Get method names for an Objective-C class in Swift

methodNames.swift

import Foundation

/// Given pointer to first element of a C array, invoke a function for each element
func enumerateCArray<T>(array: UnsafePointer<T>, count: UInt32, f: (UInt32, T) -> ()) {
    var ptr = array
    for i in 0..<count {
        f(i, ptr.memory)
        ptr = ptr.successor()
    }
}

/// Return name for a method
func methodName(m: Method) -> String? {
    let sel = method_getName(m)
    let nameCString = sel_getName(sel)
    return String.fromCString(nameCString)
}

/// Print the names for each method in a class
func printMethodNamesForClass(cls: AnyClass) {
    var methodCount: UInt32 = 0
    let methodList = class_copyMethodList(cls, &methodCount)
    if methodList != nil && methodCount > 0 {
        enumerateCArray(methodList, methodCount) { i, m in
            let name = methodName(m) ?? "unknown"
            println("#\(i): \(name)")
        }

        free(methodList)
    }
}

/// Print the names for each method in a class with a specified name
func printMethodNamesForClassNamed(classname: String) {
    // NSClassFromString() is declared to return AnyClass!, but should be AnyClass?
    let maybeClass: AnyClass? = NSClassFromString(classname)
    if let cls: AnyClass = maybeClass {
        printMethodNamesForClass(cls)
    }
    else {
        println("\(classname): no such class")
    }
}

println("NonExistentClass:")
printMethodNamesForClassNamed("NonExistentClass")

println("\nNSObject:")
printMethodNamesForClassNamed("NSObject")

println("\nNSString:")
printMethodNamesForClass(NSString)

here's a more to date version for Swift 5.8

/// Print the names for each method in a class
func printMethodNamesForClass(cls: AnyClass) {
	var methodCount: UInt32 = 0
	guard let methodList = class_copyMethodList(cls, &methodCount) else { return }
	for m in UnsafeBufferPointer(start: methodList, count: Int(methodCount)) {
		print(method_getName(m).description)
	}
	free(methodList)
}

/// Print the names for each method in a class with a specified name
func printMethodNamesForClassNamed(classname: String) {
	// NSClassFromString() is declared to return AnyClass!, but should be AnyClass?
	let maybeClass: AnyClass? = NSClassFromString(classname)
	if let cls: AnyClass = maybeClass {
		printMethodNamesForClass(cls: cls)
	}
	else {
		print("\(classname): no such class")
	}
}