Data update

Task/Generate-random-chess-position/Jq/generate-random-chess-position.jq

@@ -0,0 +1,94 @@
+### Pseuo-random numbers
+
+# Output: a prn in range(0;$n) where $n is `.`
+def prn:
+  if . == 1 then 0
+  else . as $n
+  | ([1, (($n-1)|tostring|length)]|max) as $w
+  | [limit($w; inputs)] | join("") | tonumber
+  | if . < $n then . else ($n | prn) end
+  end;
+
+def sample:
+  if length == 0 # e.g. null or []
+  then null
+  else .[length|prn]
+  end;
+
+def randFloat:
+  (1000|prn) / 1000;
+
+### Chess
+
+def isEmpty: . == "." or . == "•";
+
+def grid:
+  [range(0;4) |  (".","•") ] as $black
+  | [range(0;4) | ("•", ".")] as $white
+  | [range(0;4) | ($black, $white)] ;
+
+# input: {grid}
+def placeKings:
+  .done = false
+  | until(.done;
+      [8 | prn, prn, prn, prn] as [$r1, $c1, $r2, $c2]
+      | if $r1 != $r2 and (($r1 - $r2)|length) > 1 and (($c1 - $c2)|length) > 1
+        then   .grid[$r1][$c1] = "K"
+             | .grid[$r2][$c2] = "k"
+             | .done = true
+        else .
+        end )
+  | del(.done);
+
+# input: {grid}
+def placePieces($pieces; $isPawn):
+  ($pieces|length|prn) as $numToPlace
+  | .n = -1
+  | until(.n == $numToPlace;
+      .n += 1
+      | .done = false
+      | until(.done;
+            .r = (8 | prn)
+          | .c = (8 | prn)
+          | if (.grid[.r][.c] | isEmpty) and (($isPawn and (.r == 7 or .r == 0))|not)
+            then .done = true
+            else .
+            end )
+      | .grid[.r][.c] = $pieces[.n:.n+1] ) ;
+
+def toFen:
+    { grid,
+      fen: "",
+      countEmpty: 0 }
+    | reduce range (0;8) as $r (.;
+        reduce range(0;8) as $c (.;
+            .grid[$r][$c] as $ch
+            | .emit += " \($ch) "
+            | if ($ch | isEmpty)
+              then .countEmpty += 1
+              else
+                if .countEmpty > 0
+                then .fen +=  (.countEmpty|tostring)
+                | .countEmpty = 0
+                end
+              | .fen += $ch
+              end )
+        | if .countEmpty > 0
+          then .fen += (.countEmpty|tostring)
+          | .countEmpty = 0
+          end
+        | .fen += "/"
+        | .emit += "\n" )
+  | .emit,
+    .fen + " w - - 0 1" ;
+
+def createFen:
+  {grid: grid}
+  | placeKings
+  | placePieces("PPPPPPPP"; true)
+  | placePieces("pppppppp"; true)
+  | placePieces("RNBQBNR"; false)
+  | placePieces("rnbqbnr"; false)
+  | toFen;
+
+createFen