raising events appears to work. nondeterminism currently ignored

This commit is contained in:
Joeri Exelmans 2025-10-09 13:17:01 +02:00
parent 3f2db4457f
commit 09a87d3025
8 changed files with 243 additions and 194 deletions

View file

@ -1,16 +1,17 @@
import { computeArena, ConcreteState, isAncestorOf, Statechart, Transition } from "./ast";
import { Action, Expression } from "./label_ast";
import { act } from "react";
import { evalExpr } from "./actionlang_interpreter";
import { computeArena, ConcreteState, getDescendants, isAncestorOf, isOverlapping, OrState, Statechart, stateDescription, Transition } from "./ast";
import { Action } from "./label_ast";
import { Environment, RaisedEvents, Mode, RT_Statechart, initialRaised } from "./runtime_types";
export function initialize(ast: Statechart): RT_Statechart {
const {mode, environment, ...raised} = enterDefault(ast.root, {
const {enteredStates, environment, ...raised} = enterDefault(ast.root, {
environment: new Map(),
...initialRaised,
});
return {
mode,
mode: enteredStates,
environment,
inputEvents: [],
...raised,
};
}
@ -19,7 +20,7 @@ type ActionScope = {
environment: Environment,
} & RaisedEvents;
type EnteredScope = { mode: Mode } & ActionScope;
type EnteredScope = { enteredStates: Mode } & ActionScope;
export function enterDefault(state: ConcreteState, rt: ActionScope): EnteredScope {
let actionScope = rt;
@ -30,25 +31,29 @@ export function enterDefault(state: ConcreteState, rt: ActionScope): EnteredScop
}
// enter children...
const mode: {[uid:string]: Mode} = {};
let enteredStates = new Set([state.uid]);
if (state.kind === "and") {
// enter every child
for (const child of state.children) {
let childMode;
({mode: childMode, ...actionScope} = enterDefault(child, actionScope));
mode[child.uid] = childMode;
let enteredChildren;
({enteredStates: enteredChildren, ...actionScope} = enterDefault(child, actionScope));
enteredStates = enteredStates.union(enteredChildren);
}
}
else if (state.kind === "or") {
// same as AND-state, but we only enter the initial state(s)
for (const [_, child] of state.initial) {
let childMode;
({mode: childMode, ...actionScope} = enterDefault(child, actionScope));
mode[child.uid] = childMode;
if (state.initial.length > 0) {
if (state.initial.length > 1) {
console.warn(state.uid + ': multiple initial states, only entering one of them');
}
let enteredChildren;
({enteredStates: enteredChildren, ...actionScope} = enterDefault(state.initial[0][1], actionScope));
enteredStates = enteredStates.union(enteredChildren);
}
console.warn(state.uid + ': no initial state');
}
return { mode, ...actionScope };
return {enteredStates, ...actionScope};
}
export function enterPath(path: ConcreteState[], rt: ActionScope): EnteredScope {
@ -62,48 +67,47 @@ export function enterPath(path: ConcreteState[], rt: ActionScope): EnteredScope
}
// enter children...
const mode: {[uid:string]: Mode} = {};
let enteredStates = new Set([state.uid]);
if (state.kind === "and") {
// enter every child
for (const child of state.children) {
let childMode;
let enteredChildren;
if (rest.length > 0 && child.uid === rest[0].uid) {
({mode: childMode, ...actionScope} = enterPath(rest, actionScope));
({enteredStates: enteredChildren, ...actionScope} = enterPath(rest, actionScope));
}
else {
({mode: childMode, ...actionScope} = enterDefault(child, actionScope));
({enteredStates: enteredChildren, ...actionScope} = enterDefault(child, actionScope));
}
mode[child.uid] = childMode;
enteredStates = enteredStates.union(enteredChildren);
}
}
else if (state.kind === "or") {
if (rest.length > 0) {
let childMode;
({mode: childMode, ...actionScope} = enterPath(rest, actionScope));
mode[rest[0].uid] = childMode;
let enteredChildren;
({enteredStates: enteredChildren, ...actionScope} = enterPath(rest, actionScope));
enteredStates = enteredStates.union(enteredChildren);
}
else {
// same as AND-state, but we only enter the initial state(s)
for (const [_, child] of state.initial) {
let childMode;
({mode: childMode, ...actionScope} = enterDefault(child, actionScope));
mode[child.uid] = childMode;
let enteredChildren;
({enteredStates: enteredChildren, ...actionScope} = enterDefault(child, actionScope));
enteredStates = enteredStates.union(enteredChildren);
}
}
}
return { mode, ...actionScope };
return { enteredStates, ...actionScope };
}
// exit the given state and all its active descendants
export function exitCurrent(state: ConcreteState, rt: EnteredScope): ActionScope {
let {mode, ...actionScope} = rt;
let {enteredStates, ...actionScope} = rt;
// exit all active children...
for (const [childUid, childMode] of Object.entries(mode)) {
const child = state.children.find(child => child.uid === childUid);
if (child) {
(actionScope = exitCurrent(child, {mode: childMode, ...actionScope}));
for (const child of state.children) {
if (enteredStates.has(child.uid)) {
actionScope = exitCurrent(child, {enteredStates, ...actionScope});
}
}
@ -115,6 +119,27 @@ export function exitCurrent(state: ConcreteState, rt: EnteredScope): ActionScope
return actionScope;
}
export function exitPath(path: ConcreteState[], rt: EnteredScope): ActionScope {
let {enteredStates, ...actionScope} = rt;
const toExit = enteredStates.difference(new Set(path));
const [state, ...rest] = path;
// exit state and all its children, *except* states along the rest of the path
actionScope = exitCurrent(state, {enteredStates: toExit, ...actionScope});
if (rest.length > 0) {
actionScope = exitPath(rest, {enteredStates, ...actionScope});
}
// execute exit actions
for (const action of state.exitActions) {
(actionScope = execAction(action, actionScope));
}
return actionScope;
}
export function execAction(action: Action, rt: ActionScope): ActionScope {
if (action.kind === "assignment") {
const rhs = evalExpr(action.rhs, rt.environment);
@ -144,117 +169,73 @@ export function execAction(action: Action, rt: ActionScope): ActionScope {
throw new Error("should never reach here");
}
const UNARY_OPERATOR_MAP: Map<string, (x:any)=>any> = new Map([
["!", x => !x],
["-", x => -x as any],
]);
const BINARY_OPERATOR_MAP: Map<string, (a:any,b:any)=>any> = new Map([
["+", (a,b) => a+b],
["-", (a,b) => a-b],
["*", (a,b) => a*b],
["/", (a,b) => a/b],
["&&", (a,b) => a&&b],
["||", (a,b) => a||b],
["==", (a,b) => a==b],
["<=", (a,b) => a<=b],
[">=", (a,b) => a>=b],
["<", (a,b) => a<b],
[">", (a,b) => a>b],
]);
export function evalExpr(expr: Expression, environment: Environment): any {
if (expr.kind === "literal") {
return expr.value;
}
else if (expr.kind === "ref") {
const found = environment.get(expr.variable);
if (found === undefined) {
throw new Error(`variable '${expr.variable}' does not exist in environment`)
}
return found;
}
else if (expr.kind === "unaryExpr") {
const arg = evalExpr(expr.expr, environment);
return UNARY_OPERATOR_MAP.get(expr.operator)!(arg);
}
else if (expr.kind === "binaryExpr") {
const lhs = evalExpr(expr.lhs, environment);
const rhs = evalExpr(expr.rhs, environment);
return BINARY_OPERATOR_MAP.get(expr.operator)!(lhs,rhs);
}
throw new Error("should never reach here");
}
export function getActiveStates(mode: Mode): Set<string> {
return new Set([].concat(
...Object.entries(mode).map(([childUid, childMode]) =>
[childUid, ...getActiveStates(childMode)])
));
}
export function raiseEvent(event: string, statechart: Statechart, sourceState: ConcreteState, rt: RT_Statechart): RT_Statechart[] {
const activeStates = sourceState.children.filter(child => rt.mode.hasOwnProperty(child.uid))
for (const state of activeStates) {
const outgoing = statechart.transitions.get(state.uid) || [];
const enabled = outgoing.filter(transition => transition.label[0].trigger.kind === "event" && transition.label[0].trigger.event === event);
const enabledGuard = enabled.filter(transition =>
evalExpr(transition.label[0].guard, rt.environment)
);
if (enabledGuard.length > 0) {
const newRts = enabledGuard.map(t => fireTransition(t, statechart, rt));
return newRts;
}
else {
// no enabled outgoing transitions, try the children:
return raiseEvent(event, statechart, state, rt);
export function handleEvent(event: string, statechart: Statechart, activeParent: ConcreteState, {environment, mode, ...raised}: RT_Statechart): RT_Statechart {
const arenasFired = new Set<OrState>();
for (const state of activeParent.children) {
if (mode.has(state.uid)) {
const outgoing = statechart.transitions.get(state.uid) || [];
const triggered = outgoing.filter(transition => transition.label[0].trigger.kind === "event" && transition.label[0].trigger.event === event);
const enabled = triggered.filter(transition =>
evalExpr(transition.label[0].guard, environment)
);
if (enabled.length > 0) {
if (enabled.length > 1) {
console.warn('nondeterminism!!!!');
}
const t = enabled[0];
console.log('enabled:', transitionDescription(t));
const {arena, srcPath, tgtPath} = computeArena(t);
let overlapping = false;
for (const alreadyFired of arenasFired) {
if (isOverlapping(arena, alreadyFired)) {
overlapping = true;
}
}
if (!overlapping) {
console.log('^ firing');
({mode, environment, ...raised} = fireTransition(t, arena, srcPath, tgtPath, {mode, environment, ...raised}));
arenasFired.add(arena);
}
else {
console.log('skip (overlapping arenas)');
}
}
else {
// no enabled outgoing transitions, try the children:
({environment, mode, ...raised} = handleEvent(event, statechart, state, {environment, mode, ...raised}));
}
}
}
return [];
return {environment, mode, ...raised};
}
function setModeDeep(oldMode: Mode, pathToState: ConcreteState[], newMode: Mode): Mode {
if (pathToState.length === 0) {
return newMode;
}
const [next, ...rest] = pathToState;
return {
...oldMode,
[next.uid]: setModeDeep(oldMode[next.uid], rest, newMode),
}
function transitionDescription(t: Transition) {
return stateDescription(t.src) + ' ➔ ' + stateDescription(t.tgt);
}
function unsetModeDeep(oldMode: Mode, pathToState: ConcreteState[]): Mode {
if (pathToState.length === 0) {
return {};
}
if (pathToState.length === 1) {
const keyToDelete = pathToState[0].uid;
const newMode = {...oldMode}; // shallow copy
delete newMode[keyToDelete];
return newMode;
}
const [next, ...rest] = pathToState;
return {
...oldMode,
[next.uid]: unsetModeDeep(oldMode[next.uid], rest),
}
}
export function fireTransition(t: Transition, arena: OrState, srcPath: ConcreteState[], tgtPath: ConcreteState[], {mode, environment, ...raised}: RT_Statechart): {mode: Mode, environment: Environment} & RaisedEvents {
export function fireTransition(t: Transition, statechart: Statechart, rt: RT_Statechart): RT_Statechart {
const {arena, srcPath, tgtPath} = computeArena(t);
const pathToArena = isAncestorOf({ancestor: statechart.root, descendant: arena}) as ConcreteState[];
console.log('fire ', t.src.comments[0][1], '->', t.tgt.comments[0][1], {srcPath, tgtPath});
let {environment, ...raised} = exitCurrent(srcPath[1], rt);
const exitedMode = unsetModeDeep(rt.mode, [...pathToArena.slice(1), ...srcPath.slice(1)]);
console.log('fire ', transitionDescription(t), {arena, srcPath, tgtPath});
// exit src
({environment, ...raised} = exitPath(srcPath.slice(1), {environment, enteredStates: mode, ...raised}));
const toExit = getDescendants(arena);
toExit.delete(arena.uid); // do not exit the arena itself
const exitedMode = mode.difference(toExit);
console.log('exitedMode', exitedMode);
// exec transition actions
for (const action of t.label[0].actions) {
({environment, ...raised} = execAction(action, {environment, ...raised}));
}
let deepMode;
({mode: deepMode, environment, ...raised} = enterPath(tgtPath.slice(1), {environment, ...raised}));
// console.log('entered path:', tgtPath.slice(1), {deepMode});
const enteredMode = setModeDeep(exitedMode, [...pathToArena.slice(1), ...tgtPath.slice(1)], deepMode);
// console.log('pathToArena:', pathToArena, 'newMode:', enteredMode);
return {mode: enteredMode, environment, inputEvents: rt.inputEvents, ...raised};
// enter tgt
let enteredStates;
({enteredStates, environment, ...raised} = enterPath(tgtPath.slice(1), {environment, ...raised}));
const enteredMode = exitedMode.union(enteredStates);
console.log('enteredMode', enteredMode);
return {mode: enteredMode, environment, ...raised};
}