FAST 2021 Demo

FAST 2021 Demo
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Material used for F.A.S.T 2021 Demo in the Constant Refinement and Continuing Progress at Instantiations presentation.

License

• The code is licensed under MIT.
• The documentation is licensed under CC BY-SA 4.0.

Installation

1. Install VA Smalltalk 10.0.1 or newer.
2. Install Tonel support in your development image following this guide.
3. Clone this repository.
4. The easiest and recommended approach is to install it via a script:

| loader path |
path := (CfsPath named: '<insert path to root fast2021-futures-demo-vast local repo here>').
loader := TonelLoader readFromPath: path.
loader
	beUnattended; "do not prompt and use all defaults"
	useGitVersion.
loader loadAllMapsWithRequiredMaps.

Or you can load the Configuration Map FAST 2021 - Demo Runtime from the context menu of the Configuration Maps Browser: "Import" -> "Load Configuration Maps from Tonel repository..." -> select path to root fast2021-futures-demo-vast local repo. This will open a dialog and will use convenient defaults for the load. Refer to its documentation for more details.

Examples

Here are some of the examples used during the demo:

Futures - Basic

"A Future represents the completion of a computation."

|  computeFactorialFuture computeFactorialPlus3Future computeFactorialPlus5Future |
computeFactorialFuture := EsFuture on: [5 factorial]. "or [ 5 factorial ] async"
computeFactorialPlus3Future := computeFactorialFuture then: [:factorial |  TranscriptTTY default show: (factorial + 3) printString; cr].
computeFactorialPlus5Future := computeFactorialFuture then: [:factorial |  TranscriptTTY default show: (factorial + 5) printString; cr].
(EsFuture all: { computeFactorialPlus3Future. computeFactorialPlus5Future. } )
	then: [ TranscriptTTY default show: 'I am done!'; cr ]  

Futures - Exceptions

((EsFuture on: [Exception signal: 'oh no' "throw error somewhere in the async code" ])
	catch: [:exception :stack | TranscriptTTY default show: 'Caught error: ', exception messageText ; cr])
		ensure: [TranscriptTTY default show: 'Finished!'; cr]

Promises - Basic

"A promise to complete a future in a later time"

| future promise |
promise := EsPromise new.
future := promise future.
future then: [:number | TranscriptTTY default show: number printString].
promise complete: 42.  

Promises - OsProcess

(OsProcessStarter start: #('sleep' '5')) onCompletion
	then: [TranscriptTTY default show: 'Process finished' ]

Demo

For the demo, checkout the methods #syncProcessCovidData and #asyncProcessCovidData