Each iteration on string containing " of " leads to an "Syntax Error: Unexpected token" error

each link in ['Terms of service', 'Privacy policy', 'License']
  a= link

  > 1| each link in ['Terms of service', 'Privacy policy', 'License']
--------------------------------------^
    2|   a= link
    3|

Syntax Error: Unexpected token
    at makeError (node_modules/pug-error/lib/index.js:34:15)
    at Lexer.error (node_modules/pug-lexer/index.js:62:15)
    at Lexer.assertExpression (node_modules/pug-lexer/index.js:96:12)
    at Lexer.eachOf (node_modules/pug-lexer/index.js:1095:12)
    at Lexer.callLexerFunction (node_modules/pug-lexer/index.js:1647:23)
    at Lexer.advance (node_modules/pug-lexer/index.js:1676:12)
    at Lexer.callLexerFunction (node_modules/pug-lexer/index.js:1647:23)
    at Lexer.getTokens (node_modules/pug-lexer/index.js:1706:12)
    at lex (node_modules/pug-lexer/index.js:12:42)
    at Object.lex (node_modules/pug/lib/index.js:104:9) {
  code: 'PUG:SYNTAX_ERROR',
  msg: 'Syntax Error: Unexpected token',
  line: 1,
  column: 32,
  filename: 'test.pug',
  src: "each link in ['Terms of service', 'Privacy policy', 'License']\n  a= link\n",
  toJSON: [Function (anonymous)]
}