax in Elchemy to interface with Elixir functions. The compiler generates type checks based on Elixir's typespecs for safety, but document these calls to maintain readability, as advised in the FAQ.

Is Elchemy ready for production use?

Elchemy is still in development with incomplete features like side effects and Windows support. It's best for experimental or non-critical projects until it matures, as indicated by the low percentages in the maturity section.

Can I use Elchemy with Phoenix?

Yes, you can integrate Elchemy into Phoenix by compiling .elm files to .ex files. However, limitations with macros and side effects might affect certain components, so test thoroughly in your setup.

Elchemy vs Elixir typespecs: which is better?

Elchemy offers a stricter, compile-time type system inspired by Elm, while Elixir's typespecs are optional and checked at runtime via Dialyzer. Elchemy provides more safety but less flexibility and ecosystem maturity.

What's the performance impact of using Elchemy?

Elchemy compiles to idiomatic Elixir code, so performance is similar to hand-written Elixir. However, the compilation process adds build-time overhead, and type inference might slow down development in large codebases.

How do I handle errors in Elchemy?

Elchemy's type system prevents most runtime errors, but for edge cases, use Elixir interop with ffi calls. Ensure typespecs are accurate, as errors in interop are the primary source of runtime issues.

Elchemy — Type-Safe Elixir with Elm Syntax

What is Elchemy?

Elchemy is a compiler that allows developers to write Elixir code using Elm's statically-typed, functional syntax. It translates Elm-like source files into idiomatic Elixir, providing type safety and reducing runtime errors while leveraging the BEAM ecosystem. The project aims to combine the best of both languages—Elm's reliability and Elixir's tooling and platform.

Target Audience

Elixir developers seeking stronger type safety and Elm developers wanting to use the BEAM ecosystem. It's ideal for teams building reliable, maintainable applications where compile-time error prevention is a priority.

Value Proposition

Developers choose Elchemy for its seamless integration of Elm's type system with Elixir's ecosystem, offering type-safe interop, readable output, and a familiar syntax. It uniquely bridges two functional programming communities, providing safety without sacrificing access to Elixir's libraries and tooling.

Write Elixir code using statically-typed Elm-like syntax (compatible with Elm tooling)

Use Cases

Best For

Adding type safety to existing Elixir projects incrementally
Writing new BEAM applications with Elm-like syntax and tooling
Teams familiar with Elm transitioning to or integrating with Elixir
Preventing runtime errors in critical production code
Leveraging Elixir's ecosystem while maintaining functional purity
Educational projects comparing Elm and Elixir type systems

Not Ideal For

Projects requiring extensive side effects like file I/O or database interactions, as Elchemy's effects system is only 20% complete
Teams heavily reliant on Elixir's macro system for metaprogramming, due to poor support for macros and do..end blocks
Windows-based development environments, since Elchemy lacks official Windows support and relies on Unix tools
Applications needing battle-tested, production-ready tooling, as Elchemy is still in active development with many core features incomplete

Pros & Cons

Pros

Powerful Type Inference

Elchemy's compiler provides extensive type inference, reducing manual annotations and catching errors early, as highlighted in the features section.

Safe Elixir Interop

It enables type-safe calls to Elixir/Erlang functions using typespecs, minimizing boilerplate and maintaining safety, as described in the interop details.

Reduced Runtime Errors

The type system eliminates almost all runtime errors in Elchemy code, isolating issues to Elixir interop parts, ensuring higher reliability.

Readable Output Code

Generates idiomatic and performant Elixir code that is easy to read and analyze without referencing the source, aiding in maintenance and debugging.

Cons

Incomplete Side Effects

Elchemy-effects is only 20% complete, meaning you can't write code with side effects yet, severely limiting real-world applications like I/O or state management.

Platform Limitations

No support for Windows and heavy reliance on Unix tools, as mentioned in issues #287 and #288, restrict usability in diverse development environments.

Poor Macro Integration

Limited support for Elixir macros, including those with do..end blocks, hinders integration with macro-heavy libraries common in the Elixir ecosystem.

What is Elchemy?

Target Audience

Value Proposition

Use Cases

Best For

Adding type safety to existing Elixir projects incrementally
Writing new BEAM applications with Elm-like syntax and tooling
Teams familiar with Elm transitioning to or integrating with Elixir
Preventing runtime errors in critical production code
Leveraging Elixir's ecosystem while maintaining functional purity
Educational projects comparing Elm and Elixir type systems

Not Ideal For

Projects requiring extensive side effects like file I/O or database interactions, as Elchemy's effects system is only 20% complete
Teams heavily reliant on Elixir's macro system for metaprogramming, due to poor support for macros and do..end blocks
Windows-based development environments, since Elchemy lacks official Windows support and relies on Unix tools
Applications needing battle-tested, production-ready tooling, as Elchemy is still in active development with many core features incomplete

Pros & Cons

Pros

Powerful Type Inference

Elchemy's compiler provides extensive type inference, reducing manual annotations and catching errors early, as highlighted in the features section.

Safe Elixir Interop

It enables type-safe calls to Elixir/Erlang functions using typespecs, minimizing boilerplate and maintaining safety, as described in the interop details.

Reduced Runtime Errors

The type system eliminates almost all runtime errors in Elchemy code, isolating issues to Elixir interop parts, ensuring higher reliability.

Readable Output Code

Generates idiomatic and performant Elixir code that is easy to read and analyze without referencing the source, aiding in maintenance and debugging.

Cons

Incomplete Side Effects

Elchemy-effects is only 20% complete, meaning you can't write code with side effects yet, severely limiting real-world applications like I/O or state management.

Platform Limitations

No support for Windows and heavy reliance on Unix tools, as mentioned in issues #287 and #288, restrict usability in diverse development environments.

Poor Macro Integration

Limited support for Elixir macros, including those with do..end blocks, hinders integration with macro-heavy libraries common in the Elixir ecosystem.

Elchemy

What is Elchemy?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

Elchemy

What is Elchemy?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?