Re: Interpreter for old basic programs from the line number era

On Thu, 06 Mar 2008 20:05:46 GMT,  wrote:

> On 6 Mrz., 18:12, "Auric__" <not.my.r...@[EMAIL PROTECTED]
> wrote:
>> On Wed, 05 Mar 2008 08:04:10 GMT,  wrote:
>> > If you take a look at the description of bas7 at
>>
>> >http://seed7.sourceforge.net/scrshots/bas7.htm
>>
>> > you see that the primarily intend of Bas7 is to analyze
>> > spaghetti code. Therefore it writes a log file while
>> > interpreting the BASIC program.
>>
>> Analyze how? What exactly does it do, output a list of line
>> numbers to the log? ...
>
> The log file of a very small example program:
>
>   100 PRINT "Hello, world!"
>   105 IF I=0THEN 107ELSE 110
>   107 IF I=1THEN 110ELSE 110
>   110 INPUT "Press return to continue",a$

Wow. Hard to believe that the lack of spaces in 105 and 107 are valid 
(or even accepted). Yikes. (I realize that isn't something you came up 
with -- it works under QBASIC. Yikes yikes yikes.)

> load_prog finished
> 100 PRINT "Hello, world!"
> I is 0.0
> 105 IF -1.0 THEN - GOTO 107
> I is 0.0
> 107 IF 0.0 THEN - SKIP LABEL
> 107 ELSE - GOTO 110
> 110 INPUT "Press return to continue"
> 110 INPUT A$ <- ""
> END OF PROGRAM REACHED

That's... interesting. Not how I would do it, but then, I don't write 
interpreters.

> As you can see: First you get the program listing and
> then you get line numbers + statements + some information
> like "SKIP LABEL". Every time a variable is accessed you
> get a message like "I is 0.0". Here is a part from
> another log:

[snip]

>> ... (I'm not going to d/l it to find out -- I'm on v-e-e-e-e-e-r-y
>> slow dial-up and most downloads are painful.)
>
> The good message is: The download is only 987039 Bytes.
> The bad message is: You have to compile it. The 987039 Bytes
> consist of the Seed7 package seed7_05_20080302.tgz and is here:
> http://sourceforge.net/project/showfiles.php?group_id=151126&package
> _id=167035 After you succeded with the compilation you can start
> Bas7 with: ./hi bas7 your_basic_program

Compiling is no problem, since I run Linux at home anyway. (I prefer 
to compile from source, even when a binary is available.) My problem 
is always with the download size. Always always always. (Not just your 
stuff.) I was spoiled by high speed, which I don't have now (and won't 
due to financial issues), and downloading *anything* on dial-up is 
long and tedious. (I even browse the web with images turned off -- not 
because I don't want to see them (I usually do) but because they take 
too long to transfer.)

(FYI, took a bit over 6 minutes to d/l your 964 kib file.)

-- 
I'll see you tomorrow for our usual drink and argument.