/// <summary>
/// Evaluates the specified expression
/// </summary>
/// <param name="targetExpression">The expression to evaluate</param>
/// <param name="valueToSet">A value to set in case of a setter</param>
/// <param name="setter">true if this a setter</param>
/// <returns>The value of the targetExpression</returns>
private object GetOrSetValue(ScriptExpression targetExpression, object valueToSet, bool setter)
{
object value = null;
try
{
if (targetExpression is IScriptVariablePath nextPath)
{
if (setter)
{
nextPath.SetValue(this, valueToSet);
}
else
{
value = nextPath.GetValue(this);
}
}
else if (!setter)
{
value = Evaluate(targetExpression);
}
else
{
throw new ScriptRuntimeException(targetExpression.Span, $"Unsupported target expression for assignment."); // unit test: 105-assign-error1.txt
}
}
catch (Exception readonlyException) when(_getOrSetValueLevel == 1 && !(readonlyException is ScriptRuntimeException))
{
throw new ScriptRuntimeException(targetExpression.Span, $"Unexpected exception while accessing target expression: {readonlyException.Message}", readonlyException);
}
// If the variable being returned is a function, we need to evaluate it
// If function call is disabled, it will be only when returning the final object (level 0 of recursion)
var allowFunctionCall = (_isFunctionCallDisabled && _getOrSetValueLevel > 1) || !_isFunctionCallDisabled;
if (allowFunctionCall && ScriptFunctionCall.IsFunction(value))
{
// Allow to pipe arguments only for top level returned function
value = ScriptFunctionCall.Call(this, targetExpression, value, _getOrSetValueLevel == 1, null);
}
return(value);
}
/// <summary>
/// Evaluates the specified expression
/// </summary>
/// <param name="targetExpression">The expression to evaluate</param>
/// <param name="valueToSet">A value to set in case of a setter</param>
/// <param name="setter">true if this a setter</param>
/// <param name="level">The indirection level (0 before entering the expression)</param>
/// <returns>The value of the targetExpression</returns>
private object GetOrSetValue(ScriptExpression targetExpression, object valueToSet, bool setter, int level)
{
object value = null;
try
{
var nextVariable = targetExpression as ScriptVariable;
if (nextVariable != null)
{
if (setter)
{
SetValue(nextVariable, valueToSet, false);
}
else
{
value = GetValueFromVariable(nextVariable);
}
}
else
{
if (targetExpression is ScriptMemberExpression nextDot)
{
var targetObject = GetOrSetValue(nextDot.Target, valueToSet, false, level + 1);
if (targetObject == null)
{
throw new ScriptRuntimeException(nextDot.Span,
$"Object [{nextDot.Target}] is null. Cannot access member: {nextDot}"); // unit test: 131-member-accessor-error1.txt
}
if (targetObject is string || targetObject.GetType().GetTypeInfo().IsPrimitive)
{
throw new ScriptRuntimeException(nextDot.Span,
$"Cannot get or set a member on the primitive [{targetObject}/{targetObject.GetType()}] when accessing member: {nextDot}"); // unit test: 132-member-accessor-error2.txt
}
var accessor = GetMemberAccessor(targetObject);
var memberName = nextDot.Member.Name;
if (setter)
{
if (!accessor.TrySetValue(this, targetExpression.Span, targetObject, memberName, valueToSet))
{
throw new ScriptRuntimeException(nextDot.Member.Span,
$"Cannot set a value for the readonly member: {nextDot}"); // unit test: 132-member-accessor-error3.txt
}
}
else
{
if (!accessor.TryGetValue(this, targetExpression.Span, targetObject, memberName, out value))
{
TryGetMember?.Invoke(this, targetExpression.Span, targetObject, memberName, out value);
}
}
}
else
{
if (targetExpression is ScriptIndexerExpression nextIndexer)
{
var targetObject = GetOrSetValue(nextIndexer.Target, valueToSet, false, level + 1);
if (targetObject == null)
{
throw new ScriptRuntimeException(nextIndexer.Target.Span,
$"Object [{nextIndexer.Target}] is null. Cannot access indexer: {nextIndexer}"); // unit test: 130-indexer-accessor-error1.txt
}
else
{
var index = Evaluate(nextIndexer.Index);
if (index == null)
{
throw new ScriptRuntimeException(nextIndexer.Index.Span,
$"Cannot access target [{nextIndexer.Target}] with a null indexer: {nextIndexer}"); // unit test: 130-indexer-accessor-error2.txt
}
else
{
if (targetObject is IDictionary || targetObject is ScriptObject)
{
var accessor = GetMemberAccessor(targetObject);
var indexAsString =
ToString(nextIndexer.Index.Span, index);
if (setter)
{
if (!accessor.TrySetValue(this, targetExpression.Span, targetObject, indexAsString, valueToSet))
{
throw new ScriptRuntimeException(nextIndexer.Index.Span,
$"Cannot set a value for the readonly member [{indexAsString}] in the indexer: {nextIndexer.Target}['{indexAsString}']"); // unit test: 130-indexer-accessor-error3.txt
}
}
else
{
if (!accessor.TryGetValue(this, targetExpression.Span, targetObject, indexAsString, out value))
{
TryGetMember?.Invoke(this, targetExpression.Span, targetObject, indexAsString, out value);
}
}
}
else
{
var accessor = GetListAccessor(targetObject);
if (accessor == null)
{
throw new ScriptRuntimeException(nextIndexer.Target.Span, $"Expecting a list. Invalid value [{targetObject}/{targetObject.GetType().Name}] for the target [{nextIndexer.Target}] for the indexer: {nextIndexer}"); // unit test: 130-indexer-accessor-error4.txt
}
else
{
int i = ToInt(nextIndexer.Index.Span, index);
// Allow negative index from the end of the array
if (i < 0)
{
i = accessor.GetLength(this, targetExpression.Span, targetObject) + i;
}
if (i >= 0)
{
if (setter)
{
accessor.SetValue(this, targetExpression.Span, targetObject, i, valueToSet);
}
else
{
value = accessor.GetValue(this, targetExpression.Span, targetObject, i);
}
}
}
}
}
}
}
else if (!setter)
{
value = Evaluate(targetExpression);
}
else
{
throw new ScriptRuntimeException(targetExpression.Span,
$"Unsupported expression for target for assignment: {targetExpression} = ..."); // unit test: 105-assign-error1.txt
}
}
}
}
catch (Exception readonlyException) when(level == 0 && !(readonlyException is ScriptRuntimeException))
{
throw new ScriptRuntimeException(targetExpression.Span, $"Unexpected exception while accessing `{targetExpression}`", readonlyException);
}
// If the variable being returned is a function, we need to evaluate it
// If function call is disabled, it will be only when returning the final object (level 0 of recursion)
if ((!_isFunctionCallDisabled || level > 0) && ScriptFunctionCall.IsFunction(value))
{
value = ScriptFunctionCall.Call(this, targetExpression, value);
}
return(value);
}