// left OPERATOR right style expressions
// the most common form of expressions
// for things like 1 + 3
#region lValueOperatorrValueCalls
internal void genericExpVisitor(YarnSpinnerParser.ExpressionContext left, YarnSpinnerParser.ExpressionContext right, int op)
{
Visit(left);
Visit(right);
// TODO: temp operator call
// Indicate that we are pushing two items for comparison
compiler.Emit(OpCode.PushFloat, new Operand(2));
compiler.Emit(OpCode.CallFunc, new Operand(tokens[op].ToString()));
}
// operatorEquals style operators, eg +=
// these two should only be called during a SET operation
// eg << set $var += 1 >>
// the left expression has to be a variable
// the right value can be anything
#region operatorEqualsCalls
// generic helper for these types of expressions
internal void opEquals(string varName, YarnSpinnerParser.ExpressionContext expression, int op)
{
// Get the current value of the variable
compiler.Emit(OpCode.PushVariable, new Operand(varName));
// run the expression
Visit(expression);
// Stack now contains [currentValue, expressionValue]
// Indicate that we are pushing two items for comparison
compiler.Emit(OpCode.PushFloat, new Operand(2));
// now we evaluate the operator
// op will match to one of + - / * %
compiler.Emit(OpCode.CallFunc, new Operand(tokens[op].ToString()));
// Stack now has the destination value
// now store the variable and clean up the stack
compiler.Emit(OpCode.StoreVariable, new Operand(varName));
compiler.Emit(OpCode.Pop);
}
private void GenerateClause(string jumpLabel, ParserRuleContext clauseContext, YarnSpinnerParser.StatementContext[] children, YarnSpinnerParser.ExpressionContext expression)
{
string endOfClauseLabel = this.compiler.RegisterLabel("skipclause");
// handling the expression (if it has one) will only be called on
// ifs and elseifs
if (expression != null)
{
// Code-generate the expression
this.Visit(expression);
this.compiler.Emit(OpCode.JumpIfFalse, expression.Start, new Operand(endOfClauseLabel));
}
// running through all of the children statements
foreach (var child in children)
{
this.Visit(child);
}
this.compiler.Emit(OpCode.JumpTo, clauseContext.Stop, new Operand(jumpLabel));
if (expression != null)
{
this.compiler.CurrentNode.Labels.Add(endOfClauseLabel, this.compiler.CurrentNode.Instructions.Count);
this.compiler.Emit(OpCode.Pop, clauseContext.Stop);
}
}
internal void generateClause(string jumpLabel, YarnSpinnerParser.StatementContext[] children, YarnSpinnerParser.ExpressionContext expression)
{
string endOfClauseLabel = compiler.RegisterLabel("skipclause");
// handling the expression (if it has one)
// will only be called on ifs and elseifs
if (expression != null)
{
Visit(expression);
compiler.Emit(OpCode.JumpIfFalse, new Operand(endOfClauseLabel));
}
// running through all of the children statements
foreach (var child in children)
{
Visit(child);
}
compiler.Emit(OpCode.JumpTo, new Operand(jumpLabel));
if (expression != null)
{
compiler.CurrentNode.Labels.Add(endOfClauseLabel, compiler.CurrentNode.Instructions.Count);
compiler.Emit(OpCode.Pop);
}
}