I think bitlogic operations is the best which you can use with bitstring. 

Congratulations, you did it.

Not sure, but maybe property method GetStored can help. It is ClassMethod which accept object Id as the first argument. Full name for the method <Property>GetStored(id)

I also solved this task, and I decided to choose a bit different way. As we have some kind of programming language, we can execute it, but how. We can transpile this code to Caché code, and execute it. 

  kill
  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("c:\advent\input\day12.txt")
  set src($i(src(0))) = "start(c) new (c)"
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    set pos = $i(src(0))
    set code = $$transpile(line, pos, "start")
    set src(pos) = code
  }
  set src($i(src(0))) = " zwrite a"
  set src($i(src(0))) = " quit"
  set sc = $compile(src, 0, errs, , , , "AdventDay12New")
  do start^AdventDay12New()
  do start^AdventDay12New(1)
  quit
transpile(line, pos = 0, label) {
  set result = ""  
  set $lb(cmd, arg1, arg2) = $lfs(line," ")
  if cmd = "jnz" {
    if +arg1=arg1 set result = " goto:("_arg1_") "_label_"+"_(pos+arg2-1)
    else  set result = " goto:(+$get("_arg1_")) "_label_"+"_(pos+arg2-1)
  } elseif $lf($lb("cpy", "inc", "dec"), cmd) {
    set args = $case(cmd, "cpy": $lb(arg2, arg1), "inc": $lb(arg1, arg1_" + 1"), : $lb(arg1, arg1_" - 1"))
    set result = " set "_$lts(args, " = ")
  }
  quit result
}

Spoiler. Task 25 have the same language with one more instruction. and with some little modifications in this code, becomes quite easy to solve that task, too.

As far as I understood, they discussing mounting volumes from another container.

As I know some kind of this possibility was in some previous versions of docker-compose. When you can configure to start multiple containers, and it offered to mount volumes_from another container in this configuration. But now docker-compose becomes bigger and supports swarm configuration, they decided to change volumes_from, to just named volumes. In this way, you can define one volume, and use it in different containers at the same time. And it works pretty well. And I think, it is quite enough, with different drivers available for volumes, you can use data from almost everywhere.

And it is now possible even with current Caché versions.

But I think, that way offered in the article could be less effective. You still have to mount volume but in some different way, but what important is how real storage is used.

If these data containers are just a connectors between cluster storage and application. A think it still possible to use it as a mounted volume, or you can configure mounting during the build of an image.

  kill
  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("c:\advent\input\day10.txt")
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    if $e(line)="v" {
      set $lb(,value,,,type,bot)=$lfs(line," ")
      set list(type, bot, value)=""
    } else {
      set $lb(,bot,,,,lowTo,low,,,,highTo,high)=$lfs(line," ")
      set instructions(bot, "low") = $lb(lowTo, low)
      set instructions(bot, "high") = $lb(highTo, high)
    }
  }
  while $d(instructions) {
    set bot=""
    for {
      set bot = $o(list("bot", bot))
      quit:bot=""
      set low = $o(list("bot", bot, ""))
      set high = $o(list("bot", bot, ""), -1)
      continue:low=high
      if low=17,high=61 set result = bot
      set $lb(type, num) = instructions(bot, "low")
      set list(type, num, low) = ""
      set $lb(type, num) = instructions(bot, "high")
      set list(type, num, high) = ""
      kill list("bot", bot)
      kill instructions(bot)
    }
  }
  write !,"Result1 = ",result
  set result2 = 1
  for i=0,1,2 set result2 = result2 * $o(list("output", i, ""))
  write !,"Result2 = ",result2
  quit

and using $lb on a right side, can help, when you need to swap values without using the third variable.

set $lb(b,a)=$lb(a,b)

Interesting, you decided to use a regex here. My code looks very similar to your, but in my case, I just replaced parens and 'x' to '|' and use $lb/$lfs to catch values.

  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("c:\development\day9.txt")
  set compressed = fs.Read(fs.Size)
  set compressed = $tr(compressed, "(x)", "|||")
  write !,"Length = ",$$uncompress(compressed)
  write !,"Full Length = ",$$uncompress(compressed, 1)
  quit
uncompress(str, deep = 0) public {
  set length = 0
  while $l(str) {
    if $e(str)="|" {
      set $lb(,count,times)=$lfs($p(str, "|", 1, 3), "|")
      set $e(str, 1, $l($p(str, "|", 1, 3)) + 1) = ""
      set tmp = $e(str, 1, count)
      set length = length + $s(deep:$$uncompress(tmp,1) * times, 1: count * times)
      set $e(str, 1, count) = ""
    } else {
      set size = $l($p(str, "|"))
      if $i(length, size)
      set $e(str, 1, size) = ""
    }
  }
  quit length
}

InterSystems delivered Cache distributive as a DMG file until 2016.2. And fortunately, they decided do not do it anymore.

But all the time, it was also available as tar.gz. Which is working in exactly the same way as any other Linux version.

So, you can use ccontrol tool, to see a list of instances, their status and start or stop.

csession can be used as a terminal in windows.

To open System Management Portal, you can just this URL in a Browser - http://localhost:57772/csp/sys/UtilHome.csp

I think could be even shorter, but as is

  set sum = 0, north = ""
  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("day4.txt")
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    do line(line)
  }
  w !,"Sum = ",sum
  w !,"North = ",north
  q
line(line) [ sum, north ] {
  set name = $p(line, "-", 1, * -1)
  set checkSumm = $piece($piece(line, "]"), "[", *)
  for i=1:1:5 {
    set char = $e(checkSumm, i)
    set count = $l(name) - $l($tr(name, char))
    set order( - count, char) = ""
  }
  set testSumm = ""
  set i=""
  for {
    set i = $o(order(i))
    quit:i=""
    quit:i=0
    set c = ""
    for {
      set c = $o(order(i, c))
      quit:c=""
      set testSumm = testSumm _ c
    }
  }
  if testSumm=checkSumm {
    set sector = $piece($piece(line, "["), "-", *)
    set sum = sum + sector
    for i=1:1:sector set name = $tr(name, "zabcdefghijklmnopqrstuvwxy-", "abcdefghijklmnopqrstuvwxyz ")
    if name["north" set north = sector
  }
}

One code for both passwords

  set doorId = "reyedfim"
  set (pass1,pass2) = ""
  for i=1:1 {
    set hash = $system.Encryption.MD5Hash(doorId _ i)
    set key1 = $zla($reverse($e(hash, 1, 3))_$c(0))
    continue:key1>15
    if $l(pass1)<8 set pass1 = pass1 _ $zhex(key1)
    continue:key1>7
    continue:$tr($e(pass2, key1 + 1)," ")'=""
    set $e(pass2, key1 + 1)=$zhex($a($e(hash,4))\16)
    quit:($l($tr(pass2," "))=8)
  }
  w !,"Password #1 = ",pass1
  w !,"Password #2 = ",pass2

Mine

  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("day6.txt")
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    do line(line)
  }
  set (msg1,msg2)=""
  for i=1:1 {
    quit:'$d(count1(i))
    if $o(count1(i, ""), -1, char) set msg1 = msg1 _ char
    set msg2 = msg2 _ $o(count2(i, $o(count2(i, "")), ""))
  }
  w !,"msg1 = ",msg1
  w !,"msg2 = ",msg2
  q
line(line) [symbols, count1, count2 ] {
  f i=1:1:$l(line) {
    set char = $e(line, i)
    set count = +$get(symbols(i, char))
    kill count2(i, count, char)
    set count = $i(symbols(i, char))
    set count1(i, count) = char
    set count2(i, count, char) = ""
  }
}

Look at my solution for this task

   k
  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("day8.txt")
  set count=0,width=50,height=6
  for x = 1:1:width for y = 1:1:height set screen(x,y) = 0
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    do line(line)
  }
  do draw()
  set count = 0
  for x=1:1:width for y = 1:1:height set count = count + screen(x,y)
  w !!,"Count = ", count 
  quit
line(line) [screen, width, height, x, y] {
  set $lb(cmd, size, pos, , by) = $lfs(line, " ")
  if cmd = "rect" {
    set $lb(mx, my) = $lfs(size, "x")
    f x = 1:1:mx f y=1:1:my set screen(x,y) = 1
  } else {
    set $lb(v1, pos) = $lfs(pos, "=")
    set v2=$case(v1, "x":"y", :"x")
    set max = $case(v1,"x":height, :width)
    set @v1 = pos + 1, @v2 = 1
    for i=1:1:by {
      set prev = $g(screen(x,y))
      for @v2 = 2:1:max set $lb(screen(x,y), prev) = $lb(prev, screen(x,y))
      set @v2 = 1
      set screen(x, y) = prev
    }
  }
}
draw() [screen, width, height] {
  f y = 1:1:height {
    w !
    f x = 1:1:width {
      write $case($get(screen(x,y)), 1:"#", :" ")
    }
  }
}

And for the second part, a bit different.

  set fs = ##Class(%Stream.FileCharacter).%New()
  set sc=fs.LinkToFile("day7.txt")
  set count=0
  while 'fs.AtEnd {
    set line = fs.ReadLine()
    if $locate(line, "(\w)(?!\1)(\w)\1\w*(?:\[\w+\]\w*)*\[\w*\2\1\2\w*\]")||$locate(line, "\[\w*(\w)(?!\1)(\w)\1\w*\](?:\w*\[\w+])*\w*\2\1\2"), $i(count)
  }
  w !,count 

Interesting, but I don't understand why you still trying to parse strings manually when InterSystems already supports Regex.

 set fs = ##Class(%Stream.FileCharacter).%New()
 set sc=fs.LinkToFile("day7.txt")
 set count=0
 set abba = ##class(%Regex.Matcher).%New("(\w)(?!\1)(\w)\2\1")
 set hyper = ##class(%Regex.Matcher).%New("\[\w*(\w)(?!\1)(\w)\2\1\w*\]")
 while 'fs.AtEnd {
   set line = fs.ReadLine()
   set abba.Text = line
   set hyper.Text = line
   if abba.Locate(),'hyper.Locate(),$i(count)
 }
 w !,count 

So simple, isn't it?

For regex maniac, maybe possible to join both regex's to one to get fewer operations. But anyway, in this simple example you can see the power of Regex.

And even shorter

 set fs = ##Class(%Stream.FileCharacter).%New()
 set sc=fs.LinkToFile("day7.txt")
 set count=0
 while 'fs.AtEnd {
   set line = fs.ReadLine()
   if $locate(line, "(\w)(?!\1)(\w)\2\1"), '$locate(line, "\[\w*(\w)(?!\1)(\w)\2\1\w*\]"), $i(count)
 }
 w !,count