void ExprCompiler::visit(IfExpr& expr, int dest)
{
// Compile the condition.
compile(expr.condition(), dest);
// Leave a space for the test and jump instruction.
int jumpToElse = startJump(expr);
// Compile the then arm.
compile(expr.thenArm(), dest);
// Leave a space for the then arm to jump over the else arm.
int jumpPastElse = startJump(expr);
// Compile the else arm.
endJump(jumpToElse, OP_JUMP_IF_FALSE, dest);
if (!expr.elseArm().isNull())
{
compile(expr.elseArm(), dest);
}
else
{
// A missing 'else' arm is implicitly 'nothing'.
write(expr, OP_BUILT_IN, BUILT_IN_NOTHING, dest);
}
endJump(jumpPastElse, OP_JUMP, 1);
}
void Resolver::visit(IfExpr& expr, int dummy)
{
Scope ifScope(this);
// Resolve the condition.
resolve(expr.condition());
// Resolve the then arm.
Scope thenScope(this);
resolve(expr.thenArm());
thenScope.end();
if (!expr.elseArm().isNull())
{
Scope elseScope(this);
resolve(expr.elseArm());
elseScope.end();
}
ifScope.end();
}
Expr* IfExpr::clone() {
IfExpr* ret = new IfExpr(*this);
ret->cloneArgs();
return ret;
}
