some form of highlighting

web/root/src/highlight.ts

@@ -0,0 +1,85 @@
+import type { Span } from "./automata.ts";
+import { bus } from "./bus.ts";
+import { automaton } from "./simulation.ts";
+
+
+export type HighlightKind = "focus" | "error" | "warning" | "success";
+
+
+
+export type Highlight = {
+    span: Span,
+    kind: HighlightKind,
+}
+
+type HighlightEntry = {
+    span: Span,
+    kind: HighlightKind,
+    count: number;
+}
+
+export const current: Map<string, HighlightEntry> = new Map();
+
+
+function asKey(highlight: Highlight): string {
+    return `${highlight.span[0]}:${highlight.span[1]}:${highlight.kind}`
+}
+
+export function highlight_from_node_id(node_id: string) {
+    const state = automaton.states.get(node_id);
+    if (state) {
+        bus.emit("highlight/one/add", { kind: "success", span: state.definition })
+    }
+}
+
+export function dehighlight_from_node_id(node_id: string) {
+    const state = automaton.states.get(node_id);
+    if (state) {
+        bus.emit("highlight/one/remove", { kind: "success", span: state.definition })
+    }
+}
+
+export function highlight_from_edge_id(node_id: string) {
+    for (const edge_value of automaton.edges.get(node_id)!) {
+        bus.emit("highlight/one/add", { kind: "focus", span: edge_value.function })
+        bus.emit("highlight/one/add", { kind: "warning", span: edge_value.transition })
+    }
+}
+
+export function dehighlight_from_edge_id(node_id: string) {
+    for (const edge_value of automaton.edges.get(node_id)!) {
+        bus.emit("highlight/one/remove", { kind: "focus", span: edge_value.function })
+        bus.emit("highlight/one/remove", { kind: "warning", span: edge_value.transition })
+    }
+}
+
+bus.on("automata/update", _ => {
+    bus.emit("highlight/all/remove", undefined);
+})
+
+bus.on("highlight/one/add", (highlight) => {
+    const key = asKey(highlight);
+    if (current.has(key)) {
+        current.get(key)!.count += 1;
+    } else {
+        current.set(key, { count: 1, ...highlight });
+        bus.emit("highlight/update", undefined);
+    }
+});
+bus.on("highlight/one/remove", (highlight) => {
+    const key = asKey(highlight);
+    if (current.has(key)) {
+        const value = current.get(key)!
+        value.count -= 1;
+        if (value.count === 0) {
+            current.delete(key);
+            bus.emit("highlight/update", undefined);
+        }
+    }
+});
+bus.on("highlight/all/remove", (_) => {
+    if (current.size !== 0) {
+        current.clear();
+        bus.emit("highlight/update", undefined);
+    }
+});