Slides from talk for Code Generation 2013 in Cambridge. Most of the presentation was a live demonstration and is not reflected in the slides. Slide 5 is the code that we ended up developing during the presentation.

1. NaBL: A Meta-Language for
Declarative Name Binding
and Scope Rules
Gabriël Konat, Lennart Kats,
Guido Wachsmuth, Eelco Visser

2. Name Binding and Scope
function power(x: Int, n: Int): Int {
if(n == 0) {
return 1;
} else {
return x * power(x, n - 1);
}
}

3. Context: Spoofax Language Workbench
http://spoofax.org

4. Demonstration of NaBL in Spoofax

5. module names rules // properties and variables
imports include/Cam Property(name, t, _):
defines Property name of type t
namespaces
Module Type Property Variable Function Var(name):
refers to Variable name
rules // modules refers to Property name
Module(name, _): VarDeclInit(name, t, _):
defines Module name defines Variable name of type t
scopes Type in subsequent scope
rules // entities and types VarDecl(name, t):
defines Variable name of type t
Entity(name, _, _, _):
defines Type name Arg(name, t):
scopes Type, Property, Function, Variable defines Variable name of type t
Type0(name): rules // functions and calls
refers to Type name
FunDef(name, arg*, t, _):
Type(name, _): defines Function name of type (t*, t)
refers to Type name scopes Variable
where arg* has type t*
TypeParam(name):
defines Type name FunDecl(name, arg*, t):
defines Function name of type (t*, t)
scopes Variable
where arg* has type t*
ThisCall(name, _):
refers to Function name
Name binding and scope MethCall(e, name, e*):
rules for Cam (toy) language refers to Function name in Type t_name
where e has type Type(t_name, _)

6. Name Binding Concepts
class
defines partial class
type
refers inheritance
namespaces
namespace
using
scopes
method
field
imports variable
parameter
block

7. Outlook
Language definition = CFG + NBD + TS + DS
Single source for
Language reference manual
Efficient (incremental) compiler
Execution engine (interpreter)
Integrated development environment

8. The Language Designer’s Workbench
NWO VICI 2012 grant: 1.5M Euro for 5 years
Declarative Language Definition
Syntax Name Type Dynamic
Transforms
Definition Binding System Semantics
Editor Correctness
Compiler Tests
(IDE) Proof
bridging the gap between language engineering and semantics engineering

9. 12th International Conference
on Generative Programming:
Concepts & Experiences
(GPCE'13)