func main(args: String[]) {
    let b = "A"
    if true {
        print(b)
        let b = 1
        print(b)
    }
}

set: id -> store & return mangled id
get: mangledId -> return value
get: normalId -> for each (mangled id) compare w/ original

> mkdir -p lib/vsl/parser && nearleyc src/vsl/parser/grammar/parser.ne -o lib/vsl/parser/parser.es6.js && babel lib/vsl/parser/parser.es6.js -o lib/vsl/parser/parser.js

SyntaxError: lib/vsl/parser/parser.es6.js: Invalid left-hand side in assignment expression (72:33)
  70 |         ], [
  71 |             [[3], id],
> 72 |             [[3, "<", 15, ">"], (d, l) =? new t.Generic(d[0], d[2])]
     |                                  ^
  73 |         ], [
  74 |             [[2, ".", 2]]
  75 |         ], [

class Generator { let expressionCount = 0 }

%0 = mul i32 1 i32 2