Fix type annotations and rational matrix construction for #1739

Author: morluto

src/jacobian/math/lattices/_lattice_operations.py

@@ -88,7 +88,7 @@ def _basis_int_list(lattice: IntegerLattice) -> list[list[int]]:
 def _require_full_row_rank(lattice: IntegerLattice, *, label: str) -> list[list[int]]:
     entries = _basis_int_list(lattice)
     rows = len(entries)
-    if integer_rank(lattice.basis.entries) != rows:
+    if integer_rank(entries) != rows:
         raise ValueError(f"{label} basis must be full row rank over QQ")
     return entries
 
@@ -102,12 +102,11 @@ def _integer_matrix(matrix: list[list[int]]) -> IntegerMatrix:
 
 
 def _rational_matrix(matrix: list[list[Fraction]]) -> RationalMatrix:
+    from jacobian._exact import CanonicalRational
+
     return RationalMatrix(
         entries=tuple(
-            tuple(
-                {"num": str(frac.numerator), "den": str(frac.denominator)}
-                for frac in row
-            )
+            tuple(CanonicalRational.from_fraction(frac) for frac in row)
             for row in matrix
         )
     )

src/jacobian/math/lattices/_lattice_ops.py

@@ -56,7 +56,7 @@ def _entries_to_int(matrix: Any) -> list[list[int]]:
     return [[int(matrix[i, j]) for j in range(cols)] for i in range(rows)]
 
 
-def integer_rank(entries: list[list[str | int]]) -> int:
+def integer_rank(entries: list[list[int]]) -> int:
     """Return the exact rank over ``QQ`` of an integer entry matrix."""
     from sympy import Matrix
 

src/jacobian/math/lattices/_lattice_tools.py

@@ -40,7 +40,7 @@
 __all__ = ["LATTICE_STRUCTURE_OPERATIONS"]
 
 
-def _lattice(ambient: int, basis: list[list[int]]) -> dict:
+def _lattice(ambient: int, basis: list[list[int]]) -> dict[str, object]:
     """Return a JSON-serialable IntegerLattice payload for examples."""
     return {
         "ambient_dimension": ambient,