public CompileResult CompileFunction(Drawing drawing, string functionText)
{
CompileResult result = new CompileResult();
if (string.IsNullOrEmpty(functionText))
{
return result;
}
ParseTree ast = Parse(functionText, result);
if (!result.Errors.IsEmpty())
{
return result;
}
ExpressionTreeBuilder builder = new ExpressionTreeBuilder();
builder.SetContext(drawing, f => true);
var expressionTree = builder.CreateFunction(ast.Root, result);
if (expressionTree == null || !result.Errors.IsEmpty())
{
return result;
}
Func<double, double> function = ExpressionTreeEvaluatorProvider.InterpretFunction(expressionTree);
result.Function = function;
return result;
}
public CompileResult CompileExpression(
Drawing drawing,
string expressionText,
Predicate<IFigure> isFigureAllowed)
{
CompileResult result = new CompileResult();
if (expressionText.IsEmpty())
{
return result;
}
ParseTree ast = Parse(expressionText, result);
if (!result.Errors.IsEmpty())
{
return result;
}
ExpressionTreeBuilder builder = new ExpressionTreeBuilder();
builder.SetContext(drawing, isFigureAllowed);
var expressionTree = builder.CreateExpression(ast.Root, result);
if (expressionTree == null || !result.Errors.IsEmpty())
{
return result;
}
Func<double> function = ExpressionTreeEvaluatorProvider.InterpretExpression(expressionTree);
result.Expression = function;
return result;
}
private static Node Parse(string text, CompileResult result)
{
ParseResult ast = Parser.Parse(text);
if (!ast.Errors.IsEmpty())
{
result.Errors.AddRange(ast.Errors);
}
return ast.Root;
}
public Expression<Func<double>> CreateExpression(ParseTreeNode root, CompileResult status)
{
Status = status;
Expression body = CreateExpressionCore(root);
if (body == null)
{
return null;
}
var expressionTree = Expression.Lambda<Func<double>>(body);
return expressionTree;
}
public Expression<Func<double, double>> CreateFunction(ParseTreeNode root, CompileResult status)
{
Status = status;
ParameterExpression parameter = Expression.Parameter(typeof(double), "x");
Binder.RegisterParameter(parameter);
Expression body = CreateExpressionCore(root);
if (body == null)
{
return null;
}
var expressionTree = Expression.Lambda<Func<double, double>>(body, parameter);
return expressionTree;
}
public Expression<Func<double>> CreateExpression(Node root, CompileResult status)
{
Status = status;
Expression body = CreateExpressionCore(root);
if (body == null)
{
return null;
}
// If expression does not return double, we'll get an error. - D.H.
if (body.Type != typeof(double))
{
return null;
}
var expressionTree = Expression.Lambda<Func<double>>(body);
return expressionTree;
}
void ProcessMatch(Match match)
{
var result = match.Value;
if (result.Length < 3)
{
CompileResult error = new CompileResult();
error.AddError("Empty expression");
embeddedExpressions.Add(error);
return;
}
var expression = result.Substring(1, result.Length - 2);
var compileResult = Drawing.CompileExpression(expression);
embeddedExpressions.Add(compileResult);
if (compileResult.IsSuccess)
{
Dependencies.AddRange(compileResult.Dependencies);
}
}
void SetFunction(CompileResult result)
{
Function = result.Function;
this.UnregisterFromDependencies();
Dependencies.SetItems(result.Dependencies);
// See explanation in DrawingExpression.Recalculate().
if (Drawing.Figures.Contains(this))
{
this.RegisterWithDependencies();
this.RecalculateAllDependents();
}
}
private static ParseTree Parse(string text, CompileResult result)
{
ParseTree ast = ParserInstance.Parse(text);
var compileErrors = GetCompilerErrors(ast.ParserMessages);
if (!compileErrors.IsEmpty())
{
result.Errors.AddRange(compileErrors);
}
return ast;
}
