Re: LOGO-L> Re: Punctuation (was: what is logo useful for anyways?)

["Dreyfuss Pierre-Andre" <p.a.dreyfuss@mailexcite.com>]

If you want to use variables without :

It is very easy  Logo is powerfull enough to let you do everything you want.



for each varianle you want to use this way then writes:
to a 
op :a
end

to b 
op :b
end

to c
op :c
end

And you don't need : any more

make  "a 5
make "b 6
pr a * b

and if you want to get rid of "


then


to c_IS :value
make "a :value
end


to a_is :value
make "a :value
end

to b_is :value
make "b :value
end


a_is 5
b_is 6
c_is a + b
pr c

Or more general:

to defvar :name

define word :name "_is ~
list [value] list "make word "" :name ":value]
define :name list [] list "op word ": :name
end

This program could have some bugs I just write it here without testing it , But the
Idea is there.


Just declare your variables with defvar.

You need once a quote to do that.

defvar "x

and then you can use x_is and x

But you still have a notation for affectation and a notation for extracting the value.


a works like cap or pos, it is a function just outputing its value. 


Regards.


P-A Dreyfuss



 

This is answer to :



> Brian Harvey wrote: 
> > Is this worth pursuing?  How much of a problem are quotes and
> > colons, really?
>
>To the serious computer scientist who needs a tool for list manipulation
>and lambda calculus, Logo is under-powered.   To an amateur programmer and
>to kids, I believe that the complications introduced by the "quotes and
>colons" are detrimental, and the benefit is marginal.  
>
>In an unscientific survey that I made, not even one kid knew what these
>"quotes and colons" are for, even if they knew when to use them.  At best,
>kids could get used to these marks because "that's how things are done".  I
>am sure that none of the readers of this group thinks that kids should be
>educated to do things without understanding why.  
>
>My guess is that 99 out of 100 Logo users will not be able to explain why
>these signs are needed.  I could be wrong.  But if I'm not wrong, then, to
>answer your question - this is well worth pursuing.
>
>I remember a post by Olga Tuzova a few months ago about a student of hers
>who got stuck with the Logo syntax when she wanted to use the Pythagorean
>theorem in a program.  What she wanted to express was
>    C = A^2 + B^2;
>The above equation is a legal C statement, with a clear beginning and end.
>Now translate it to Logo and compare.
>
>Chuck Shavit
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