Add Generate CACHE HEAD property and improve PChain behaviour

FoxDot/lib/Patterns/Generators.py

@@ -182,18 +182,29 @@ def __init__(self, mapping, **kwargs):
         self.mapping = {}
         i = 0
         for key, value in mapping.items():
-            self.mapping[key] = asStream(value)
+            self.mapping[key] = self._convert_to_list(value)
             # Use the first key to start with
             if i == 0:
                 self.last_value = key
                 i += 1
 
         self.init_random(**kwargs)
 
-    def func(self, index):
-        self.last_value = self.choice(self.mapping[self.last_value])
+    def func(self, *args, **kwargs):
+        index = self.last_value
+        if isinstance(self.last_value, GeneratorPattern):
+            index = index.CACHE_HEAD
+        if index in self.mapping:
+            self.last_value = self.choice(self.mapping[index])
         return self.last_value
 
+    def _convert_to_list(self, value):
+        if isinstance(value, list):
+            return value
+        elif isinstance(value, Pattern):
+            return value.data
+        return [value]
+
 class PZ12(GeneratorPattern):
     """ Implementation of the PZ12 algorithm for predetermined random numbers. Using
         an irrational value for p, however, results in a non-determined order of values. 

FoxDot/lib/Patterns/Main.py

@@ -1338,6 +1338,11 @@ def getitem(self, index=None, *args):
             self.cache[index] = value
             return value
 
+    @property
+    def CACHE_HEAD(self):
+        ''' Returns the last value used if it exists '''
+        return self.cache.get(self.index - 1)
+
     def new(self, other, func=Nil):
         """ Creates a new `GeneratorPattern` that references
             this pattern but returns a modified value based on