Merge pull request #382 from egraphs-good/demo

Convert to multisets, facts as actions, and update multiset example

Author: saulshanabrook

Cargo.lock

@@ -4,6 +4,8 @@ _This project uses semantic versioning_
 
 ## UNRELEASED
 
+- Support using facts as union actions, add conversions to multisets, and update multiset examlpe [#382](https://github.com/egraphs-good/egglog-python/pull/382)
+
 ## 12.0.0 (2025-11-16)
 
 - Add support for setting report level with `egraph.set_report_level` [#375](https://github.com/egraphs-good/egglog-python/pull/375)

docs/changelog.md

@@ -39,6 +39,7 @@
     "Map",
     "MapLike",
     "MultiSet",
+    "MultiSetLike",
     "Primitive",
     "PyObject",
     "Rational",
@@ -583,6 +584,17 @@ def __add__(self, other: MultiSet[T]) -> MultiSet[T]: ...
     def map(self, f: Callable[[T], T]) -> MultiSet[T]: ...
 
 
+converter(
+    tuple,
+    MultiSet,
+    lambda t: MultiSet[get_type_args()[0]](  # type: ignore[misc,operator]
+        *(convert(x, get_type_args()[0]) for x in t)
+    ),
+)
+
+MultiSetLike: TypeAlias = MultiSet[T] | tuple[TO, ...]
+
+
 class Rational(BuiltinExpr, egg_sort="Rational"):
     @method(preserve=True)
     @deprecated("use .value")

python/egglog/builtins.py

@@ -367,6 +367,8 @@ def __replace_expr__(self, new_expr: Self) -> None:
         Replace the current expression with the new expression in place.
         """
 
+    def __hash__(self) -> int: ...  # type: ignore[empty-body]
+
 
 class BuiltinExpr(BaseExpr, metaclass=_ExprMetaclass):
     """
@@ -1933,23 +1935,32 @@ def seq(*schedules: Schedule) -> Schedule:
     return Schedule(Thunk.fn(Declarations.create, *schedules), SequenceDecl(tuple(s.schedule for s in schedules)))
 
 
-ActionLike: TypeAlias = Action | BaseExpr
-
-
 def _action_likes(action_likes: Iterable[ActionLike]) -> tuple[Action, ...]:
     return tuple(map(_action_like, action_likes))
 
 
 def _action_like(action_like: ActionLike) -> Action:
     if isinstance(action_like, Action):
         return action_like
+    if isinstance(action_like, Fact):
+        match action_like.fact:
+            case EqDecl(tp, left, right):
+                return Action(
+                    action_like.__egg_decls__,
+                    UnionDecl(tp, left, right),
+                )
+            case ExprFactDecl(expr):
+                return Action(
+                    action_like.__egg_decls__,
+                    ExprActionDecl(expr),
+                )
+            case _:
+                assert_never(action_like.fact)
     return expr_action(action_like)
 
 
 Command: TypeAlias = Action | RewriteOrRule
 
-CommandLike: TypeAlias = ActionLike | RewriteOrRule
-
 
 def _command_like(command_like: CommandLike) -> Command:
     if isinstance(command_like, RewriteOrRule):
@@ -1976,6 +1987,8 @@ def _rewrite_or_rule_generator(gen: RewriteOrRuleGenerator, frame: FrameType) ->
 
 
 FactLike = Fact | BaseExpr
+ActionLike: TypeAlias = Action | BaseExpr | Fact
+CommandLike: TypeAlias = ActionLike | RewriteOrRule
 
 
 def _fact_likes(fact_likes: Iterable[FactLike]) -> tuple[Fact, ...]:

python/egglog/egraph.py

@@ -6,55 +6,81 @@
 
 from __future__ import annotations
 
-from collections import Counter
-
 from egglog import *
 
 
 class Math(Expr):
     def __init__(self, x: i64Like) -> None: ...
+    def __add__(self, other: MathLike) -> Math: ...
+    def __radd__(self, other: MathLike) -> Math: ...
+    def __mul__(self, other: MathLike) -> Math: ...
+    def __rmul__(self, other: MathLike) -> Math: ...
 
 
-@function
-def square(x: Math) -> Math: ...
-
-
-@ruleset
-def math_ruleset(i: i64):
-    yield rewrite(square(Math(i))).to(Math(i * i))
-
+MathLike = Math | i64Like
+converter(i64, Math, Math)
 
-egraph = EGraph()
 
-xs = MultiSet(Math(1), Math(2), Math(3))
-egraph.register(xs)
+@function
+def sum(xs: MultiSetLike[Math, MathLike]) -> Math: ...
 
-egraph.check(xs == MultiSet(Math(1), Math(3), Math(2)))
-egraph.check_fail(xs == MultiSet(Math(1), Math(1), Math(2), Math(3)))
 
-assert Counter(egraph.extract(xs).value) == Counter({Math(1): 1, Math(2): 1, Math(3): 1})
+@function
+def product(xs: MultiSetLike[Math, MathLike]) -> Math: ...
 
 
-inserted = MultiSet(Math(1), Math(2), Math(3), Math(4))
-egraph.register(inserted)
-egraph.check(xs.insert(Math(4)) == inserted)
-egraph.check(xs.contains(Math(1)))
-egraph.check(xs.not_contains(Math(4)))
-assert Math(1) in xs
-assert Math(4) not in xs
+@function
+def square(x: Math) -> Math: ...
 
-egraph.check(xs.remove(Math(1)) == MultiSet(Math(2), Math(3)))
 
-assert egraph.extract(xs.length()).value == 3
-assert len(xs) == 3
+x = constant("x", Math)
+expr1 = 2 * (x + 3)
+expr2 = 6 + 2 * x
 
-egraph.check(MultiSet(Math(1), Math(1)).length() == i64(2))
 
-egraph.check(MultiSet(Math(1)).pick() == Math(1))
+@ruleset
+def math_ruleset(a: Math, b: Math, c: Math, i: i64, j: i64, xs: MultiSet[Math], ys: MultiSet[Math], zs: MultiSet[Math]):
+    yield rewrite(a + b).to(sum(MultiSet(a, b)))
+    yield rewrite(a * b).to(product(MultiSet(a, b)))
+    # 0 or 1 elements sums/products also can be extracted back to numbers
+    yield rule(a == sum(xs), xs.length() == i64(1)).then(a == xs.pick())
+    yield rule(a == product(xs), xs.length() == i64(1)).then(a == xs.pick())
+    yield rewrite(sum(MultiSet[Math]())).to(Math(0))
+    yield rewrite(product(MultiSet[Math]())).to(Math(1))
+    # distributive rule (a * (b + c) = a*b + a*c)
+    yield rule(
+        b == product(ys),
+        a == sum(xs),
+        ys.contains(a),
+        ys.length() > 1,
+        zs == ys.remove(a),
+    ).then(
+        b == sum(xs.map(lambda x: product(zs.insert(x)))),
+    )
+    # constants
+    yield rule(
+        a == sum(xs),
+        b == Math(i),
+        xs.contains(b),
+        ys == xs.remove(b),
+        c == Math(j),
+        ys.contains(c),
+    ).then(
+        a == sum(ys.remove(c).insert(Math(i + j))),
+    )
+    yield rule(
+        a == product(xs),
+        b == Math(i),
+        xs.contains(b),
+        ys == xs.remove(b),
+        c == Math(j),
+        ys.contains(c),
+    ).then(
+        a == product(ys.remove(c).insert(Math(i * j))),
+    )
 
-mapped = xs.map(square)
-egraph.register(mapped)
-egraph.run(math_ruleset)
-egraph.check(mapped == MultiSet(Math(1), Math(4), Math(9)))
 
-egraph.check(xs + xs == MultiSet(Math(1), Math(2), Math(3), Math(1), Math(2), Math(3)))
+egraph = EGraph()
+egraph.register(expr1, expr2)
+egraph.run(math_ruleset.saturate())
+egraph.check(expr1 == expr2)