fix game state representation

config.nims

@@ -1,5 +1,4 @@
 --threads: on
 --d: release
+--d: lto
 --opt: speed
---passC: -flto
---passL: -flto

cup.nim

@@ -5,8 +5,7 @@ when isMainModule:
   let config = parseArgs()
   var b: Board
   b.init
-  b.setState(config.state, [])
-  b.diceRolled = config.diceRolled
+  b.setState(config.state)
   
   let legScores = b.getLegScores
   let gameScores = b.randomGames(1_000_000)

fixedseq.nim

@@ -101,12 +101,16 @@ proc delete*(s: var FixedSeq, idx: Natural) =
   when not defined(danger):
     if idx > s.last:
       raise newException(IndexDefect, "index " & $idx & " is out of bounds.")
-  s.data[idx] = -1
+  s.data[idx] = -1 # do we even need this?
   dec s.last
   for i in typeof(s.last)(idx) .. s.last:
     swap(s.data[i], s.data[i + 1])
 
 
+proc clear*(s: var FixedSeq) =
+  s.last = -1
+
+
 proc find*(s: FixedSeq, needle: FixedSeq.Contents): FixedSeq.Pointer =
   for i, v in s.data:
     if v == needle:
@@ -127,6 +131,9 @@ proc reverse*(s: var FixedSeq; first, last: Natural) =
 proc shuffle*(s: var FixedSeq, r: var Rand) =
   r.shuffle(s.data)
 
+proc shuffle*(s: var FixedSeq) =
+  shuffle(s.data)
+
 
 proc moveSubstack*(src, dst: var FixedSeq; start: Natural) =
   var count: typeof(src.last) = 0 # have to track this separately apparently

game.nim

@@ -53,6 +53,11 @@ type
     camels*: ColorStack
     tile*: Option[Tile]
 
+  GameState* = object
+    dice*: array[Color, bool]
+    camels*: FixedSeq[5, tuple[c: Color, p: range[1..16]], int8]
+    tiles*: FixedSeq[8, tuple[t: Tile, p: range[1..16]], int8] # max 8 players, so max 8 tiles
+
   Board* = object
     squares*: array[1..16, Square]
     camels*: array[Color, range[1..16]]
@@ -62,6 +67,14 @@ type
     initialized: bool
 
 
+proc init*(state: var GameState) =
+  state.camels.initFixedSeq
+  state.tiles.initFixedSeq
+
+proc newGameState*(): GameState =
+  result.init
+
+
 # use a template here for better inlining
 template `[]`*[T](b: var Board, idx: T): var Square =
   b.squares[idx]
@@ -107,16 +120,38 @@ proc display*(b: Board, start, stop: int) =
   echo ""
 
 
-proc setState*(b: var Board; 
-               camels: openArray[tuple[c: Color, p: int]];
-               tiles: openArray[tuple[t: Tile, p: int]]) =
-  for (color, dest) in camels: # note that `camels` is ordered, as this determines stacking
+proc setState*(b: var Board; state: GameState) =
+  for color, pos in b.camels:
+    if pos > 0:
+      b[pos].camels.clear()
+
+  for (color, dest) in state.camels: # note that `camels` is ordered, as this determines stacking
     b[dest].camels.add(color)
     b.camels[color] = dest
 
-  for (tile, dest) in tiles:
+  for (tile, dest) in state.tiles:
     b[dest].tile = some(tile)
 
+  b.diceRolled = state.dice
+
+
+proc getState*(b: Board): GameState =
+  result.init
+  var camelCount = 0
+  let start = min(b.camels)
+  for pos in start .. b.squares.high:
+    let sq = b[pos]
+    for color in sq.camels:
+      result.camels.add((c: color, p: pos))
+      camelCount += 1
+
+    if sq.tile.isSome:
+      result.tiles.add((t: sq.tile.get, p: pos))
+    if camelCount >= 5:
+      break
+
+  result.dice = b.diceRolled
+
 
 proc diceRemaining*(b: Board): ColorStack =
   result.initFixedSeq

simulation.nim

@@ -43,11 +43,14 @@ iterator legEndStates(b: Board): Board =
   for i, c in b.diceRolled:
     if not c: diceRemaining.add(i)
 
+  let origState = b.getState
+  var prediction = b
   for future in possibleFutures(diceRemaining):
-    var prediction = b # make a copy so we can mutate
+    # var prediction = b # make a copy so we can mutate
     for dieRoll in future:
       prediction.advance(dieRoll)
     yield prediction
+    prediction.setState(origState)
 
 
 proc getLegScores*(b: Board): ScoreSet =

test.nim

@@ -39,12 +39,15 @@ proc summarize(tr: TestResults, opname = "operations") =
 
 proc newRandomGame(): Board =
   randomize()
-  var dice: array[5, tuple[c: Color, p: int]]
-  for i in 0 .. 4:
-    dice[i] = (Color(i), rand(1..3))
-
   result.init
-  result.setState(dice, [])
+
+  var state = newGameState()
+  for i in 0 .. 4:
+    let pos = rand(1..3)
+    state.camels.add((c: Color(i), p: pos))
+  state.camels.shuffle()
+
+  result.setState(state)
 
 
 template executionTime(body: untyped): Duration =

ui.nim

@@ -16,7 +16,7 @@ const help = block:
 
 type
   CmdConfig* = object
-    state*: seq[tuple[c: Color, p: int]]
+    state*: GameState
     interactive*: bool
     diceRolled*: array[Color, bool]
 
@@ -34,17 +34,18 @@ proc parseColor(c: char): Color =
   of 'P', 'p':
     return cPurple
   else:
-    raise newException(ValueError, "Invalid camel color specified.")
+    raise newException(ValueError, "Invalid camel color specified: " & c)
 
 
 proc parseArgs*(): CmdConfig =
+  result.state.init()
   for p in os.commandLineParams():
     if p == "-h":
       echo help
       quit 0
     elif p == "-i":
       result.interactive = true
-    elif result.state.len < 5:
+    elif result.state.camels.len < 5:
       let splat = p.split(':')
       
       let sq = splat[0]
@@ -53,11 +54,14 @@ proc parseArgs*(): CmdConfig =
       let colors = splat[1]
       for c in colors:
         let color = parseColor(c)
-        result.state.add((color, square))
+        result.state.camels.add((c: color, p: square))
     else:
       for c in p:
         let color = parseColor(c)
-        result.diceRolled[color] = true
+        result.state.dice[color] = true
+
+  if result.state.camels.len != 5:
+    raise newException(ValueError, "Please specify positions for all camels.")
 
 
 # ==========================
@@ -98,7 +102,6 @@ proc showSpaces*(b: Board; start, stop: Natural): string =
 proc showPercents*(scores: ScoreSet): string =
   var lines: array[5, string]
   for color, pct in scores.percents:
-    let label = align($color, 7) # e.g. " Green"
     var bar = repeat(" ", 20)
     let percentage = round(pct * 100, 2)
     # populate the progress bar
@@ -106,5 +109,5 @@ proc showPercents*(scores: ScoreSet): string =
     for i in 0 ..< barFill:
       bar[i] = '='
 
-    lines[int(color)] = fmt"{label}: [{bar}] {percentage}%"
+    lines[int(color)] = fmt"{color:>7}: [{bar}] {percentage:5.2f}%"
     result = lines.join("\n")