[net] transitionEntryFire -- try to fire one transition entry

TODO.md

@@ -1,14 +1,16 @@
 # net
 
-[net] `fireTransitionEntry` -- try to fire one transition entry
-
-[net] `run`
+[net] `react`
 
 - when we add a data into a place,
   all the neighboring transitions are checked for preparedness,
   prepared transitions are executed
   -- let's not handle non-deterministic for now.
 
+[net] transitionEntryPutOutputs -- error handling
+
+- task should have more information
+
 # type system
 
 Type -- simple structrual type system -- for JSON

src/lang/net/transitionEntryFire.ts

@@ -0,0 +1,45 @@
+import { TransitionEntry } from "./Net"
+
+export type FiringResult = "Fired" | "NotFired" | "FiringError"
+
+export async function fireTransitionEntry(
+  transitionEntry: TransitionEntry,
+): Promise<FiringResult> {
+  if (!transitionEntry.task) return "NotFired"
+
+  const inputs = transitionEntryGetInputs(transitionEntry)
+  if (inputs === undefined) return "NotFired"
+
+  try {
+    const outputs = await transitionEntry.task.fn(...inputs)
+    transitionEntryPutOutputs(transitionEntry, outputs)
+    return "Fired"
+  } catch (error) {
+    return "FiringError"
+  }
+}
+
+function transitionEntryGetInputs(
+  transitionEntry: TransitionEntry,
+): Array<any> | undefined {
+  if (
+    transitionEntry.inputPlaceEntries.some(
+      (placeEntry) => placeEntry.queue.length === 0,
+    )
+  ) {
+    return undefined
+  }
+
+  return transitionEntry.inputPlaceEntries.map((placeEntry) =>
+    placeEntry.queue.pop(),
+  )
+}
+
+function transitionEntryPutOutputs(
+  transitionEntry: TransitionEntry,
+  outputs: Array<any>,
+): void {
+  for (const placeEntry of [...transitionEntry.outputPlaceEntries].reverse()) {
+    placeEntry.queue.push(outputs.pop())
+  }
+}

src/lang/task/Task.ts

@@ -1,4 +1,4 @@
-export type TaskFunction = (...args: Array<any>) => Promise<Array<any>>
+export type TaskFunction = (...inputs: Array<any>) => Promise<Array<any>>
 
 export type Task = {
   fn: TaskFunction