amber/src/Kernel-Promises.st

Smalltalk createPackage: 'Kernel-Promises'!
Object subclass: #Thenable
	instanceVariableNames: ''
	package: 'Kernel-Promises'!
!Thenable commentStamp!
I am the abstract base class for Promises.

My subclasses should wrap existing JS implementations.

I contain methods that wrap Promises/A+ `.then` behaviour.!

!Thenable methodsFor: 'promises'!

all: nadicBlock
<return self.then(function (array) {
    return nadicBlock._valueWithPossibleArguments_(array);
})>
!

catch: aBlock
<return self.then(null, function (err) {
    return aBlock._value_(err);
})>
!

on: aClass do: aBlock
<return self.then(null, function (err) {
    if (err._isKindOf_(aClass)) return aBlock._value_(err);
    else throw err;
})>
!

on: aClass do: aBlock catch: anotherBlock
<return self.then(null, function (err) {
    try { if (err._isKindOf_(aClass)) return aBlock._value_(err); } catch (e) { err = e; }
    return anotherBlock._value_(err);
})>
!

then: aBlock
<return self.then(function (result) {
    return aBlock._value_(result);
})>
! !