Bugfixes in mutator and in turmit

Turmit stack size was 0 sometimes
Mutator sometimes delete leading to empty expressions

gte/__main__.py

@@ -100,7 +100,8 @@ if 'pool_size' in args:
         #        for _ in range(args.pool_size)]
     else:
         prog = rpnlib.RpnExpr.from_string(args.prog)
-        progs = [mutate(prog, force=True) for _ in range(args.pool_size-1)]
+        progs = [prog]
+        progs += [mutate(prog, force=True) for _ in range(args.pool_size-1)]
 
     generation = 0
 

gte/mutator.py

@@ -59,6 +59,8 @@ def mutadd(expr):
     return expr
 
 def mutdel(expr):
+    if len(expr) == 1:
+        return mutadd(expr)
     pos = randint(0, len(expr)-1)
     del(expr[pos])
     return expr

gte/turmit.py

@@ -1,5 +1,9 @@
+import logging
+
 from .rpnlib import *
 
+logger = logging.getLogger()
+
 class Turmit(object):
     ''' @brief Represent a turmit that act given an RPN expression with an
         infinite looping stack with variable stack size.
@@ -101,7 +105,7 @@ class Turmit(object):
             @return popped value
         '''
         res = self._stack[self._cur]
-        if self._cur == 0:
+        if self._cur <= 0:
             self._cur = len(self._stack) - 1
         else:
             self._cur -= 1
@@ -137,10 +141,10 @@ class Turmit(object):
         ''' @brief Update memory stack size
         '''
 	    
-        if new_sz < 2:
-            new_sz = 2
         stksz = len(self._stack)
         new_sz %= 0xFFF
+        if new_sz < 2:
+            new_sz = 2
         if new_sz > stksz:
             self._stack += [ 0 for _ in range(new_sz - stksz) ]
         elif new_sz < stksz:
@@ -253,6 +257,7 @@ class Turmit(object):
         if a == 0:
             self.__ip += offset
 
+    """
     @RpnOp
     def jnz(self, a, offset):
         ''' @brief Increments IP if a != 0
@@ -261,6 +266,7 @@ class Turmit(object):
         '''
         if a != 0:
             self.__ip += offset
+    """
 
     @RpnOp
     def jcmp(self, a, b, cnd, offset):