faster mv xor and new merge fct

src/kyupy/logic.py

@@ -81,6 +81,29 @@ on a signal. ``'N'``, ``'n'``, and ``'v'`` are interpreted as ``NPULSE``.
 """
 
 
+#                      0 X - 1 P R F N
+_mv_xor   = np.array([[0,1,1,3,4,5,6,7], # 0
+                      [1,1,1,1,1,1,1,1], # X
+                      [1,1,1,1,1,1,1,1], # -
+                      [3,1,1,0,7,6,5,4], # 1
+                      [4,1,1,7,4,5,6,7], # P
+                      [5,1,1,6,5,4,7,6], # R
+                      [6,1,1,5,6,7,4,5], # F
+                      [7,1,1,4,7,6,5,4], # N
+                      ], dtype=np.uint8)
+
+#                      0 X - 1 P R F N
+_mv_merge = np.array([[0,0,0,1,1,1,1,1], # 0
+                      [0,1,1,3,4,5,6,7], # X
+                      [0,1,2,3,4,5,6,7], # -
+                      [1,3,3,3,1,1,1,1], # 1
+                      [1,4,4,1,4,1,1,1], # P
+                      [1,5,5,1,1,5,1,1], # R
+                      [1,6,6,1,1,1,6,1], # F
+                      [1,7,7,1,1,1,1,7], # N
+                      ], dtype=np.uint8)
+
+
 def interpret(value):
     """Converts characters, strings, and lists of them to lists of logic constants defined above.
 
@@ -191,19 +214,26 @@ def mv_and(x1, x2, out=None):
     return out
 
 
-def _mv_xor(out, *ins):
-    any_unknown = (ins[0] == UNKNOWN) | (ins[0] == UNASSIGNED)
-    for inp in ins[1:]: any_unknown |= (inp == UNKNOWN) | (inp == UNASSIGNED)
+def mv_xor(x1, x2, out=None):
+    """A multi-valued XOR operator.
 
-    out[...] = ZERO
-    for inp in ins:
-        np.bitwise_xor(out, inp & 0b011, out=out)
-        np.bitwise_or(out, inp & 0b100, out=out)
-    np.putmask(out, any_unknown, UNKNOWN)
+    :param x1: A multi-valued array.
+    :param x2: A multi-valued array.
+    :param out: An optional storage destination. If None, a new multi-valued array is returned.
+    :return: A multi-valued array with the result.
+    """
+    out = out or np.empty(np.broadcast(x1, x2).shape, dtype=np.uint8)
+    out[...] = _mv_xor[x1, x2]
+    return out
 
 
-def mv_xor(x1, x2, out=None):
-    """A multi-valued XOR operator.
+def mv_merge(x1, x2, out=None):
+    """A multi-valued merge operator.
+
+    Merging identical values ``a`` and ``a`` yields ``a``.
+    Merging ``X`` and ``-`` yields ``X``.
+    Merging any value ``a`` with ``X`` or ``-`` yields ``a``.
+    Merging any other values ``a != b`` yields ``X``.
 
     :param x1: A multi-valued array.
     :param x2: A multi-valued array.
@@ -211,7 +241,7 @@ def mv_xor(x1, x2, out=None):
     :return: A multi-valued array with the result.
     """
     out = out or np.empty(np.broadcast(x1, x2).shape, dtype=np.uint8)
-    _mv_xor(out, x1, x2)
+    out[...] = _mv_merge[x1, x2]
     return out