void MulExpr(out Expression expr, Expression leftOperand)
{
expr = leftOperand;
while (la.kind == 47 || la.kind == 50 || la.kind == 51) {
expr = new BinaryExpression(leftOperand);
if (la.kind == 47) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Mul;
} else if (la.kind == 50) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Div;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Rem;
}
expr.t = t;
UnaryExpr(out (expr as BinaryExpression).rightOperand);
}
}
void LogExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
AddExpr(out expr, leftOperand);
while (la.kind == 17 || la.kind == 18 || la.kind == 19) {
expr = new BinaryExpression(expr);
if (la.kind == 17) {
Get();
(expr as BinaryExpression).op = BinaryOperator.And;
} else if (la.kind == 18) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Or;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Xor;
}
expr.t = t;
UnaryExpr(out rightOperand);
AddExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
void AddExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
MulExpr(out expr, leftOperand);
while (la.kind == 40 || la.kind == 42) {
expr = new BinaryExpression(expr);
if (la.kind == 42) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Add;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Sub;
}
expr.t = t;
UnaryExpr(out rightOperand);
MulExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
void EqExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
LogExpr(out expr, leftOperand);
while (StartOf(4)) {
expr = new BinaryExpression(expr);
switch (la.kind) {
case 33: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Eq;
break;
}
case 48: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Neq;
break;
}
case 34: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Gt;
break;
}
case 39: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Lt;
break;
}
case 35: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Geq;
break;
}
case 49: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Leq;
break;
}
}
expr.t = t;
UnaryExpr(out rightOperand);
LogExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
/// <summary>
/// Emits code for this statement
/// </summary>
/// <param name="ilGen">IL generator object</param>
/// <param name="scope">The scope of this statement</param>
public override void EmitCode(ILGenerator ilGen, Scope scope)
{
// Define labels
Label loopLabel = ilGen.DefineLabel();
Label endLabel = ilGen.DefineLabel();
// Call EmitAssignement for parameter, assigning it the initial expression
(variable as AssignableExpression).EmitAssignement(ilGen, scope, initial);
// Mark beginning of loop
ilGen.MarkLabel(loopLabel);
// Emit parameter code (load value onto the stack)
variable.EmitCode(ilGen, scope);
// Emit final expression (load expression value onto the stack)
final.EmitCode(ilGen, scope);
// If parameter is increased
if (direction == ForDirection.Up)
{
// If parameter is greater than final, jump to the end of the statement
ilGen.Emit(OpCodes.Bgt, endLabel);
}
// If parameter is decreased
else
{
// If parameter is less than final, jump to the end of the statement
ilGen.Emit(OpCodes.Blt, endLabel);
}
// Emit code for repetitive statement
body.EmitCode(ilGen, scope);
// Increment or decrement parameter:
// Create a new binary expression with the parameter as left operand
BinaryExpression step = new BinaryExpression(variable);
// If parameter is increasing, operator is Add, if it is decreasing, operator is Sub
step.op = direction == ForDirection.Up ? BinaryOperator.Add : BinaryOperator.Sub;
// Right operand is 1
step.rightOperand = new ConstantExpression(Primitive.Int, "1");
// Emit assignement - parameter is assigned the result of the binary expression
(variable as AssignableExpression).EmitAssignement(ilGen, scope, step);
// Emit unconditional break to beginning of loop
ilGen.Emit(OpCodes.Br, loopLabel);
// Mark end label
ilGen.MarkLabel(endLabel);
}
