Operators.swift

import Foundation
import SourceKittenFramework

let source = """
// Diamond operator
infix operator <>

func <> <A: AnyObject>(f: @escaping (A) -> Void, g: @escaping (A) -> Void) -> (A) -> Void {
return { a in
f(a)
g(a)
}
}

infix operator |>

func |> <A, B>(x: A, f: (A) -> B) -> B {
return f(x)
}
"""

struct CoolOperator {
    let name: String
    let readableName: String
}

let knownOperators = [
    CoolOperator(name: "<>", readableName: "Diamond"),
    CoolOperator(name: "|>", readableName: "Pipe")
]


try (Structure(file: File(contents: source))
    .dictionary["key.substructure"] as? [SourceKitRepresentable])?
    .flatMap { $0 as? [String: SourceKitRepresentable]}
    .filter { $0["key.kind"]?.isEqualTo("source.lang.swift.decl.function.free") ?? false }
    .flatMap { ($0["key.name"] as? String)?.split(separator: "(").first }
    .forEach { op in
        if let found = knownOperators.first(where: { op == $0.name }) {
            print("Found \(found.readableName) operator!")
        }
        
    }