Added regression test for input as signal.

mtl/test_eval.py

@@ -1,3 +1,5 @@
+from discrete_signals import signal
+
 import mtl
 
 
@@ -20,3 +22,13 @@ def test_eval_regression_next_neg():
     v = f(d, quantitative=False, dt=1, time=None)
     assert not f(d, quantitative=False, dt=1)
     assert min(t for t, _ in v) >= 0
+
+
+def test_eval_with_signal():
+    spec = mtl.parse('F(above_three)')
+
+    raw_data = signal([(0, 1), (1, 2), (2, 3)], start=0, end=10, tag='a')
+    processed = raw_data.map(lambda val: val['a'] > 3, tag="above_three")
+
+    assert not spec(processed, quantitative=False)
+    assert spec(processed, quantitative=True) == 0