Return a tuple of (past, future) elements
时间解析的额外参数,适应一些语义模糊的情况
按历法调整参考时间范围,农历1850~2150,上下2000年
Performs best when pred1 is smaller grain than pred2
Limits how deep into lists of segments to look
Applies f
to each interval yielded by g
.
Applies f
to each interval yielded by g
.
Intervals including "now" are in the future.
Given an interval and range, compute a single new interval
First-layer series generator
Series generator for values that come from f