statebuddy/src/statecharts/parser.ts

361 lines
10 KiB
TypeScript

import { AbstractState, ConcreteState, OrState, PseudoState, Statechart, Transition } from "./abstract_syntax";
import { findNearestArrow, findNearestSide, findRountangle, Rountangle, VisualEditorState } from "./concrete_syntax";
import { isEntirelyWithin } from "../VisualEditor/geometry";
import { Action, EventTrigger, Expression, ParsedText } from "./label_ast";
import { parse as parseLabel, SyntaxError } from "./label_parser";
export type TraceableError = {
shapeUid: string;
message: string;
data?: any;
}
function addEvent(events: EventTrigger[], e: EventTrigger, textUid: string) {
const haveEvent = events.find(({event}) => event === e.event);
if (haveEvent) {
if (haveEvent.paramName !== e.paramName === undefined) {
return [{
shapeUid: textUid,
message: "inconsistent event parameter",
}];
}
return [];
}
else {
events.push(e);
events.sort((a,b) => a.event.localeCompare(b.event));
return [];
}
}
export function parseStatechart(state: VisualEditorState): [Statechart, TraceableError[]] {
const errors: TraceableError[] = [];
// implicitly, the root is always an Or-state
const root: OrState = {
kind: "or",
uid: "root",
children: [],
initial: [],
comments: [],
entryActions: [],
exitActions: [],
depth: 0,
timers: [],
}
const uid2State = new Map<string, ConcreteState|PseudoState>([["root", root]]);
// we will always look for the smallest parent rountangle
const parentCandidates: Rountangle[] = [{
kind: "or",
uid: root.uid,
topLeft: {x: -Infinity, y: -Infinity},
size: {x: Infinity, y: Infinity},
}];
const parentLinks = new Map<string, string>();
// step 1: figure out state hierarchy
// IMPORTANT ASSUMPTION: state.rountangles is sorted from big to small surface area:
for (const rt of state.rountangles) {
const common = {
kind: rt.kind,
uid: rt.uid,
comments: [],
entryActions: [],
exitActions: [],
};
let state;
if (rt.kind === "or") {
state = {
...common,
initial: [],
children: [],
timers: [],
};
}
else if (rt.kind === "and") {
state = {
...common,
children: [],
timers: [],
};
}
// iterate in reverse:
for (let i=parentCandidates.length-1; i>=0; i--) {
const candidate = parentCandidates[i];
if (candidate.uid === "root" || isEntirelyWithin(rt, candidate)) {
// found our parent
const parentState = uid2State.get(candidate.uid)! as ConcreteState;
parentState.children.push(state as unknown as ConcreteState);
parentCandidates.push(rt);
parentLinks.set(rt.uid, candidate.uid);
state = {
...state,
parent: parentState,
depth: parentState.depth + 1,
}
break;
}
}
uid2State.set(rt.uid, state as ConcreteState);
}
for (const d of state.diamonds) {
uid2State.set(d.uid, {
kind: "pseudo",
uid: d.uid,
comments: [],
});
}
// step 2: figure out transitions
const transitions = new Map<string, Transition[]>();
const uid2Transition = new Map<string, Transition>();
for (const arr of state.arrows) {
const sides = [...state.rountangles, ...state.diamonds];
const srcUID = findNearestSide(arr, "start", sides)?.uid;
const tgtUID = findNearestSide(arr, "end", sides)?.uid;
if (!srcUID) {
if (!tgtUID) {
// dangling edge
errors.push({shapeUid: arr.uid, message: "dangling"});
}
else {
// target but no source, so we treat is as an 'initial' marking
const tgtState = uid2State.get(tgtUID)!;
if (tgtState.kind === "pseudo") {
// maybe allow this in the future?
errors.push({
shapeUid: arr.uid,
message: "pseudo-state cannot be initial state",
});
}
else {
const ofState = uid2State.get(parentLinks.get(tgtUID)!)!;
if (ofState.kind === "or") {
ofState.initial.push([arr.uid, tgtState]);
}
else {
// and states do not have an 'initial' state
errors.push({
shapeUid: arr.uid,
message: "AND-state cannot have an initial state",
});
}
}
}
}
else {
if (!tgtUID) {
errors.push({
shapeUid: arr.uid,
message: "no target",
});
}
else {
// add transition
const transition: Transition = {
uid: arr.uid,
src: uid2State.get(srcUID)!,
tgt: uid2State.get(tgtUID)!,
label: [],
};
const existingTransitions = transitions.get(srcUID) || [];
existingTransitions.push(transition);
transitions.set(srcUID, existingTransitions);
uid2Transition.set(arr.uid, transition);
}
}
}
for (const state of uid2State.values()) {
if (state.kind === "or") {
if (state.initial.length > 1) {
errors.push(...state.initial.map(([uid,childState]) => ({
shapeUid: uid,
message: "multiple initial states",
})));
}
else if (state.initial.length === 0) {
errors.push({
shapeUid: state.uid,
message: "no initial state",
});
}
}
}
let variables = new Set<string>();
const inputEvents: EventTrigger[] = [];
const internalEvents: EventTrigger[] = [];
const outputEvents = new Set<string>();
// step 3: figure out labels
const textsSorted = state.texts.toSorted((a,b) => a.topLeft.y - b.topLeft.y);
for (const text of textsSorted) {
let parsed: ParsedText;
try {
parsed = parseLabel(text.text); // may throw
parsed.uid = text.uid;
} catch (e) {
if (e instanceof SyntaxError) {
errors.push({
shapeUid: text.uid,
message: e.message,
data: e,
});
parsed = {
kind: "parserError",
uid: text.uid,
}
}
else {
throw e;
}
}
const belongsToArrow = findNearestArrow(text.topLeft, state.arrows);
if (belongsToArrow) {
const belongsToTransition = uid2Transition.get(belongsToArrow.uid);
if (belongsToTransition) {
const {src} = belongsToTransition;
belongsToTransition.label.push(parsed);
if (parsed.kind === "transitionLabel") {
// collect events
// triggers
if (parsed.trigger.kind === "event") {
if (src.kind === "pseudo") {
errors.push({shapeUid: text.uid, message: "pseudo state outgoing transition must not have event trigger"});
}
else {
const {event} = parsed.trigger;
if (event.startsWith("_")) {
errors.push(...addEvent(internalEvents, parsed.trigger, parsed.uid));
}
else {
errors.push(...addEvent(inputEvents, parsed.trigger, parsed.uid));
}
}
}
else if (parsed.trigger.kind === "after") {
if (src.kind === "pseudo") {
errors.push({shapeUid: text.uid, message: "pseudo state outgoing transition must not have after-trigger"});
}
else {
src.timers.push(parsed.trigger.durationMs);
src.timers.sort();
}
}
else if (["entry", "exit"].includes(parsed.trigger.kind)) {
errors.push({shapeUid: text.uid, message: "entry/exit trigger not allowed on transitions"});
}
else if (parsed.trigger.kind === "triggerless") {
if (src.kind !== "pseudo") {
errors.push({shapeUid: text.uid, message: "triggerless transitions only allowed on pseudo-states"});
}
}
// // raise-actions
// for (const action of parsed.actions) {
// if (action.kind === "raise") {
// const {event} = action;
// if (event.startsWith("_")) {
// internalEvents.add(event);
// }
// else {
// outputEvents.add(event);
// }
// }
// }
// collect variables
variables = variables.union(findVariables(parsed.guard));
for (const action of parsed.actions) {
variables = variables.union(findVariablesAction(action));
}
}
}
}
else {
// text does not belong to transition...
// so it belongs to a rountangle (a state)
const rountangle = findRountangle(text.topLeft, state.rountangles);
const belongsToState = rountangle ? uid2State.get(rountangle.uid)! as ConcreteState : root;
if (parsed.kind === "transitionLabel") {
// labels belonging to a rountangle (= a state) must by entry/exit actions
// if we cannot find a containing state, then it belong to the root
if (parsed.trigger.kind === "entry") {
belongsToState.entryActions.push(...parsed.actions);
}
else if(parsed.trigger.kind === "exit") {
belongsToState.exitActions.push(...parsed.actions);
}
else {
errors.push({
shapeUid: text.uid,
message: "states can only have entry/exit triggers",
data: {start: {offset: 0}, end: {offset: text.text.length}},
});
}
}
else if (parsed.kind === "comment") {
// just append comments to their respective states
belongsToState.comments.push([text.uid, parsed.text]);
}
}
}
for (const transition of uid2Transition.values()) {
if (transition.label.length === 0) {
errors.push({
shapeUid: transition.uid,
message: "no label",
});
}
else if (transition.label.length > 1) {
errors.push({
shapeUid: transition.uid,
message: "multiple labels",
});
}
}
return [{
root,
transitions,
variables,
inputEvents,
internalEvents,
outputEvents,
uid2State,
}, errors];
}
function findVariables(expr: Expression): Set<string> {
if (expr.kind === "ref") {
return new Set([expr.variable]);
}
else if (expr.kind === "unaryExpr") {
return findVariables(expr.expr);
}
else if (expr.kind === "binaryExpr") {
return findVariables(expr.lhs).union(findVariables(expr.rhs));
}
return new Set();
}
function findVariablesAction(action: Action): Set<string> {
if (action.kind === "assignment") {
return new Set([action.lhs, ...findVariables(action.rhs)]);
}
return new Set();
}