PassByConstruction
From Erights
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This code should be positioned in a file in the java classpath at the location "tests.makeVector.emaker" | This code should be positioned in a file in the java classpath at the location "tests.makeVector.emaker" | ||
| - | <code> | + | <code>def makeVector implements pbc { |
| - | def makeVector implements pbc { | + | |
to run(var x, var y) { | to run(var x, var y) { | ||
def vector implements pbc { | def vector implements pbc { | ||
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return [<import>, "get", ["tests.makeVector"]] | return [<import>, "get", ["tests.makeVector"]] | ||
} | } | ||
| - | } | + | }</code> |
| - | </code> | + | |
Example of usage: | Example of usage: | ||
| - | <code> | + | <code>#create a new Vector object |
| - | #create a new Vector object | + | |
? def makeVector := <import:tests.makeVector&lgt; | ? def makeVector := <import:tests.makeVector&lgt; | ||
# value: <makeVector> | # value: <makeVector> | ||
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# value: <Remote Promise> | # value: <Remote Promise> | ||
| - | ? Thing: <Vector 6.6 7.7> | + | ? Thing: <Vector 6.6 7.7></code> |
| - | + | ||
| - | </code> | + | |
Revision as of 10:28, 18 April 2007
An object declared as, for example
def foo implements pbc {
to __optUncall() { return [1, "add", [2]] }
# ...
}
will be passed-by-construction across CapTP. This means that its __optUncall() method will be called on the sending side, the elements of the result triple will be passed, and the corresponding triple as received will be called (here, as “E.call(1, "add", [2])”) to create the object as received.
Example
The first part of the example is a maker for a 2D Vector. The created vectors are Pass By Construction, they should pass the guard :pbc. The method __optUncall is a [Miranda_Method miranda method]. When the vector is copied to another [vat], the method __optUncall is called by the CapTP networking subsystem of E. The result of the method is used to recreate the object in the destination [vat]. This code should be positioned in a file in the java classpath at the location "tests.makeVector.emaker"
def makeVector implements pbc {
to run(var x, var y) {
def vector implements pbc {
to getX() :any { return x }
to getY() :any { return y }
to __optUncall() :any { return [makeVector, "run", [x,y]] }
to __printOn(out) {out.print(`<Vector $x $y>`)}
}
return vector
}
to __optUncall() :any {
return [<import>, "get", ["tests.makeVector"]]
}
}
Example of usage:
#create a new Vector object
? def makeVector := <import:tests.makeVector&lgt;
- value: <makeVector>
? def vector := makeVector(6.6,7.7)
- value: <Vector 6.6 7.7>
- create a new vat
? introducer.onTheAir()
- value: ["3DES_SDH_M2", "3DES_SDH_M"]
? def seedVatAuthor := <elang:interp.seedVatAuthor>(<unsafe>).virtualize((introducer))
- value: <virtualSeedVat>
- source code for the new vat
? def scriptSource:="def run(thing :pbc) {println(`Thing: $thing`)}"
- value: "def run(thing :near) {println(`Thing: $thing`)}"
? def [scriptObj, vat] := seedVatAuthor(scriptSource)
- value: [<Promise>, <Vat newVirtualSeedVat in <runs in newVirtualSeedVat>>]
? scriptObj <- run(vector)
- value: <Remote Promise>
? Thing: <Vector 6.6 7.7>
