[euwren](https://github.com/liquid600pgm/euwren) uses macros to create a DSL
that allows its users to easily add scripting support to their programs.
import euwren
type
Greeter = object
target*: string
proc newGreeter(target: string): Greeter = Greeter(target: target)
proc greet(greeter: Greeter) = echo "Hello, " & greeter.target & "!"
var wren = newWren()
wren.foreign("greeter"):
Greeter:
[new] newGreeter
greet
wren.ready()
Run
Then, scripts like this can be executed using `wren.run(sourceCode)`:
import "greeter" for Greeter
var greeter = Greeter.new("world")
greeter.greet() // -> Hello, world!
greeter.target = "Nim"
greeter.greet() // -> Hello, Nim!
Run
Because Wren is a C library, you'd normally have to deal with a low-level,
verbose API full of passing pointers around and other unsafe things. euwren
abstracts that away, and provides a much more user friendly API that doesn't
require non-idiomatic code to be used.
euwren's `foreign()` is a prime example of how macros can lead to cleaner and
more maintainable code: reading a list of names is much easier than reading
through a bunch of `addProc` and `addClass` calls with low level procs mixed
inbetween. This makes every proc you bind consistently the same, no matter what
it is, which embraces the DRY rule.
