Hello world
"Hello world!" print
Factorial
Number factorial := method(n := 1; for(i, 1, self, n = n * i); n)
Vectorized Factorial
Number factorial := method(Vector clone setSize(self) rangeFill product)
99 bottles of beer
bottle := method(i,
if(i == 0, return "no more bottles")
if(i == 1, return "1 bottle")
return "" .. i .. " bottles"
)
for(i, 99, 1,
writeln(i, " of beer on the wall, ", i, " of beer,")
writeln("take one down, pass it around,")
writeln(bottle(i - 1), " of beer on the wall.")
)
Create a simple object and show how to use it
Account := Object clone do(
balance := 0
deposit := method(v, balance = balance + v)
withdraw := method(v, balance = balance - v)
show := method(writeln("Account balance: $", balance))
)
myAccount := Account clone
myAccount show
"Depositing $10\n" print
myAccount deposit(10)
myAccount show
Concurrency example - the following will print "112233"
o1 := Object clone
o1 test := method(for(n, 1, 3, n print; yield))
o2 := o1 clone
// @ means send an asynchronous message
o1 @test; o2 @test
// here we pause the main coroutine
// the process will exit after async messages are processed and there
// are no yielding coroutines to be switched to
Coroutine currentCoroutine pause
Look up a class/prototype given its name as a string
Lobby getSlot("PrototypeName")
Execute a method given its name as a string
anObject perform("SomeMethodName", arg1, arg2)
Find out if a method with a given name (again a string) exists
anObject hasSlot("SomeMethodName")
Given an arbitrary reference to a class/prototype, instantiate it
newInstance := objectRef clone
Add a method to a primitive
Number double := method(self * 2)
1 double
==> 2
Subclass a primitive
MyList := List clone // Same as creating an instance
Iterate through an inheritance hierarchy
Object printAllSlots := method(
self slotNames foreach(slotName,
writeln(slotName)
if(self hasSlot("proto"), self proto printAllSlots)
)
)
Object printAllSlots
Implement a generic proxy
Proxy = Object clone
Proxy forward := method(
methodName := call message name
args := call message argsEvaluatedIn(call sender)
// When an unrecognized message is received,
// this method will be invoked.
// Do what you like with the message here -
// such as send it over a network, etc.
)
Implement a singleton
Foo := Object clone
Foo clone := Foo
Print the source code of a method
myMethod := method(return testing(1+2+3))
getSlot("myMethod") code print
==> "return(testing(1+(2)+(3)))"
Add an operator method to an object
MyObject := Object clone
MyObject setSlot("+", method(n, write("adding ", n, "\n")))
MyObject + 123
==> "adding 123"
Mixins and Aspects
Mix := Object clone
Mix logData := Buffer clone
Mix init := method(logData = logData clone)
Mix log := method(s, logData append(s))
a := Object clone
a appendProto(Mix clone) // Now a also inherits the state and behavior of Mix
b := Object clone
b appendProto(Mix clone) // Now multiple objects use it so it's an "aspect"
An auto source file importer
Object searchPaths = List clone append(launchPath)
Object forward := method(
methodName := thisMessage name
if (methodName characterAt(0) isUpperCase,
searchPaths foreach(searchPath,
fileName := Path with(searchPath, methodName .. ".io")
sourceFile := File clone setPath(fileName)
if (sourceFile exists) then(
Lobby doFile(path)
return Lobby getSlot(methodName)
)
)
)
Exception raise("Importer: Could not find slot for " .. methodName)
)
Fetch a URL and find the links in it
aString := URL with("http://www.yahoo.com/") fetch
links := aString asXML elementsWithName("a") map(attributes at("href"))
A simple whois client
whois := method(host,
socket := Socket clone setHostName("rs.internic.net") setPort(43)
socket connect streamWrite(host, "\n")
while(socket streamReadNextChunk, nil) // sockets auto yield to other coros
return socket readBuffer
)
A minimal web server
WebRequest := Object clone do(
handleSocket := method(aSocket,
aSocket streamReadNextChunk
request := aSocket readBuffer betweenSeq("GET ", " HTTP")
f := File with(request)
if(f exists, f streamTo(aSocket), aSocket streamWrite("not found"))
aSocket close
)
)
WebServer := Server clone do(
setPort(8000)
handleSocket := method(aSocket,
WebRequest clone @handleSocket(aSocket)
)
)
WebServer start
OpenGL
See the Io versions of the NeHe OpenGL tutorials.
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