Fix: allow literal tab

Author: antonmedv

build/index.cjs

@@ -88,7 +88,7 @@ function parse(source) {
         if (ch === `
 `)
           throw new SyntaxError(errorSnippet());
-        if (ch < " " || ch === "\x7F")
+        if (ch < " " && ch !== "	" || ch === "\x7F")
           throw new SyntaxError(errorSnippet());
         str += ch;
       }

build/index.js

@@ -104,7 +104,7 @@ export function parse(source: string): any {
         break
       } else if ((ch as string) === '\n') {
         throw new SyntaxError(errorSnippet())
-      } else if ((ch as string) < '\x20' || ch === '\x7F') {
+      } else if (((ch as string) < '\x20' && ch !== '\t') || ch === '\x7F') {
         throw new SyntaxError(errorSnippet())
       } else {
         str += ch

build/maml.min.js

@@ -61,6 +61,19 @@ describe('extra', () => {
     expect('MAML' in globalThis).toBeTruthy()
   })
 
+  test('string allows literal tab', () => {
+    const output = parse('"hello\tworld"')
+    expect(output).toStrictEqual('hello\tworld')
+  })
+
+  test('string rejects control char U+001F', () => {
+    expect(() => parse('"\x1F"')).toThrow()
+  })
+
+  test('string rejects DEL U+007F', () => {
+    expect(() => parse('"\x7F"')).toThrow()
+  })
+
   test('raw string with CRLF newlines', () => {
     const output = parse('"""line1\r\nline2\r\nline3"""')
     expect(output).toStrictEqual('line1\r\nline2\r\nline3')