Fix a bug in Variable._update_context when type was missing in a comp…

…osing (further in the sequence) variable.

lena/variables/variable.py

@@ -188,10 +188,13 @@ def _update_context(context, var_context):
         cvar = context.get("variable")
         # preserve variable composition information if that is present
         composed = []
-        if cvar and ("type" in var_context) and ("type" in cvar):
+        if cvar and ("type" in cvar):
             # If cvar has no "type",
             # then no types were in the recent variable or earlier
-            cur_type = var_context["type"]
+            if "type" in var_context:
+                cur_type = var_context["type"]
+            else:
+                cur_type = []
             if "compose" in cvar:
                 assert isinstance(cvar["compose"], list)
             else:
@@ -200,7 +203,8 @@ def _update_context(context, var_context):
                 assert isinstance(var_context["compose"], list)
                 cvar["compose"].extend(cur_type)
             else:
-                cvar["compose"].append(cur_type)
+                if cur_type:
+                    cvar["compose"].append(cur_type)
             composed = cvar["compose"]
 
         old_cvar = context.get("variable", {})
@@ -276,7 +280,15 @@ def __init__(self, *args, **kwargs):
         name = kwargs.pop("name", None)
         if name is None:
             name = "_".join([var.name for var in self._vars])
+
         var_context = {}
+        # we don't preserve types of combined variables,
+        # because they will take too much space in context (visually).
+        # types = [var.var_context.get("type", None) for var in args]
+        # type1 = types[0]
+        # # preserve type it is same for all variables
+        # if all((tp == type1 for tp in types[1:])):
+        #     var_context["type"] = type1
         var_context.update(kwargs)
         assert "dim" not in kwargs  # to set it manually is meaningless
         var_context.update({"dim": self.dim})

tests/variables/test_variable.py

@@ -1,5 +1,6 @@
 import copy
 import pytest
+from copy import deepcopy
 
 import lena.core
 import lena.context
@@ -8,6 +9,10 @@
 from lena.variables.variable import Combine, Compose, Variable
 
 
+# "double events"
+dev_data = [((1, 2.2, 3), (1.5, 2., 3))]
+
+
 def test_combine():
     ## init and getitem work
     # must have arguments
@@ -45,6 +50,7 @@ def test_combine():
     results = map(c, data)
     assert c.name == "mm_m"
     assert [res[0] for res in results]  == [(10,0.01), (20,0.02), (30,0.03)]
+
     # combination of Combines works
     c = Combine(mm, Combine(mm, m))
     results = [c(dt) for dt in data]
@@ -104,6 +110,32 @@ def test_combine():
         }
     }
 
+    # composition of variables works with Combine
+    positron = Variable("positron", getter=lambda dev: dev[0], type="particle")
+    x = Variable("x", getter=lambda coord: coord[0], type="coordinate")
+    y = Variable("y", getter=lambda coord: coord[1], type="coordinate")
+    xy = Combine(x, y)
+    seq = Sequence(positron, xy)
+    res = list(seq.run(deepcopy(dev_data)))
+    assert len(res) == 1
+    assert res[0][0] == (1, 2.2)
+    assert res[0][1] == {
+        'variable': {
+            'combine': (
+                {
+                    'coordinate': {'name': 'x'}, 'name': 'x', 'type': 'coordinate'
+                },
+                {
+                    'coordinate': {'name': 'y'}, 'name': 'y', 'type': 'coordinate'
+                }
+            ),
+            'compose': ['particle'],
+            'dim': 2,
+            'name': 'x_y',
+            'particle': {'name': 'positron'},
+        }
+    }
+
 
 def test_compose():
     data = [((1.05, 0.98, 0.8), (1.1, 1.1, 1.3))]