PassByConstruction
From Erights
m |
m |
||
| Line 15: | Line 15: | ||
<code> | <code> | ||
| - | |||
def makeVector implements pbc { | def makeVector implements pbc { | ||
to run(var x, var y) { | to run(var x, var y) { | ||
| Line 22: | Line 21: | ||
to getY() :any { return y } | to getY() :any { return y } | ||
to __optUncall() :any { return [makeVector, "run", [x,y]] } | to __optUncall() :any { return [makeVector, "run", [x,y]] } | ||
| - | to __printOn(out) {out.print(` | + | to __printOn(out) {out.print(`<Vector $x $y>`)} |
} | } | ||
return vector | return vector | ||
| Line 30: | Line 29: | ||
} | } | ||
} | } | ||
| - | |||
</code> | </code> | ||
| Line 36: | Line 34: | ||
<code> | <code> | ||
| - | |||
#create a new Vector object | #create a new Vector object | ||
| - | ? def makeVector := | + | ? def makeVector := <import:tests.makeVector&lgt; |
| - | # value: | + | # value: <makeVector> |
? def vector := makeVector(6.6,7.7) | ? def vector := makeVector(6.6,7.7) | ||
| - | # value: | + | # value: <Vector 6.6 7.7> |
#create a new vat | #create a new vat | ||
| Line 48: | Line 45: | ||
# value: ["3DES_SDH_M2", "3DES_SDH_M"] | # value: ["3DES_SDH_M2", "3DES_SDH_M"] | ||
| - | ? def seedVatAuthor := | + | ? def seedVatAuthor := <elang:interp.seedVatAuthor>(<unsafe>).virtualize((introducer)) |
| - | # value: | + | # value: <virtualSeedVat> |
# source code for the new vat | # source code for the new vat | ||
| Line 56: | Line 53: | ||
? def [scriptObj, vat] := seedVatAuthor(scriptSource) | ? def [scriptObj, vat] := seedVatAuthor(scriptSource) | ||
| - | # value: [ | + | # value: [<Promise>, <Vat newVirtualSeedVat in <runs in newVirtualSeedVat>>] |
| - | ? scriptObj | + | ? scriptObj <- run(vector) |
| - | # value: | + | # value: <Remote Promise> |
| - | ? Thing: | + | ? Thing: <Vector 6.6 7.7> |
</code> | </code> | ||
Revision as of 10:26, 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>
