Implement the Highs backend

build/pkgs/highspy/SPKG.rst

@@ -0,0 +1,43 @@
+highs: Linear optimization solver with Python bindings
+======================================================
+
+Description
+-----------
+
+HiGHS is a high performance serial and parallel solver for large scale sparse
+linear optimization problems of the form:
+
+    min c'x subject to L <= Ax <= U; l <= x <= u
+
+where c, x, L, U, l, u are vectors and A is a matrix.
+
+HiGHS has implementations of the dual revised simplex method, primal and dual
+revised simplex solvers, an interior point solver, and a MIP solver.
+
+This package includes the highspy Python bindings built using pybind11.
+
+License
+-------
+
+- MIT License
+
+Upstream Contact
+----------------
+
+- https://github.com/ERGO-Code/HiGHS
+- https://www.highs.dev
+- Email: [email protected]
+
+Dependencies
+------------
+
+- CMake (build dependency)
+- scikit-build-core (build dependency)
+- pybind11 (build dependency)
+- numpy
+
+Special Update/Build Instructions
+----------------------------------
+
+The Python bindings (highspy) are built automatically via pip using the
+pyproject.toml included in the HiGHS source distribution.

build/pkgs/highspy/checksums.ini

@@ -0,0 +1,4 @@
+tarball=highs-VERSION.tar.gz
+sha1=576cf6f0fe03a57ebcf6acc6fe77b230b454b0bd
+sha256=2b44b074cf41439325ce4d0bbdac2d51379f56faf17ba15320a410d3c1f07275
+upstream_url=https://github.com/ERGO-Code/HiGHS/archive/refs/tags/vVERSION.tar.gz

build/pkgs/highspy/dependencies

@@ -0,0 +1,4 @@
+$(PYTHON) numpy scikit_build_core pybind11 cmake | $(PYTHON_TOOLCHAIN)
+
+----------
+All lines of this file are ignored except the first.

build/pkgs/highspy/package-version.txt

@@ -0,0 +1 @@
+1.11.0

build/pkgs/highspy/spkg-install.in

@@ -0,0 +1,2 @@
+cd src
+sdh_pip_install .

build/pkgs/highspy/type

@@ -0,0 +1 @@
+optional

build/pkgs/scikit_build_core/SPKG.rst

@@ -0,0 +1,35 @@
+scikit_build_core: Build backend for CMake Python projects
+===========================================================
+
+Description
+-----------
+
+Scikit-build-core is a build backend for CMake-based Python projects.
+It is a complete ground-up rewrite of scikit-build that provides modern
+standards-based build backend support for CMake.
+
+This package is required as a build dependency for packages that use
+scikit-build-core, such as HiGHS.
+
+License
+-------
+
+- Apache-2.0
+
+Upstream Contact
+----------------
+
+- https://github.com/scikit-build/scikit-build-core
+- https://scikit-build-core.readthedocs.io/
+
+Dependencies
+------------
+
+- packaging
+- pathspec
+- pyproject_metadata
+
+Special Update/Build Instructions
+----------------------------------
+
+None.

build/pkgs/scikit_build_core/checksums.ini

@@ -0,0 +1,4 @@
+tarball=scikit_build_core-VERSION.tar.gz
+sha1=52e4271301132ecd35d16534f63d6ec723ae5780
+sha256=5982ccd839735be99cfd3b92a8847c6c196692f476c215da84b79d2ad12f9f1b
+upstream_url=https://pypi.io/packages/source/s/scikit-build-core/scikit_build_core-VERSION.tar.gz

build/pkgs/scikit_build_core/dependencies

@@ -0,0 +1,4 @@
+$(PYTHON) packaging pathspec pyproject_metadata|hatchling hatch_vcs $(PYTHON_TOOLCHAIN)
+
+----------
+All lines of this file are ignored except the first.

build/pkgs/scikit_build_core/package-version.txt

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+0.11.6

build/pkgs/scikit_build_core/spkg-install.in

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+cd src
+sdh_pip_install .

build/pkgs/scikit_build_core/type

@@ -0,0 +1 @@
+optional

src/sage/numerical/backends/generic_backend.pyx

@@ -1712,8 +1712,15 @@ def default_mip_solver(solver=None):
         except ImportError:
             raise ValueError("SCIP is not available. Please refer to the documentation to install it.")
 
+    elif solver == "Highs":
+        try:
+            from sage.numerical.backends.highs_backend import HiGHSBackend
+            default_solver = solver
+        except ImportError:
+            raise ValueError("HiGHS is not available. Please refer to the documentation to install it.")
+
     else:
-        raise ValueError("'solver' should be set to 'GLPK', 'Coin', 'CPLEX', 'CVXOPT', 'CVXPY', 'Gurobi', 'PPL', 'SCIP', 'InteractiveLP', a callable, or None.")
+        raise ValueError("'solver' should be set to 'GLPK', 'Coin', 'CPLEX', 'CVXOPT', 'CVXPY', 'Gurobi', 'PPL', 'SCIP', 'HiGHS', 'InteractiveLP', a callable, or None.")
 
 
 cpdef GenericBackend get_solver(constraint_generation=False, solver=None, base_ring=None):
@@ -1883,5 +1890,9 @@ cpdef GenericBackend get_solver(constraint_generation=False, solver=None, base_r
         from sage.numerical.backends.scip_backend import SCIPBackend
         return SCIPBackend()
 
+    elif solver == "Highs":
+        from sage.numerical.backends.highs_backend import HiGHSBackend
+        return HiGHSBackend()
+
     else:
-        raise ValueError("'solver' should be set to 'GLPK', 'GLPK/exact', 'Coin', 'CPLEX', 'CVXOPT', 'CVXPY', 'Gurobi', 'PPL', 'SCIP', 'InteractiveLP', None (in which case the default one is used), or a callable.")
+        raise ValueError("'solver' should be set to 'GLPK', 'GLPK/exact', 'Coin', 'CPLEX', 'CVXOPT', 'CVXPY', 'Gurobi', 'PPL', 'SCIP', 'HiGHS', 'InteractiveLP', None (in which case the default one is used), or a callable.")

src/sage/numerical/backends/highs_backend.pxd

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+#*****************************************************************************
+#       Copyright (C) 2025 SageMath Developers
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  http://www.gnu.org/licenses/
+#*****************************************************************************
+
+from sage.numerical.backends.generic_backend cimport GenericBackend
+
+cdef class HiGHSBackend(GenericBackend):
+    cdef object highs_model
+    cdef str prob_name
+    cdef dict col_name_var
+    cdef dict row_name_var
+    cdef dict row_data_cache
+    cdef int numcols
+    cdef int numrows
+    cpdef __copy__(self)
+    cpdef get_row_prim(self, int i)
+    cpdef double get_row_dual(self, int i) except? -1
+    cpdef double get_col_dual(self, int j) except? -1
+    cpdef int get_row_stat(self, int i) except? -1
+    cpdef int get_col_stat(self, int j) except? -1
+    cpdef set_row_stat(self, int i, int stat)
+    cpdef set_col_stat(self, int j, int stat)
+    cpdef int warm_up(self) noexcept