1 files changed, 74 insertions, 0 deletions
diff --git a/doc/_static/demo-worker.js b/doc/_static/demo-worker.js
new file mode 100644
index 0000000..22b8b3d
--- /dev/null
+++ b/doc/_static/demo-worker.js
@@ -0,0 +1,74 @@
+importScripts('/_static/pyodide/pyodide.js');
+
+async function loadPyodideAndPygments() {
+    self.pyodide = await loadPyodide();
+    await self.pyodide.loadPackage(["Pygments"]);
+    const styles = self.pyodide.runPython(`
+        from pygments.formatters.html import HtmlFormatter
+        from pygments.styles import STYLE_MAP
+        {s: HtmlFormatter(style=s).get_style_defs('.demo-highlight') for s in STYLE_MAP}
+    `).toJs();
+    self.postMessage({loaded: {styles}})
+}
+let pyodideReadyPromise = loadPyodideAndPygments();
+
+self.onmessage = async (event) => {
+    // Make sure loading is done.
+    await pyodideReadyPromise;
+    if (event.data.highlight) {
+        self.pyodide.globals.set('code', event.data.highlight.code);
+        self.pyodide.globals.set('lexer_name', event.data.highlight.lexer);
+
+        self.pyodide.runPython(`
+            import pygments.lexers
+
+            lexer = pygments.lexers.get_lexer_by_name(lexer_name)
+            if type(code) == memoryview:
+                code = bytes(code)
+            tokens = lexer.get_tokens(code)
+        `);
+
+        const formatter = event.data.highlight.formatter;
+        if (formatter == 'html') {
+
+            const html = self.pyodide.runPython(`
+                import io
+                from pygments.formatters.html import HtmlFormatter
+
+                fmter = HtmlFormatter(cssclass='demo-highlight')
+                buf = io.StringIO()
+                fmter.format(tokens, buf)
+                buf.getvalue()
+            `);
+            self.postMessage({html});
+        } else if (formatter == 'tokens') {
+            const tokens = self.pyodide.runPython('list(tokens)').toJs();
+            self.postMessage({tokens});
+        } else {
+            console.warn('unknown formatter:', formatter);
+        }
+    } else if (event.data.guess_lexer) {
+        self.pyodide.globals.set('code', event.data.guess_lexer.code);
+        self.pyodide.globals.set('filename', event.data.guess_lexer.filename);
+        const lexer = self.pyodide.runPython(`
+            import sys
+            sys.setrecursionlimit(1000)
+            # TODO: remove after upgrading to Pyodide 0.19
+
+            import pygments.lexers
+            import pygments.util
+
+            if type(code) == memoryview:
+                code = bytes(code)
+
+            if filename:
+                lexer = pygments.lexers.guess_lexer_for_filename(filename, code)
+            else:
+                lexer = pygments.lexers.guess_lexer(code)
+            lexer.aliases[0]
+        `);
+        self.postMessage({lexer});
+    } else {
+        console.warn('unknown command: expected highlight or guess_lexer but received ', event.data);
+    }
+}