/// <summary>
/// Initializes an exception with the specified variable, message, and inner exception
/// </summary>
/// <param name="variable">The unbound variable</param>
/// <param name="message">The message that describes the error</param>
/// <param name="inner">The exception that is the cause of this exception</param>
public UnboundVariableException(Variable variable, string message, Exception inner)
: base(message, inner)
{
Contract.Requires(variable != null);
Variable = variable;
}
/// <summary>
/// Initializes a calculation with the specified output variable and expression
/// </summary>
/// <param name="outputVariable">The variable to which the output of this calculation is assigned</param>
/// <param name="expression">The expression tree which defines the body of this calculation</param>
public Calculation(Variable outputVariable, Expression expression)
{
Contract.Requires(outputVariable != null);
Contract.Requires(expression != null);
OutputVariable = outputVariable;
Expression = expression;
}
/// <summary>
/// Initializes a function calculator with the specified output variable and function
/// </summary>
/// <param name="outputVariable">The variable to which the output of the specified function is assigned</param>
/// <param name="function">The function which calculates the value to be assigned to the specified output variable</param>
public FunctionCalculator(Variable outputVariable, Func<GraspRuntime, object> function)
{
Contract.Requires(outputVariable != null);
Contract.Requires(function != null);
OutputVariable = outputVariable;
Function = function;
}
/// <summary>
/// Initializes a binding with the specified variable and value
/// </summary>
/// <param name="variable">The bound variable</param>
/// <param name="value">The value to which the specified variable is bound</param>
public VariableBinding(Variable variable, object value)
{
Contract.Requires(variable != null);
// TODO: Ensure that the value is assignable to the variable type
Variable = variable;
Value = value;
}
/// <summary>
/// Gets the value of the specified variable
/// </summary>
/// <param name="variable">The variable for which to get the value</param>
/// <returns>The value of the specified variable</returns>
/// <exception cref="UnboundVariableException">Thrown if the specified variable is not bound</exception>
public object GetVariableValue(Variable variable)
{
Contract.Requires(variable != null);
var binding = TryGetBinding(variable);
if(binding == null)
{
throw new UnboundVariableException(variable, Resources.VariableNotBound.FormatInvariant(variable));
}
return binding.Value;
}
public static VariableExpression Expression(Variable variable)
{
Contract.Requires(variable != null);
return new VariableExpression(variable);
}
protected override void Given()
{
_variable = new Variable("Grasp", "Test", typeof(int));
_value = 1;
}
private VariableBinding TryGetBinding(Variable variable)
{
VariableBinding binding;
_bindingsByVariable.TryGetValue(variable, out binding);
return binding;
}
/// <summary>
/// Sets the value of the specified variable
/// </summary>
/// <param name="variable">The variable for which to set the specified value</param>
/// <param name="value">The new value of the specified variable</param>
public void SetVariableValue(Variable variable, object value)
{
Contract.Requires(variable != null);
var binding = TryGetBinding(variable);
if(binding != null)
{
binding.Value = value;
}
else
{
binding = new VariableBinding(variable, value);
_bindingsByVariable[variable] = binding;
}
}
/// <summary>
/// Initializes an exception with the specified variable
/// </summary>
/// <param name="variable">The unbound variable</param>
public UnboundVariableException(Variable variable)
{
Contract.Requires(variable != null);
Variable = variable;
}
protected override void Given()
{
_outputVariable = new Variable("Grasp", "Test", typeof(int));
_expression = Expression.Constant(0);
}
object IRuntimeSnapshot.GetValue(Variable variable)
{
Contract.Requires(variable != null);
return null;
}
public static readonly ExpressionType ExpressionType = (ExpressionType) 1000; // Create a space separate from base expression trees
#endregion Fields
#region Constructors
internal VariableExpression(Variable variable)
{
Variable = variable;
}