Data commit

Task/Amb/Nim/amb.nim

@@ -0,0 +1,33 @@
+import sugar, strutils
+
+proc amb(comp: proc(a, b: string): bool,
+         options: seq[seq[string]],
+         prev: string = ""): seq[string] =
+
+  if options.len == 0: return @[]
+
+  for opt in options[0]:
+    # If this is the base call, prev is nil and we need to continue.
+    if prev.len != 0 and not comp(prev, opt): continue
+
+    # Take care of the case where we have no options left.
+    if options.len == 1: return @[opt]
+
+    # Traverse into the tree.
+    let res = amb(comp, options[1..options.high], opt)
+
+    # If it was a failure, try the next one.
+    if res.len > 0: return opt & res    # We have a match.
+
+  return @[]
+
+const sets = @[@["the", "that", "a"],
+               @["frog", "elephant", "thing"],
+               @["walked", "treaded", "grows"],
+               @["slowly", "quickly"]]
+
+let result = amb((s, t: string) => (s[s.high] == t[0]), sets)
+if result.len == 0:
+  echo "No matches found!"
+else:
+  echo result.join " "