Use 'ecma_value_t' in Jerry API

[LaszloLango]

JerryScript-DCO-1.0-Signed-off-by: László Langó [email protected]

[zherczeg]

"value" is not needed.

[zherczeg]

I think the general direction is very good. However, I feel people will not understand how the exception handling works in Jerry. Namely a value has an exception bit, and a value with an exception bit set cannot be passed to any function as input argument.

I am open to other ideas, but I see two directions at this moment:

• all functions should return with a bool (exception or not), and a value as an output argument. The output contains the exception value in case of exception, but the exception bit is cleared, so they can pass it to other functions.
• all functions return with a jerry value, where the exception bit can be set. There is an API function to check exceptions. For all input arguments the exception bit is cleared manually (so people cannot accidentally pass exception objects as values when setting a field of an object).

[LaszloLango]

@zherczeg, I prefer the second, but maybe the first one would be better for newcomers.

[zherczeg]

The second is obviously simpler and faster, but it might be confusing. What do others think?

[dbatyai]

In my opinion going with the simpler solution is always the best choice, and would also behave similarly to how the engine currently works. The first approach would be the complete opposite, which, the way I see it, could create more confusion than the second one.

[LaszloLango]

@zherczeg, I raised an issue for this problem. I think we can do it in a follow up patch, because this PR is big enough and barely related to the problem.

[zherczeg]

Ok, LGTM

[dbatyai]

LGTM