async/await demo

asyncawait.boo

# Using Python/Mozilla style coroutine-like generators (yield as 
# expression) and Boo's metaprogramming facilities to easily model 
# asynchronous APIs (Promise/A based) into sequential code logic. 
# Avoiding the need to for nested callbacks and handling error 
# conditions with standard try/except blocks.
#
# Change the ENDPOINT variable to an invalid URL to check the 
# error handling.
#

import Async
import Browser(alert)
import Api.jQuery as jq

[async] def foo():
    global ENDPOINT
    status = jq('#status')
    status.html('start')
    try:
        result = jq('#result')
        
        status.html('Fetching remote resource waiting 3 seconds at least')
        await data, delay = jq.post(ENDPOINT, {'html': 'Hello World!'}), sleep(3s)
            
        status.html('Remote resource fetched')
        result.html(data)            
        await result.fadeIn(delay).promise()
            
        status.html("Sleeping for $delay milliseconds")
        await sleep(delay)
        result.fadeOut()        
    except:
        alert('Error downloading')

    status.html('end')

            
foo();