μετά: after, beyond, self, adjacent
metaprogramming: The classic definition for a metaprogram is “a computer program that writes new computer programs”
by @KevinHazzard and @JasonBock
JavaScript eval() as metaprogramming example
from Metaprogramming in .Net by @KevinHazzard and @JasonBock
Initial state
Simple multiplication
Injection values into local execution scope
C# is multiparadigm language
"Languages are losing their classifications. No longer can we say that a language is just an object-oriented language, or just a dynamic language, because so many of them borrow from lots of different ideas
Anders Hejlsberg talk about C# 3.0
- object-oriented: class-based and statically typed
- imperative
- C# 2.0: generic programming
- C# 3.0: functional/declarative: LINQ, Rx
- C# 4.0: dynamic: DLR, microORM
Microsoft® “Roslyn” CTP
Traditionally, compilers are black boxes.Source code goes in one end, magic happens in the middle, and object files or assemblies come out the other end.
As compilers perform their magic, they build up deep understanding of the code they are processing, but that knowledge is unavailable to anyone but the compiler implementation wizards.
The core mission of the Roslyn project: opening up the black boxes and allowing tools and end users to share in the wealth of information compilers have about our code.
Bootstrapping for compilers
Bootstrapping is the process of writing a compiler in the target programming language which it is intended to compile.
Applying this technique leads to a self-hosting compiler.
Compiler as a Service
Demo #01
CodeDom is a precursor to Roslyn, but is only marginally related.
- CodeDom is a simple and (somewhat) langage agnostic way to generate code
- Roslyn has an advantage of building them in managed code is that users can reference the real compilers as libraries from .NET applications
Metaprogramming by …
- Scripting
- Code generation
- Dynamic objects and λ-expression
- Reflection
Demo #02
Scripting: `eval()`-like for C# using Roslyn
Demo #03
Scripting: Roslyn Script vs. IronPython
Note about "Code-as-Data"
- Roslyn vs. MEF
- Roslyn vs. DSL
Note about "Dynamic" programming
- Roslyn vs. λ-expression and DLR
Demo #06
Reflection/Inspection: Cyclomatic complexity
Corner cases
- Breaking changes with compilers
- dynamic keyword support
- async/await keywords
- Implementation issues of current version
- Sandbox for scripts
- Support: Dustin Campbell, Eric Lippert, Kevin Pilch-Bisson and whole team!
- Roslyn CTP license limitations