Étoilé: Pragmatic Smalltalk

by David Chisnall


The Étoilé project was founded by a small group, mostly PhD students, who were disenchanted with the direction of modern desktop software development. The project aims to develop a modern, flexible, user environment, that is easy to use and extend.

Étoilé is built on top of GNUstep, an open source Objective-C framework that is source-compatible with Apple's Cocoa. Objective-C is a hybrid language, allowing a subset of Smalltalk to be used in C code. This has the advantage that it allows very low-level work, including inline assembly and the use of compiler intrinsics for things like vector operations, but has the disadvantage that the user is always forced to be aware of these things.

This talk will explain some of the philosophy of Étoilé and the tools that have been developed, with particular focus on LanguageKit, a framework for implementing dynamic language, and in particular on Pragmatic Smalltalk, a dialect of Smalltalk implemented using this framework.

Pragmatic Smalltalk compiles (using either static or JIT compilation) to native code that runs without a virtual machine, and is ABI-compatible with Objective-C code. This means that it's possible to write a class that has some methods implemented in Smalltalk and some in C, without any bridging code or foreign function interfaces being required. In effect, Objective-C becomes a domain-specific language for calling C from Smalltalk code.

If there is sufficient time, then this talk will also cover some of the recently implemented optimisations that have improved performance of Objective-C and Smalltalk code.


David Chisnall is a freelance writer and developer. He is a founding member of the Étoilé project, maintainer of GNU Objective-C runtime family support in the Clang Objective-C compiler, and both original author and maintainer of the GNUstep runtime, and of the LanguageKit framework an Pragmatic Smalltalk compiler in Étoilé.

David is the author of several books, including the Objective-C Phrasebook and the Definitive Guide to the Xen Hypervisor. He usually works from a comfy chair overlooking the sea and dances argentine tango when not writing or hacking.




Slides with annotations


Part 1: http://youtu.be/87A5589nuy8

Part 2: http://youtu.be/HcD-H1MlJIM