public Function Get(string formula)
{
Calculator c = new Calculator( );
this.Create( formula, ref c );
return c.Execute;
}
private void Create(string formula, ref Calculator ret)
{
formula = this.PreProcess( formula );
CodeSnippetExpression snippet = new CodeSnippetExpression( formula );
CodeMemberMethod meth = new CodeMemberMethod( );
meth.Name = "Execute";
meth.Attributes = MemberAttributes.Static | MemberAttributes.Public;
meth.ReturnType = new CodeTypeReference( typeof( float ) );
meth.Parameters.Add( new CodeParameterDeclarationExpression( new CodeTypeReference( typeof( float ) ), "x" ) );
meth.Statements.Add( new CodeMethodReturnStatement( new CodeCastExpression(
new CodeTypeReference(typeof(float)), snippet ) ) );
CodeTypeDeclaration cl = new CodeTypeDeclaration( );
cl.IsClass = true;
cl.Name = "Evaluator";
cl.Attributes = MemberAttributes.Public;
cl.Members.Add( meth );
CodeNamespace namesp = new CodeNamespace( "ExpressionEvaluator" );
namesp.Imports.Add( new CodeNamespaceImport( "System" ) );
namesp.Types.Add( cl );
CodeCompileUnit unit = new CodeCompileUnit( );
unit.Namespaces.Add( namesp );
CompilerParameters cparams = new CompilerParameters( );
cparams.CompilerOptions = "/target:library /optimize";
cparams.GenerateExecutable = false;
cparams.GenerateInMemory = true;
cparams.IncludeDebugInformation = false;
cparams.ReferencedAssemblies.Add( "mscorlib.dll" );
cparams.ReferencedAssemblies.Add( "System.dll" );
cparams.TreatWarningsAsErrors = true;
using ( CSharpCodeProvider prov = new CSharpCodeProvider( ) )
{
StringWriter w = new StringWriter();
prov.GenerateCodeFromCompileUnit( unit, w, new CodeGeneratorOptions( ) );
this.PreProcess( w.ToString( ) );
CompilerResults results = prov.CompileAssemblyFromDom( cparams, unit );
if ( results.Errors.Count > 0 )
throw new CompileException( results );
ret.assembly = results.CompiledAssembly;
Type t = ret.assembly.GetType( "ExpressionEvaluator.Evaluator" );
foreach ( MethodInfo m in t.GetMethods( BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly ) )
{
if ( m.Name == "Execute" )
{
ret.method = m;
break;
}
}
}
return;
}
