Find overlap between 2 integer conversions of hex strings

i have some area flags in hex format e.g. "090A", "3BFF", "0400", "2025".

In SQL I can use the following syntax to work out the overlap between 2 area flags, for example:

SELECT 
STRTOL('090A', 16) as area1
,STRTOL('3BFF', 16) as area2
,STRTOL('090A', 16) & STRTOL('3BFF', 16) as overlap;

this shows that area1 is fully included in area2.

Another example:

SELECT 
STRTOL('0400', 16) as area3
,STRTOL('2025', 16) as area4
,STRTOL('0400', 16) & STRTOL('2025', 16) as overlap;

this shows that there is no overlap between area3 and area4.

I see we can use R.utils::strtoi and that gives me the same conversion for each area that I get in SQL. However if i use the syntax

strtoi("0400", 16L) & strtoi("2025", 16L)

I get TRUE even when there is no overlap. Is there a way to get the overlap in R using strtoi like we can in SQL?

You can use the function bitwAnd() to compute the bitwise and:

bitwAnd(strtoi("0400", 16L), strtoi("2025", 16L))
## [1] 0
bitwAnd(strtoi("090A", 16L), strtoi("3BFF", 16L))
## [1] 2314

The reason that this

strtoi("0400", 16L) & strtoi("2025", 16L)

gives TRUE is the following: & is the logical and-operator in R. And numbers larger than 0 are converted to TRUE. So your code is equivalent to

TRUE & TRUE

which evaluates to TRUE.