fix: conflicting ranges

odex/condition.py

@@ -101,7 +101,7 @@ class Literal(Condition):
     value: Any
 
     def __str__(self) -> str:
-        return str(self.value)
+        return repr(self.value)
 
 
 @dataclass

odex/index.py

@@ -1,6 +1,6 @@
 from abc import abstractmethod
 from typing import Generic, TypeVar, Set, Any, Optional, Iterable, List, cast, Dict, Type, Callable
-from typing_extensions import Protocol
+from typing_extensions import Protocol, runtime_checkable
 
 from sortedcontainers import SortedDict  # type: ignore
 
@@ -37,6 +37,9 @@ def match(self, condition: BinOp, operand: Condition) -> Optional[Plan]:
             `IndexLoop` plan if it can.
         """
 
+
+@runtime_checkable
+class SupportsLookup(Protocol[T]):
     @abstractmethod
     def lookup(self, value: Any) -> Set[T]:
         """
@@ -48,6 +51,9 @@ def lookup(self, value: Any) -> Set[T]:
             Result set
         """
 
+
+@runtime_checkable
+class SupportsRange(Protocol[T]):
     @abstractmethod
     def range(self, rng: Range) -> Set[T]:
         """
@@ -60,7 +66,7 @@ def range(self, rng: Range) -> Set[T]:
         """
 
 
-class HashIndex(Generic[T], Index[T]):
+class HashIndex(Generic[T], Index[T], SupportsLookup[T]):
     """
     Hash table index.
 
@@ -95,9 +101,6 @@ def remove(self, objs: Set[T], ctx: Context[T]) -> None:
     def lookup(self, value: Any) -> Set[T]:
         return self.idx.get(value) or set()
 
-    def range(self, rng: Range) -> Set[T]:
-        raise ValueError(f"{self.__class__.__name__} does not support range queries")
-
     def match(self, condition: BinOp, operand: Condition) -> Optional[Plan]:
         if isinstance(condition, Eq) and isinstance(operand, Literal):
             return IndexLookup(index=self, value=operand.value)
@@ -121,7 +124,7 @@ def __str__(self) -> str:
         return f"{self.__class__.__name__}({self.attr})"
 
 
-class SortedDictIndex(Generic[T], HashIndex[T]):
+class SortedDictIndex(Generic[T], HashIndex[T], SupportsRange[T]):
     """
     Same as `HashIndex`, except this uses a `sortedcontainers.SortedDict` as the index
     and supports range queries.

odex/optimize.py

@@ -1,4 +1,5 @@
-from typing import Callable, Sequence, Dict, TYPE_CHECKING, Any, List
+from collections import defaultdict
+from typing import Callable, Sequence, Dict, TYPE_CHECKING, List, Union as UnionType
 from typing_extensions import Protocol
 
 from odex.condition import and_, BinOp, Attribute
@@ -13,6 +14,7 @@
     IndexRange,
     IndexLookup,
     Bound,
+    Empty,
 )
 
 if TYPE_CHECKING:
@@ -90,40 +92,52 @@ class CombineRanges(TransformerRule):
 
     def transform(self, plan: Plan, ctx: Context) -> Plan:
         if isinstance(plan, Intersect):
-            ranges: Dict[Index, Range] = {}
+            # Group the plans by ones that support ranges and by index
+            plans_by_index: Dict[Index, List[UnionType[IndexLookup, IndexRange]]] = defaultdict(
+                list
+            )
             others = []
-
             for i in plan.inputs:
-                if isinstance(i, IndexLookup):
-                    rng: Range[Any] = Range(
-                        left=Bound(i.value, True),
-                        right=Bound(i.value, True),
-                    )
-                    existing = ranges.get(i.index)
-                    ranges[i.index] = existing.combine(rng) if existing else rng
-                elif isinstance(i, IndexRange):
-                    existing = ranges.get(i.index)
-                    ranges[i.index] = existing.combine(i.range) if existing else i.range
+                if isinstance(i, (IndexLookup, IndexRange)):
+                    plans_by_index[i.index].append(i)
                 else:
                     others.append(i)
 
             inputs: List[Plan] = []
-            for index, rng in ranges.items():
-                if (
-                    isinstance(rng.left, Bound)
-                    and isinstance(rng.right, Bound)
-                    and rng.left.value == rng.right.value
-                    and rng.left.inclusive
-                    and rng.right.inclusive
-                ):
-                    inputs.append(IndexLookup(index=index, value=rng.left.value))
-                else:
-                    inputs.append(
-                        IndexRange(
-                            index=index,
-                            range=rng,
-                        )
+
+            for index, plans in plans_by_index.items():
+                if len(plans) == 1:
+                    inputs.append(plans[0])
+                    continue
+
+                ranges = [
+                    # Treat a lookup as a range
+                    Range(
+                        left=Bound(i.value, True),
+                        right=Bound(i.value, True),
                     )
+                    if isinstance(i, IndexLookup)
+                    else i.range
+                    for i in plans
+                ]
+
+                new_range = ranges[0]
+                for rng in ranges[1:]:
+                    combined = new_range.combine(rng)
+
+                    # None means there is a range that always evaluates to False
+                    if combined is None:
+                        return Empty()
+                    else:
+                        new_range = combined
+
+                inputs.append(
+                    IndexRange(
+                        index=index,
+                        range=new_range,
+                    )
+                )
+
             inputs.extend(others)
 
             if len(inputs) == 1:

odex/plan.py

@@ -14,6 +14,7 @@
     Generic,
     TypeVar,
     NamedTuple,
+    Optional,
 )
 from typing_extensions import Protocol
 
@@ -41,10 +42,18 @@ class Comparable(Protocol):
     def __lt__(self: "C", other: "C") -> bool:
         pass
 
+    @abstractmethod
+    def __le__(self: "C", other: "C") -> bool:
+        pass
+
     @abstractmethod
     def __gt__(self: "C", other: "C") -> bool:
         pass
 
+    @abstractmethod
+    def __ge__(self: "C", other: "C") -> bool:
+        pass
+
 
 C = TypeVar("C", bound=Comparable)
 
@@ -94,6 +103,11 @@ def transform(self, transformer: Transformer) -> "Plan":
         return transformer(self)
 
 
+class Empty(Plan):
+    def to_s(self, depth: int = 0) -> str:
+        return "Empty"
+
+
 @dataclass
 class ScanFilter(Plan):
     """Return all objects in the collection, filtering with `condition`"""
@@ -149,10 +163,19 @@ class Range(Generic[C]):
     left: OptionalBound = UNSET
     right: OptionalBound = UNSET
 
-    def combine(self, other: "Range[C]") -> "Range[C]":
+    def combine(self, other: "Range[C]") -> "Optional[Range[C]]":
         left = self._combine_bounds(self.left, other.left, lambda a, b: a > b)
         right = self._combine_bounds(self.right, other.right, lambda a, b: a < b)
 
+        # Check for an invalid range
+        if isinstance(left, Bound) and isinstance(right, Bound):
+            if left.inclusive and right.inclusive:
+                if left.value > right.value:
+                    return None
+            else:
+                if left.value >= right.value:
+                    return None
+
         return Range(
             left=left,
             right=right,
@@ -184,11 +207,13 @@ class IndexRange(Plan):
     def to_s(self, depth=0):
         if self.range.left is UNSET:
             assert isinstance(self.range.right, Bound)
-            return f"IndexRange: {self.index} {self.range.right.symbol()} {self.range.right.value}"
+            return f"IndexRange: {self.index} {self.range.right.symbol()} {repr(self.range.right.value)}"
         if self.range.right is UNSET:
             assert isinstance(self.range.left, Bound)
-            return f"IndexRange: {self.range.left.value} {self.range.left.symbol()} {self.index}"
-        return f"IndexRange: {self.range.left.value} {self.range.left.symbol()} {self.index} {self.range.right.symbol()} {self.range.right.value}"
+            return (
+                f"IndexRange: {repr(self.range.left.value)} {self.range.left.symbol()} {self.index}"
+            )
+        return f"IndexRange: {repr(self.range.left.value)} {self.range.left.symbol()} {self.index} {self.range.right.symbol()} {repr(self.range.right.value)}"
 
     def __deepcopy__(self, memodict):
         return IndexRange(
@@ -205,7 +230,7 @@ class IndexLookup(Plan):
     value: Any
 
     def to_s(self, depth=0):
-        return f"IndexLookup: {self.index} = {self.value}"
+        return f"IndexLookup: {self.index} = {repr(self.value)}"
 
     def __deepcopy__(self, memodict):
         return IndexLookup(index=self.index, value=deepcopy(self.value))

odex/set.py

@@ -21,7 +21,17 @@
 from odex.index import Index, InvertedIndex, SortedDictIndex, HashIndex
 from odex.optimize import Chain, Rule
 from odex.parse import Parser
-from odex.plan import Plan, Union, Intersect, ScanFilter, Filter, Planner, IndexLookup, IndexRange
+from odex.plan import (
+    Plan,
+    Union,
+    Intersect,
+    ScanFilter,
+    Filter,
+    Planner,
+    IndexLookup,
+    IndexRange,
+    Empty,
+)
 from odex import condition as cond
 from odex.condition import BinOp, UnaryOp, Attribute, Literal, Condition
 from odex.utils import intersect
@@ -122,6 +132,7 @@ def __init__(
             Intersect: lambda plan: intersect(*(self.execute(i) for i in plan.inputs)),  # type: ignore
             IndexLookup: lambda plan: plan.index.lookup(plan.value),  # type: ignore
             IndexRange: lambda plan: plan.index.range(plan.range),  # type: ignore
+            Empty: lambda plan: set(),  # type: ignore
         }
 
         def match_binop(op: Callable[[Any, Any], Any]) -> Callable[[BinOp, T], Any]:

tests/fixtures/e2e.yaml

@@ -118,7 +118,7 @@ setups:
         - ScanFilter: 1 > a
         - ScanFilter: 3 <= a
     optimized_plan: |-
-      IndexRange: 3 <= SortedDictIndex(a) < 1
+      Empty
     result: []
   - title: Combining ranges leads to =
     condition: a > 1 AND a >= 3 AND a <= 3
@@ -129,9 +129,18 @@ setups:
           - ScanFilter: a >= 3
         - ScanFilter: a <= 3
     optimized_plan: |-
-      IndexLookup: SortedDictIndex(a) = 3
+      IndexRange: 3 <= SortedDictIndex(a) <= 3
     result:
     - 2
+  - title: Conflicting equalities
+    condition: a = 1 AND a = 2
+    plan: |-
+      Intersect
+        - ScanFilter: a = 1
+        - ScanFilter: a = 2
+    optimized_plan: |-
+      Empty
+    result: []
 - objects:
   - a: 1
     b: 2
@@ -211,29 +220,52 @@ setups:
     optimized_plan: |-
       IndexRange: SortedDictIndex(a) <= 2
     result:
-      - 0
-      - 1
-      - 3
-      - 4
+    - 0
+    - 1
+    - 3
+    - 4
   - title: Bisect left (>)
     condition: a > 1
     plan: |-
       ScanFilter: a > 1
     optimized_plan: |-
       IndexRange: 1 < SortedDictIndex(a)
     result:
-      - 1
-      - 2
-      - 4
-      - 5
+    - 1
+    - 2
+    - 4
+    - 5
   - title: Bisect right (>=)
     condition: a >= 2
     plan: |-
       ScanFilter: a >= 2
     optimized_plan: |-
       IndexRange: 2 <= SortedDictIndex(a)
     result:
-      - 1
-      - 2
-      - 4
-      - 5
+    - 1
+    - 2
+    - 4
+    - 5
+- objects:
+  - a: foo
+  - a: bar
+  - a: baz
+  indexes: [a]
+  tests:
+  - title: String equality
+    condition: a = 'foo'
+    plan: |-
+      ScanFilter: a = 'foo'
+    optimized_plan: |-
+      IndexLookup: HashIndex(a) = 'foo'
+    result:
+    - 0
+  - title: Conflicting equalities, string
+    condition: a = 'foo' AND a = 'bar'
+    plan: |-
+      Intersect
+        - ScanFilter: a = 'foo'
+        - ScanFilter: a = 'bar'
+    optimized_plan: |-
+      Empty
+    result: []