[ASTERIXDB-2371] Implement null-related functions

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: FUN - Functions
• Assignee: Dmitry Lychagin
• Reporter: Dmitry Lychagin
• Created: 24/Apr/18 23:43
• Updated: 26/Apr/18 22:42
• Resolved: 26/Apr/18 22:42

Description

Implement null-related functions: MISSINGIF, NULLIF, NANIF, NEGINFIF, POSINFIF

they accept two arguments

1) if any argument is MISSING then result is MISSING
2) if any argument is NULL then result is NULL
3) if arg1 == arg2 then result MISSING/NULL/NaN/-INF/+INF (corresponding to the function name)
4) otherwise the result is arg1