Parameterize Preserve type

src/syndicate.nim

@@ -1,14 +1,11 @@
-# SPDX-License-Identifier: ISC
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
 
 import std/[asyncdispatch, macros, options]
 import preserves, preserves/records
 import syndicate/[assertions, dataspaces, events, skeletons]
 
-export preserves.`%`
 export preserves.fromPreserve
-export records.init
-export assertions.`?_`
-export assertions.`?*`
 export assertions.Observe
 export dataspaces.Facet
 export dataspaces.FieldId
@@ -128,7 +125,7 @@ proc onEvent(event: EventKind, pattern, handler: NimNode): NimNode =
       proc getCurrentFacet(): Facet {.inject, used.} = facet
       `handler`
       let a = `pattern`
-      result.assertion = Observe.init(a)
+      result.assertion = observe(a)
       result.analysis = some(analyzeAssertion(a))
       result.callback = wrap(facet, EventKind(`event`), `handlerSym`)
 
@@ -197,13 +194,13 @@ template withFacet*(f: Facet; body: untyped): untyped =
   ## Execute a Syndicate ``body`` using the ``Facet`` at ``f``.
   runnableExamples:
     import preserves, preserves/records
-    type Foo = ref object
+    type Foo {.record: "foo".} = ref object
       facet: Facet
       i: int
     proc incAndAssert(foo: Foo) =
       inc(foo.i)
       withFacet foo.facet:
-        react: assert: initRecord("Foo", %foo.i)
+        react: assert: foo
   proc getCurrentFacet(): Facet {.inject, used.} = f
   body
 
@@ -219,3 +216,13 @@ type BootProc* = proc (facet: Facet) {.gcsafe.}
 template boot*(module: BootProc) =
   mixin getCurrentFacet
   module(getCurrentFacet())
+
+macro `?`*(x: untyped): untyped =
+  ## Sugar for generating Syndicate patterns.
+  ## `?_` is a pattern that matches but discards arbitrary
+  ## values and `?` combined with any other identifier is
+  ## a match and capture.
+  if eqIdent(x, "_"):
+    quote: toPreserve(Discard())
+  else:
+    quote: toPreserve(Capture())

src/syndicate/assertions.nim

@@ -1,21 +1,29 @@
-# SPDX-License-Identifier: ISC
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
 
-import preserves, preserves/records
+import std/options
+import preserves
 
-const
-  Discard* = RecordClass(label: symbol"discard", arity: 0)
-  Capture* = RecordClass(label: symbol"capture", arity: 1)
-  Observe* = RecordClass(label: symbol"observe", arity: 1)
-  #Inbound* = RecordClass(label: symbol"inbound", arity: 1)
-  #Outbound* = RecordClass(label: symbol"outbound", arity: 1)
-  #Instance* = RecordClass(label: symbol"instance", arity: 1)
+type
+  Discard* {.record: "discard", pure.}  = object
+    discard
 
-  `?_`* = initRecord("discard")
-  `?*`* = Capture % `?_`
+  Capture* {.record: "capture", pure.} = object
+    _: Discard
+
+  Observe* {.record: "observe", pure.} = object
+    pattern: Preserve
+
+proc observe*[T](x: T): Preserve =
+  Observe(pattern: x.toPreserve).toPreserve
 
 proc captureCount*(pattern: Preserve): int =
-  if Capture.isClassOf pattern:
+  if pattern.preserveTo(Capture).isSome:
     result = 1
   else:
     for e in pattern.items:
       result.inc captureCount(e)
+
+when isMainModule:
+  let a = observe(`?*`)
+  assert($toPreserve(a) == "<capture <discard>>")

src/syndicate/dataspaces.nim

@@ -1,4 +1,5 @@
-# SPDX-License-Identifier: ISC
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
 
 import ./bags, ./dataflow, ./events, ./skeletons
 import preserves
@@ -70,7 +71,7 @@ type
 
   Field* = object of RootObj
     id*: FieldId
-  Fields* = seq[Preserve]
+  Fields* = seq[Value]
     # TODO: compile-time tuples
 
   Turn = object
@@ -403,7 +404,7 @@ proc initActivationAction(script: ActivationScript; name: string): Action =
     ds.activations.add(script)
     proc boot(root: Facet) =
       root.addStartScript(script)
-    ds.addActor(name, boot, Preserve(kind: pkSet), actor)
+    ds.addActor(name, boot, Value(kind: pkSet), actor)
   Action(impl: impl, kind: activationAction)
 
 proc activate(facet; name: string; script: ActivationScript) =
@@ -547,15 +548,15 @@ template declareField*(facet: Facet; F: untyped; T: typedesc; initial: T): untyp
   let fieldOff = facet.fields.high
   proc set(f: DistinctField; x: T) {.used.} =
     facet.actor.dataspace.dataflow.recordDamage(f.id)
-    facet.fields[fieldOff] = toPreserve[T](x)
-  proc set(f: DistinctField; x: Preserve) {.used.} =
+    facet.fields[fieldOff] = toPreserve(x)
+  proc set(f: DistinctField; x: Value) {.used.} =
     facet.actor.dataspace.dataflow.recordDamage(f.id)
     facet.fields[fieldOff] = x
   proc get(f: DistinctField): T {.used.} =
     facet.actor.dataspace.dataflow.recordObservation(f.id)
-    if not fromPreserve[T](result, facet.fields[fieldOff]):
+    if not fromPreserve(result, facet.fields[fieldOff]):
       raise newException(ValueError, "cannot convert field " & $F & " to " & $T)
-  proc getPreserve(f: DistinctField): Preserve {.used.} =
+  proc getPreserve(f: DistinctField): Value {.used.} =
     facet.actor.dataspace.dataflow.recordObservation(f.id)
     facet.fields[fieldOff]
 

src/syndicate/drivers/timers.nim

@@ -2,7 +2,7 @@
 
 import std/[asyncdispatch, monotimes, times]
 import preserves, preserves/records
-import syndicate
+import syndicate, syndicate/assertions
 
 type TimeLaterThan* {.record: "TimeLaterThan".} = object
     `deadline`*: Monotime
@@ -21,7 +21,7 @@ proc fromPreserveHook*(mt: var Monotime; p: Preserve): bool =
 syndicate timerDriver:
 
   spawn "timer":
-    during(Observe % (prsTimeLaterThan(`?*`))) do (deadline: MonoTime):
+    during(observe(prsTimeLaterThan(?deadline))) do (deadline: MonoTime):
       let
         now = getMonoTime()
         period = inMilliseconds(deadline - now)

src/syndicate/skeletons.nim

@@ -1,4 +1,5 @@
-# SPDX-License-Identifier: ISC
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
 
 import ./assertions, ./bags, ./events
 import preserves, preserves/records
@@ -36,9 +37,9 @@ proc projectPaths(v: Value; paths: seq[Path]): seq[Value] =
 proc analyzeAssertion*(a: Value): Analysis =
   var path: Path
   proc walk(analysis: var Analysis; a: Value): Skeleton[Shape] =
-    if Discard.isClassOf a:
+    if a.preserveTo(Discard).isSome:
       discard
-    elif Capture.isClassOf a:
+    elif a.preserveTo(Capture).isSome:
       analysis.capturePaths.add(path)
       result = walk(analysis, a.fields[0])
     else:

syndicate.nimble

@@ -9,4 +9,4 @@ srcDir        = "src"
 
 # Dependencies
 
-requires "nim >= 1.4.8", "preserves >= 0.3.0"
+requires "nim >= 1.4.8", "preserves >= 1.0.0"

tests/box_and_client.nim

@@ -1,9 +1,10 @@
 
-## Date of generation: 2021-08-28 10:14
+## Date of generation: 2021-09-01 13:32
 import
   std/typetraits, preserves
 
 type
+  EmbeddedType = void
   BoxState* {.record: "box-state".} = object ## ``<box-state @value int>``
     `value`*: BiggestInt
 
@@ -11,7 +12,9 @@ type
     `value`*: BiggestInt
 
 proc prsBoxState*(value: Preserve | BiggestInt): Preserve =
-  initRecord(symbol("box-state"), value)
+  initRecord[EmbeddedType](symbol("box-state", EmbeddedType),
+                           toPreserve(value, EmbeddedType))
 
 proc prsSetBox*(value: Preserve | BiggestInt): Preserve =
-  initRecord(symbol("set-box"), value)
+  initRecord[EmbeddedType](symbol("set-box", EmbeddedType),
+                           toPreserve(value, EmbeddedType))

tests/test_box_and_client.nim

@@ -8,9 +8,9 @@ import ./box_and_client
 
 const N = 100000
 
-const
-  `?_` = init(Discard)
-  `?$` = init(Capture, `?_`)
+let
+  `?_` = Discard().toPreserve
+  `?$` = Capture().toPreserve
 
 proc boot(facet: Facet) =
 
@@ -28,19 +28,19 @@ proc boot(facet: Facet) =
           echo "terminated box root facet"
 
     facet.addEndpoint do (facet: Facet) -> EndpointSpec:
-      const a = prsSetBox(`?$`)
+      let a = prsSetBox(`?$`)
       result.analysis = some analyzeAssertion(a)
       proc cb(facet: Facet; vs: seq[Value]) =
         facet.scheduleScript do (facet: Facet):
           value.set(vs[0])
           # echo "box updated value ", vs[0]
       result.callback = facet.wrap(messageEvent, cb)
-      result.assertion = Observe.init(prsSetBox(`?$`))
+      result.assertion = observe(prsSetBox(`?$`))
 
   facet.spawn("client") do (facet: Facet):
 
     facet.addEndpoint do (facet: Facet) -> EndpointSpec:
-      const a = prsBoxState(`?$`)
+      let a = prsBoxState(`?$`)
       result.analysis = some analyzeAssertion(a)
       proc cb(facet: Facet; vs: seq[Value]) =
         facet.scheduleScript do (facet: Facet):
@@ -48,16 +48,16 @@ proc boot(facet: Facet) =
           # echo "client sending ", v
           facet.send(v)
       result.callback = facet.wrap(addedEvent, cb)
-      result.assertion = Observe.init(prsBoxState(`?$`))
+      result.assertion = observe(prsBoxState(`?$`))
 
     facet.addEndpoint do (facet: Facet) -> EndpointSpec:
-      const a = prsBoxState(`?_`)
+      let a = prsBoxState(`?_`)
       result.analysis = some analyzeAssertion(a)
       proc cb(facet: Facet; vs: seq[Value]) =
         facet.scheduleScript do (facet: Facet):
           echo "box gone"
       result.callback = facet.wrap(removedEvent, cb)
-      result.assertion = Observe.init(prsBoxState(`?_`))
+      result.assertion = observe(prsBoxState(`?_`))
 
   facet.actor.dataspace.ground.addStopHandler do (_: Dataspace):
     echo "stopping box-and-client"

tests/test_dsl.nim

@@ -1,7 +1,8 @@
-# SPDX-License-Identifier: ISC
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
 
-import asyncdispatch
-import preserves, preserves/records
+import std/asyncdispatch
+import preserves
 import syndicate
 
 import ./box_and_client
@@ -13,7 +14,7 @@ syndicate testDsl:
     asserting prsBoxState(currentValue.get)
     stopIf currentValue.get == 10:
       echo "box: terminating"
-    onMessage(prsSetBox(`?*`)) do (newValue: int):
+    onMessage(prsSetBox(?newValue)) do (newValue: int):
       # The SetBox message is unpacked to `newValue: int`
       echo "box: taking on new value ", newValue
       currentValue.set(newValue)
@@ -21,10 +22,10 @@ syndicate testDsl:
   spawn "client":
     #stopIf retracted(observe(SetBox, _)):
     #  echo "client: box has gone"
-    onAsserted(prsBoxState(`?*`)) do (v: BiggestInt):
+    onAsserted(prsBoxState(?v)) do (v: BiggestInt):
       echo "client: learned that box's value is now ", v
       send(prsSetBox(v.succ))
-    onRetracted(prsBoxState(`?_`)) do (_):
+    onRetracted(prsBoxState(?_)) do (_):
       echo "client: box state disappeared"
     onStop:
       quit(0) # Quit explicitly rather than let the dispatcher run empty.