The UPOS Function

The UPOS function returns an integer value that is equal to the index of the nth UTF-8 or UTF-16 character in a character string argument that is encoded in UTF-8 or UTF-16.

The function type is integer.

General Format

Arguments

argument-1

Must be alphabetic, alphanumeric, national, or UTF-8. argument-1 must contain valid UTF-8 or UTF-16 data based on its class:

If argument-1 is of class alphabetic, alphanumeric, or UTF-8, it must contain valid UTF-8 data.
If argument-1 is of class national, it must contain valid UTF-16 data.

argument-2

The nth UTF-8 or UTF-16 character to locate in argument-1. argument-2 must be a positive integer and not exceed ULENGTH(argument-1), otherwise zero is returned.

Returned Value

The returned value is an integer that is equal to the index of the nth UTF-8 or UTF-16 character (as specified by argument-2) in argument-1.

Comments

This function supports ideographic variation selectors (IVS), allowing the font software to select a different glyph from the default. (If no variation exists or supported then the font software will ignore it.) An IVS consists of Unicode characters in the range U-E0100 – U-E01EF. UTF-16 strings use surrogate pairs in the range U-DB40 + DD00 - U-DB40 + DDEF, and UTF-8 strings use the range 0xF3A08480 - 0xF3A087AF.

A Unicode character followed by an IVS is treated as one character when this function is processed.