[SR-3582] Counting emoji flags

[swift-ci]

Previous ID	SR-3582
Radar	None
Original Reporter	S2dent (JIRA User)
Type	Bug
Status	Resolved
Resolution	Invalid

Environment

MacOSX iOS

Additional Detail from JIRA

Votes	0
Component/s	Standard Library
Labels	Bug
Assignee	None
Priority	Medium

md5: 3ed43ec703bc4462ba30ecf03b6067e2

is duplicated by:

• SR-4077 Consecutive flag emoji are treated as a single character

relates to:

• SR-6076 [String] var count: String.CharacterView.IndexDistance { get } returns a wrong value on Linux when "Regional Indicator Symbols" are contained.

Issue Description:

Flags are not distinguished in characters.count

Example:

 // Here are three country flags emojis
let flags = "\u{1F1E6}\u{1F1E8}\u{1F1F7}\u{1F1F4}\u{1F1F7}\u{1F1FA}"
flags.characters.count // 1

No matter how many flags, or in which order, the result is always 1.

[belkadan]

This is "correct" (standards-compliant) behavior in Unicode 8, and will be "fixed" when Swift upgrades to implement Unicode 9.

[belkadan]

For more information, see UAX #29 in Unicode 8 and Unicode 9.