/// <summary>
/// Evaluates a given particle, and returns the result.
/// </summary>
public override object VisitParticle([NotNull] algoParser.ParticleContext context)
{
//Get the last result of the particle before this.
AlgoValue current = Particles.GetParticleResult();
if (current == null)
{
Error.Internal("Particle chain started without setting an initial value.");
return(null);
}
//Prepare an "old" scope for swapping.
AlgoScopeCollection oldScope = null;
//What type of particle is it?
//CHILD VARIABLE
if (context.IDENTIFIER() != null)
{
//Sub-variable. Attempt to get from the object.
if (current.Type != AlgoValueType.Object)
{
Error.Fatal(context, "Cannot access children when given variable is not an object, and has no children to access.");
return(null);
}
//Does the sub-variable exist?
AlgoObject curObj = (AlgoObject)current.Value;
AlgoValue newObj = curObj.ObjectScopes.GetVariable(context.IDENTIFIER().GetText());
if (newObj == null)
{
Error.Fatal(context, "No child of the given object exists with name '" + context.IDENTIFIER().GetText() + "'.");
return(null);
}
//Yes, set result and return.
Particles.SetParticleInput(newObj);
return(null);
}
//ARRAY ACCESS
else if (context.array_access_particle() != null)
{
var aap = context.array_access_particle();
//Indexing.
//For each index, iterate over.
AlgoValue currentLV = current;
foreach (var index in aap.literal_params().expr())
{
//Is the current list value a list?
if (currentLV.Type != AlgoValueType.List)
{
Error.Fatal(context, "Cannot index into variable that is not a list or indexable object.");
return(null);
}
//Need to switch scopes for evaluating indexes?
if (Particles.funcArgumentScopes != null)
{
oldScope = Scopes;
Scopes = Particles.funcArgumentScopes;
}
//Evaluate the expression.
AlgoValue indexVal = (AlgoValue)VisitExpr(index);
//Back to normal.
if (Particles.funcArgumentScopes != null)
{
Scopes = oldScope;
}
//Valid?
if (indexVal.Type != AlgoValueType.Integer)
{
Error.Fatal(context, "Index value provided is not an integer. Indexes must be whole integer values.");
return(null);
}
//Is the index outside of the bounds of the array?
if (((List <AlgoValue>)currentLV.Value).Count <= (BigInteger)indexVal.Value)
{
Error.Fatal(context, "Index provided is outside the bounds of the array.");
return(null);
}
//Index into it, set the current value.
currentLV = ((List <AlgoValue>)currentLV.Value)[(int)((BigInteger)indexVal.Value)];
}
//Set result.
Particles.SetParticleInput(currentLV);
return(null);
}
//CHILD FUNCTION
else if (context.functionCall_particle() != null)
{
//Function call.
if (current.Type != AlgoValueType.Object)
{
Error.Fatal(context, "Cannot call a child function on a value with no children (given value was not an object).");
return(null);
}
//Get the child, see if it's a function.
AlgoObject thisObj = current.Value as AlgoObject;
string funcName = context.functionCall_particle().IDENTIFIER().GetText();
AlgoValue childFunc = thisObj.ObjectScopes.GetVariable(funcName);
if (childFunc == null || (childFunc.Type != AlgoValueType.Function && childFunc.Type != AlgoValueType.EmulatedFunction))
{
Error.Fatal(context, "No child function exists with name '" + funcName + "'.");
return(null);
}
//Set the particle result as the function value, call the function call particle.
Particles.SetParticleInput(childFunc);
var result = VisitFunctionCall_particle(context.functionCall_particle());
if (result == null)
{
Particles.ResetParticleInput(); //Returned no result.
}
else
{
//A result came back, set input for the next particle.
Particles.SetParticleInput((AlgoValue)result);
}
return(null);
}
else
{
//Unrecognized!
Error.Internal("Unrecognized particle type to parse, implementation either unfinished or incorrect.");
return(null);
}
}
//When a function is called.
public override object VisitStat_functionCall([NotNull] algoParser.Stat_functionCallContext context)
{
//If there are particles, get the last value.
AlgoValue currentVal = null; bool isLibraryTopLevelCall = false;
if (context.IDENTIFIER() != null)
{
//Is the identifier a library and has no particles?
if (!Scopes.VariableExists(context.IDENTIFIER().GetText()) &&
Scopes.LibraryExists(context.IDENTIFIER().GetText()) &&
(context.particle() == null || context.particle().Length == 0))
{
//Library top level call, so don't evaluate like normal particles.
isLibraryTopLevelCall = true;
//Just get the very last function like a normal variable, but from the library.
string libName = context.IDENTIFIER().GetText();
string name = context.functionCall_particle().IDENTIFIER().GetText();
var lib = Scopes.GetLibrary(libName);
if (!lib.VariableExists(name))
{
Error.Fatal(context, "No variable named '" + name + "' exists in library '" + libName + "'.");
return(null);
}
currentVal = lib.GetVariable(name);
}
else
{
//Not a library top level call, so execute like a normal particle block.
currentVal = Particles.ParseParticleBlock(this, context, context.IDENTIFIER(), context.particle());
}
}
else
{
//No particles, just grab the value as an identifier.
string name = context.functionCall_particle().IDENTIFIER().GetText();
if (!Scopes.VariableExists(name))
{
Error.Fatal(context, "No function exists with name '" + name + "'.");
return(null);
}
currentVal = Scopes.GetVariable(name);
}
//Attempt to execute the final function on the result.
if (context.IDENTIFIER() == null || isLibraryTopLevelCall)
{
//Visit and execute THIS value, not a child value (this was a straight normal call).
Particles.SetParticleInput(currentVal);
return(VisitFunctionCall_particle(context.functionCall_particle()));
}
else
{
//There were particles, visit and execute CHILD value.
if (currentVal.Type != AlgoValueType.Object)
{
Error.Fatal(context, "Cannot call a child function on a value with no children (given value was not an object).");
return(null);
}
//Get the child, see if it's a function.
AlgoObject thisObj = currentVal.Value as AlgoObject;
string funcName = context.IDENTIFIER().GetText();
AlgoValue childFunc = thisObj.ObjectScopes.GetVariable(funcName);
if (childFunc == null || (childFunc.Type != AlgoValueType.Function && childFunc.Type != AlgoValueType.EmulatedFunction))
{
Error.Fatal(context, "No child function exists with name '" + funcName + "'.");
return(null);
}
//Set the particle result as the function value, call the function call particle.
Particles.SetParticleInput(childFunc);
return(VisitFunctionCall_particle(context.functionCall_particle()));
}
}
