/// <summary>
/// Iterates through the list of conditions and performs each one in turn. Checks the top element of the stack to see
/// if a true value has been pushed on. If it has it performs the corresponding compiled statement in that KVP.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
CelesteStack.CurrentScope = FlowScope;
Debug.Assert(ConditionsAndBodies.Count > 0, "No conditions or functions specified for flow control");
foreach (KeyValuePair <CompiledStatement, CompiledStatement> condBody in ConditionsAndBodies)
{
condBody.Key.PerformOperation();
Debug.Assert(CelesteStack.StackSize > 0, "No true or false value pushed onto stack");
CelesteObject celObject = CelesteStack.Pop();
if (celObject.IsBool())
{
if (celObject.As <bool>())
{
condBody.Value.PerformOperation();
break;
}
}
else
{
Debug.Fail("Condition must be evaluatable to a bool value");
}
}
CelesteStack.Scopes.Remove(FlowScope);
CelesteStack.CurrentScope = FlowScope.ParentScope;
}
/// <summary>
/// Assigns the expression on the right to the local variable on the left
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we cannot perform this operator
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for equality operator");
Scope scope = CelesteStack.CurrentScope;
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
Debug.Assert(lhs.IsReference());
// All functions are references so check this condition first
if (rhs.IsFunction())
{
Debug.Assert(lhs.IsFunction(), "A function can only be assigned to another function");
Function lhsFunc = lhs.AsFunction();
Function rhsFunc = rhs.AsFunction();
Debug.Assert(CelesteStack.CurrentScope != lhsFunc.FunctionScope, "Cannot reassign functions inside their own scope");
lhsFunc.FunctionScope = rhsFunc.FunctionScope;
lhsFunc.ParameterNames = rhsFunc.ParameterNames;
lhsFunc.Ref = rhsFunc.Ref; // This is equivalent to setting their implementation to be the same
}
else if (rhs.IsReference())
{
lhs.Value = rhs.Value;
}
else
{
lhs.AsReference().Value = rhs.Value;
}
}
/// <summary>
/// Removes the two objects at the top of the stack and divides them together.
/// Then, pushes the result on to the top of the stack.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we cannot do this
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for divide operator");
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
// The stack will wrap our division result in a CelesteObject, so just push the actual value of the division
if (lhs.IsNumber() && rhs.IsNumber())
{
float rhsAsFloat = rhs.As <float>();
if (rhsAsFloat != 0)
{
CelesteStack.Push(lhs.As <float>() / rhsAsFloat);
}
else
{
Debug.Fail("Division by zero");
}
}
else
{
Debug.Fail("Invalid parameters to add operation.");
}
}
public override void PerformOperation()
{
// Set up our parameters if required
if (ParameterNames.Count > 0)
{
Debug.Assert(ChildCount > 0, "Fatal error in function call - no arguments to process");
CompiledStatement thisCallsParams = ChildCompiledStatements[0];
ChildCompiledStatements.RemoveAt(0);
// This will run through each stored parameter and add them to the stack
thisCallsParams.PerformOperation();
}
// Set up our parameters - read them off the stack with the first parameter at the top
for (int i = 0; i < ParameterNames.Count; i++)
{
Debug.Assert(CelesteStack.StackSize > 0, "Insufficient parameters to function");
CelesteObject input = CelesteStack.Pop();
Variable functionParameter = FunctionScope.GetLocalVariable(ParameterNames[i], ScopeSearchOption.kThisScope);
if (input.IsReference())
{
functionParameter.Value = input.ValueImpl;
}
else
{
(functionParameter.Value as Reference).Value = input.Value;
}
}
CelesteStack.CurrentScope = FunctionScope;
// Performs all the operators on the children first
foreach (CompiledStatement statement in FuncImpl.ChildCompiledStatements)
{
statement.PerformOperation();
if (statement is ReturnKeyword)
{
// Stop iterating through if we have hit a ReturnKeyword in our function
break;
}
}
CelesteStack.Scopes.Remove(FunctionScope);
CelesteStack.CurrentScope = FunctionScope.ParentScope;
}
/// <summary>
/// Removes the two objects at the top of the stack and performs logical operations them.
/// Then, pushes the result of the operation on to the top of the stack.
/// </summary>
public sealed override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we cannot perform this operation
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for the equality operator");
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
// The stack will wrap our result in a CelesteObject, so just push the actual result of the operation
bool result = false;
Reference lhsRef = lhs.AsReference();
Reference rhsRef = rhs.AsReference();
// Check to see whether our lhs is a reference
if (lhsRef != null)
{
if (rhsRef != null)
{
// If the rhs is a reference too, we compare references
result = ReferenceReferenceOperation(lhsRef, rhsRef);
}
else
{
// Otherwise we compare the value of the rhs with the value of the lhs' referenced object
result = ReferenceValueOperation(lhsRef, rhs.Value);
}
}
else
{
if (rhsRef != null)
{
// If the rhs is a reference, we compare the value of the rhs' referenced object with the value of the lhs
result = ReferenceValueOperation(rhsRef, lhs.Value);
}
else
{
// Otherwise we compare the value of the rhs with the value of the lhs - they are both values
result = ValueValueOperation(lhs.Value, rhs.Value);
}
}
// We then finally push the result of the equality test onto the stack
CelesteStack.Push(result);
}
/// <summary>
/// Removes the two objects at the top of the stack and multiplies them together.
/// Then, pushes the result on to the top of the stack.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we are el-bonerino-ed
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for multiply operator");
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
// The stack will wrap our multiplication result in a CelesteObject, so just push the actual value of the multiplication
if (lhs.IsNumber() && rhs.IsNumber())
{
CelesteStack.Push(lhs.As <float>() * rhs.As <float>());
}
else
{
Debug.Fail("Invalid parameters to add operation.");
}
}
// When we compile we need to check which end the increment is on and then check for a variable name accordingly
/// <summary>
/// Pops the first element on the top of the stack and checks to see if it is a reference to a number.
/// If it is, it increments the number and then pushes the object back onto the stack.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
Debug.Assert(CelesteStack.StackSize > 0, "Must be an object on the stack for the increment operator");
CelesteObject rhs = CelesteStack.Pop();
if (rhs.IsNumber())
{
float newFloat = rhs.As <float>();
newFloat++;
rhs.Value = newFloat;
}
else
{
Debug.Fail("Increment operator can only be applied to a variable with a numerical value");
}
CelesteStack.Push(rhs);
}
/// <summary>
/// Removes the two objects at the top of the stack and subtracts the top most object on the stack from the other.
/// Then, pushes the result on to the top of the stack.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we are el-bonerino-ed
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for subtract operator");
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
// The stack will wrap our subtraction result in a CelesteObject, so just push the actual value of the subtraction
if (lhs.IsNumber() && rhs.IsNumber())
{
CelesteStack.Push(lhs.As <float>() - rhs.As <float>());
}
else if (lhs.IsString() && rhs.IsString())
{
string lhsAsString = lhs.As <string>();
string rhsAsString = rhs.As <string>();
if (lhsAsString.Contains(rhsAsString))
{
// Push the lhs string having removed the rhs string
CelesteStack.Push(lhsAsString.Remove(lhsAsString.IndexOf(rhsAsString), rhsAsString.Length));
}
else
{
// If our lhs does not contain our rhs, we just push the original unaltered lhs string
CelesteStack.Push(lhsAsString);
}
}
else if (lhs.IsList() && rhs.IsList())
{
// The subtract operator for lists removes all elements in the first list who are equal to an element in the second, either by reference or value
List <object> lhsList = lhs.AsList <object>();
List <object> rhsList = rhs.AsList <object>();
// Remove ALL occurrences in the list of any object in the rhs list - otherwise there is non-deterministic behaviour in which instance to remove
lhsList.RemoveAll(x => rhsList.Exists(y => y.Equals(x) || y.ValueEquals(x)));
CelesteStack.Push(lhs);
}
else if (lhs.IsTable() && rhs.IsList())
{
// Subtraction of tables does not make sense
// What does make sense, is subtracting elements in a table using a list of keys
// Subtracting a list from a table will remove any elements in the table with a matching key as an element in our list
Dictionary <object, object> lhsTable = lhs.AsTable();
List <object> rhsList = rhs.AsList <object>();
foreach (object obj in rhsList)
{
if (lhsTable.Contains(new KeyValuePair <object, object>(obj, null), new TableKeyComparer()))
{
lhsTable.Remove(lhsTable.First(x => x.Key.Equals(obj) || x.Key.ValueEquals(obj)));
}
}
CelesteStack.Push(lhs);
}
else
{
Debug.Fail("Invalid parameters to subtract operation.");
}
}
/// <summary>
/// Removes the two objects at the top of the stack and adds them together.
/// Then, pushes the result on to the top of the stack.
/// </summary>
public override void PerformOperation()
{
base.PerformOperation();
// If we have fewer than 2 objects on the stack we are el-bonerino-ed
Debug.Assert(CelesteStack.StackSize >= 2, "Not enough elements on the stack for add operator");
CelesteObject rhs = CelesteStack.Pop();
CelesteObject lhs = CelesteStack.Pop();
// The stack will wrap our addition result in a CelesteObject, so just push the actual value of the addition
if (lhs.IsNumber() && rhs.IsNumber())
{
CelesteStack.Push(lhs.As <float>() + rhs.As <float>());
}
else if (lhs.IsString() && rhs.IsString())
{
CelesteStack.Push(lhs.As <string>() + rhs.As <string>());
}
else if (lhs.IsList() && rhs.IsList())
{
lhs.AsList <object>().AddRange(rhs.AsList <object>());
CelesteStack.Push(lhs);
}
else if (lhs.IsTable() && rhs.IsTable())
{
Dictionary <object, object> lhsTable = lhs.AsTable();
Dictionary <object, object> rhsTable = rhs.AsTable();
// Tables can be added, but only if they are all indexed by number or string completely
// No other way can be used because the reference type of 'object' makes value equality difficult
// These two types of adding are the only two we can realistically support
// Check whether our lhs table has all number keys
if (lhsTable.Keys.Count(x => x is float) == lhsTable.Keys.Count)
{
// If it does, check the rhs table too
if (rhsTable.Keys.Count(x => x is float) == rhsTable.Keys.Count)
{
// We now go through and see if any keys overlap in the two tables
if (lhsTable.Intersect(rhsTable, new TableKeyComparer()).Count() == 0)
{
foreach (KeyValuePair <object, object> pair in rhsTable)
{
lhsTable.Add((float)pair.Key, pair.Value);
}
}
else
{
Debug.Fail("Invalid parameters to add operation. Right hand side table has at least one key the same as the left hand side table");
}
}
else
{
Debug.Fail("Invalid parameters to add operation. Right hand side table has inconsistent key types (should be numbers)");
}
}
// Check whether our lhs table has all string keys
else if (lhsTable.Keys.Count(x => x is string) == lhsTable.Keys.Count)
{
// If it does, check the rhs table too
if (rhsTable.Keys.Count(x => x is string) == rhsTable.Keys.Count)
{
// We now go through and see if any keys overlap in the two tables
if (lhsTable.Intersect(rhsTable, new TableKeyComparer()).Count() == 0)
{
foreach (KeyValuePair <object, object> pair in rhsTable)
{
lhsTable.Add((string)pair.Key, pair.Value);
}
}
else
{
Debug.Fail("Invalid parameters to add operation. Right hand side table has at least one key the same as the left hand side table");
}
}
else
{
Debug.Fail("Invalid parameters to add operation. Right hand side table has inconsistent key types (should be strings)");
}
}
else
{
Debug.Fail("Invalid parameters to add operation. Left hand side table has inconsistent key types (should be numbers or strings)");
}
CelesteStack.Push(lhs);
}
else
{
Debug.Fail("Invalid parameters to add operation.");
}
}