Refacto C# interface

highs/interfaces/Highs/Enums/BasisStatus.cs

@@ -0,0 +1,28 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This defines the status of a variable (or slack variable for a constraint) in a basis
+/// </summary>
+public enum BasisStatus
+{
+    /// <summary>
+    /// The variable is nonbasic at its lower bound (or fixed value)
+    /// </summary>
+    Lower = 0,
+    /// <summary>
+    /// The variable is basic
+    /// </summary>
+    Basic,
+    /// <summary>
+    /// he variable is at its upper bound
+    /// </summary>
+    Upper,
+    /// <summary>
+    /// A free variable is nonbasic and set to zero
+    /// </summary>
+    Zero,
+    /// <summary>
+    /// The variable is nonbasic
+    /// </summary>
+    Nonbasic
+}

highs/interfaces/Highs/Enums/HessianFormat.cs

@@ -0,0 +1,16 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// The format in which the Hessian is stored
+/// </summary>
+public enum HessianFormat
+{
+    /// <summary>
+    /// Store the Hessian in triangular format
+    /// </summary>
+    Triangular = 1,
+    /// <summary>
+    /// Store the Hessian in square format
+    /// </summary>
+    Square
+}

highs/interfaces/Highs/Enums/HighsStatus.cs

@@ -0,0 +1,20 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This is (part of) the return value of most HiGHS methods
+/// </summary>
+public enum HighsStatus
+{
+    /// <summary>
+    /// The method has exposed an error
+    /// </summary>
+    Error = -1,
+    /// <summary>
+    /// The method has completed successfully
+    /// </summary>
+    Ok,
+    /// <summary>
+    /// The method has recovered from an unusual event, or has terminated due to reaching a time or iteration limit
+    /// </summary>
+    Warning
+}

highs/interfaces/Highs/Enums/MatrixFormat.cs

@@ -0,0 +1,16 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This defines the format of a HighsSparseMatrix
+/// </summary>
+public enum MatrixFormat
+{
+    /// <summary>
+    /// The matrix is stored column-wise
+    /// </summary>
+    ColumnWise = 1,
+    /// <summary>
+    /// The matrix is stored row-wise
+    /// </summary>
+    RowWise
+}

highs/interfaces/Highs/Enums/ModelStatus.cs

@@ -0,0 +1,75 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This defines the status of the model after a call to run
+/// </summary>
+public enum ModelStatus
+{
+    /// <summary>
+    /// The model status has not been set
+    /// </summary>
+    Notset = 0,
+    LoadError,
+    /// <summary>
+    /// There is an error in the model
+    /// </summary>
+    ModelError,
+    PresolveError,
+    /// <summary>
+    /// There has been an error when solving the model
+    /// </summary>
+    SolveError,
+    PostsolveError,
+    /// <summary>
+    /// The model is empty
+    /// </summary>
+    ModelEmpty,
+    /// <summary>
+    /// The model has been solved to optimality
+    /// </summary>
+    Optimal,
+    /// <summary>
+    /// The model is infeasible
+    /// </summary>
+    Infeasible,
+    /// <summary>
+    /// The model is unbounded or infeasible
+    /// </summary>
+    UnboundedOrInfeasible,
+    /// <summary>
+    /// The model is unbounded
+    /// </summary>
+    Unbounded,
+    /// <summary>
+    /// The bound on the model objective value has been reached
+    /// </summary>
+    ObjectiveBound,
+    /// <summary>
+    /// The target value for the model objective has been reached
+    /// </summary>
+    ObjectiveTarget,
+    /// <summary>
+    /// The run time limit has been reached
+    /// </summary>
+    TimeLimit,
+    /// <summary>
+    /// The iteration limit has been reached
+    /// </summary>
+    IterationLimit,
+    /// <summary>
+    /// The model status is unknown
+    /// </summary>
+    Unknown,
+    /// <summary>
+    /// The MIP solver has reached the limit on the number of LPs solved
+    /// </summary>
+    SolutionLimit,
+    /// <summary>
+    /// The solver has been interrupted by the user
+    /// </summary>
+    Interrupt,
+    /// <summary>
+    /// The solver has been unable to allocate sufficient memory
+    /// </summary>
+    MemoryLimit
+}

highs/interfaces/Highs/Enums/ObjectiveSense.cs

@@ -0,0 +1,16 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This defines optimization sense of a HighsLp
+/// </summary>
+public enum ObjectiveSense
+{
+    /// <summary>
+    /// The objective is to be minimized
+    /// </summary>
+    Minimize = 1,
+    /// <summary>
+    /// The objective is to be maximized
+    /// </summary>
+    Maximize = -1
+}

highs/interfaces/Highs/Enums/VariableType.cs

@@ -0,0 +1,28 @@
+namespace Highs.Enums;
+
+/// <summary>
+/// This defines the feasible values of a variable within a model
+/// </summary>
+public enum VariableType
+{
+    /// <summary>
+    /// The variable can take continuous values between its bounds
+    /// </summary>
+    Continuous = 0,
+    /// <summary>
+    /// The variable must take integer values between its bounds
+    /// </summary>
+    Integer,
+    /// <summary>
+    /// The variable must be zero or take continuous values between its bounds
+    /// </summary>
+    SemiContinuous,
+    /// <summary>
+    /// The variable must be zero or take integer values between its bounds
+    /// </summary>
+    SemiInteger,
+    /// <summary>
+    /// The variable must take implicit integer values between its bounds
+    /// </summary>
+    ImplicitInteger,
+}

highs/interfaces/Highs/Highs.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

highs/interfaces/Highs/Highs.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36811.4 d17.14
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Highs", "Highs.csproj", "{5BEA6A69-23A3-426C-A849-3B9A9A8D518A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5BEA6A69-23A3-426C-A849-3B9A9A8D518A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5BEA6A69-23A3-426C-A849-3B9A9A8D518A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5BEA6A69-23A3-426C-A849-3B9A9A8D518A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5BEA6A69-23A3-426C-A849-3B9A9A8D518A}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {F1C5253E-03B0-407C-B6C6-27C74E5FDF9F}
+	EndGlobalSection
+EndGlobal