[Lang] Move sparse matrix/solver into subfolder

python/taichi/lang/__init__.py

@@ -23,13 +23,12 @@
 from taichi.lang.ops import *
 from taichi.lang.quant_impl import quant
 from taichi.lang.runtime_ops import async_flush, sync
-from taichi.lang.sparse_matrix import SparseMatrix, SparseMatrixBuilder
-from taichi.lang.sparse_solver import SparseSolver
 from taichi.lang.struct import Struct
 from taichi.lang.type_factory_impl import type_factory
 from taichi.lang.util import (has_pytorch, is_taichi_class, python_scope,
                               taichi_scope, to_numpy_type, to_pytorch_type,
                               to_taichi_type)
+from taichi.linalg import SparseMatrix, SparseMatrixBuilder, SparseSolver
 from taichi.misc.util import deprecated
 from taichi.profiler import KernelProfiler, get_default_kernel_profiler
 from taichi.snode.fields_builder import FieldsBuilder

python/taichi/lang/kernel_arguments.py

@@ -2,8 +2,8 @@
 from taichi.lang.any_array import AnyArray
 from taichi.lang.enums import Layout
 from taichi.lang.expr import Expr
-from taichi.lang.sparse_matrix import SparseMatrixBuilder
 from taichi.lang.util import cook_dtype
+from taichi.linalg import SparseMatrixBuilder
 from taichi.type.primitive_types import u64
 
 

python/taichi/linalg/__init__.py

@@ -0,0 +1,2 @@
+from taichi.linalg.sparse_matrix import SparseMatrix, SparseMatrixBuilder
+from taichi.linalg.sparse_solver import SparseSolver

python/taichi/lang/sparse_solver.py → python/taichi/linalg/sparse_solver.py

@@ -1,12 +1,11 @@
 import numpy as np
 from taichi.core.util import ti_core as _ti_core
-from taichi.lang import Field
-from taichi.lang.impl import get_runtime
-from taichi.lang.sparse_matrix import SparseMatrix
+from taichi.linalg import SparseMatrix
 
 
 class SparseSolver:
     def __init__(self, solver_type="LLT", ordering="AMD"):
+        from taichi.lang.impl import get_runtime
         solver_type_list = ["LLT", "LDLT", "LU"]
         solver_ordering = ['AMD', 'COLAMD']
         if solver_type in solver_type_list and ordering in solver_ordering:
@@ -39,6 +38,7 @@ def factorize(self, sparse_matrix):
             self.type_assert(sparse_matrix)
 
     def solve(self, b):
+        from taichi.lang import Field
         if isinstance(b, Field):
             return self.solver.solve(b.to_numpy())
         elif isinstance(b, np.ndarray):