Sync

You can use the sync expression to run two or more async expressions at the same time. For example:

# All three async functions effectively start at the same time
Results = sync:
    AsyncFunction1()  # task 1
    AsyncFunction2()  # task 2
    AsyncFunction3()  # task 3
# Called after all three tasks complete (regardless of order)
MyLog.Print("Done with list of results: {Results}")
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# All three async functions effectively start at the same time Results = sync: AsyncFunction1() # task 1 AsyncFunction2() # task 2 AsyncFunction3() # task 3 # Called after all three tasks complete (regardless of order) MyLog.Print("Done with list of results: {Results}")

The following code shows the syntax for the sync expression with an accompanying diagram that shows the execution flow of the expressions.

expression0
sync:
    slow-expression
    mid-expression
    fast-expression
expression1
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expression0 sync: slow-expression mid-expression fast-expression expression1

Sync Expression Use

At least two top-level expressions must be async.

sync:
    AsyncFunction1()
    MyLog.Print("Second top level expression")
    AsyncFunction2()
    MyLog.Print("Third top level expression")

sync:
    AsyncFunction1()
    # Error: expected at least two top-level expressions
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sync: AsyncFunction1() MyLog.Print("Second top level expression") AsyncFunction2() MyLog.Print("Third top level expression") sync: AsyncFunction1() # Error: expected at least two top-level expressions

Top-level expressions can be compound expressions, such as nested code blocks:

# sync may also have compound expressions
# with each top-level expression its own task
sync:
    block: # task 1
        # Evaluated in serial order
        AsyncFunction1a()
        AsyncFunction1b()
    block: # task 2
        AsyncFunction2a()
        AsyncFunction2b()
        AsyncFunction2c()
    AsyncFunction3() # task 3

# AsyncFunction1a(), AsyncFunction2a() and AsyncFunction3() all start essentially at the same time
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# sync may also have compound expressions # with each top-level expression its own task sync: block: # task 1 # Evaluated in serial order AsyncFunction1a() AsyncFunction1b() block: # task 2 AsyncFunction2a() AsyncFunction2b() AsyncFunction2c() AsyncFunction3() # task 3 # AsyncFunction1a(), AsyncFunction2a() and AsyncFunction3() all start essentially at the same time

Since tuples can be used as self-splatting arguments, sync expressions can be used directly as arguments since they have a tuple result. This allows async arguments to evaluate simultaneously, and the function they are being passed to is called when all the expressions in the sync code block are completed.

# All three coroutine arguments start their evaluation at the same time
DoStuff(sync{AsyncFunctionArg1(); AsyncFunctionArg2(); AsyncFunctionArg3()})

# Not every argument needs to be async - a minimum of two justifies the use of sync
DoOtherStuff(sync{AsyncFunctionArg1(); 42; AsyncFunctionArg2(); AsyncFunctionArg3()})
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# All three coroutine arguments start their evaluation at the same time DoStuff(sync{AsyncFunctionArg1(); AsyncFunctionArg2(); AsyncFunctionArg3()}) # Not every argument needs to be async - a minimum of two justifies the use of sync DoOtherStuff(sync{AsyncFunctionArg1(); 42; AsyncFunctionArg2(); AsyncFunctionArg3()})