Comments on negative and parentheses

[mynet43]

The description under the 'let' command says that negative numbers and parentheses are not supported and that the parsing works strictly from left to right.

Comment 1: The negative arithmetic actually works if you write the equation like:

temp = 0-12 + 15

The answer comes out 3, which is right. Since this works already, how about including the negate feature when the first item is preceded by a minus sign?

Comment 2: Even though you don't support parentheses when parsing, it would be really helpful if you included precedence, wherein the * and / are performed before the + or -.
It took me a while to figure out that

temp = 12 - 3*i

is parsed as (12 - 3)*i rather than as 12 - (3*i) which is what you get if you run it on VB.

Just food for thought. Keep up the good work.

Jim


 

 

[Technical]

temp = -12 + 15 is already supported by the compiler and will work as you expect.

But it is not true support of negative numbers, in fact it is a really a double overflow - back to 246 and then forward again to 3.

Strictly left to right means just that, no priority is given to anything.

 

[mynet43]

Am I missing something?

I ran the following program with the simulator:

symbol temp = b0
loop1:
temp = -12 + 15
if temp <> 3 then loop1
end

When it executes the line:
temp = -12 + 15
it displays the error message:
"Unknown math operator in let."

When I substitute:
temp = 0-12 + 15 then everything works great!

Did you try it before you said it would work?


 

 

[BeanieBots]

b0=-12+15 compiles and runs OK for me.
Editor 5.0.8 enhanced mode enabled.
What editor version do you have?
Do you have "enhanced" selected?

 

[hippy]

It compiles, runs on a PICAXE and simply seems to be a buggette in the Simulator.

 

[mynet43]

AHA!

Thanks for clearing that up!

Now it all makes sense.

 

 

[mynet43]

Forgot to say. Yes, I'm running 5.0.8, with the enhanced compiler.

You can't use the simulator unless the enhanced compiler is turned on.

 

 

[mynet43]

Technical:

Would you please fix the minor bug in the simulator that doesn't handle negative correctly.

b0 = -12 + 15

works fine with the compiler but gives an error in the simulator.

Thanks


 

 

[Technical]

It is fixed
Make sure your 5.08 patch files have updated correctly.

http://www.rev-ed.co.uk/picaxe/forum/topic.asp?topic_id=6419&forum_id=6

 

[mynet43]

Not sure what you mean about the 5.0.8 patch.

When I display Help/About, it shows:

PICAXE Programming Editor
Version 5.0.8 (Syntax DLL 131072)

Should I have something else?

If I run the following code in the 08M, it displays '3' on the terminal.

b0 = -12 + 15
sertxd(#b0)

When I run the same code in the simulator, I get the message: "Unknown math operator in let" when it executes the first line.

Please let me know if I'm missing something.

Thanks for your help.

 

 

[Technical]

The Help>About mesage is the progedit file, nothing to do with the compilers. Please follow the process already described to manually delete the compilers and then reinstall the patch!

 

[mynet43]

Thanks for your help. That solved it.

It would be nice if the help/about menu would also provide information about the compiler.

Thanks again,

Jim