🚀 go-pugleaf

In article <1992Aug5.203847.20530@beaver.cs.washington.edu> rrogers@cs.washington.edu (Richard Rogers) writes:
> ...
> In any case, Logo is missing control structures which I feel are
> basic enough that they should be part of the standard language 
> rather than requiring extra work to implement yourself.

Object Logo has WHILE, DOUNTIL, FOR, MAP, WHEN, WHENEVER, and many
other iterative control structures. Some of these, in fact, were
written by Brian, though he's too modest to mention that (well...).


> I find it more difficult to debug dynamically scoped languages.

Object Logo is lexically scoped by default. A variable can be scoped
dynamically by declaring it "PUBLIC" (just as it can be made local to
a procedure by declaring it "LOCAL", or to an object by using "HAVE").
A procedure can be considered inside another (so, in effect, its
upstream variables are dynamically scoped), by declaring it INSIDE the
other procedure--or inside every procedure by declaring it INSIDEALL.
The last of these capabilities is what let Brian define the control
structures he needed. Incidentally, all the above-mentioned control
structures are now provided as primitives in the language, although
there's nothing to prevent one from providing source code in a startup
file as Brian describes.

-- 
Larry Davidson                        
Learning Strategies            
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