Rewrite compute and remove reference to computing in OPERATORS

mapytex/calculus/core/compute/__init__.py

@@ -12,6 +12,15 @@ Computing with MO
 
 from ..operator import OPERATORS
 from .exceptions import ComputeError
+from .add import add
+from .minus import minus
+from .multiply import multiply
+
+OPERATIONS = {
+        "+": add, 
+        "-": minus, 
+        "*": multiply,
+        }
 
 def compute(node, left_v, right_v):
     """ 
@@ -19,28 +28,24 @@ def compute(node, left_v, right_v):
 
     :example:
 
-    >>> compute("+", 1, 2)
-    3
-    >>> compute("-", None, 2)
-    -2
-    >>> compute("-", 1, 2)
+    >>> from ..MO.mo import MOnumber
+    >>> compute("+", MOnumber(1), MOnumber(2))
+    <MOnumber 3>
+    >>> compute("-", None, MOnumber(2))
+    <MOnumber - 2>
+    >>> compute("*", MOnumber(1), MOnumber(2))
+    <MOnumber 2>
+    >>> compute("~", MOnumber(1), MOnumber(2))
     Traceback (most recent call last):
         ...
-    mapytex.calculus.core.compute.exceptions.ComputeError: left_v need to be None for operator with arity 1
+    mapytex.calculus.core.compute.exceptions.ComputeError: Unknown operation (~)
     """
-    op = OPERATORS[node]
-    lv = left_v
-    rv = right_v
-    if op['arity'] == 1:
-        if lv is None:
-            return op["operate"](rv)()
-        else:
-            raise ComputeError("left_v need to be None for operator with arity 1")
-    else:
-        try:
-            return op["operate"](lv)(rv)
-        except NotImplemented:
-            return op["roperate"](rv)(lv)
+    try:
+        operation = OPERATIONS[node]
+    except KeyError:
+        raise ComputeError(f"Unknown operation ({node})")
+
+    return operation(left_v, right_v)
 
 
 # -----------------------------