[ty] Improve .toml support in the ty playground

playground/shared/src/Icons.tsx

@@ -255,6 +255,27 @@ export function Json({
   );
 }
 
+/** https://github.com/material-extensions/vscode-material-icon-theme/blob/main/icons/toml.svg **/
+export function Toml({
+  height = 24,
+  width = 24,
+}: {
+  height?: number;
+  width?: number;
+}) {
+  return (
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      viewBox="0 0 16 16"
+      width={width}
+      height={height}
+    >
+      <path fill="#cfd8dc" d="M4 6V4h8v2H9v7H7V6z" />
+      <path fill="#ef5350" d="M4 1v1H2v12h2v1H1V1zm8 0v1h2v12h-2v1h3V1z" />
+    </svg>
+  );
+}
+
 /** https://github.com/material-extensions/vscode-material-icon-theme/blob/main/icons/jupyter.svg **/
 export function Jupyter({
   height = 24,

playground/shared/src/setupMonaco.tsx

@@ -37,6 +37,7 @@ export function setupMonaco(
   defineFirLanguage(monaco);
   defineRustPythonTokensLanguage(monaco);
   defineRustPythonAstLanguage(monaco);
+  defineTomlLanguage(monaco);
   defineCommentsLanguage(monaco);
 
   monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
@@ -832,3 +833,122 @@ function defineFirLanguage(monaco: Monaco) {
     ],
   });
 }
+
+function defineTomlLanguage(monaco: Monaco) {
+  monaco.languages.register({
+    id: "toml",
+    extensions: [".toml"],
+    aliases: ["TOML", "toml"],
+  });
+
+  monaco.languages.setMonarchTokensProvider("toml", {
+    keywords: ["true", "false"],
+    tokenizer: {
+      root: [
+        // Comments
+        [/#.*$/, "comment"],
+
+        // Array-of-tables header: [[...]]
+        [/^\s*\[\[/, { token: "tag", next: "@array_table" }],
+
+        // Table header: [...]
+        [/^\s*\[/, { token: "tag", next: "@table" }],
+
+        // Whitespace
+        [/[ \t\r\n]+/, "white"],
+
+        // Keys are context-sensitive in TOML. Match the full left-hand side of
+        // a key/value pair before value rules run, otherwise identifiers like
+        // `include` compete with value tokens and numeric prefixes in values
+        // such as `79.5` or `07:32:00.123` get misclassified as keys.
+        [
+          /(?:"(?:[^"\\]|\\.)*"|'[^']*'|[A-Za-z0-9_-]+)(?:\s*\.\s*(?:"(?:[^"\\]|\\.)*"|'[^']*'|[A-Za-z0-9_-]+))*\s*(?==)/,
+          "variable",
+        ],
+
+        // Key-value separator
+        [/=/, "delimiter"],
+
+        // Multiline strings (must come before single-line strings)
+        [/"""/, { token: "string", next: "@multiline_basic_string" }],
+        [/'''/, { token: "string", next: "@multiline_literal_string" }],
+
+        // Single-line strings
+        [/"/, { token: "string", next: "@basic_string" }],
+        [/'/, { token: "string", next: "@literal_string" }],
+
+        // Numbers: hex, octal, binary, then float/int
+        [/0x[0-9a-fA-F][0-9a-fA-F_]*/, "number"],
+        [/0o[0-7][0-7_]*/, "number"],
+        [/0b[01][01_]*/, "number"],
+        [/[-+]?(?:inf|nan)/, "number"],
+        // Date-time (ISO 8601)
+        [
+          /\d{4}-\d{2}-\d{2}[T ]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}:\d{2})?/,
+          "number",
+        ],
+        // Float
+        [/[-+]?\d[\d_]*(?:\.[\d_]+)?(?:[eE][-+]?[\d_]+)?/, "number"],
+
+        // Booleans / keywords
+        [
+          /[a-zA-Z_][\w-]*/,
+          {
+            cases: {
+              "@keywords": "keyword",
+              "@default": "variable",
+            },
+          },
+        ],
+
+        // Brackets (inline tables and arrays)
+        [/[{}[\]]/, "@brackets"],
+
+        // Punctuation
+        [/[,.]/, "delimiter"],
+      ],
+
+      table: [
+        [/\]\]/, { token: "tag", next: "@pop" }],
+        [/\]/, { token: "tag", next: "@pop" }],
+        [/[^\]]+/, "tag"],
+      ],
+
+      array_table: [
+        [/\]\]/, { token: "tag", next: "@pop" }],
+        [/[^\]]+/, "tag"],
+      ],
+
+      basic_string: [
+        [/[^"\\]+/, "string"],
+        [/\\(?:[btnfr"\\]|u[0-9a-fA-F]{4}|U[0-9a-fA-F]{8})/, "string.escape"],
+        [/"/, { token: "string", next: "@pop" }],
+      ],
+
+      literal_string: [
+        [/[^']+/, "string"],
+        [/'/, { token: "string", next: "@pop" }],
+      ],
+
+      multiline_basic_string: [
+        [/"""/, { token: "string", next: "@pop" }],
+        [
+          /\\(?:[btnfr"\\]|u[0-9a-fA-F]{4}|U[0-9a-fA-F]{8}|\n[ \t]*)/,
+          "string.escape",
+        ],
+        [/[^"\\]+/, "string"],
+        [/"/, "string"],
+      ],
+
+      multiline_literal_string: [
+        [/'''/, { token: "string", next: "@pop" }],
+        [/[^']+/, "string"],
+        [/'/, "string"],
+      ],
+    },
+    brackets: [
+      { open: "{", close: "}", token: "delimiter.curly" },
+      { open: "[", close: "]", token: "delimiter.bracket" },
+    ],
+  });
+}

playground/ty/src/Editor/Files.tsx

@@ -148,6 +148,8 @@ function FileEntry({ name, onClicked, onRenamed, selected }: FileEntryProps) {
       <Icons.Json width={12} height={12} />
     ) : extension === "ipynb" ? (
       <Icons.Jupyter width={12} height={12} />
+    ) : extension === "toml" ? (
+      <Icons.Toml width={12} height={12} />
     ) : (
       <Icons.File width={12} height={12} />
     );