mathcoding
diff --git a/‎scripts/pairslist.py‎
Lines changed: 100 additions & 33 deletions b/‎scripts/pairslist.py‎
Lines changed: 100 additions & 33 deletions
@@ -5,13 +5,14 @@
 @author: gualandi
 """
 
-from pairslist_impl import Head, Tail, EmptyList, MakeList
-from random import seed, randint
+#from pairslist_impl import Head, Tail, EmptyList, MakeList
+from pairslist_array import Head, Tail, EmptyList, MakeList
+
+from random import randint
 
 # Inizializza il generatore di numeri casuali
 # Vedi la documentazione del modulo random:
 # https://docs.python.org/3/library/random.html
-seed(13)
 def MakeRandomInts(n, a, b):
     """ Restituisce una lista n di numeri causali, uniformente distribuiti
         nell'intervallo [a,b] (estremi compresi) """
@@ -57,6 +58,18 @@ def Nth(As, i):
         return Head(As)
     return Nth(Tail(As), i-1)
 
+def Equal(As, Bs):
+    """ Check if two lists have the same sequence of elements """
+    if IsEmpty(As) and IsEmpty(Bs):
+        return True
+    if IsEmpty(As) and not IsEmpty(Bs):
+        return False
+    if not IsEmpty(As) and IsEmpty(Bs):
+        return False
+    if Head(As) != Head(Bs):
+        return False
+    return Equal(Tail(As), Tail(Bs))
+    
 def Length(As):
     """ Restituisce il numero di elementi contenuto nella lista As """
     def LengthI(Ls, n):
@@ -109,37 +122,91 @@ def ReverseI(Ls, Rs):
         return ReverseI(Tail(Ls), MakeList(Head(Ls), Rs))
     return ReverseI(Tail(As), MakeList(Head(As)))
 
-
-#-----------------------------------------------
-# MAIN function per testare tutte le soluzioni
-#-----------------------------------------------
-if __name__ == "__main__":
-    Ls = MakeRange(1, 5)
-    print("MakeList(7): ", end='')
-    PrintList(Ls)
-    
-    Rs = MakeRandomInts(10, 1, 100)
-    print("MakeRandomInts(10, 1, 100): ", end='')
-    PrintList(Rs)
+def Contains(As, value):
+    """ Controlla se la lista As contiene un elemento pari a 'value' """
+    if IsEmpty(As):
+        return False
+    if Head(As) == value:
+        return True
+    return Contains(Tail(As), value)
+
+def Count(As, value):
+    """ Conta il numero di elementi pari a 'value' nella lista As """
+    def CountI(Ls, counter):
+        if IsEmpty(Ls):
+            return counter
+        if Head(Ls) == value:
+            return CountI(Tail(Ls), counter+1)
+        return CountI(Tail(Ls), counter)
 
-    Cs = MakeRange(3,7)
-    print("MakeRange(3,7): ", end='')
-    PrintList(Cs)
+    return CountI(As, 0)
 
-    print("Head(Ls):", Head(Ls))
-    print("Tail(Ls):", Tail(Ls))
-    
-    print("Nth(Ls, 5):", Nth(Ls, 5))
-    
-    print("Length(Ls):", Length(Ls))
+def RemoveFirst(As, value):
+    """ Rimuovi il primo elemento di 'value' trovato in As """
+    if IsEmpty(As):
+        return As
+    if Head(As) == value:
+        return Tail(As)
+    return MakeList(Head(As), RemoveFirst(Tail(As), value))
 
-    Bs = MakeRange(1, 3)
-    print("Append:", Append(Ls, Bs))
-    
-    print("Scala:", Scala(Bs, 0.5))
-    print("Quadrati:", Quadrati(Bs))
-        
-    print("Map:", Map(lambda x: x**3, Ls))        
-    print("Filter:", Filter(lambda x: x % 2 == 0, Ls))
+def RemoveAll(As, value):
+    """ Rimuovi tutti gli elementi di 'value' trovato in As """
+    if IsEmpty(As):
+        return As
+    if Head(As) == value:
+        return RemoveAll(Tail(As), value)
+    return MakeList(Head(As), RemoveAll(Tail(As), value))
+
+def FoldRight(Op, As, z):
+    """ Riduci la lista As, applicando ad ogni suo elemento la funzione F()
+        e accumulando i risultati tramite l'operazione Op() """
+    if IsEmpty(As):
+        return z
+    return Op(Head(As), FoldRight(Op, Tail(As), z))
+
+def FoldLeft(Op, As, z):
+    if IsEmpty(As):
+        return z
+    return FoldLeft(Op, Tail(As), Op(Head(As), z))
 
-    print("Reverse:", Reverse(Ls))    
+Fold = FoldLeft
+
+# SOLUZIONI IN TERMINI DI FOLD (Right)
+
+def FoldLength(Ls):
+    """ Lunghezza di una lista in termini di fold """
+    return Fold(lambda x,y: 1+y, Ls, 0)
+
+def Sum(As):
+    """ Calcola la somma di tutti gli elementi nella lista As """
+    def Add(a, b):
+        return a+b
+    return Fold(Add, As, 0)
+
+def Prod(As):
+    """ Calcola la somma di tutti gli elementi nella lista As """
+    def Mul(a, b):
+        return a*b
+    return Fold(Mul, As, 1)
+
+def Min(As):
+    """ Più piccolo elemento della lista As """
+    return Fold(min, Tail(As), Head(As))
+
+def Max(As):
+    """ Più grande elemento della lista As """
+    return Fold(max, Tail(As), Head(As))
+
+def FoldMap(F, Ls):
+    """ Map in termini di Fold """
+    return Fold(lambda x,y: MakeList(F(x), y), Ls, EmptyList())
+
+def FoldFilter(P, Ls):
+    """ Filter in termini di Fold """
+    return Fold(lambda x,y: MakeList(x, y) if P(x) else y, Ls, EmptyList())
+
+def FoldReverse(Ls):
+    """ Reverse in termini di Fold """
+    def Concatenate(x, Ls):
+        return Append(Ls, MakeList(x))
+    return Fold(Concatenate, Ls, EmptyList())