Index?  Function Summary
Summary:
Returns the index number of the current position in the series.
Usage:
index? series
Arguments:
series  The series argument. (must be: series port)
Description:
The index function returns the position within a series. For
example, the first value in a series is an index of one, the
second is an index of two, etc.
str: "with all things considered"
print index? str
1 
print index? find str "things"
10 
blk: [264 "Rebol Dr." "Calpella" CA 95418]
print index? find blk 95418
5 
Use the OFFSET? function when you need the index difference
between two positions in a series.
Related:
head  Returns the series at its head. head?  Returns TRUE if a series is at its head. length?  Returns the length of the series from the current position. offset?  Returns the offset between two series positions. pick  Returns the value at the specified position in a series. skip  Returns the series forward or backward from the current position. tail  Returns the series at the position after the last value. tail?  Returns TRUE if a series is at its tail.
