How to do a bit mask operation Pharo?

Question

In Pharo, I want to do bit masking on integers, which looks like this in Python:

((b1 & 0x3F) << 4) | (b2 >> 4)

I know that & and | work in Pharo, but I'm pretty sure they're not bit-wise.

Answer 1

but you are wrong :)

look at the implementation of &, |, <<, >> in Pharo:

& aNumber
    ^ self bitAnd: aNumber

| anInteger
    ^self bitOr: anInteger

<< shiftAmount
    "left shift"

    shiftAmount < 0 ifTrue: [self error: 'negative arg'].
    ^ self bitShift: shiftAmount

>> shiftAmount
    "right shift"

    shiftAmount < 0 ifTrue: [self error: 'negative arg'].
    ^ self bitShift: 0 - shiftAmount

That basically means that your code will work out of the box except for the translation of hex C style to hex Pharo style:

((b1 & 16r3F) << 4) | (b2 >> 4)