Data commit

Task/Zebra-puzzle/Jq/zebra-puzzle-1.jq

@@ -0,0 +1,22 @@
+# Attempt to unify the input object with the specified object
+def unify( object ):
+  # Attempt to unify the input object with the specified tag:value
+  def unify2(tag; value):
+    if . == null then null
+    elif .[tag] == value then .
+    elif .[tag] == null then .[tag] = value
+    else null
+    end;
+  reduce (object|keys[]) as $key
+    (.; unify2($key; object[$key]) );
+
+# Input: an array
+# Output: if the i-th element can be made to satisfy the condition,
+# then the updated array, otherwise empty.
+def enforce(i; cond):
+  if 0 <= i and i < length
+  then
+    (.[i] | cond) as $ans
+    | if $ans then .[i] = $ans else empty end
+  else empty
+  end ;

Task/Zebra-puzzle/Jq/zebra-puzzle-2.jq

@@ -0,0 +1,60 @@
+# Each house is a JSON object of the form:
+# { "number": _, "nation": _, "owns": _, "color": _, "drinks": _, "smokes": _}
+
+# The list of houses is represented by an array of five such objects.
+
+# Input: an array of objects representing houses.
+# Output: [i, solution] where i is the entity unified with obj
+# and solution is the updated array
+def solve_with_index( obj ):
+  . as $Houses
+  | range(0; length) as $i
+  | ($Houses[$i] | unify(obj)) as $H
+  | if $H then $Houses[$i] = $H else empty end
+  | [ $i, .] ;
+
+def solve( object ):
+  solve_with_index( object )[1];
+
+def adjacent( obj1; obj2 ):
+  solve_with_index(obj1) as $H
+  | $H[1]
+  | (enforce(  $H[0] - 1; unify(obj2) ),
+     enforce(  $H[0] + 1; unify(obj2) )) ;
+
+def left_right( obj1; obj2 ):
+  solve_with_index(obj1) as $H
+  | $H[1]
+  | enforce(  $H[0] + 1; unify(obj2) ) ;
+
+
+# All solutions by generate-and-test
+def zebra:
+  [range(0;5)] | map({"number": .})                        # Five houses
+
+  | enforce( 0; unify( {"nation": "norwegian"} ) )
+  | enforce( 2; unify( {"drinks": "milk"} ) )
+
+  | solve( {"nation": "englishman",  "color": "red"} )
+  | solve( {"nation": "swede", "owns": "dog"} )
+  | solve( {"nation": "dane", "drinks": "tea"} )
+
+  | left_right( {"color": "green"}; {"color": "white"})
+
+  | solve( {"drinks": "coffee", "color": "green"} )
+  | solve( {"smokes": "Pall Mall", "owns": "birds"} )
+  | solve( {"color": "yellow", "smokes":  "Dunhill"} )
+
+  | adjacent( {"smokes": "Blend" }; {"owns": "cats"} )
+  | adjacent( {"owns": "horse"}; {"smokes": "Dunhill"})
+
+  | solve( {"drinks": "beer", "smokes": "Blue Master"} )
+  | solve( {"nation": "german", "smokes": "Prince"})
+
+  | adjacent( {"nation": "norwegian"}; {"color": "blue"})
+  | adjacent( {"drinks": "water"}; {"smokes": "Blend"})
+
+  | solve( {"owns": "zebra"} )
+;
+
+zebra

Task/Zebra-puzzle/Jq/zebra-puzzle-3.jq

@@ -0,0 +1,48 @@
+$ time jq -n -f zebra.jq
+[
+  {
+    "number": 0,
+    "nation": "norwegian",
+    "color": "yellow",
+    "smokes": "Dunhill",
+    "owns": "cats",
+    "drinks": "water"
+  },
+  {
+    "number": 1,
+    "drinks": "tea",
+    "nation": "dane",
+    "smokes": "Blend",
+    "owns": "horse",
+    "color": "blue"
+  },
+  {
+    "number": 2,
+    "drinks": "milk",
+    "color": "red",
+    "nation": "englishman",
+    "owns": "birds",
+    "smokes": "Pall Mall"
+  },
+  {
+    "number": 3,
+    "color": "green",
+    "drinks": "coffee",
+    "nation": "german",
+    "smokes": "Prince",
+    "owns": "zebra"
+  },
+  {
+    "number": 4,
+    "nation": "swede",
+    "owns": "dog",
+    "color": "white",
+    "drinks": "beer",
+    "smokes": "Blue Master"
+  }
+]
+
+# Times include compilation:
+real	0m0.284s
+user	0m0.260s
+sys	0m0.005s