Implementation of the business card generator in Nim

shoddygenerator.nim

# A quick Nim translation of https://gist.github.com/munificent/b1bcd969063da3e6c298be070a22b604
# With some help of the JS version 

import random

const
  HEIGHT = 40
  WIDTH = 80
  PLAYER = '@'
  TREASURE = '$'
  VOID = ' '
  CORNER = '!'
  WALL = '#'
  FLOOR = '.'
  DOOR1 = '+'
  DOOR2 = '\\'

var
  map: seq[seq[char]] = newSeq[seq[char]](HEIGHT)

proc startMap() =
  for y in 0 ..< map.len:
    map[y] = newSeq[char](WIDTH)
    for x in 0 ..< map.len:
      map[y][x] = VOID

proc cave(start: bool) =
  randomize()
  let
    width = rand(10 ..< 15)
    height = rand(4 ..< 12)
    left = rand(WIDTH - width - 3) + 1
    top = rand(HEIGHT - height - 3) + 1

  for y in top-1 ..< top+height+2:
    for x in left-1 ..< left+width+2:
      if map[y][x] == FLOOR: return

  var
    doors = 0
    doorX: int
    doorY: int

  if not start:
    for y in top-1 ..< top+height+2:
      for x in left-1 ..< left+width+2:
        let s = x < left or x > left + width
        let t = y < top or y > top + height
        let q = s != t
        if q and map[y][x] == WALL:
          inc(doors)
          if rand(0 ..< doors) == 0:
            doorX = x
            doorY = y
    if doors == 0: return

  for y in top-1 ..< top + height + 2:
    for x in left-1 ..< left + width + 2:
      let s = x < left or x > left + width
      let t = y < top or y > top + height
      map[y][x] = if s and t:
        CORNER
      elif s xor t:
        WALL
      else: FLOOR

  if doors > 0:
    let typeDoor = rand(10)
    let kind = if typeDoor > 5: DOOR2 else: DOOR1
    map[doorY][doorX] = kind
  let go = if start: 1 else: rand(6)+1
  for j in 0 ..< go:
    map[rand(height) + top][rand(width)+left] = if start: PLAYER
      else:
        if rand(4) == 0:
          TREASURE
        else:
          (rand(62) + 65).char

proc generate() =
  for j in 0 ..< 1000000:
    cave(j == 0)

when isMainModule:
  startMap()
  generate()
  for y in 0 ..< HEIGHT:
    for x in 0 ..< WIDTH:
      let c = map[y][x]
      let dungeon = if c == CORNER: WALL else: c
      stdout.write(dungeon)
      if x == WIDTH-1:
        echo("")