Commit

webapp/src/app.js

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+import { jsx as _jsx, Fragment as _Fragment, jsxs as _jsxs } from "react/jsx-runtime";
+import { autocompletion, completionKeymap } from "@codemirror/autocomplete";
+import { closeBrackets, closeBracketsKeymap } from "@codemirror/closebrackets";
+import { indentWithTab, standardKeymap } from "@codemirror/commands";
+import { history, historyKeymap } from "@codemirror/history";
+import { indentOnInput } from "@codemirror/language";
+import { bracketMatching } from "@codemirror/matchbrackets";
+import { searchKeymap } from "@codemirror/search";
+import { EditorState, StateField } from "@codemirror/state";
+import { drawSelection, dropCursor, EditorView, highlightSpecialChars, keymap, } from "@codemirror/view";
+import * as commands from "./commands";
+import { markdown } from "./markdown";
+import { lineWrapper } from "./lineWrapper";
+import customMarkDown from "./parser";
+import customMarkdownStyle from "./style";
+import { HttpFileSystem } from "./fs";
+import ReactDOM from "react-dom";
+import { useEffect, useRef } from "react";
+const fs = new HttpFileSystem("http://localhost:2222/fs");
+class Editor {
+    constructor(parent, currentNote, text) {
+        this.view = new EditorView({
+            state: this.createEditorState(text),
+            parent: parent,
+        });
+        this.currentNote = currentNote;
+    }
+    load(name, text) {
+        this.currentNote = name;
+        this.view.setState(this.createEditorState(text));
+    }
+    async save() {
+        await fs.writeNote(this.currentNote, this.view.state.sliceDoc());
+    }
+    focus() {
+        this.view.focus();
+    }
+    createEditorState(text) {
+        return EditorState.create({
+            doc: text,
+            extensions: [
+                highlightSpecialChars(),
+                history(),
+                drawSelection(),
+                dropCursor(),
+                indentOnInput(),
+                customMarkdownStyle,
+                bracketMatching(),
+                closeBrackets(),
+                autocompletion(),
+                EditorView.lineWrapping,
+                lineWrapper([
+                    { selector: "ATXHeading1", class: "line-h1" },
+                    { selector: "ATXHeading2", class: "line-h2" },
+                    { selector: "ListItem", class: "line-li" },
+                    { selector: "Blockquote", class: "line-blockquote" },
+                    { selector: "CodeBlock", class: "line-code" },
+                    { selector: "FencedCode", class: "line-fenced-code" },
+                ]),
+                keymap.of([
+                    ...closeBracketsKeymap,
+                    ...standardKeymap,
+                    ...searchKeymap,
+                    ...historyKeymap,
+                    ...completionKeymap,
+                    indentWithTab,
+                    {
+                        key: "Ctrl-b",
+                        mac: "Cmd-b",
+                        run: commands.insertMarker("**"),
+                    },
+                    {
+                        key: "Ctrl-i",
+                        mac: "Cmd-i",
+                        run: commands.insertMarker("_"),
+                    },
+                    {
+                        key: "Ctrl-s",
+                        mac: "Cmd-s",
+                        run: (target) => {
+                            Promise.resolve()
+                                .then(async () => {
+                                console.log("Saving");
+                                await this.save();
+                            })
+                                .catch((e) => console.error(e));
+                            return true;
+                        },
+                    },
+                ]),
+                EditorView.domEventHandlers({
+                    click: (event, view) => {
+                        if (event.metaKey || event.ctrlKey) {
+                            console.log("Navigate click");
+                            let coords = view.posAtCoords(event);
+                            console.log("Coords", view.state.doc.sliceString(coords, coords + 1));
+                            return false;
+                        }
+                    },
+                }),
+                markdown({
+                    base: customMarkDown,
+                }),
+                StateField.define({
+                    create: () => null,
+                    update: (value, transaction) => {
+                        if (transaction.docChanged) {
+                            console.log("Something changed");
+                        }
+                        return null;
+                    },
+                }),
+            ],
+        });
+    }
+}
+export const App = () => {
+    const editorRef = useRef();
+    useEffect(() => {
+        let editor = new Editor(editorRef.current, "", "");
+        editor.focus();
+        // @ts-ignore
+        window.editor = editor;
+        fs.readNote("start").then((text) => {
+            editor.load("start", text);
+        });
+    }, []);
+    return (_jsxs(_Fragment, { children: [_jsx("div", { id: "top", children: "Hello" }, void 0), _jsx("div", { id: "editor", ref: editorRef }, void 0), _jsx("div", { id: "bottom", children: "Bottom" }, void 0)] }, void 0));
+};
+ReactDOM.render(_jsx(App, {}, void 0), document.body);

webapp/src/app.tsx

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+import { autocompletion, completionKeymap } from "@codemirror/autocomplete";
+import { closeBrackets, closeBracketsKeymap } from "@codemirror/closebrackets";
+import { indentWithTab, standardKeymap } from "@codemirror/commands";
+import { history, historyKeymap } from "@codemirror/history";
+import { indentOnInput } from "@codemirror/language";
+import { bracketMatching } from "@codemirror/matchbrackets";
+import { searchKeymap } from "@codemirror/search";
+import { EditorState, StateField } from "@codemirror/state";
+
+import {
+  drawSelection,
+  dropCursor,
+  EditorView,
+  highlightSpecialChars,
+  keymap,
+} from "@codemirror/view";
+import * as commands from "./commands";
+import { markdown } from "./markdown";
+import { lineWrapper } from "./lineWrapper";
+import customMarkDown from "./parser";
+import customMarkdownStyle from "./style";
+import { HttpFileSystem } from "./fs";
+
+import ReactDOM from "react-dom";
+import { MutableRefObject, useEffect, useRef, useState } from "react";
+
+const fs = new HttpFileSystem("http://localhost:2222/fs");
+
+type AppState = {
+  currentNote: string;
+};
+
+class Editor {
+  view: EditorView;
+  currentNote: string;
+
+  constructor(parent: Element, currentNote: string, text: string) {
+    this.view = new EditorView({
+      state: this.createEditorState(text),
+      parent: parent,
+    });
+    this.currentNote = currentNote;
+  }
+
+  load(name: string, text: string) {
+    this.currentNote = name;
+    this.view.setState(this.createEditorState(text));
+  }
+
+  async save() {
+    await fs.writeNote(this.currentNote, this.view.state.sliceDoc());
+  }
+
+  focus() {
+    this.view.focus();
+  }
+
+  private createEditorState(text: string): EditorState {
+    return EditorState.create({
+      doc: text,
+      extensions: [
+        highlightSpecialChars(),
+        history(),
+        drawSelection(),
+        dropCursor(),
+        indentOnInput(),
+        customMarkdownStyle,
+        bracketMatching(),
+        closeBrackets(),
+        autocompletion(),
+        EditorView.lineWrapping,
+        lineWrapper([
+          { selector: "ATXHeading1", class: "line-h1" },
+          { selector: "ATXHeading2", class: "line-h2" },
+          { selector: "ListItem", class: "line-li" },
+          { selector: "Blockquote", class: "line-blockquote" },
+          { selector: "CodeBlock", class: "line-code" },
+          { selector: "FencedCode", class: "line-fenced-code" },
+        ]),
+        keymap.of([
+          ...closeBracketsKeymap,
+          ...standardKeymap,
+          ...searchKeymap,
+          ...historyKeymap,
+          ...completionKeymap,
+          indentWithTab,
+          {
+            key: "Ctrl-b",
+            mac: "Cmd-b",
+            run: commands.insertMarker("**"),
+          },
+          {
+            key: "Ctrl-i",
+            mac: "Cmd-i",
+            run: commands.insertMarker("_"),
+          },
+          {
+            key: "Ctrl-s",
+            mac: "Cmd-s",
+            run: (target: EditorView): boolean => {
+              Promise.resolve()
+                .then(async () => {
+                  console.log("Saving");
+                  await this.save();
+                })
+                .catch((e) => console.error(e));
+              return true;
+            },
+          },
+        ]),
+        EditorView.domEventHandlers({
+          click: (event: MouseEvent, view: EditorView) => {
+            if (event.metaKey || event.ctrlKey) {
+              console.log("Navigate click");
+              let coords = view.posAtCoords(event);
+              console.log(
+                "Coords",
+                view.state.doc.sliceString(coords!, coords! + 1)
+              );
+              return false;
+            }
+          },
+        }),
+        markdown({
+          base: customMarkDown,
+        }),
+        StateField.define({
+          create: () => null,
+          update: (value, transaction) => {
+            if (transaction.docChanged) {
+              console.log("Something changed");
+            }
+            return null;
+          },
+        }),
+      ],
+    });
+  }
+}
+
+function TopBar({ editor }: { editor: Editor | null }) {
+  return (
+    <div id="top">
+      This is the top bar, do something cool: {editor?.currentNote}
+    </div>
+  );
+}
+
+function App() {
+  const editorRef = useRef<HTMLDivElement>(null);
+  const [editor, setEditor] = useState<Editor | null>(null);
+
+  useEffect(() => {
+    let editor = new Editor(editorRef.current!, "", "");
+    editor.focus();
+    // @ts-ignore
+    window.editor = editor;
+    fs.readNote("start").then((text) => {
+      editor.load("start", text);
+    });
+    setEditor(editor);
+  }, []);
+
+  return (
+    <>
+      <TopBar editor={editor} />
+      <div id="editor" ref={editorRef}></div>
+      <div id="bottom">Bottom</div>
+    </>
+  );
+}
+
+ReactDOM.render(<App />, document.body);

webapp/src/commands.js

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+import { EditorSelection, Transaction } from "@codemirror/state";
+import { Text } from "@codemirror/text";
+export function insertMarker(marker) {
+    return ({ state, dispatch }) => {
+        const changes = state.changeByRange((range) => {
+            const isBoldBefore = state.sliceDoc(range.from - marker.length, range.from) === marker;
+            const isBoldAfter = state.sliceDoc(range.to, range.to + marker.length) === marker;
+            const changes = [];
+            changes.push(isBoldBefore ? {
+                from: range.from - marker.length,
+                to: range.from,
+                insert: Text.of([''])
+            } : {
+                from: range.from,
+                insert: Text.of([marker]),
+            });
+            changes.push(isBoldAfter ? {
+                from: range.to,
+                to: range.to + marker.length,
+                insert: Text.of([''])
+            } : {
+                from: range.to,
+                insert: Text.of([marker]),
+            });
+            const extendBefore = isBoldBefore ? -marker.length : marker.length;
+            const extendAfter = isBoldAfter ? -marker.length : marker.length;
+            return {
+                changes,
+                range: EditorSelection.range(range.from + extendBefore, range.to + extendAfter),
+            };
+        });
+        dispatch(state.update(changes, {
+            scrollIntoView: true,
+            annotations: Transaction.userEvent.of('input'),
+        }));
+        return true;
+    };
+}

webapp/src/commands.ts

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+import { EditorSelection, EditorState, StateCommand, Transaction } from "@codemirror/state";
+import { Text } from "@codemirror/text";
+
+export function insertMarker(marker: string): StateCommand {
+    return ({ state, dispatch }) => {
+        const changes = state.changeByRange((range) => {
+            const isBoldBefore = state.sliceDoc(range.from - marker.length, range.from) === marker;
+            const isBoldAfter = state.sliceDoc(range.to, range.to + marker.length) === marker;
+            const changes = [];
+
+            changes.push(isBoldBefore ? {
+                from: range.from - marker.length,
+                to: range.from,
+                insert: Text.of([''])
+            } : {
+                from: range.from,
+                insert: Text.of([marker]),
+            })
+
+            changes.push(isBoldAfter ? {
+                from: range.to,
+                to: range.to + marker.length,
+                insert: Text.of([''])
+            } : {
+                from: range.to,
+                insert: Text.of([marker]),
+            })
+
+            const extendBefore = isBoldBefore ? -marker.length : marker.length;
+            const extendAfter = isBoldAfter ? -marker.length : marker.length;
+
+            return {
+                changes,
+                range: EditorSelection.range(range.from + extendBefore, range.to + extendAfter),
+            }
+        })
+
+        dispatch(
+            state.update(changes, {
+                scrollIntoView: true,
+                annotations: Transaction.userEvent.of('input'),
+            })
+        )
+
+        return true
+    };
+}

webapp/src/customtags.js

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+import { Tag } from '@codemirror/highlight';
+export const WikiLinkTag = Tag.define();
+export const TagTag = Tag.define();
+export const MentionTag = Tag.define();

webapp/src/customtags.ts

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+import { Tag } from '@codemirror/highlight';
+
+export const WikiLinkTag = Tag.define();
+export const TagTag = Tag.define();
+export const MentionTag = Tag.define();

webapp/src/fs.js

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+export class HttpFileSystem {
+    constructor(url) {
+        this.url = url;
+    }
+    async listNotes() {
+        let req = await fetch(this.url, {
+            method: 'GET'
+        });
+        return (await req.json()).map((name) => ({ name }));
+    }
+    async readNote(name) {
+        let req = await fetch(`${this.url}/${name}`, {
+            method: 'GET'
+        });
+        return await req.text();
+    }
+    async writeNote(name, text) {
+        let req = await fetch(`${this.url}/${name}`, {
+            method: 'PUT',
+            body: text
+        });
+        await req.text();
+    }
+}

webapp/src/fs.ts

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+
+export interface NoteMeta {
+    name: string;
+}
+
+export interface FileSystem {
+    listNotes(): Promise<NoteMeta>;
+    readNote(name: string): Promise<string>;
+    writeNote(name: string, text: string): Promise<void>;
+}
+
+export class HttpFileSystem implements FileSystem {
+    url: string;
+
+    constructor(url: string) {
+        this.url = url;
+    }
+    async listNotes(): Promise<NoteMeta> {
+        let req = await fetch(this.url, {
+            method: 'GET'
+        });
+
+        return (await req.json()).map((name: string) => ({ name }));
+    }
+    async readNote(name: string): Promise<string> {
+        let req = await fetch(`${this.url}/${name}`, {
+            method: 'GET'
+        });
+        return await req.text();
+    }
+    async writeNote(name: string, text: string): Promise<void> {
+        let req = await fetch(`${this.url}/${name}`, {
+            method: 'PUT',
+            body: text
+        });
+        await req.text();
+    }
+}

webapp/src/index.html

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+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>Noot</title>
+    <link rel="stylesheet" href="styles.css" />
+    <script type="module" src="app.tsx"></script>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width" />
+  </head>
+  <body></body>
+</html>

webapp/src/lineWrapper.js

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+import { syntaxTree } from '@codemirror/language';
+import { Decoration, ViewPlugin } from '@codemirror/view';
+function wrapLines(view, wrapElements) {
+    let widgets = [];
+    for (let { from, to } of view.visibleRanges) {
+        const doc = view.state.doc;
+        syntaxTree(view.state).iterate({
+            from, to,
+            enter: (type, from, to) => {
+                const bodyText = doc.sliceString(from, to);
+                // console.log("Enter", type.name, bodyText);
+                for (let wrapElement of wrapElements) {
+                    if (type.name == wrapElement.selector) {
+                        const bodyText = doc.sliceString(from, to);
+                        // console.log("Found", type.name, "with: ", bodyText);
+                        let idx = from;
+                        for (let line of bodyText.split("\n")) {
+                            widgets.push(Decoration.line({
+                                class: wrapElement.class,
+                            }).range(doc.lineAt(idx).from));
+                            idx += line.length + 1;
+                        }
+                    }
+                }
+            },
+            leave(type, from, to) {
+                // console.log("Leaving", type.name);
+            }
+        });
+    }
+    // console.log("All widgets", widgets);
+    return Decoration.set(widgets);
+}
+export const lineWrapper = (wrapElements) => ViewPlugin.fromClass(class {
+    constructor(view) {
+        this.decorations = wrapLines(view, wrapElements);
+    }
+    update(update) {
+        if (update.docChanged || update.viewportChanged) {
+            this.decorations = wrapLines(update.view, wrapElements);
+        }
+    }
+}, {
+    decorations: v => v.decorations,
+});

webapp/src/lineWrapper.ts

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+import { syntaxTree } from '@codemirror/language';
+import {
+    Decoration,
+    DecorationSet, EditorView, ViewPlugin,
+    ViewUpdate
+} from '@codemirror/view';
+
+import { Range } from '@codemirror/rangeset';
+
+interface WrapElement {
+    selector: string;
+    class: string;
+}
+function wrapLines(view: EditorView, wrapElements: WrapElement[]) {
+    let widgets: Range<Decoration>[] = [];
+    for (let { from, to } of view.visibleRanges) {
+        const doc = view.state.doc;
+        syntaxTree(view.state).iterate({
+            from, to,
+            enter: (type, from, to) => {
+                const bodyText = doc.sliceString(from, to);
+                for (let wrapElement of wrapElements) {
+                    if (type.name == wrapElement.selector) {
+                        const bodyText = doc.sliceString(from, to);
+                        let idx = from;
+                        for (let line of bodyText.split("\n")) {
+                            widgets.push(Decoration.line({
+                                class: wrapElement.class,
+                            }).range(doc.lineAt(idx).from));
+                            idx += line.length + 1;
+                        }
+                    }
+                }
+            },
+            leave(type, from: number, to: number) {
+            }
+        });
+    }
+    // console.log("All widgets", widgets);
+    return Decoration.set(widgets);
+}
+export const lineWrapper = (wrapElements: WrapElement[]) => ViewPlugin.fromClass(class {
+    decorations: DecorationSet;
+
+    constructor(view: EditorView) {
+        this.decorations = wrapLines(view, wrapElements);
+    }
+
+    update(update: ViewUpdate) {
+        if (update.docChanged || update.viewportChanged) {
+            this.decorations = wrapLines(update.view, wrapElements);
+        }
+    }
+}, {
+    decorations: v => v.decorations,
+});

webapp/src/markdown/commands.js

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+import { EditorSelection } from "@codemirror/state";
+import { syntaxTree } from "@codemirror/language";
+import { markdownLanguage } from "./markdown";
+function nodeStart(node, doc) {
+    return doc.sliceString(node.from, node.from + 50);
+}
+class Context {
+    constructor(node, from, to, spaceBefore, spaceAfter, type, item) {
+        this.node = node;
+        this.from = from;
+        this.to = to;
+        this.spaceBefore = spaceBefore;
+        this.spaceAfter = spaceAfter;
+        this.type = type;
+        this.item = item;
+    }
+    blank(trailing = true) {
+        let result = this.spaceBefore;
+        if (this.node.name == "Blockquote")
+            result += ">";
+        else
+            for (let i = this.to - this.from - result.length - this.spaceAfter.length; i > 0; i--)
+                result += " ";
+        return result + (trailing ? this.spaceAfter : "");
+    }
+    marker(doc, add) {
+        let number = this.node.name == "OrderedList" ? String((+itemNumber(this.item, doc)[2] + add)) : "";
+        return this.spaceBefore + number + this.type + this.spaceAfter;
+    }
+}
+function getContext(node, line, doc) {
+    let nodes = [];
+    for (let cur = node; cur && cur.name != "Document"; cur = cur.parent) {
+        if (cur.name == "ListItem" || cur.name == "Blockquote")
+            nodes.push(cur);
+    }
+    let context = [], pos = 0;
+    for (let i = nodes.length - 1; i >= 0; i--) {
+        let node = nodes[i], match, start = pos;
+        if (node.name == "Blockquote" && (match = /^[ \t]*>( ?)/.exec(line.slice(pos)))) {
+            pos += match[0].length;
+            context.push(new Context(node, start, pos, "", match[1], ">", null));
+        }
+        else if (node.name == "ListItem" && node.parent.name == "OrderedList" &&
+            (match = /^([ \t]*)\d+([.)])([ \t]*)/.exec(nodeStart(node, doc)))) {
+            let after = match[3], len = match[0].length;
+            if (after.length >= 4) {
+                after = after.slice(0, after.length - 4);
+                len -= 4;
+            }
+            pos += len;
+            context.push(new Context(node.parent, start, pos, match[1], after, match[2], node));
+        }
+        else if (node.name == "ListItem" && node.parent.name == "BulletList" &&
+            (match = /^([ \t]*)([-+*])([ \t]+)/.exec(nodeStart(node, doc)))) {
+            let after = match[3], len = match[0].length;
+            if (after.length > 4) {
+                after = after.slice(0, after.length - 4);
+                len -= 4;
+            }
+            pos += len;
+            context.push(new Context(node.parent, start, pos, match[1], after, match[2], node));
+        }
+    }
+    return context;
+}
+function itemNumber(item, doc) {
+    return /^(\s*)(\d+)(?=[.)])/.exec(doc.sliceString(item.from, item.from + 10));
+}
+function renumberList(after, doc, changes, offset = 0) {
+    for (let prev = -1, node = after;;) {
+        if (node.name == "ListItem") {
+            let m = itemNumber(node, doc);
+            let number = +m[2];
+            if (prev >= 0) {
+                if (number != prev + 1)
+                    return;
+                changes.push({ from: node.from + m[1].length, to: node.from + m[0].length, insert: String(prev + 2 + offset) });
+            }
+            prev = number;
+        }
+        let next = node.nextSibling;
+        if (!next)
+            break;
+        node = next;
+    }
+}
+/// This command, when invoked in Markdown context with cursor
+/// selection(s), will create a new line with the markup for
+/// blockquotes and lists that were active on the old line. If the
+/// cursor was directly after the end of the markup for the old line,
+/// trailing whitespace and list markers are removed from that line.
+///
+/// The command does nothing in non-Markdown context, so it should
+/// not be used as the only binding for Enter (even in a Markdown
+/// document, HTML and code regions might use a different language).
+export const insertNewlineContinueMarkup = ({ state, dispatch }) => {
+    let tree = syntaxTree(state), { doc } = state;
+    let dont = null, changes = state.changeByRange(range => {
+        if (!range.empty || !markdownLanguage.isActiveAt(state, range.from))
+            return dont = { range };
+        let pos = range.from, line = doc.lineAt(pos);
+        let context = getContext(tree.resolveInner(pos, -1), line.text, doc);
+        while (context.length && context[context.length - 1].from > pos - line.from)
+            context.pop();
+        if (!context.length)
+            return dont = { range };
+        let inner = context[context.length - 1];
+        if (inner.to - inner.spaceAfter.length > pos - line.from)
+            return dont = { range };
+        let emptyLine = pos >= (inner.to - inner.spaceAfter.length) && !/\S/.test(line.text.slice(inner.to));
+        // Empty line in list
+        if (inner.item && emptyLine) {
+            // First list item or blank line before: delete a level of markup
+            if (inner.node.firstChild.to >= pos ||
+                line.from > 0 && !/[^\s>]/.test(doc.lineAt(line.from - 1).text)) {
+                let next = context.length > 1 ? context[context.length - 2] : null;
+                let delTo, insert = "";
+                if (next && next.item) { // Re-add marker for the list at the next level
+                    delTo = line.from + next.from;
+                    insert = next.marker(doc, 1);
+                }
+                else {
+                    delTo = line.from + (next ? next.to : 0);
+                }
+                let changes = [{ from: delTo, to: pos, insert }];
+                if (inner.node.name == "OrderedList")
+                    renumberList(inner.item, doc, changes, -2);
+                if (next && next.node.name == "OrderedList")
+                    renumberList(next.item, doc, changes);
+                return { range: EditorSelection.cursor(delTo + insert.length), changes };
+            }
+            else { // Move this line down
+                let insert = "";
+                for (let i = 0, e = context.length - 2; i <= e; i++)
+                    insert += context[i].blank(i < e);
+                insert += state.lineBreak;
+                return { range: EditorSelection.cursor(pos + insert.length), changes: { from: line.from, insert } };
+            }
+        }
+        if (inner.node.name == "Blockquote" && emptyLine && line.from) {
+            let prevLine = doc.lineAt(line.from - 1), quoted = />\s*$/.exec(prevLine.text);
+            // Two aligned empty quoted lines in a row
+            if (quoted && quoted.index == inner.from) {
+                let changes = state.changes([{ from: prevLine.from + quoted.index, to: prevLine.to },
+                    { from: line.from + inner.from, to: line.to }]);
+                return { range: range.map(changes), changes };
+            }
+        }
+        let changes = [];
+        if (inner.node.name == "OrderedList")
+            renumberList(inner.item, doc, changes);
+        let insert = state.lineBreak;
+        let continued = inner.item && inner.item.from < line.from;
+        // If not dedented
+        if (!continued || /^[\s\d.)\-+*>]*/.exec(line.text)[0].length >= inner.to) {
+            for (let i = 0, e = context.length - 1; i <= e; i++)
+                insert += i == e && !continued ? context[i].marker(doc, 1) : context[i].blank();
+        }
+        let from = pos;
+        while (from > line.from && /\s/.test(line.text.charAt(from - line.from - 1)))
+            from--;
+        changes.push({ from, to: pos, insert });
+        return { range: EditorSelection.cursor(from + insert.length), changes };
+    });
+    if (dont)
+        return false;
+    dispatch(state.update(changes, { scrollIntoView: true, userEvent: "input" }));
+    return true;
+};
+function isMark(node) {
+    return node.name == "QuoteMark" || node.name == "ListMark";
+}
+function contextNodeForDelete(tree, pos) {
+    let node = tree.resolveInner(pos, -1), scan = pos;
+    if (isMark(node)) {
+        scan = node.from;
+        node = node.parent;
+    }
+    for (let prev; prev = node.childBefore(scan);) {
+        if (isMark(prev)) {
+            scan = prev.from;
+        }
+        else if (prev.name == "OrderedList" || prev.name == "BulletList") {
+            node = prev.lastChild;
+            scan = node.to;
+        }
+        else {
+            break;
+        }
+    }
+    return node;
+}
+/// This command will, when invoked in a Markdown context with the
+/// cursor directly after list or blockquote markup, delete one level
+/// of markup. When the markup is for a list, it will be replaced by
+/// spaces on the first invocation (a further invocation will delete
+/// the spaces), to make it easy to continue a list.
+///
+/// When not after Markdown block markup, this command will return
+/// false, so it is intended to be bound alongside other deletion
+/// commands, with a higher precedence than the more generic commands.
+export const deleteMarkupBackward = ({ state, dispatch }) => {
+    let tree = syntaxTree(state);
+    let dont = null, changes = state.changeByRange(range => {
+        let pos = range.from, { doc } = state;
+        if (range.empty && markdownLanguage.isActiveAt(state, range.from)) {
+            let line = doc.lineAt(pos);
+            let context = getContext(contextNodeForDelete(tree, pos), line.text, doc);
+            if (context.length) {
+                let inner = context[context.length - 1];
+                let spaceEnd = inner.to - inner.spaceAfter.length + (inner.spaceAfter ? 1 : 0);
+                // Delete extra trailing space after markup
+                if (pos - line.from > spaceEnd && !/\S/.test(line.text.slice(spaceEnd, pos - line.from)))
+                    return { range: EditorSelection.cursor(line.from + spaceEnd),
+                        changes: { from: line.from + spaceEnd, to: pos } };
+                if (pos - line.from == spaceEnd) {
+                    let start = line.from + inner.from;
+                    // Replace a list item marker with blank space
+                    if (inner.item && inner.node.from < inner.item.from && /\S/.test(line.text.slice(inner.from, inner.to)))
+                        return { range, changes: { from: start, to: line.from + inner.to, insert: inner.blank() } };
+                    // Delete one level of indentation
+                    if (start < pos)
+                        return { range: EditorSelection.cursor(start), changes: { from: start, to: pos } };
+                }
+            }
+        }
+        return dont = { range };
+    });
+    if (dont)
+        return false;
+    dispatch(state.update(changes, { scrollIntoView: true, userEvent: "delete" }));
+    return true;
+};

webapp/src/markdown/commands.ts

@@ -0,0 +1,221 @@
+import {StateCommand, Text, EditorSelection, ChangeSpec} from "@codemirror/state"
+import {syntaxTree} from "@codemirror/language"
+import {SyntaxNode, Tree} from "@lezer/common"
+import {markdownLanguage} from "./markdown"
+
+function nodeStart(node: SyntaxNode, doc: Text) {
+  return doc.sliceString(node.from, node.from + 50)
+}
+
+class Context {
+  constructor(
+    readonly node: SyntaxNode,
+    readonly from: number,
+    readonly to: number,
+    readonly spaceBefore: string,
+    readonly spaceAfter: string,
+    readonly type: string,
+    readonly item: SyntaxNode | null
+  ) {}
+
+  blank(trailing: boolean = true) {
+    let result = this.spaceBefore
+    if (this.node.name == "Blockquote") result += ">"
+    else for (let i = this.to - this.from - result.length - this.spaceAfter.length; i > 0; i--) result += " "
+    return result + (trailing ? this.spaceAfter : "")
+  }
+
+  marker(doc: Text, add: number) {
+    let number = this.node.name == "OrderedList" ? String((+itemNumber(this.item!, doc)[2] + add)) : ""
+    return this.spaceBefore + number + this.type + this.spaceAfter
+  }
+}
+
+function getContext(node: SyntaxNode, line: string, doc: Text) {
+  let nodes = []
+  for (let cur: SyntaxNode | null = node; cur && cur.name != "Document"; cur = cur.parent) {
+    if (cur.name == "ListItem" || cur.name == "Blockquote")
+      nodes.push(cur)
+  }
+  let context = [], pos = 0
+  for (let i = nodes.length - 1; i >= 0; i--) {
+    let node = nodes[i], match, start = pos
+    if (node.name == "Blockquote" && (match = /^[ \t]*>( ?)/.exec(line.slice(pos)))) {
+      pos += match[0].length
+      context.push(new Context(node, start, pos, "", match[1], ">", null))
+    } else if (node.name == "ListItem" && node.parent!.name == "OrderedList" &&
+               (match = /^([ \t]*)\d+([.)])([ \t]*)/.exec(nodeStart(node, doc)))) {
+      let after = match[3], len = match[0].length
+      if (after.length >= 4) { after = after.slice(0, after.length - 4); len -= 4 }
+      pos += len
+      context.push(new Context(node.parent!, start, pos, match[1], after, match[2], node))
+    } else if (node.name == "ListItem" && node.parent!.name == "BulletList" &&
+               (match = /^([ \t]*)([-+*])([ \t]+)/.exec(nodeStart(node, doc)))) {
+      let after = match[3], len = match[0].length
+      if (after.length > 4) { after = after.slice(0, after.length - 4); len -= 4 }
+      pos += len
+      context.push(new Context(node.parent!, start, pos, match[1], after, match[2], node))
+    }
+  }
+  return context
+}
+
+function itemNumber(item: SyntaxNode, doc: Text) {
+  return /^(\s*)(\d+)(?=[.)])/.exec(doc.sliceString(item.from, item.from + 10))!
+}
+
+function renumberList(after: SyntaxNode, doc: Text, changes: ChangeSpec[], offset = 0) {
+  for (let prev = -1, node = after;;) {
+    if (node.name == "ListItem") {
+      let m = itemNumber(node, doc)
+      let number = +m[2]
+      if (prev >= 0) {
+        if (number != prev + 1) return
+        changes.push({from: node.from + m[1].length, to: node.from + m[0].length, insert: String(prev + 2 + offset)})
+      }
+      prev = number
+    }
+    let next = node.nextSibling
+    if (!next) break
+    node = next
+  }
+}
+
+/// This command, when invoked in Markdown context with cursor
+/// selection(s), will create a new line with the markup for
+/// blockquotes and lists that were active on the old line. If the
+/// cursor was directly after the end of the markup for the old line,
+/// trailing whitespace and list markers are removed from that line.
+///
+/// The command does nothing in non-Markdown context, so it should
+/// not be used as the only binding for Enter (even in a Markdown
+/// document, HTML and code regions might use a different language).
+export const insertNewlineContinueMarkup: StateCommand = ({state, dispatch}) => {
+  let tree = syntaxTree(state), {doc} = state
+  let dont = null, changes = state.changeByRange(range => {
+    if (!range.empty || !markdownLanguage.isActiveAt(state, range.from)) return dont = {range}
+    let pos = range.from, line = doc.lineAt(pos)
+    let context = getContext(tree.resolveInner(pos, -1), line.text, doc)
+    while (context.length && context[context.length - 1].from > pos - line.from) context.pop()
+    if (!context.length) return dont = {range}
+    let inner = context[context.length - 1]
+    if (inner.to - inner.spaceAfter.length > pos - line.from) return dont = {range}
+
+    let emptyLine = pos >= (inner.to - inner.spaceAfter.length) && !/\S/.test(line.text.slice(inner.to))
+    // Empty line in list
+    if (inner.item && emptyLine) {
+      // First list item or blank line before: delete a level of markup
+      if (inner.node.firstChild!.to >= pos ||
+          line.from > 0 && !/[^\s>]/.test(doc.lineAt(line.from - 1).text)) {
+        let next = context.length > 1 ? context[context.length - 2] : null
+        let delTo, insert = ""
+        if (next && next.item) { // Re-add marker for the list at the next level
+          delTo = line.from + next.from
+          insert = next.marker(doc, 1)
+        } else {
+          delTo = line.from + (next ? next.to : 0)
+        }
+        let changes: ChangeSpec[] = [{from: delTo, to: pos, insert}]
+        if (inner.node.name == "OrderedList") renumberList(inner.item!, doc, changes, -2)
+        if (next && next.node.name == "OrderedList") renumberList(next.item!, doc, changes)
+        return {range: EditorSelection.cursor(delTo + insert.length), changes}
+      } else { // Move this line down
+        let insert = ""
+        for (let i = 0, e = context.length - 2; i <= e; i++) insert += context[i].blank(i < e)
+        insert += state.lineBreak
+        return {range: EditorSelection.cursor(pos + insert.length), changes: {from: line.from, insert}}
+      }
+    }
+
+    if (inner.node.name == "Blockquote" && emptyLine && line.from) {
+      let prevLine = doc.lineAt(line.from - 1), quoted = />\s*$/.exec(prevLine.text)
+      // Two aligned empty quoted lines in a row
+      if (quoted && quoted.index == inner.from) {
+        let changes = state.changes([{from: prevLine.from + quoted.index, to: prevLine.to},
+                                     {from: line.from + inner.from, to: line.to}])
+        return {range: range.map(changes), changes}
+      }
+    }
+
+    let changes: ChangeSpec[] = []
+    if (inner.node.name == "OrderedList") renumberList(inner.item!, doc, changes)
+    let insert = state.lineBreak
+    let continued = inner.item && inner.item.from < line.from
+    // If not dedented
+    if (!continued || /^[\s\d.)\-+*>]*/.exec(line.text)![0].length >= inner.to) {
+      for (let i = 0, e = context.length - 1; i <= e; i++)
+        insert += i == e && !continued ? context[i].marker(doc, 1) : context[i].blank()
+    }
+    let from = pos
+    while (from > line.from && /\s/.test(line.text.charAt(from - line.from - 1))) from--
+    changes.push({from, to: pos, insert})
+    return {range: EditorSelection.cursor(from + insert.length), changes}
+  })
+  if (dont) return false
+  dispatch(state.update(changes, {scrollIntoView: true, userEvent: "input"}))
+  return true
+}
+
+function isMark(node: SyntaxNode) {
+  return node.name == "QuoteMark" || node.name == "ListMark"
+}
+
+function contextNodeForDelete(tree: Tree, pos: number) {
+  let node = tree.resolveInner(pos, -1), scan = pos
+  if (isMark(node)) {
+    scan = node.from
+    node = node.parent!
+  }
+  for (let prev; prev = node.childBefore(scan);) {
+    if (isMark(prev)) {
+      scan = prev.from
+    } else if (prev.name == "OrderedList" || prev.name == "BulletList") {
+      node = prev.lastChild!
+      scan = node.to
+    } else {
+      break
+    }
+  }
+  return node
+}
+
+/// This command will, when invoked in a Markdown context with the
+/// cursor directly after list or blockquote markup, delete one level
+/// of markup. When the markup is for a list, it will be replaced by
+/// spaces on the first invocation (a further invocation will delete
+/// the spaces), to make it easy to continue a list.
+///
+/// When not after Markdown block markup, this command will return
+/// false, so it is intended to be bound alongside other deletion
+/// commands, with a higher precedence than the more generic commands.
+export const deleteMarkupBackward: StateCommand = ({state, dispatch}) => {
+  let tree = syntaxTree(state)
+  let dont = null, changes = state.changeByRange(range => {
+    let pos = range.from, {doc} = state
+    if (range.empty && markdownLanguage.isActiveAt(state, range.from)) {
+      let line = doc.lineAt(pos)
+      let context = getContext(contextNodeForDelete(tree, pos), line.text, doc)
+      if (context.length) {
+        let inner = context[context.length - 1]
+        let spaceEnd = inner.to - inner.spaceAfter.length + (inner.spaceAfter ? 1 : 0)
+        // Delete extra trailing space after markup
+        if (pos - line.from > spaceEnd && !/\S/.test(line.text.slice(spaceEnd, pos - line.from)))
+          return {range: EditorSelection.cursor(line.from + spaceEnd),
+                  changes: {from: line.from + spaceEnd, to: pos}}
+        if (pos - line.from == spaceEnd) {
+          let start = line.from + inner.from
+          // Replace a list item marker with blank space
+          if (inner.item && inner.node.from < inner.item.from && /\S/.test(line.text.slice(inner.from, inner.to)))
+            return {range, changes: {from: start, to: line.from + inner.to, insert: inner.blank()}}
+          // Delete one level of indentation
+          if (start < pos)
+            return {range: EditorSelection.cursor(start), changes: {from: start, to: pos}}
+        }
+      }
+    }
+    return dont = {range}
+  })
+  if (dont) return false
+  dispatch(state.update(changes, {scrollIntoView: true, userEvent: "delete"}))
+  return true
+}

webapp/src/markdown/index.js

@@ -0,0 +1,37 @@
+import { Prec } from "@codemirror/state";
+import { keymap } from "@codemirror/view";
+import { LanguageSupport } from "@codemirror/language";
+import { MarkdownParser, parseCode } from "@lezer/markdown";
+import { html } from "@codemirror/lang-html";
+import { commonmarkLanguage, markdownLanguage, mkLang, getCodeParser } from "./markdown";
+import { insertNewlineContinueMarkup, deleteMarkupBackward } from "./commands";
+export { commonmarkLanguage, markdownLanguage, insertNewlineContinueMarkup, deleteMarkupBackward };
+/// A small keymap with Markdown-specific bindings. Binds Enter to
+/// [`insertNewlineContinueMarkup`](#lang-markdown.insertNewlineContinueMarkup)
+/// and Backspace to
+/// [`deleteMarkupBackward`](#lang-markdown.deleteMarkupBackward).
+export const markdownKeymap = [
+    { key: "Enter", run: insertNewlineContinueMarkup },
+    { key: "Backspace", run: deleteMarkupBackward }
+];
+const htmlNoMatch = html({ matchClosingTags: false });
+/// Markdown language support.
+export function markdown(config = {}) {
+    let { codeLanguages, defaultCodeLanguage, addKeymap = true, base: { parser } = commonmarkLanguage } = config;
+    if (!(parser instanceof MarkdownParser))
+        throw new RangeError("Base parser provided to `markdown` should be a Markdown parser");
+    let extensions = config.extensions ? [config.extensions] : [];
+    let support = [htmlNoMatch.support], defaultCode;
+    if (defaultCodeLanguage instanceof LanguageSupport) {
+        support.push(defaultCodeLanguage.support);
+        defaultCode = defaultCodeLanguage.language;
+    }
+    else if (defaultCodeLanguage) {
+        defaultCode = defaultCodeLanguage;
+    }
+    let codeParser = codeLanguages || defaultCode ? getCodeParser(codeLanguages || [], defaultCode) : undefined;
+    extensions.push(parseCode({ codeParser, htmlParser: htmlNoMatch.language.parser }));
+    if (addKeymap)
+        support.push(Prec.high(keymap.of(markdownKeymap)));
+    return new LanguageSupport(mkLang(parser.configure(extensions)), support);
+}

webapp/src/markdown/index.ts

@@ -0,0 +1,56 @@
+import {Prec} from "@codemirror/state"
+import {KeyBinding, keymap} from "@codemirror/view"
+import {Language, LanguageSupport, LanguageDescription} from "@codemirror/language"
+import {MarkdownExtension, MarkdownParser, parseCode} from "@lezer/markdown"
+import {html} from "@codemirror/lang-html"
+import {commonmarkLanguage, markdownLanguage, mkLang, getCodeParser} from "./markdown"
+import {insertNewlineContinueMarkup, deleteMarkupBackward} from "./commands"
+export {commonmarkLanguage, markdownLanguage, insertNewlineContinueMarkup, deleteMarkupBackward}
+
+/// A small keymap with Markdown-specific bindings. Binds Enter to
+/// [`insertNewlineContinueMarkup`](#lang-markdown.insertNewlineContinueMarkup)
+/// and Backspace to
+/// [`deleteMarkupBackward`](#lang-markdown.deleteMarkupBackward).
+export const markdownKeymap: readonly KeyBinding[] = [
+  {key: "Enter", run: insertNewlineContinueMarkup},
+  {key: "Backspace", run: deleteMarkupBackward}
+]
+
+const htmlNoMatch = html({matchClosingTags: false})
+
+/// Markdown language support.
+export function markdown(config: {
+  /// When given, this language will be used by default to parse code
+  /// blocks.
+  defaultCodeLanguage?: Language | LanguageSupport,
+  /// A collection of language descriptions to search through for a
+  /// matching language (with
+  /// [`LanguageDescription.matchLanguageName`](#language.LanguageDescription^matchLanguageName))
+  /// when a fenced code block has an info string.
+  codeLanguages?: readonly LanguageDescription[],
+  /// Set this to false to disable installation of the Markdown
+  /// [keymap](#lang-markdown.markdownKeymap).
+  addKeymap?: boolean,
+  /// Markdown parser
+  /// [extensions](https://github.com/lezer-parser/markdown#user-content-markdownextension)
+  /// to add to the parser.
+  extensions?: MarkdownExtension,
+  /// The base language to use. Defaults to
+  /// [`commonmarkLanguage`](#lang-markdown.commonmarkLanguage).
+  base?: Language
+} = {}) {
+  let {codeLanguages, defaultCodeLanguage, addKeymap = true, base: {parser} = commonmarkLanguage} = config
+  if (!(parser instanceof MarkdownParser)) throw new RangeError("Base parser provided to `markdown` should be a Markdown parser")
+  let extensions = config.extensions ? [config.extensions] : []
+  let support = [htmlNoMatch.support], defaultCode
+  if (defaultCodeLanguage instanceof LanguageSupport) {
+    support.push(defaultCodeLanguage.support)
+    defaultCode = defaultCodeLanguage.language
+  } else if (defaultCodeLanguage) {
+    defaultCode = defaultCodeLanguage
+  }
+  let codeParser = codeLanguages || defaultCode ? getCodeParser(codeLanguages || [], defaultCode) : undefined
+  extensions.push(parseCode({codeParser, htmlParser: htmlNoMatch.language.parser}))
+  if (addKeymap) support.push(Prec.high(keymap.of(markdownKeymap)))
+  return new LanguageSupport(mkLang(parser.configure(extensions)), support)
+}

webapp/src/markdown/markdown.js

@@ -0,0 +1,75 @@
+import { Language, defineLanguageFacet, languageDataProp, foldNodeProp, indentNodeProp, LanguageDescription, ParseContext } from "@codemirror/language";
+import { styleTags, tags as t } from "@codemirror/highlight";
+import { parser as baseParser, GFM, Subscript, Superscript, Emoji } from "@lezer/markdown";
+const data = defineLanguageFacet({ block: { open: "<!--", close: "-->" } });
+export const commonmark = baseParser.configure({
+    props: [
+        styleTags({
+            "Blockquote/...": t.quote,
+            HorizontalRule: t.contentSeparator,
+            "ATXHeading1/... SetextHeading1/...": t.heading1,
+            "ATXHeading2/... SetextHeading2/...": t.heading2,
+            "ATXHeading3/...": t.heading3,
+            "ATXHeading4/...": t.heading4,
+            "ATXHeading5/...": t.heading5,
+            "ATXHeading6/...": t.heading6,
+            "Comment CommentBlock": t.comment,
+            Escape: t.escape,
+            Entity: t.character,
+            "Emphasis/...": t.emphasis,
+            "StrongEmphasis/...": t.strong,
+            "Link/... Image/...": t.link,
+            "OrderedList/... BulletList/...": t.list,
+            // "CodeBlock/... FencedCode/...": t.blockComment,
+            "InlineCode CodeText": t.monospace,
+            URL: t.url,
+            "HeaderMark HardBreak QuoteMark ListMark LinkMark EmphasisMark CodeMark": t.processingInstruction,
+            "CodeInfo LinkLabel": t.labelName,
+            LinkTitle: t.string,
+            Paragraph: t.content
+        }),
+        foldNodeProp.add(type => {
+            if (!type.is("Block") || type.is("Document"))
+                return undefined;
+            return (tree, state) => ({ from: state.doc.lineAt(tree.from).to, to: tree.to });
+        }),
+        indentNodeProp.add({
+            Document: () => null
+        }),
+        languageDataProp.add({
+            Document: data
+        })
+    ]
+});
+export function mkLang(parser) {
+    return new Language(data, parser, parser.nodeSet.types.find(t => t.name == "Document"));
+}
+/// Language support for strict CommonMark.
+export const commonmarkLanguage = mkLang(commonmark);
+const extended = commonmark.configure([GFM, Subscript, Superscript, Emoji, {
+        props: [
+            styleTags({
+                "TableDelimiter SubscriptMark SuperscriptMark StrikethroughMark": t.processingInstruction,
+                "TableHeader/...": t.heading,
+                "Strikethrough/...": t.strikethrough,
+                TaskMarker: t.atom,
+                Task: t.list,
+                Emoji: t.character,
+                "Subscript Superscript": t.special(t.content),
+                TableCell: t.content
+            })
+        ]
+    }]);
+/// Language support for [GFM](https://github.github.com/gfm/) plus
+/// subscript, superscript, and emoji syntax.
+export const markdownLanguage = mkLang(extended);
+export function getCodeParser(languages, defaultLanguage) {
+    return (info) => {
+        let found = info && LanguageDescription.matchLanguageName(languages, info, true);
+        if (!found)
+            return defaultLanguage ? defaultLanguage.parser : null;
+        if (found.support)
+            return found.support.language.parser;
+        return ParseContext.getSkippingParser(found.load());
+    };
+}

webapp/src/markdown/markdown.ts

@@ -0,0 +1,84 @@
+import {
+    Language, defineLanguageFacet, languageDataProp, foldNodeProp, indentNodeProp,
+    LanguageDescription, ParseContext
+} from "@codemirror/language"
+import {styleTags, tags as t} from "@codemirror/highlight"
+import {parser as baseParser, MarkdownParser, GFM, Subscript, Superscript, Emoji, MarkdownConfig} from "@lezer/markdown"
+
+const data = defineLanguageFacet({block: {open: "<!--", close: "-->"}})
+
+export const commonmark = baseParser.configure({
+    props: [
+        styleTags({
+            "Blockquote/...": t.quote,
+            HorizontalRule: t.contentSeparator,
+            "ATXHeading1/... SetextHeading1/...": t.heading1,
+            "ATXHeading2/... SetextHeading2/...": t.heading2,
+            "ATXHeading3/...": t.heading3,
+            "ATXHeading4/...": t.heading4,
+            "ATXHeading5/...": t.heading5,
+            "ATXHeading6/...": t.heading6,
+            "Comment CommentBlock": t.comment,
+            Escape: t.escape,
+            Entity: t.character,
+            "Emphasis/...": t.emphasis,
+            "StrongEmphasis/...": t.strong,
+            "Link/... Image/...": t.link,
+            "OrderedList/... BulletList/...": t.list,
+
+            // "CodeBlock/... FencedCode/...": t.blockComment,
+            "InlineCode CodeText": t.monospace,
+            URL: t.url,
+            "HeaderMark HardBreak QuoteMark ListMark LinkMark EmphasisMark CodeMark": t.processingInstruction,
+            "CodeInfo LinkLabel": t.labelName,
+            LinkTitle: t.string,
+            Paragraph: t.content
+        }),
+        foldNodeProp.add(type => {
+            if (!type.is("Block") || type.is("Document")) return undefined
+            return (tree, state) => ({from: state.doc.lineAt(tree.from).to, to: tree.to})
+        }),
+        indentNodeProp.add({
+            Document: () => null
+        }),
+        languageDataProp.add({
+            Document: data
+        })
+    ]
+})
+
+export function mkLang(parser: MarkdownParser) {
+    return new Language(data, parser, parser.nodeSet.types.find(t => t.name == "Document")!)
+}
+
+/// Language support for strict CommonMark.
+export const commonmarkLanguage = mkLang(commonmark)
+
+const extended = commonmark.configure([GFM, Subscript, Superscript, Emoji, {
+    props: [
+        styleTags({
+            "TableDelimiter SubscriptMark SuperscriptMark StrikethroughMark": t.processingInstruction,
+            "TableHeader/...": t.heading,
+            "Strikethrough/...": t.strikethrough,
+            TaskMarker: t.atom,
+            Task: t.list,
+            Emoji: t.character,
+            "Subscript Superscript": t.special(t.content),
+            TableCell: t.content
+        })
+    ]
+}])
+
+/// Language support for [GFM](https://github.github.com/gfm/) plus
+/// subscript, superscript, and emoji syntax.
+export const markdownLanguage = mkLang(extended)
+
+export function getCodeParser(languages: readonly LanguageDescription[],
+                              defaultLanguage?: Language) {
+    return (info: string) => {
+        let found = info && LanguageDescription.matchLanguageName(languages, info, true)
+        if (!found) return defaultLanguage ? defaultLanguage.parser : null
+        if (found.support) return found.support.language.parser
+        return ParseContext.getSkippingParser(found.load())
+    }
+}

webapp/src/parser.js

@@ -0,0 +1,57 @@
+import { styleTags } from '@codemirror/highlight';
+import { commonmark, mkLang } from "./markdown/markdown";
+import * as ct from './customtags';
+const WikiLink = {
+    defineNodes: ["WikiLink"],
+    parseInline: [{
+            name: "WikiLink",
+            parse(cx, next, pos) {
+                let match;
+                if (next != 91 /* '[' */ || !(match = /^\[[^\]]+\]\]/.exec(cx.slice(pos + 1, cx.end)))) {
+                    return -1;
+                }
+                return cx.addElement(cx.elt("WikiLink", pos, pos + 1 + match[0].length));
+            },
+            after: "Emphasis"
+        }]
+};
+const AtMention = {
+    defineNodes: ["AtMention"],
+    parseInline: [{
+            name: "AtMention",
+            parse(cx, next, pos) {
+                let match;
+                if (next != 64 /* '@' */ || !(match = /^[A-Za-z\.]+/.exec(cx.slice(pos + 1, cx.end)))) {
+                    return -1;
+                }
+                return cx.addElement(cx.elt("AtMention", pos, pos + 1 + match[0].length));
+            },
+            after: "Emphasis"
+        }]
+};
+const TagLink = {
+    defineNodes: ["TagLink"],
+    parseInline: [{
+            name: "TagLink",
+            parse(cx, next, pos) {
+                let match;
+                if (next != 35 /* '#' */ || !(match = /^[A-Za-z\.]+/.exec(cx.slice(pos + 1, cx.end)))) {
+                    return -1;
+                }
+                return cx.addElement(cx.elt("TagLink", pos, pos + 1 + match[0].length));
+            },
+            after: "Emphasis"
+        }]
+};
+const WikiMarkdown = commonmark.configure([WikiLink, AtMention, TagLink, {
+        props: [
+            styleTags({
+                WikiLink: ct.WikiLinkTag,
+                AtMention: ct.MentionTag,
+                TagLink: ct.TagTag,
+            })
+        ]
+    }]);
+/// Language support for [GFM](https://github.github.com/gfm/) plus
+/// subscript, superscript, and emoji syntax.
+export default mkLang(WikiMarkdown);

webapp/src/parser.ts

@@ -0,0 +1,60 @@
+import { styleTags } from '@codemirror/highlight';
+import { MarkdownConfig } from "@lezer/markdown";
+import { commonmark, mkLang } from "./markdown/markdown";
+import * as ct from './customtags';
+
+const WikiLink: MarkdownConfig = {
+    defineNodes: ["WikiLink"],
+    parseInline: [{
+        name: "WikiLink",
+        parse(cx, next, pos) {
+            let match: RegExpMatchArray | null;
+            if (next != 91 /* '[' */ || !(match = /^\[[^\]]+\]\]/.exec(cx.slice(pos + 1, cx.end)))) {
+                return -1;
+            }
+            return cx.addElement(cx.elt("WikiLink", pos, pos + 1 + match[0].length));
+        },
+        after: "Emphasis"
+    }]
+};
+const AtMention: MarkdownConfig = {
+    defineNodes: ["AtMention"],
+    parseInline: [{
+        name: "AtMention",
+        parse(cx, next, pos) {
+            let match: RegExpMatchArray | null;
+            if (next != 64 /* '@' */ || !(match = /^[A-Za-z\.]+/.exec(cx.slice(pos + 1, cx.end)))) {
+                return -1;
+            }
+            return cx.addElement(cx.elt("AtMention", pos, pos + 1 + match[0].length));
+        },
+        after: "Emphasis"
+    }]
+};
+const TagLink: MarkdownConfig = {
+    defineNodes: ["TagLink"],
+    parseInline: [{
+        name: "TagLink",
+        parse(cx, next, pos) {
+            let match: RegExpMatchArray | null;
+            if (next != 35 /* '#' */ || !(match = /^[A-Za-z\.]+/.exec(cx.slice(pos + 1, cx.end)))) {
+                return -1;
+            }
+            return cx.addElement(cx.elt("TagLink", pos, pos + 1 + match[0].length));
+        },
+        after: "Emphasis"
+    }]
+};
+const WikiMarkdown = commonmark.configure([WikiLink, AtMention, TagLink, {
+    props: [
+        styleTags({
+            WikiLink: ct.WikiLinkTag,
+            AtMention: ct.MentionTag,
+            TagLink: ct.TagTag,
+        })
+    ]
+}]);
+/// Language support for [GFM](https://github.github.com/gfm/) plus
+/// subscript, superscript, and emoji syntax.
+
+export default mkLang(WikiMarkdown);

webapp/src/style.js

@@ -0,0 +1,31 @@
+import { HighlightStyle, tags as t } from '@codemirror/highlight';
+import * as ct from './customtags';
+export default HighlightStyle.define([
+    { tag: t.heading1, class: "h1" },
+    { tag: t.heading2, class: "h2" },
+    { tag: t.link, class: "link" },
+    { tag: t.meta, class: "meta" },
+    { tag: t.quote, class: "quote" },
+    { tag: t.monospace, class: "code" },
+    { tag: t.url, class: "url" },
+    { tag: ct.WikiLinkTag, class: "wiki-link" },
+    { tag: ct.TagTag, class: "tag" },
+    { tag: ct.MentionTag, class: "mention" },
+    { tag: t.emphasis, class: "emphasis" },
+    { tag: t.strong, class: "strong" },
+    { tag: t.atom, class: "atom" },
+    { tag: t.bool, class: "bool" },
+    { tag: t.url, class: "url" },
+    { tag: t.inserted, class: "inserted" },
+    { tag: t.deleted, class: "deleted" },
+    { tag: t.literal, class: "literal" },
+    { tag: t.list, class: "list" },
+    { tag: t.definition, class: "li" },
+    { tag: t.string, class: "string" },
+    { tag: t.number, class: "number" },
+    { tag: [t.regexp, t.escape, t.special(t.string)], class: "string2" },
+    { tag: t.variableName, class: "variableName" },
+    { tag: t.comment, class: "comment" },
+    { tag: t.invalid, class: "invalid" },
+    { tag: t.punctuation, class: "punctuation" }
+]);

webapp/src/style.ts

@@ -0,0 +1,32 @@
+import { HighlightStyle, tags as t } from '@codemirror/highlight';
+import * as ct from './customtags';
+
+export default HighlightStyle.define([
+    { tag: t.heading1, class: "h1" },
+    { tag: t.heading2, class: "h2" },
+    { tag: t.link, class: "link" },
+    { tag: t.meta, class: "meta" },
+    { tag: t.quote, class: "quote" },
+    { tag: t.monospace, class: "code" },
+    { tag: t.url, class: "url" },
+    { tag: ct.WikiLinkTag, class: "wiki-link" },
+    { tag: ct.TagTag, class: "tag" },
+    { tag: ct.MentionTag, class: "mention" },
+    { tag: t.emphasis, class: "emphasis" },
+    { tag: t.strong, class: "strong" },
+    { tag: t.atom, class: "atom" },
+    { tag: t.bool, class: "bool" },
+    { tag: t.url, class: "url" },
+    { tag: t.inserted, class: "inserted" },
+    { tag: t.deleted, class: "deleted" },
+    { tag: t.literal, class: "literal" },
+    { tag: t.list, class: "list" },
+    { tag: t.definition, class: "li" },
+    { tag: t.string, class: "string" },
+    { tag: t.number, class: "number" },
+    { tag: [t.regexp, t.escape, t.special(t.string)], class: "string2" },
+    { tag: t.variableName, class: "variableName" },
+    { tag: t.comment, class: "comment" },
+    { tag: t.invalid, class: "invalid" },
+    { tag: t.punctuation, class: "punctuation" }
+]);

webapp/src/styles.css

@@ -0,0 +1,132 @@
+html,
+body {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+}
+
+body {
+  display: flex;
+  flex-direction: column;
+}
+
+#top {
+  height: 40px;
+  background-color: #eee;
+}
+
+#bottom {
+  height: 40px;
+  background-color: #eee;
+  margin: 0;
+}
+
+#editor {
+  flex-grow: 1;
+  width: 100%;
+  overflow-y: hidden;
+}
+
+:root {
+  --ident: 18px;
+}
+
+.cm-editor {
+  width: 100%;
+  height: 100%;
+  font-size: var(--ident);
+}
+
+.cm-editor .cm-content {
+  font-family: "Menlo";
+  margin: 25px;
+}
+
+.cm-editor .cm-selectionBackground {
+  background-color: #d7e1f6 !important;
+}
+
+.cm-editor .h1 {
+  font-size: 1.5em;
+  color: #fff;
+  font-weight: bold;
+}
+
+.cm-editor .cm-line.line-h1 {
+  display: block;
+  background-color: rgba(0, 15, 52, 0.6);
+}
+
+.cm-editor .h1.meta {
+  color: orange;
+}
+
+.cm-editor .h2 {
+  font-size: 1.2em;
+  color: #fff;
+  font-weight: bold;
+}
+
+.cm-editor .cm-line.line-h2 {
+  display: block;
+  background-color: rgba(0, 15, 52, 0.6);
+}
+
+.cm-editor .h2.meta {
+  color: orange;
+}
+
+.cm-editor .line-code {
+  background-color: #efefef;
+  margin-left: 30px;
+}
+
+.cm-editor .line-fenced-code {
+  background-color: #efefef;
+}
+
+.cm-editor .meta {
+  color: #520130;
+}
+
+.cm-editor .line-blockquote {
+  background-color: #eee;
+  color: #676767;
+  text-indent: calc(-1 * (var(--ident) + 3px));
+  padding-left: var(--ident);
+}
+
+.cm-editor .emphasis {
+  font-style: italic;
+}
+
+.cm-editor .strong {
+  font-weight: 900;
+}
+
+.cm-editor .link:not(.meta, .url) {
+  color: #0330cb;
+  text-decoration: underline;
+}
+
+.cm-editor .link.url {
+  color: #7e7d7d;
+}
+
+.cm-editor .wiki-link {
+  color: #0330cb;
+  /*text-decoration: underline;*/
+}
+
+.cm-editor .mention {
+  color: gray;
+}
+
+.cm-editor .tag {
+  color: #8d8d8d;
+}
+
+.cm-editor .line-li {
+  text-indent: calc(-1 * var(--ident) - 3px);
+  margin-left: var(--ident);
+}