Stack trace for errors

[geseq]

PR for stack trace.

#93

[geseq]

I'm working on further optimization (unrelated to this). I will make a separate PR when I'm done.

[geseq]

What do you think about introducing another Operator (something like OpBinaryOp) that'd be emitted before all the operators that call Object.BinaryOp()?

I've been testing it out and it gets rid of a lot of redundant duplicate code without any loss of performance (a slight performance gain in fact, but probably not one to make it worth it just for the performance, especially for fib(35) which relies significantly on binary operations).

[geseq]

Resolves #106

[d5]

I think this can be further reduced?

for v.framesIndex > 1 {
	v.framesIndex--
	v.curFrame = &v.frames[v.framesIndex-1]

	filePos := v.fileSet.Position(v.curFrame.fn.SourceMap[v.curFrame.ip-1])
	err = fmt.Errorf("%s\nin %s", err.Error(), filePos)
}

[d5]

Actually, now that I think about this, we're mutating the VM state partially, so we probably need to either

1. remove v.FrameInfo() because it may return partially correct info, or,
2. mutate everything as if VM actually returned from all function calls

I guess #1 is easier because the main purpose of v.FrameInfo was to see where the error occurred during test in the first place. Now that we have stack info in error messages, it's not needed anymore.

[geseq]

Updated.

True, I don't think v.FrameInfo adds any more useful information for debugging. Shall I remove it?

[d5]

Yes please

[geseq]

Done

[d5]

Tell me more about OpBinaryOp. I'm not sure if I understand what you're trying to do. Probably seeing some code is easier 😄 .

[geseq]

I'll make a separate PR with the OpBinaryOp tomorrow.