Portafilter does one thing: it evaluates an expression and returns a value. An expression can be evaluated on different implementations
across multiple languages and will always return the same result. This makes it possible to re-use the same semantics in separate application tiers,
and that's really quite rad.
This is the JavaScript implementation of Portafilter. The standard lib is pretty bare at the moment, but it's the easiest part to build.
SO: in <12hrs I wrote & tested this implementation from scratch. I guess this shows that it's an easy-to-port language!
Here's what it can do right now:
// the only function I implemented is "+"... 'let' and 'f' are language constructs
1 + 2 // 3
let(a = 1, b = 2) a + b // 3
f(a, b) { a + b }(1, 2) // 3
let(a = 40 + 2, b = 13) let(c = a + b) c + 5 // 60
Here's what it'll be able to do soon:
// just need to add the ">" and "?" functions to the std lib (they already parse)
user.age > 18 ? "beer" : "water"
// functions are first-class citizens
let(youngPopular = users.filter(f(u) {
tweets.length < 100 && followers.length > 10000
}))
map(youngPopular, f(u) {
u.username
})
Oh, ALSO: you can already do this: you can serialize expression to JSON.
expr("1 + 2").serialize("X") => ["X", "`", ["X", "~", "+"], [1, 2]]
This means you can embed Portafiler expressions directly in JSON documents:
var foo = {
"class": "character",
"fields": ["str", "dex", "con", "int", "wis", "cha"],
"check": expr("map(fields, f(stat) { stat > 7 && stat < 13 })").serialize(uuid)
};
www.post(server, foo);