[Info-vax] Some questions on software for VMS 7.3 VAX

[Johnny Billquist]

On 2016-01-01 21:27, David Froble wrote:
> Stephen Hoffman wrote:
>> On 2016-01-01 15:31:47 +0000, David Froble said:
>>
>>> lists at openmailbox.org wrote:
>>>>
>>>> BTW is the BASIC on VAX/VMS a true compiler or is it interpreted?
>>>
>>> Ya know, that's really funny.  You say you don't like Basic, but you
>>> don't even know what it is.  It's a true compiler, with only one
>>> fault that I'm aware of. I didn't even know about the fault until
>>> John Reagan (spell?) explained it.
>>
>> The BASIC layered product provides both an interpreter and a compiler
>> on VAX.   There's no JIT associated with the interpreter, however.
>>
>>
>
> At the time it was developed, the Basic guys called it "incremental
> compilation", as to differentiate it from the interpreter on RSTS/E.
>
> Not sure how much different it is.

While I don't know specifically about VMS BASIC, BASIC+2 is indeed 
compiling, even when in immediate mode. It compiles the program when you 
type "RUN", or compiles individual lines as you press enter. So it never 
"interprets" the lines in the common sense of the word. But the 
compilation only goes to object code in this case, which is loaded into 
memory and executed under the context of the BASIC itself. You can even 
load other object files to be included when running, if your program is 
split into several modules. But, no proper linking using the task 
builder. And it was optional if you wanted to include this ability or not.

I would have assumed that VMS BASIC did the same, but like I said, I 
don't really know.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
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