refactor modules to clean up indenting

11 files changed, 417 insertions, 438 deletions

diff --git a/solutions/day1.fs b/solutions/day1.fs
index 0b2c519..5561601 100644
--- a/solutions/day1.fs
+++ b/solutions/day1.fs
@@ -1,19 +1,17 @@
-namespace Solutions
+module Solutions.Day1
+open System.IO
 
-module Day1 =
-    open System.IO
+let lines = File.ReadLines("inputs/day1.txt")
+let totalWeights = seq {
+    let mutable subseq = 0
 
-    let lines = File.ReadLines("inputs/day1.txt")
-    let totalWeights = seq {
-        let mutable subseq = 0
+    for line in lines do
+    if line.Equals("") then
+        yield subseq
+        subseq <- 0
+    else
+        subseq <- subseq + int line
+}
 
-        for line in lines do
-        if line.Equals("") then
-            yield subseq
-            subseq <- 0
-        else
-            subseq <- subseq + int line
-    }
-
-    let part1 () = totalWeights |> Seq.max
-    let part2 () = totalWeights |> Seq.sortDescending |> Seq.take 3 |> Seq.sum
+let part1 () = totalWeights |> Seq.max
+let part2 () = totalWeights |> Seq.sortDescending |> Seq.take 3 |> Seq.sum
diff --git a/solutions/day10.fs b/solutions/day10.fs
index 799850d..59ede91 100644
--- a/solutions/day10.fs
+++ b/solutions/day10.fs
@@ -1,34 +1,32 @@
-namespace Solutions
-
-module Day10 =
-    open System.IO
-    open System.Text.RegularExpressions
-
-    let (|InstRegex|_|) pattern line =
-        let matched = Regex.Match(line, pattern)
-        if matched.Success then
-            matched.Groups |> Seq.tail |> Seq.map (fun x -> x.Value) |> List.ofSeq |> Some
-        else None
-
-    let parseInst line =
-        match line with
-        | InstRegex "noop" [] -> [0]
-        | InstRegex "addx (-?\d+)" x -> [0; (int x[0])]
-        | _ -> failwith "invalid input"
-
-    let changes = File.ReadLines("inputs/day10.txt") |> Seq.map parseInst |> List.concat
-
-    let executeInsts changes =
-        List.scan (+) 1 changes
-
-    let getStateSum cycles (states: int list) =
-        cycles |> List.map (fun x -> x * states[x-1]) |> List.sum
-
-    let part1 () = executeInsts changes |> getStateSum [20; 60; 100; 140; 180; 220]
-
-    let part2 () = executeInsts changes 
-                    |> List.mapi (fun pixel signal -> abs (signal - (pixel % 40)) <= 1) 
-                    |> List.map (fun x -> if x then "#" else " ")
-                    |> List.chunkBySize 40
-                    |> List.map (String.concat "")
-                    |> List.iter (printf "%s\n")
\ No newline at end of file
+module Solutions.Day10
+open System.IO
+open System.Text.RegularExpressions
+
+let (|InstRegex|_|) pattern line =
+    let matched = Regex.Match(line, pattern)
+    if matched.Success then
+        matched.Groups |> Seq.tail |> Seq.map (fun x -> x.Value) |> List.ofSeq |> Some
+    else None
+
+let parseInst line =
+    match line with
+    | InstRegex "noop" [] -> [0]
+    | InstRegex "addx (-?\d+)" x -> [0; (int x[0])]
+    | _ -> failwith "invalid input"
+
+let changes = File.ReadLines("inputs/day10.txt") |> Seq.map parseInst |> List.concat
+
+let executeInsts changes =
+    List.scan (+) 1 changes
+
+let getStateSum cycles (states: int list) =
+    cycles |> List.map (fun x -> x * states[x-1]) |> List.sum
+
+let part1 () = executeInsts changes |> getStateSum [20; 60; 100; 140; 180; 220]
+
+let part2 () = executeInsts changes 
+                |> List.mapi (fun pixel signal -> abs (signal - (pixel % 40)) <= 1) 
+                |> List.map (fun x -> if x then "#" else " ")
+                |> List.chunkBySize 40
+                |> List.map (String.concat "")
+                |> List.iter (printf "%s\n")
\ No newline at end of file
diff --git a/solutions/day11.fs b/solutions/day11.fs
index 2b93042..d9a9d17 100644
--- a/solutions/day11.fs
+++ b/solutions/day11.fs
@@ -1,108 +1,106 @@
-namespace Solutions
+module Solutions.Day11
+type Monkey = {
+    Items: int64 list
+    Operation: int64 -> int64
+    Test: int64
+    TrueMonkey: int
+    FalseMonkey: int
+    Inspections: int64
+}
 
-module Day11 =
-    type Monkey = {
-        Items: int64 list
-        Operation: int64 -> int64
-        Test: int64
-        TrueMonkey: int
-        FalseMonkey: int
-        Inspections: int64
-    }
+let monkeys = 
+    [ { Items = [89; 95; 92; 64; 87; 68]
+        Operation = (*) 11L
+        Test = 2
+        TrueMonkey = 7
+        FalseMonkey = 4
+        Inspections = 0 }
+      { Items = [87; 67]
+        Operation = (+) 1L;
+        Test = 13;
+        TrueMonkey = 3
+        FalseMonkey = 6
+        Inspections = 0 }
+      { Items = [95; 79; 92; 82; 60]
+        Operation = (+) 6L
+        Test = 3
+        TrueMonkey = 1
+        FalseMonkey = 6
+        Inspections = 0 }
+      { Items = [67; 97; 56]
+        Operation = fun x -> x * x
+        Test = 17
+        TrueMonkey = 7
+        FalseMonkey = 0
+        Inspections = 0 }
+      { Items = [80; 68; 87; 94; 61; 59; 50; 68]
+        Operation = (*) 7L
+        Test = 19
+        TrueMonkey = 5
+        FalseMonkey = 2
+        Inspections = 0 }
+      { Items = [73; 51; 76; 59]
+        Operation = (+) 8L
+        Test = 7
+        TrueMonkey = 2
+        FalseMonkey = 1
+        Inspections = 0 }
+      { Items = [92]
+        Operation = (+) 5L
+        Test = 11
+        TrueMonkey = 3
+        FalseMonkey = 0
+        Inspections = 0 }
+      { Items = [99; 76; 78; 76; 79; 90; 89]
+        Operation = (+) 7L
+        Test = 5
+        TrueMonkey = 4
+        FalseMonkey = 5
+        Inspections = 0 } ]
 
-    let monkeys = 
-        [ { Items = [89; 95; 92; 64; 87; 68]
-            Operation = (*) 11L
-            Test = 2
-            TrueMonkey = 7
-            FalseMonkey = 4
-            Inspections = 0 }
-          { Items = [87; 67]
-            Operation = (+) 1L;
-            Test = 13;
-            TrueMonkey = 3
-            FalseMonkey = 6
-            Inspections = 0 }
-          { Items = [95; 79; 92; 82; 60]
-            Operation = (+) 6L
-            Test = 3
-            TrueMonkey = 1
-            FalseMonkey = 6
-            Inspections = 0 }
-          { Items = [67; 97; 56]
-            Operation = fun x -> x * x
-            Test = 17
-            TrueMonkey = 7
-            FalseMonkey = 0
-            Inspections = 0 }
-          { Items = [80; 68; 87; 94; 61; 59; 50; 68]
-            Operation = (*) 7L
-            Test = 19
-            TrueMonkey = 5
-            FalseMonkey = 2
-            Inspections = 0 }
-          { Items = [73; 51; 76; 59]
-            Operation = (+) 8L
-            Test = 7
-            TrueMonkey = 2
-            FalseMonkey = 1
-            Inspections = 0 }
-          { Items = [92]
-            Operation = (+) 5L
-            Test = 11
-            TrueMonkey = 3
-            FalseMonkey = 0
-            Inspections = 0 }
-          { Items = [99; 76; 78; 76; 79; 90; 89]
-            Operation = (+) 7L
-            Test = 5
-            TrueMonkey = 4
-            FalseMonkey = 5
-            Inspections = 0 } ]
+let throw item target monkeys =
+    let monkey = List.item target monkeys
     
-    let throw item target monkeys =
-        let monkey = List.item target monkeys
-        
-        List.updateAt target {monkey with Items = (List.append monkey.Items [item])} monkeys
+    List.updateAt target {monkey with Items = (List.append monkey.Items [item])} monkeys
 
-    let doItem operation monkey monkeys item =
-        let worryLevel = monkey.Operation item
-        let boredLevel = operation worryLevel
-        let target = if boredLevel % monkey.Test = 0L then monkey.TrueMonkey else monkey.FalseMonkey
-        throw boredLevel target monkeys
-    
-    let playTurn operation monkeys id =
-        let monkey = List.item id monkeys
+let doItem operation monkey monkeys item =
+    let worryLevel = monkey.Operation item
+    let boredLevel = operation worryLevel
+    let target = if boredLevel % monkey.Test = 0L then monkey.TrueMonkey else monkey.FalseMonkey
+    throw boredLevel target monkeys
 
-        let cleared = monkeys 
-                      |> List.updateAt 
-                                id 
-                                {monkey with Items = []
-                                             Inspections = monkey.Inspections + (int64 monkey.Items.Length)}
-        
-        monkey.Items |> List.fold (doItem operation monkey) cleared
-    
-    let playRound operation monkeys =
-        let players = [ 0 .. (List.length monkeys - 1)]
-        List.fold (playTurn operation) monkeys players
+let playTurn operation monkeys id =
+    let monkey = List.item id monkeys
+
+    let cleared = monkeys 
+                  |> List.updateAt 
+                            id 
+                            {monkey with Items = []
+                                         Inspections = monkey.Inspections + (int64 monkey.Items.Length)}
     
-    let rec playRounds operation nb monkeys =
-        if nb = 0 then monkeys
-        else
-            let next = playRound operation monkeys
-            playRounds operation (nb - 1) next
+    monkey.Items |> List.fold (doItem operation monkey) cleared
 
-    let solve operation count =
-        monkeys
-        |> playRounds operation count
-        |> List.map (fun m -> m.Inspections)
-        |> List.sortDescending
-        |> List.take 2
-        |> List.reduce (*)
+let playRound operation monkeys =
+    let players = [ 0 .. (List.length monkeys - 1)]
+    List.fold (playTurn operation) monkeys players
 
-    let part1 () = 
-        solve (fun x -> x / 3L) 20
-    
-    let part2 () = 
-        let safeMod = monkeys |> Seq.map (fun m -> m.Test) |> Seq.reduce (*)
-        solve (fun x -> x % safeMod) 10_000
+let rec playRounds operation nb monkeys =
+    if nb = 0 then monkeys
+    else
+        let next = playRound operation monkeys
+        playRounds operation (nb - 1) next
+
+let solve operation count =
+    monkeys
+    |> playRounds operation count
+    |> List.map (fun m -> m.Inspections)
+    |> List.sortDescending
+    |> List.take 2
+    |> List.reduce (*)
+
+let part1 () = 
+    solve (fun x -> x / 3L) 20
+
+let part2 () = 
+    let safeMod = monkeys |> Seq.map (fun m -> m.Test) |> Seq.reduce (*)
+    solve (fun x -> x % safeMod) 10_000
diff --git a/solutions/day2.fs b/solutions/day2.fs
index 5822d00..5ae5552 100644
--- a/solutions/day2.fs
+++ b/solutions/day2.fs
@@ -1,31 +1,30 @@
-namespace Solutions
+module Solutions.Day2
+open System.IO
 
-module Day2 =
-    open System.IO
-    let lines = File.ReadLines("inputs/day2.txt") |> Seq.map (fun x -> x[0], x[2])
+let lines = File.ReadLines("inputs/day2.txt") |> Seq.map (fun x -> x[0], x[2])
 
-    let outcomes1 = Map.empty
-                        .Add(('A', 'X'), 4) // rock: 1 + tie: 3
-                        .Add(('A', 'Y'), 8) // paper: 2 + rock win: 6
-                        .Add(('A', 'Z'), 3) // scissors: 3 + rock lose: 0
-                        .Add(('B', 'X'), 1) // rock: 1 + paper lose: 0
-                        .Add(('B', 'Y'), 5) // paper: 2 + tie: 3
-                        .Add(('B', 'Z'), 9) // scissors: 3 + paper win: 6
-                        .Add(('C', 'X'), 7) // rock: 1 + scissors win: 6
-                        .Add(('C', 'Y'), 2) // paper: 2 + scissors lose: 0
-                        .Add(('C', 'Z'), 6) // scissors: 3 + tie: 3
+let outcomes1 = Map.empty
+                    .Add(('A', 'X'), 4) // rock: 1 + tie: 3
+                    .Add(('A', 'Y'), 8) // paper: 2 + rock win: 6
+                    .Add(('A', 'Z'), 3) // scissors: 3 + rock lose: 0
+                    .Add(('B', 'X'), 1) // rock: 1 + paper lose: 0
+                    .Add(('B', 'Y'), 5) // paper: 2 + tie: 3
+                    .Add(('B', 'Z'), 9) // scissors: 3 + paper win: 6
+                    .Add(('C', 'X'), 7) // rock: 1 + scissors win: 6
+                    .Add(('C', 'Y'), 2) // paper: 2 + scissors lose: 0
+                    .Add(('C', 'Z'), 6) // scissors: 3 + tie: 3
 
-    let part1 () = lines |> Seq.map outcomes1.TryFind |> Seq.map (function | Some value -> value | None -> 0) |> Seq.sum
+let part1 () = lines |> Seq.map outcomes1.TryFind |> Seq.map (function | Some value -> value | None -> 0) |> Seq.sum
 
-    let outcomes2 = Map.empty
-                        .Add(('A', 'X'), 3) // lose to rock: 0 pts + 3 for scissors
-                        .Add(('A', 'Y'), 4) // draw to rock: 3 pts + 1 for rock
-                        .Add(('A', 'Z'), 8) // win to rock: 6 pts + 2 for paper
-                        .Add(('B', 'X'), 1) // lose to paper: 0 pts + 1 for rock
-                        .Add(('B', 'Y'), 5) // draw to paper: 3 pts + 2 for paper
-                        .Add(('B', 'Z'), 9) // win to paper: 6 pts + 3 for scissors
-                        .Add(('C', 'X'), 2) // lose to scissors: 0 pts + 2 for paper
-                        .Add(('C', 'Y'), 6) // draw to scissors: 3 pts + 3 for scissors
-                        .Add(('C', 'Z'), 7) // win to scissors: 6 pts + 1 for rock
-    
-    let part2 () = lines |> Seq.map outcomes2.TryFind |> Seq.map (function | Some value -> value | None -> 0) |> Seq.sum
+let outcomes2 = Map.empty
+                    .Add(('A', 'X'), 3) // lose to rock: 0 pts + 3 for scissors
+                    .Add(('A', 'Y'), 4) // draw to rock: 3 pts + 1 for rock
+                    .Add(('A', 'Z'), 8) // win to rock: 6 pts + 2 for paper
+                    .Add(('B', 'X'), 1) // lose to paper: 0 pts + 1 for rock
+                    .Add(('B', 'Y'), 5) // draw to paper: 3 pts + 2 for paper
+                    .Add(('B', 'Z'), 9) // win to paper: 6 pts + 3 for scissors
+                    .Add(('C', 'X'), 2) // lose to scissors: 0 pts + 2 for paper
+                    .Add(('C', 'Y'), 6) // draw to scissors: 3 pts + 3 for scissors
+                    .Add(('C', 'Z'), 7) // win to scissors: 6 pts + 1 for rock
+
+let part2 () = lines |> Seq.map outcomes2.TryFind |> Seq.map (function | Some value -> value | None -> 0) |> Seq.sum
diff --git a/solutions/day3.fs b/solutions/day3.fs
index cebfde5..541a0b4 100644
--- a/solutions/day3.fs
+++ b/solutions/day3.fs
@@ -1,26 +1,24 @@
-namespace Solutions
+module Solutions.Day3
+open System.IO
 
-module Day3 =
-    open System.IO
-    
-    let lines = File.ReadLines("inputs/day3.txt")
-    let rucksacks = lines 
-                    |> Seq.map (fun x -> (Set.ofSeq x[0..x.Length / 2 - 1], Set.ofSeq x[x.Length/2..x.Length]))
-    let groups = lines 
-                    |> Seq.map Set.ofSeq 
-                    |> Seq.splitInto (Seq.length lines / 3)
-    
-    let prioritize ch =
-        match ch with
-        | x when 'a' <= x && x <= 'z' -> int x - int 'a' + 1
-        | x when 'A' <= x && x <= 'Z' -> int x - int 'A' + 27
-        | _ -> 0
-    
-    // extract the single element from the set with maxElement
-    let part1 () = rucksacks 
-                    |> Seq.map ((fun (x, y) -> Set.intersect x y |> Set.maxElement) >> prioritize)
-                    |> Seq.sum
-    
-    let part2 () = groups
-                    |> Seq.map (Set.intersectMany >> Set.maxElement >> prioritize)
-                    |> Seq.sum
\ No newline at end of file
+let lines = File.ReadLines("inputs/day3.txt")
+let rucksacks = lines 
+                |> Seq.map (fun x -> (Set.ofSeq x[0..x.Length / 2 - 1], Set.ofSeq x[x.Length/2..x.Length]))
+let groups = lines 
+                |> Seq.map Set.ofSeq 
+                |> Seq.splitInto (Seq.length lines / 3)
+
+let prioritize ch =
+    match ch with
+    | x when 'a' <= x && x <= 'z' -> int x - int 'a' + 1
+    | x when 'A' <= x && x <= 'Z' -> int x - int 'A' + 27
+    | _ -> 0
+
+// extract the single element from the set with maxElement
+let part1 () = rucksacks 
+                |> Seq.map ((fun (x, y) -> Set.intersect x y |> Set.maxElement) >> prioritize)
+                |> Seq.sum
+
+let part2 () = groups
+                |> Seq.map (Set.intersectMany >> Set.maxElement >> prioritize)
+                |> Seq.sum
\ No newline at end of file
diff --git a/solutions/day4.fs b/solutions/day4.fs
index beb0515..82b523c 100644
--- a/solutions/day4.fs
+++ b/solutions/day4.fs
@@ -1,35 +1,33 @@
-namespace Solutions
+module Solutions.Day4
+open System.IO
+open System.Text.RegularExpressions
 
-module Day4 =
-    open System.IO
-    open System.Text.RegularExpressions
+type range = {
+    startID: int;
+    endID: int
+}
 
-    type range = {
-        startID: int;
-        endID: int
-    }
+let getRanges input =
+    let matches = Regex.Matches(input, "(\d+)-(\d+),(\d+)-(\d+)") 
+                    |> Seq.head 
+                    |> fun x -> x.Groups 
+                    |> Seq.map (fun x -> x.Value) 
+                    |> List.ofSeq 
+                    |> List.tail
+    assert (Seq.length matches = 4)
+    {startID = int matches[0]; endID = int matches[1]}, {startID = int matches[2]; endID = int matches[3]}
+    
+let ranges = File.ReadLines("inputs/day4.txt") |> Seq.map getRanges
 
-    let getRanges input =
-        let matches = Regex.Matches(input, "(\d+)-(\d+),(\d+)-(\d+)") 
-                        |> Seq.head 
-                        |> fun x -> x.Groups 
-                        |> Seq.map (fun x -> x.Value) 
-                        |> List.ofSeq 
-                        |> List.tail
-        assert (Seq.length matches = 4)
-        {startID = int matches[0]; endID = int matches[1]}, {startID = int matches[2]; endID = int matches[3]}
-        
-    let ranges = File.ReadLines("inputs/day4.txt") |> Seq.map getRanges
+let contains (rangeA, rangeB) =
+    (rangeA.startID <= rangeB.startID && rangeA.endID >= rangeB.endID) || (rangeA.startID >= rangeB.startID && rangeA.endID <= rangeB.endID)
 
-    let contains (rangeA, rangeB) =
-        (rangeA.startID <= rangeB.startID && rangeA.endID >= rangeB.endID) || (rangeA.startID >= rangeB.startID && rangeA.endID <= rangeB.endID)
+let part1 () = ranges |> Seq.filter contains |> Seq.length
 
-    let part1 () = ranges |> Seq.filter contains |> Seq.length
+let overlaps (rangeA, rangeB) =
+    (rangeA.startID >= rangeB.startID && rangeA.startID <= rangeB.endID) ||
+    (rangeA.endID >= rangeB.startID && rangeA.endID <= rangeB.endID)     ||
+    (rangeB.startID >= rangeA.startID && rangeB.startID <= rangeA.endID) ||
+    (rangeB.endID >= rangeA.startID && rangeB.endID <= rangeA.endID)
 
-    let overlaps (rangeA, rangeB) =
-        (rangeA.startID >= rangeB.startID && rangeA.startID <= rangeB.endID) ||
-        (rangeA.endID >= rangeB.startID && rangeA.endID <= rangeB.endID)     ||
-        (rangeB.startID >= rangeA.startID && rangeB.startID <= rangeA.endID) ||
-        (rangeB.endID >= rangeA.startID && rangeB.endID <= rangeA.endID)
-    
-    let part2 () = ranges |> Seq.filter overlaps |> Seq.length
\ No newline at end of file
+let part2 () = ranges |> Seq.filter overlaps |> Seq.length
\ No newline at end of file
diff --git a/solutions/day5.fs b/solutions/day5.fs
index 6c8bce3..2355e00 100644
--- a/solutions/day5.fs
+++ b/solutions/day5.fs
@@ -1,61 +1,59 @@
-namespace Solutions
+module Solutions.Day5
+open System.IO
+open System.Text.RegularExpressions
 
-module Day5 =
-    open System.IO
-    open System.Text.RegularExpressions
+// forgive me lord for what i'm about to do
+// too lazy to figure out how to parse initial state so hardcoding instead
+let initState = [|
+                ['D'; 'T'; 'W'; 'N'; 'L']; 
+                ['H'; 'P'; 'C'];
+                ['J'; 'M'; 'G'; 'D'; 'N'; 'H'; 'P'; 'W'];
+                ['L'; 'Q'; 'T'; 'N'; 'S'; 'W'; 'C'];
+                ['N'; 'C'; 'H'; 'P'];
+                ['B'; 'Q'; 'W'; 'M'; 'D'; 'N'; 'H'; 'T'];
+                ['L'; 'S'; 'G'; 'J'; 'R'; 'B'; 'M'];
+                ['T'; 'R'; 'B'; 'V'; 'G'; 'W'; 'N'; 'Z'];
+                ['L'; 'P'; 'N'; 'D'; 'G'; 'W'] 
+                |]
 
-    // forgive me lord for what i'm about to do
-    // too lazy to figure out how to parse initial state so hardcoding instead
-    let initState = [|
-                    ['D'; 'T'; 'W'; 'N'; 'L']; 
-                    ['H'; 'P'; 'C'];
-                    ['J'; 'M'; 'G'; 'D'; 'N'; 'H'; 'P'; 'W'];
-                    ['L'; 'Q'; 'T'; 'N'; 'S'; 'W'; 'C'];
-                    ['N'; 'C'; 'H'; 'P'];
-                    ['B'; 'Q'; 'W'; 'M'; 'D'; 'N'; 'H'; 'T'];
-                    ['L'; 'S'; 'G'; 'J'; 'R'; 'B'; 'M'];
-                    ['T'; 'R'; 'B'; 'V'; 'G'; 'W'; 'N'; 'Z'];
-                    ['L'; 'P'; 'N'; 'D'; 'G'; 'W'] 
-                    |]
+type instruction = {
+    amount: int;
+    source: int;
+    target: int
+}
 
-    type instruction = {
-        amount: int;
-        source: int;
-        target: int
-    }
+let getInstruction inst =
+    let matches = Regex.Matches(inst, "move (\d+) from (\d+) to (\d+)")
+                    |> Seq.head
+                    |> fun x -> x.Groups
+                    |> List.ofSeq |> List.tail
+                    |> List.map (fun x -> int x.Value)
+    assert (List.length matches = 3)
+    {amount = matches[0]; source = matches[1] - 1; target = matches[2] - 1}
 
-    let getInstruction inst =
-        let matches = Regex.Matches(inst, "move (\d+) from (\d+) to (\d+)")
-                        |> Seq.head
-                        |> fun x -> x.Groups
-                        |> List.ofSeq |> List.tail
-                        |> List.map (fun x -> int x.Value)
-        assert (List.length matches = 3)
-        {amount = matches[0]; source = matches[1] - 1; target = matches[2] - 1}
-    
-    let instructions = File.ReadLines("inputs/day5.txt") 
-                        |> Array.ofSeq 
-                        |> fun x -> Array.splitAt (Array.findIndex ((=) "") x) x
-                        |> snd |> Array.tail |> Array.map getInstruction
+let instructions = File.ReadLines("inputs/day5.txt") 
+                    |> Array.ofSeq 
+                    |> fun x -> Array.splitAt (Array.findIndex ((=) "") x) x
+                    |> snd |> Array.tail |> Array.map getInstruction
 
-    let executeInstruction1 (state: list<char>[]) inst =
-        for _ in 1..inst.amount do
-            match state[inst.source] with
-            | top::bottom ->
-                state[inst.source] <- bottom
-                state[inst.target] <- top::state[inst.target]
-            | _ -> failwith "this shouldn't happen"
+let executeInstruction1 (state: list<char>[]) inst =
+    for _ in 1..inst.amount do
+        match state[inst.source] with
+        | top::bottom ->
+            state[inst.source] <- bottom
+            state[inst.target] <- top::state[inst.target]
+        | _ -> failwith "this shouldn't happen"
 
-    let part1 () = 
-        let mutable currentState = initState
-        Array.iter (executeInstruction1 currentState) instructions
-        Array.map (List.head >> string) currentState |> String.concat ""
+let part1 () = 
+    let mutable currentState = initState
+    Array.iter (executeInstruction1 currentState) instructions
+    Array.map (List.head >> string) currentState |> String.concat ""
 
-    let executeInstruction2 (state: char [] []) inst =
-        state[inst.target] <- Array.append state[inst.source].[..inst.amount-1] state[inst.target]
-        state[inst.source] <- state[inst.source][inst.amount..]
-        
-    let part2 () = 
-        let mutable currentState = initState |> Array.map Array.ofList
-        Array.iter (executeInstruction2 currentState) instructions
-        Array.map (Array.head >> string) currentState |> String.concat ""
\ No newline at end of file
+let executeInstruction2 (state: char [] []) inst =
+    state[inst.target] <- Array.append state[inst.source].[..inst.amount-1] state[inst.target]
+    state[inst.source] <- state[inst.source][inst.amount..]
+    
+let part2 () = 
+    let mutable currentState = initState |> Array.map Array.ofList
+    Array.iter (executeInstruction2 currentState) instructions
+    Array.map (Array.head >> string) currentState |> String.concat ""
\ No newline at end of file
diff --git a/solutions/day6.fs b/solutions/day6.fs
index bb83388..fb2d451 100644
--- a/solutions/day6.fs
+++ b/solutions/day6.fs
@@ -1,20 +1,18 @@
-namespace Solutions
+module Solutions.Day6
+open System.IO
 
-module Day6 =
-    open System.IO
+let buf = File.ReadAllText("inputs/day6.txt")
 
-    let buf = File.ReadAllText("inputs/day6.txt")
-
-    let rec scan size str index =
-        if String.length str < size then -1
+let rec scan size str index =
+    if String.length str < size then -1
+    else
+        let current = str[..size - 1] |> Set.ofSeq
+        if Set.count current = size then index + size
         else
-            let current = str[..size - 1] |> Set.ofSeq
-            if Set.count current = size then index + size
-            else
-                scan size str[1..] index + 1
+            scan size str[1..] index + 1
 
-    let part1 () =
-        scan 4 buf 0
+let part1 () =
+    scan 4 buf 0
 
-    let part2 () =
-        scan 14 buf 0
\ No newline at end of file
+let part2 () =
+    scan 14 buf 0
\ No newline at end of file
diff --git a/solutions/day7.fs b/solutions/day7.fs
index 622c54c..5f507c4 100644
--- a/solutions/day7.fs
+++ b/solutions/day7.fs
@@ -1,56 +1,54 @@
-namespace Solutions
-
-module Day7 =
-    open System.IO
-    open System.Text.RegularExpressions
-    
-    type Listing =
-    | LS
-    | CD of target: string
-    | Dir of name: string
-    | File of name: string * size: int
-
-    let (|RegexMatch|_|) pattern line =
-        let matched = Regex.Match(line, pattern)
-        if matched.Success then
-            let groups =
-                matched.Groups |> Seq.map (fun x -> x.Value) |> Seq.tail |> List.ofSeq
-            Some groups
-        else None
-
-    let parseListing = function
-    | RegexMatch "\$ cd (\/|\S+)" args -> CD args[0]
-    | RegexMatch "\$ ls" [] -> LS
-    | RegexMatch "dir (\S+)" name -> Dir name[0]
-    | RegexMatch "(\d+) (\S+)" data -> File (data[1], int data[0])
-    | _ -> failwith "shouldn't happen"
-
-    let input = File.ReadLines("inputs/day7.txt") |> Seq.map parseListing |> List.ofSeq
-
-
-    let dirSizes listings = 
-        let processListing (pwd, tree) listing =
-            match listing with 
-            | CD ".." -> (List.tail pwd, tree)
-            | CD target -> (target::pwd, tree)
-            | File (name, size) -> 
-                let rec addFileSize rem dirs =
-                    match rem with
-                    | [] -> dirs
-                    | _ :: t ->
-                        let addIfExists current = defaultArg current 0 + size
-                        let newDirs = Map.change rem (addIfExists >> Some) dirs
-                        addFileSize t newDirs
-                pwd, addFileSize pwd tree
-            | _ -> pwd, tree
-        listings |> List.fold processListing ([], Map.empty) |> snd
-    
-    let part1 () = dirSizes input |> Map.values |> Seq.filter (fun size -> size <= 100000) |> Seq.sum
-
-    let part2 () = 
-        let sizes = dirSizes input
-        let totalSpace = 70000000
-        let targetSpace = 30000000
-        let usedSpace = sizes[[ "/" ]]
-        let needToFree = usedSpace - (totalSpace - targetSpace)
-        sizes.Values |> Seq.sort |> Seq.find (fun x -> x >= needToFree)
\ No newline at end of file
+module Solutions.Day7
+open System.IO
+open System.Text.RegularExpressions
+
+type Listing =
+| LS
+| CD of target: string
+| Dir of name: string
+| File of name: string * size: int
+
+let (|RegexMatch|_|) pattern line =
+    let matched = Regex.Match(line, pattern)
+    if matched.Success then
+        let groups =
+            matched.Groups |> Seq.map (fun x -> x.Value) |> Seq.tail |> List.ofSeq
+        Some groups
+    else None
+
+let parseListing = function
+| RegexMatch "\$ cd (\/|\S+)" args -> CD args[0]
+| RegexMatch "\$ ls" [] -> LS
+| RegexMatch "dir (\S+)" name -> Dir name[0]
+| RegexMatch "(\d+) (\S+)" data -> File (data[1], int data[0])
+| _ -> failwith "shouldn't happen"
+
+let input = File.ReadLines("inputs/day7.txt") |> Seq.map parseListing |> List.ofSeq
+
+
+let dirSizes listings = 
+    let processListing (pwd, tree) listing =
+        match listing with 
+        | CD ".." -> (List.tail pwd, tree)
+        | CD target -> (target::pwd, tree)
+        | File (name, size) -> 
+            let rec addFileSize rem dirs =
+                match rem with
+                | [] -> dirs
+                | _ :: t ->
+                    let addIfExists current = defaultArg current 0 + size
+                    let newDirs = Map.change rem (addIfExists >> Some) dirs
+                    addFileSize t newDirs
+            pwd, addFileSize pwd tree
+        | _ -> pwd, tree
+    listings |> List.fold processListing ([], Map.empty) |> snd
+
+let part1 () = dirSizes input |> Map.values |> Seq.filter (fun size -> size <= 100000) |> Seq.sum
+
+let part2 () = 
+    let sizes = dirSizes input
+    let totalSpace = 70000000
+    let targetSpace = 30000000
+    let usedSpace = sizes[[ "/" ]]
+    let needToFree = usedSpace - (totalSpace - targetSpace)
+    sizes.Values |> Seq.sort |> Seq.find (fun x -> x >= needToFree)
\ No newline at end of file
diff --git a/solutions/day8.fs b/solutions/day8.fs
index 757cb74..8978700 100644
--- a/solutions/day8.fs
+++ b/solutions/day8.fs
@@ -1,53 +1,51 @@
-namespace Solutions
+module Solutions.Day8
+open System.IO
 
-module Day8 =
-    open System.IO
+let input = File.ReadLines("inputs/day8.txt") |> Array.ofSeq |> Array.map (Array.ofSeq >> Array.map (fun x -> int x - int '0')) |> array2D
 
-    let input = File.ReadLines("inputs/day8.txt") |> Array.ofSeq |> Array.map (Array.ofSeq >> Array.map (fun x -> int x - int '0')) |> array2D
-
-    let rec countVisible line index indices max =
-        if line = [||] then indices
+let rec countVisible line index indices max =
+    if line = [||] then indices
+    else
+        let current = Array.head line
+        if current > max then
+            countVisible (Array.tail line) (index + 1) (Set.add index indices) current
         else
-            let current = Array.head line
-            if current > max then
-                countVisible (Array.tail line) (index + 1) (Set.add index indices) current
-            else
-                countVisible (Array.tail line) (index + 1) indices max
-
-    let countBidirectional goHorizontal index line =
-        let dirSet dir =
-            countVisible (Array.tail dir) 1 (Set.singleton 0) (Array.head dir)
-        let forwards = dirSet line
-        let backwards = dirSet (Array.rev line) |> Set.map (fun x -> Array.length line - 1 - x)
-        Set.union forwards backwards |> Set.map(fun x -> if goHorizontal then (index, x) else (x, index))
-
-    let countGridVisible grid =
-        let rows, cols = Array2D.length1 grid, Array2D.length2 grid
-        let rowSet = seq { for x in 0..rows - 1 -> x } |> Seq.map (fun x -> grid[x, *] |> countBidirectional true x)  |> Set.unionMany
-        let colSet = seq { for y in 0..cols - 1 -> y } |> Seq.map (fun y -> grid[*, y] |> countBidirectional false y)  |> Set.unionMany
-        Set.union rowSet colSet |> Set.count
-
-    let part1 () = countGridVisible input
-
-    let getViewingDistance index (line: int array) =
-        let before, after = Array.rev line[..index - 1], line[index + 1..]
-        let getDistance height trees =
-            try
-                1 + Array.findIndex (fun x -> x >= height) trees
-            with
-            | :? System.Collections.Generic.KeyNotFoundException -> Array.length trees
-            | :? System.ArgumentNullException -> failwith "should never happen"
-        
-        getDistance line[index] before * getDistance line[index] after
-
-    let getScore (grid: int[,]) (x, y)  =
-        let row, col = grid[x, *], grid[*, y]
-        let hScore = getViewingDistance y row
-        let vScore = getViewingDistance x col
-        hScore * vScore
-
-    let part2 () = 
-        seq {for x in 0..Array2D.length1 input - 1 do 
-             for y in 0..Array2D.length2 input - 1 -> (x, y)}
-            |> Seq.map (getScore input)
-            |> Seq.max
\ No newline at end of file
+            countVisible (Array.tail line) (index + 1) indices max
+
+let countBidirectional goHorizontal index line =
+    let dirSet dir =
+        countVisible (Array.tail dir) 1 (Set.singleton 0) (Array.head dir)
+    let forwards = dirSet line
+    let backwards = dirSet (Array.rev line) |> Set.map (fun x -> Array.length line - 1 - x)
+    Set.union forwards backwards |> Set.map(fun x -> if goHorizontal then (index, x) else (x, index))
+
+let countGridVisible grid =
+    let rows, cols = Array2D.length1 grid, Array2D.length2 grid
+    let rowSet = seq { for x in 0..rows - 1 -> x } |> Seq.map (fun x -> grid[x, *] |> countBidirectional true x)  |> Set.unionMany
+    let colSet = seq { for y in 0..cols - 1 -> y } |> Seq.map (fun y -> grid[*, y] |> countBidirectional false y)  |> Set.unionMany
+    Set.union rowSet colSet |> Set.count
+
+let part1 () = countGridVisible input
+
+let getViewingDistance index (line: int array) =
+    let before, after = Array.rev line[..index - 1], line[index + 1..]
+    let getDistance height trees =
+        try
+            1 + Array.findIndex (fun x -> x >= height) trees
+        with
+        | :? System.Collections.Generic.KeyNotFoundException -> Array.length trees
+        | :? System.ArgumentNullException -> failwith "should never happen"
+    
+    getDistance line[index] before * getDistance line[index] after
+
+let getScore (grid: int[,]) (x, y)  =
+    let row, col = grid[x, *], grid[*, y]
+    let hScore = getViewingDistance y row
+    let vScore = getViewingDistance x col
+    hScore * vScore
+
+let part2 () = 
+    seq {for x in 0..Array2D.length1 input - 1 do 
+            for y in 0..Array2D.length2 input - 1 -> (x, y)}
+        |> Seq.map (getScore input)
+        |> Seq.max
\ No newline at end of file
diff --git a/solutions/day9.fs b/solutions/day9.fs
index 9c1407f..b681266 100644
--- a/solutions/day9.fs
+++ b/solutions/day9.fs
@@ -1,39 +1,37 @@
-namespace Solutions
+module Solutions.Day9
+open System.IO
+open System.Text.RegularExpressions
+open FSharpPlus.Operators
 
-module Day9 =
-    open System.IO
-    open System.Text.RegularExpressions
-    open FSharpPlus.Operators
+let parseInstruction line =
+    let groups = Regex.Match(line, "([LRUD]) (\d+)").Groups
+                    |> Seq.map (fun x -> x.Value)
+                    |> Array.ofSeq
+    match groups[1], groups[2] with
+    | "L", count -> List.replicate (int count) (-1, 0)
+    | "R", count -> List.replicate (int count) (1, 0)
+    | "U", count -> List.replicate (int count) (0, 1)
+    | "D", count -> List.replicate (int count) (0, -1)
+    | _ -> failwith "invalid input"
 
-    let parseInstruction line =
-        let groups = Regex.Match(line, "([LRUD]) (\d+)").Groups
-                     |> Seq.map (fun x -> x.Value)
-                     |> Array.ofSeq
-        match groups[1], groups[2] with
-        | "L", count -> List.replicate (int count) (-1, 0)
-        | "R", count -> List.replicate (int count) (1, 0)
-        | "U", count -> List.replicate (int count) (0, 1)
-        | "D", count -> List.replicate (int count) (0, -1)
-        | _ -> failwith "invalid input"
+let headPositions steps = List.scan (fun (x1, y1) (x2, y2) -> (x1 + x2, y1 + y2)) (0, 0) steps
+let instructions = File.ReadLines("inputs/day9.txt") |> Seq.map parseInstruction |> Seq.concat |> List.ofSeq |> headPositions    
 
-    let headPositions steps = List.scan (fun (x1, y1) (x2, y2) -> (x1 + x2, y1 + y2)) (0, 0) steps
-    let instructions = File.ReadLines("inputs/day9.txt") |> Seq.map parseInstruction |> Seq.concat |> List.ofSeq |> headPositions    
+let rec followPath (rope: list<int * int>) (tailSet: Set<int*int>) (heads: list<int*int>) =
+    let touches pointA pointB = abs (fst pointA - fst pointB) <= 1 && abs (snd pointA - snd pointB) <= 1
+    let moveTowards head tail = (fst tail + signum (fst head - fst tail), snd tail + signum (snd head - snd tail))
 
-    let rec followPath (rope: list<int * int>) (tailSet: Set<int*int>) (heads: list<int*int>) =
-        let touches pointA pointB = abs (fst pointA - fst pointB) <= 1 && abs (snd pointA - snd pointB) <= 1
-        let moveTowards head tail = (fst tail + signum (fst head - fst tail), snd tail + signum (snd head - snd tail))
+    if List.length heads = 0 then Set.count tailSet
+    else
+        let newHead = List.head heads
+        let newRope = List.scan (fun head tail -> if touches head tail then tail else moveTowards head tail) newHead (List.tail rope)
+        followPath newRope (Set.add (List.last newRope) tailSet) (List.tail heads)
 
-        if List.length heads = 0 then Set.count tailSet
-        else
-            let newHead = List.head heads
-            let newRope = List.scan (fun head tail -> if touches head tail then tail else moveTowards head tail) newHead (List.tail rope)
-            followPath newRope (Set.add (List.last newRope) tailSet) (List.tail heads)
-    
-    let solution ropeSize =
-        followPath (List.replicate ropeSize (0, 0)) Set.empty
+let solution ropeSize =
+    followPath (List.replicate ropeSize (0, 0)) Set.empty
 
-    let part1 () = instructions
-                   |> solution 2
+let part1 () = instructions
+                |> solution 2
 
-    let part2 () = instructions
-                   |> solution 10
\ No newline at end of file
+let part2 () = instructions
+                |> solution 10
\ No newline at end of file