BQN launch discards whitespace from input

[paul7]

Currently, BQN expects its input from command line arguments. However, using cat ... sends it through the shell's parser which tokenizes it using whitespace. Therefore all whitespace characters from input are lost.

https://github.com/aderepas/WeekGolf/blob/c95f32bb299d8d2d6b915ff2cecbefe9d1ca7fdc/docker/bqn/launch.sh#L9

[tkr-sh]

cat -v /mnt/in/input$testcount.txt

Should do it ?

[ovs-code]

Expanding on what I just said on Discord, I think there are two possible ways to fix this:

1. Pass input via stdin:

./bin/bqn -f /mnt/in/prog.bqn         \
    < /mnt/in/input$testcount.txt     \
    > /mnt/out/out$testcount.txt      \
    2> /mnt/out/err$testcount.txt

2. Pass input as a single command line argument. By my shell knowledge this should look something like this

./bin/bqn -f /mnt/in/prog.bqn         \
    "$(cat /mnt/in/input$testcount.txt)" \
    > /mnt/out/out$testcount.txt      \
    2> /mnt/out/err$testcount.txt

Either of those solution will break many of the existing solutions in BQN, but I think this is worth it to make sure future holes can be solved with BQN.

[ovs-code]

A third option, suggested by attinat: Pass each line of input as a separate command line argument, could be implemented as such:

cat /mnt/in/input$testcount.txt \
    | tr '\n' '\0' \
    | xargs -0 ./bin/bqn -f /mnt/in/prog.bqn \
    > /mnt/out/out$testcount.txt      \
    2> /mnt/out/err$testcount.txt

This has the advantage of keeping all existing solutions that dealt with one input per line working. Therefore my vote would be on this.