The document discusses dynamic programming in C# and compares static and dynamic languages. It provides examples of how dynamic features like method missing in Ruby can be achieved in C#. It also summarizes the Dynamic Language Runtime (DLR) and how it allows multiple languages to run on the Common Language Runtime (CLR). Key people who worked on DLR implementations for languages like IronRuby are mentioned.

1. by @AntyaDev
DYNAMIC C#

2. STATIC VS DYNAMIC

3. The many faces of “dynamic”
Generate code
at runtime
Changing types
at runtime
No types
at all
Simplified
deployment

4. • Trend on non-schematized data
• Remember WSDL, SOAP, XSD?
• How about REST, JSON?
• The next browser war
• JavaScript on the web
• Optimized scripting engines
• Towards metaprogramming?
• Ruby community
• Code as data
IT’S A DYNAMIC WORLD

5. Dynamic
Languages
Simple and succinct
Implicitly typed
Meta-programming
No compilation
Static
Languages
Robust
Performant
Intelligent tools
Better scaling
STATIC VS DYNAMIC

6. DLR Hero
• Jim Hugunin
Co-designer ASpectJ
Jython implementation
• Python on the JVM
IronRuby implementation
• Python on the .NET

7. DLR Hero
• John Lam
RubyCLR
bridge between the Ruby
interpreter and the CLR
IronRuby
Ruby on the .NET

8. DLR Hero
Martin Maly
Common Language
Runtime
Dynamic Language
Runtime

9. C# compiler team
Chris Burrow, Sam Ng

10. Action Python Ruby C# VB.NET
GetMember x.Foo x.Foo x.Foo x.Foo
SetMember x.Foo = y x.Foo = y x.Foo = y x.Foo = y
DeleteMember del d.Foo
x.send
:remove_instance_variable
:@foo
No syntax No syntax
UnaryOperation -x -x -x -x
BinaryOperation x + y x + y x + y x + y
Convert No syntax No syntax (Foo)x CType(x,Foo)
InvokeMember x.Foo(a,b) x.Foo(a,b) x.Foo(a,b) x.Foo(a,b)
Invoke x(a,b) x.call(a,b) x(a,b) x(a,b)
CreateInstance X(a,b) X.new(a,b) No syntax No syntax
GetIndex x[a,b] x[a,b] x[a,b] x(a,b)
SetIndex x[a,b] = y x[a,b] = y x[a,b] = y X(a,b) = y
DeleteIndex del x[a,b] No syntax No syntax No syntax
Common actions

11. IDynamicMetaObjectProvider
public interface IDynamicMetaObjectProvider
{
DynamicMetaObject GetMetaObject(Expression parameter);
}

12. DynamicMetaObject
public class DynamicMetaObject
{
public BindingRestrictions Restrictions { get; }
public Expression Expression { get; }
public bool HasValue { get; }
public object Value { get; }
public Type RuntimeType { get; }
public virtual DynamicMetaObject BindGetMember(GetMemberBinder b);
public virtual DynamicMetaObject BindSetMember(SetMemberBinder b,
DynamicMetaObject value);
public virtual DynamicMetaObject BindDeleteMember(DeleteMemberBinder b);
// Other bind operations…
}

13. System.Dynamic.DynamicObject
public class DynamicObject : IDynamicMetaObjectProvider
{
public virtual bool TryBinaryOperation(BinaryOperationBinder binder, object arg, out
object result);
public virtual bool TryConvert(ConvertBinder binder, out object result);
public virtual bool TryCreateInstance(CreateInstanceBinder binder, object[] args, out
object result);
public virtual bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object
result);
public virtual bool TryGetMember(GetMemberBinder binder, out object result);
public virtual bool TryInvoke(InvokeBinder binder, object[] args, out object result);
public virtual bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out
object result);
public virtual bool TrySetIndex(SetIndexBinder binder, object[] indexes, object
value);
public virtual bool TrySetMember(SetMemberBinder binder, object value);
}

14. Python
Binder
Ruby
Binder
COM
Binder
JavaScript
Binder
Object
Binder
DYNAMIC LANGUAGE RUNTIME (DLR)
Dynamic Language Runtime
DLR Trees Dynamic Dispatch Call Site Caching
IronPython IronRuby C# VB.NET Others…

15. CALL SITES
• Old Idea: Polymorphic Inline Cache
• Implemented with delegates and generics
• No changes in CLR runtime engine (today)
• Major Addition: Multiple languages on CLR
• Interop for sharing objects across languages
• Customization to work for each language
• Customization for library writers
• System.Runtime.CompilerServices

16. CLR
Compile Run
Bind call
Expression
Tree
DLR
Cache
COM Binder
IronPython
Binder
C# Runtime
Binder
…
HOW DYNAMIC WORKS

17. CALLSITE<T>
static CallSite<Func<CallSite, object, int, bool>> _site = …;
if (_site.Target(_site, x, 0)) { … }
if (x == 0) { … }
static bool _0(Site site, object x, int y) {
return site.Update(site, x, y); //tailcall
}
As strongly
typed as
possible
Cache is learning

18. CALLSITE<T>
static CallSite<Func<CallSite, object, int, bool>> _site = …;
if (_site.Target(_site, x, 0)) { … }
if (x == 0) { … }
static bool _2(Site site, object x, int y) {
if (x is int) {
return (int)x == y;
} else if (x is BigInteger) {
return BigInteger.op_Equality((BigInteger)x, y);
} else {
return site.Update(site, x, y); //tailcall
}
}

19. DynamicMetaObject
public class DynamicMetaObject
{
public BindingRestrictions Restrictions { get; }
public Expression Expression { get; }
public bool HasValue { get; }
public object Value { get; }
public Type RuntimeType { get; }
public virtual DynamicMetaObject BindGetMember(GetMemberBinder b);
public virtual DynamicMetaObject BindSetMember(SetMemberBinder b,
DynamicMetaObject value);
public virtual DynamicMetaObject BindDeleteMember(DeleteMemberBinder b);
// Other bind operations…
}

20. Show me Dynamic C#

21. Ruby’s Markup Builder is an example of
what can be achieved with
method missing
b = Builder::XmlMarkup.new
html = b.html {
b.head {
b.title "XML Builder Test"
}
b.body {
b.h1 "Title of Page“
b.p "Sample paragraph text“
b.p "Sample paragraph text“
}
}
<head>
<title>XML Builder Test</title>
- <body>
<h1>Title of Page</h1>
<p>Sample paragraph text</p>
<p>Sample paragraph text</p>
</body>
</head>

22. class User < ActiveRecord::Base; end
users = User.find_all_by_state("TX")
user = User.find_or_create_by_email("foo@bar.com")

24. by @AntyaDev

25. Oak
Frictionless development
for ASP.NET MVC single
page web apps.
Prototypical and dynamic
capabilities brought to C#.

26. STATIC TYPING WHERE POSSIBLE,
DYNAMIC TYPING WHEN NEEDED

27. LINKS
• KingAOP: https://github.com/AntyaDev/KingAOP
• Simple.Data: https://github.com/markrendle/Simple.Data
• Massive: https://github.com/robconery/massive
• CarealBox: https://github.com/JonCanning/CerealBox
• Oak: http://amirrajan.github.io/Oak/

28. https://twitter.com/AntyaDev
https://github.com/AntyaDev
http://antyadev.blogspot.com/
THANK YOU!