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Integrating Rust with C via the Foreign Function Interface (FFI) requires a strict protocol for managing heap-allocated memory across the language boundary. When Rust transfers ownership of a resource to a C consumer using Box::into_raw , the Rust compiler ceases to track the lifetime of that allocation. The primary constraint is ensuring that the memory is
Goal Pass a reference to a Crystal object into a C library callback so the C side can retain and later invoke it, while the Crystal process uses the default Boehm conservative garbage collector. Constraint The Boehm GC does not automatically treat pointers stored in C memory as roots, and Crystal's FFI documentation does not clearly specify a supported API f
Integration Boundary Gleam's @external FFI mechanism maps Gleam functions to Erlang modules, with a dedicated Atom type representing BEAM atoms. The BEAM runtime maintains a global atom table that is not garbage collected in standard implementations, while Gleam's type system treats atoms as first-class values subject to normal scoping rules. Unresolved Beha
Goal We want a seamless way to call a JavaScript function that returns a Promise from PureScript, automatically mapping it to PureScript’s Effect or Async monad. Current Constraints The foreign import syntax treats imported values as raw JavaScript, so a Promise returned by the imported function is passed through untouched. There is no automatic conversion;
Incremental JavaScript-to-PureScript migration with a shared FFI boundary I am migrating a small browser application from plain JavaScript to PureScript one module at a time, and both sides must keep running together in production during the transition. The plan is to wrap the remaining JavaScript modules behind foreign import declarations so new PureScript
Goal: achieve deterministic builds for a PureScript project that calls JavaScript via FFI. Constraint: Spago’s Dhall lockfile guarantees exact PureScript package versions but does not capture the npm packages used in foreign imports, leaving the JS dependency tree vulnerable to drift. Uncertainty: teams can either rely solely on Spago's lockfile and manage J
Memory Safety Across the FFI Boundary Rust provides strict memory safety guarantees via its ownership and borrowing system. When interfacing with C through the Foreign Function Interface (FFI), developers utilize unsafe blocks and repr(C) attributes to ensure layout compatibility and allow raw pointer dereferencing. Concurrency and Data Race Uncertainty Whil
PureScript FFI and JavaScript modules: choosing a multi-argument calling convention When a PureScript module exposes a two-argument function to JavaScript through the FFI, the calling convention must be decided at the language boundary. The default expectation is a curried JavaScript export, but the standard library also provides Data.Function.Uncurried with
rust
gleam
purescript