commit c552834741d8f953b14983e98cb529f375aca5a5
Author: Joseph Montanaro <jfmontanaro@modg.org>
Date:   Thu Mar 18 15:40:09 2021 -0700

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..adb36c8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*.exe
\ No newline at end of file
diff --git a/main.nim b/main.nim
new file mode 100644
index 0000000..1bbc9ef
--- /dev/null
+++ b/main.nim
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+import options, sequtils, sugar
+
+
+type
+  Color = enum
+    cRed, cGreen, cBlue, cYellow, cPurple
+
+  Tile = enum
+    tForward = -1,
+    tBackward = 1
+
+  Square = object
+    camels: seq[Color]
+    tile: Option[Tile]
+
+  Die = tuple[color: Color, value: range[1..3]]
+
+  Board = object
+    squares: array[1..16, Square]
+    camels: array[Color, range[1..16]]
+
+
+proc `[]`(b: var Board, idx: range[1..16]): var Square =
+  b.squares[idx]
+
+
+proc display(b: Board, start, stop: int) =
+  for i in start..stop:
+    let sq = b.squares[i]
+    let lead = $i & ": "
+    if sq.tile.isSome:
+      echo lead, sq.tile.get
+    else:
+      echo lead, sq.camels
+  echo "\n"
+
+
+proc preRoll(b: var Board) =
+  let colors = [cGreen, cYellow, cPurple, cBlue, cRed]
+  var rolls = [range[1..16]3, 2, 3, 2, 1]
+
+  for (color, roll) in zip(colors, rolls):
+    let dest = roll + 1
+    b[dest].camels.add(color)
+    b.camels[color] = dest
+
+
+proc advance(b: var Board, die: Die) =
+  let
+    (color, roll) = die
+    startPos = b.camels[color]
+  var prepend = false
+  var endPos = startPos + roll
+  if b[endPos].tile.isSome:
+    endPos += int(b[endPos].tile.get)
+    if b[endPos].tile.get == tBackward: prepend = true # if moving backward, we will prepend camel to the seq
+
+  for i, c in b[startPos].camels:
+    if c == color:
+      let subStack = b[startPos].camels[i .. ^1]
+      b[endPos].camels.add(subStack)
+      if prepend:
+        # figure out how to prepend a sequence to another sequence
+      else:
+        b[startPos].camels[i .. ^1] = @[]
+      for moved in subStack:
+        b.camels[moved] = endPos
+    break # breaking the outer loop here, not the inner
+
+
+var b: Board
+# b.display(1, 5)
+b.preRoll
+let c = b.dup(advance((cRed, range[1..3]3)))
+b.display(1, 5)
+c.display(1, 5)