Progress report in Pen programming language

February 19th, 2022

@raviqqe

Agenda

• Progress report
  • Multiple system packages
• Next plans

Progress report

Multiple system packages (#744)

• Multiple system packages can be used in one application package now!
• Previously, we needed to choose only a system package per application package.
  • e.g. the standard Os or OsSync packages
  • All other system-dependent codes were built on top of them.
• This enables developers to build plugin system packages.
  • e.g. An Http package works along with the Os package.
• Linking applications is still done by one of system packages in an application package.
  • Multiple link scripts are simply forbidden.

Multiple system packages (examples)

import Http'Client
import Os'File

fetch = \(ctx context) none | error {
  s = Client'Get(ctx.Http, "https://pen-lang.org")?
  File'Write(ctx.Os, File'StdOut(), s)?

  none
}

Even more...

• Thunk lock handling (#774)
• Algorithm examples (#747)
• Several bug fixes and performance improvements

Next plans

• Proper tail calls in Rust FFI (#757)
  • Without this, some programs in Pen can leak stack memory.
• Built-in map type (#634)
  • Some language design work is still required.

Summary

• Progress
  • Multiple system packages can be used in one application package now!
• Future plans
  • More work to stabilize Rust FFI...
  • Built-in map type