Method concatenate

packages/messageformat/src/compiler.js:91–96

(tokens, root)

  }

  concatenate(tokens, root) {
    const asValues = this.options.returnType === 'values';
    return asValues && (root || tokens.length > 1)
      ? '[' + tokens.join(', ') + ']'
      : tokens.join(' + ') || '""';
  }

  token(token, pluralToken) {
    if (typeof token == 'string') return JSON.stringify(token);