internal override string ToString(string indent)
{
var sb = new StringBuilder(128);
sb.AppendFormat("{0}WHEN ", indent);
if (WhenExpression.OneLine())
{
sb.Append(WhenExpression.ToString(""));
}
else
{
sb.Append("\r\n");
sb.Append(WhenExpression.ToString(indent + " "));
}
sb.Append(" THEN ");
if (ThenExpression.OneLine())
{
sb.Append(ThenExpression.ToString(""));
}
else
{
sb.Append("\r\n");
sb.Append(ThenExpression.ToString(indent + " "));
}
return(sb.ToString());
}
/// <summary>
/// Tries to evaluate the given expression in the context of
/// the given environment.
/// </summary>
/// <param name="env">Environment in which to evaluate the
/// expression.</param>
/// <param name="value">On success, receives the evaluation
/// result.</param>
/// <returns>true on success; false otherwise.</returns>
public override bool TryEvaluate(ExpressionEnvironment env, out string value)
{
if (env == null)
{
throw new ArgumentNullException(nameof(env));
}
if (!Condition.TryEvaluate(env, out string condition) ||
!ThenExpression.TryEvaluate(env, out string thenValue))
{
value = null;
return(false);
}
string elseValue = string.Empty;
if (ElseExpression.HasValue &&
!ElseExpression.Value.TryEvaluate(env, out elseValue))
{
value = null;
return(false);
}
var conditionValue = !string.IsNullOrEmpty(condition);
value = conditionValue ? thenValue : elseValue;
return(true);
}
public override int GetHashCode()
{
unchecked
{
var hashCode = 10 + Condition.GetHashCode();
hashCode = (hashCode * 397) ^ ThenExpression.GetHashCode();
hashCode = (hashCode * 397) ^ ElseExpression.GetHashCode();
return(hashCode);
}
}
/// <inheritdoc />
protected override EvaluationResult DoEval(Context context, ModuleLiteral env, EvaluationStackFrame frame)
{
var condition = ConditionExpression.Eval(context, env, frame);
if (condition.IsErrorValue)
{
return(condition);
}
return(IsTruthy(condition.Value) ? ThenExpression.Eval(context, env, frame) : ElseExpression.Eval(context, env, frame));
}
public override void GenerateCode(CodeGeneration.CodeGenerator cg)
{
Label elseeval = cg.IlGenerator.DefineLabel();
Label endofif = cg.IlGenerator.DefineLabel();
IfCondition.GenerateCode(cg);
cg.IlGenerator.Emit(OpCodes.Brfalse, elseeval);
ThenExpression.GenerateCode(cg);
cg.IlGenerator.Emit(OpCodes.Br, endofif);
cg.IlGenerator.MarkLabel(elseeval);
ElseExpression.GenerateCode(cg);
cg.IlGenerator.MarkLabel(endofif);
}
internal override bool OneLine()
{
return(WhenExpression.OneLine() && ThenExpression.OneLine());
}
/// <inheritdoc />
public override string ToDebugString()
{
return(I($"{ConditionExpression.ToDebugString()} ? {ThenExpression.ToDebugString()} : {ElseExpression.ToDebugString()}"));
}
/// <inheritdoc />
protected override void DoSerialize(BuildXLWriter writer)
{
ConditionExpression.Serialize(writer);
ThenExpression.Serialize(writer);
ElseExpression.Serialize(writer);
}
