In my previous question I found the following about tone sandhi and yī 'one':
yī on its own or not followed by other tones
yī → yí when followed by a fourth tone
yī → yì when followed by other tones
I would like to know if tone sandhi effects the way that set idioms such as 成语 are pronounced.
A prime example is 一年四季, is this pronounced "yī nián sìjì" or "yì nián sìjì"