Steven D'Aprano writes: > On Wed, 2 Sep 2015 02:20 am, Marko Rauhamaa wrote: >> Steven D'Aprano: >> >>> I believe that Marko is wrong. It is not so easy to compile Python >>> to machine language for real machines. That's why the compiler >>> targets a virtual machine instead. >> >> Somehow Guile manages it even though Scheme is at least as dynamic a >> language as Python. > > It's not about the dynamicism precisely, it's about what counts as > primitive data types and operations. > > What are the primitives in Scheme? In Python, the primitives are > pretty complex. I don't know how accurate this page is: > > https://en.wikibooks.org/wiki/Scheme_Programming/Scheme_Datatypes > > but it suggests that Scheme primitives are quite close to the > machine. That may keep the runtime small.
I think I spotted a tiny inaccuracy, but the real problem with that page is that it's *very* incomplete: no mention of exact integers and rationals, strings appear in text but not as an entry, were vectors even mentioned?, nothing about procedures!, let alone reified continuations, nothing about input/output ports. Also records (definable types with named fields) are now officially in for some time already, so that's another kind of structured types. Many implementations have object systems, possibly modules as objects. It's quite analogous to Python's objects. Eval in Scheme is more restricted. Procedure internals are not accessible at all, and implementations typically offer ways to declare that standard names in a compilation unit indeed have their standard meaning and variables will not be assigned outside the given compilation unit, so the compiler can propagate information about expected argument types around, infer more types, inline code, and lot's of things that are way beyond me. Some Scheme implementations use quite aggressive compilation techniques. Guile is one, I think. Gambit and Larceny are two others. [- -] -- https://mail.python.org/mailman/listinfo/python-list
