Merge dbsp/live-source into dbsp/pushdown

crates/improvise-core/src/model/source.rs

@@ -70,7 +70,13 @@ impl Numbers {
         greatest: Option<f64>,
     ) -> Result<Self, BadParts> {
         let bad = |why| Err(BadParts(why));
+        if count == 0 && sum != ExactSum::new() {
+            return bad("a sum with no numbers");
+        }
         match (least, greatest) {
+            (None, None) if count > 0 && !sum.value().is_nan() => {
+                return bad("no extremes but a sum that is not NaN");
+            }
             (None, None) => {}
             (Some(_), Some(_)) if count == 0 => return bad("extremes with no numbers"),
             (Some(l), Some(g)) if l.is_nan() || g.is_nan() => return bad("a NaN extreme"),
@@ -535,13 +541,15 @@ mod tests {
     #[test]
     fn the_exact_sum_of_a_pool_of_cancelling_values_is_not_the_sum_of_rounded_parts() {
         let rounded = [1e16, 1.0].iter().sum::<f64>() + [-1e16].iter().sum::<f64>();
-        let mut pooled = Numbers::of([1e16, 1.0]);
-        pooled.merge(&Numbers::of([-1e16]));
         assert_eq!(
             rounded, 0.0,
-            "the fixture is inexact: summing rounded parts loses the 1"
+            "the fixture is inexact: rounded parts lose the 1"
         );
-        assert_eq!(pooled.total(), 1.0);
+        for (first, second) in [([1e16, 1.0], [-1e16, 0.0]), ([-1e16, 0.0], [1e16, 1.0])] {
+            let mut pooled = Numbers::of(first);
+            pooled.merge(&Numbers::of(second));
+            assert_eq!(pooled.total(), 1.0, "{first:?} then {second:?}");
+        }
     }
 
     fn pair(c: &str, i: &str) -> (String, String) {
@@ -854,7 +862,19 @@ mod tests {
             refused(Numbers::from_parts(2, sum(), Some(1.0), None)),
             "one extreme without the other"
         );
-        let ok = Numbers::from_parts(2, sum(), None, None).unwrap();
+        let mut one = ExactSum::new();
+        one.add(1.0, 1);
+        assert_eq!(
+            refused(Numbers::from_parts(0, one.clone(), None, None)),
+            "a sum with no numbers"
+        );
+        assert_eq!(
+            refused(Numbers::from_parts(2, one, None, None)),
+            "no extremes but a sum that is not NaN"
+        );
+        let mut nan = ExactSum::new();
+        nan.add(f64::NAN, 1);
+        let ok = Numbers::from_parts(2, nan, None, None).unwrap();
         assert!(
             ok.reduce(&AggFunc::Min).unwrap().is_nan(),
             "all NaN: no extremes, a count"