nl_tokens: transform of to in ， 以支持for = item of items 语法
pl_tokens: function transformOfToIn ( newValue ) { const wordArray = newValue . trim ( ) . split ( ' ' ) ; const index = wordArray . indexOf ( 'of' ) ; if ( index !== - 1 && ! wordArray . includes ( 'in' ) ) { wordArray [ index ] = 'in' ; newValue = wordArray . <mask> ( ' ' ) ; } return newValue ; }