[E-Lang] Thoughts on Persistence in E.

[steve jenson]

Whoops! I found a few mistakes. I actually pasted my message from
two seperate elmer sesssions. Let me rectify my mistakes:

Quoting steve jenson (stevej@sieve.net):

> Gang,
> 
> Having spent a few hours playing with persistence in E, using MarcS's
> persistent echat.e as a beginning point for Serializer/Unserializer semantics,
> as well as the org.erights.e.elib.serial package's source for other hints,
> I've come to recognize a few things sofar with E's persistence.
> 
> I'm trying to use proper UpDoc syntax so that this email is easily testable
> in an Elmer session. Serializer/Unserializer syntax is as follows:
> 
> 
> ? def ser__uriGetter := <unsafe:org.erights.e.elib.serial.*>
> # value: <unsafe:org.erights.e.elib.serial.*>
> 
> ? def Serializer := <ser:Serializer>
> # value: <unsafe:org.erights.e.elib.serial.Serializer>
> 
> ? def Unserializer := <ser:Unserializer>
> # value: <unsafe:org.erights.e.elib.serial.Unserializer>
> 
> ? var x := 1
> # value: 1
> 
> ? introducer onTheAir()
> # value: ["3DES_SDH_M2", "3DES_SDH_M"]
> 
> ? def counter {
> >     to incr() :any { x += 1}
> > }
> # value: <counter>
> 
> 
> ? counter incr()
> # value: 4
> 
> 
> ? def sr := sturdyRef(counter)
> # value: <SturdyRef>
> 
> ? var uri := introducer sturdyToURI(sr)
> # value: "cap://66.92.8.63:33525/5agVa4XHV5D3F9G2=Vfpdd_fVDy/09uX50LDIp3kWLQKA8Z_ahVcWu6w"
> 
> Define a filename now.
> 
> ? var filename := "/home/stevej/pickledCap.ser"
> # value: "/home/stevej/pickledCap.ser"
> 
> ? var file := <file: filename>
> # value: <file:/home/stevej/pickledCap.ser>
> 
> ? Serializer recordFile(file, [uri, sr])
> No output here.. 
> 
> ? def [newURI, newSR] := Unserializer playFile(file)
> # value: ["cap://66.92.8.63:33525/5agVa4XHV5D3F9G2=Vfpdd_fVDy/09uX50LDIp3kWLQKA8Z_ahVcWu6w", <SturdyRef>]
> 
> ? def farCounter := sr liveRef()
This should read as:

? def farCounter := newSr liveRef()
> # problem: <NullPointerException>
> #
> #   <SturdyRef> liveRef()
> #   <interactive interp> evalPrint(e`def farCounter :any := sr liveRef()`)

> ? println(uri)
> cap://66.92.8.63:33525/5agVa4XHV5D3F9G2=Vfpdd_fVDy/09uX50LDIp3kWLQKA8Z_ahVcWu6w
> 
> ? def newSR := introducer sturdyFromURI(uri)
Should read as:
? def newerSR := ...

> # value: <SturdyRef>
> 
> ? def farCounter := newSR liveRef()
again, newerSR
> # value: <Eventual ref>
> 
> ? def newX := farCounter <- incr()
> # value: <Eventual ref>
> 
> ? newX
> # value: 5

Sorry for the confusion. :-(


regards,
steve

-- 
steve jenson <stevej@sieve.net> http://sieve.net/
PGP fingerprint: 79D0 4836 11E4 A43A 0179  FC97 3AE2 008E 1E57 6138