AoC 2022, day 3, part 2 (smalltalk)

#!/usr/local/bin/gst -q

Collection extend [
    apply: method [ ^self collect: [:x | x perform: method] ]
]

Character extend [
    " XXX: assuming only letters "
    priority [
        ^self isLowercase ifTrue:  [ self asInteger - 96 ]
                          ifFalse: [ self asInteger - 38 ]  " - 64 + 26 "
    ]
]

"
| Mainline
"
part2 := 0.

sacks := ReadStream on: (stdin contents lines apply: #asSet).

[ sacks atEnd ] whileFalse: [
    badge := (sacks next: 3) fold: [:a :b | a & b].
    part2 := part2 + badge anyOne priority
].

('Part 2: %1' % {part2}) displayNl.