3 ms·

The point is to remove obstacles that prevent you from introducing backward incompatible changes into the language, obstacles than prevent your language from ev

by xaduha 10y ago

The point is to remove obstacles that prevent you from introducing backward incompatible changes into the language, obstacles than prevent your language from evolving. Implementations can support several specifications of the language, you can keep those source code files as is or you can mix them. You can take advantage of new features in new files, but keep everything else working. Imagine you updated your pom file and bunch of stuff stopped working. If it's easy enough to fix you do it, if not you might just revert pom changes and stay with older version of the language, module or whatever. That wouldn't happen with versioned specification languages. > I see no particular advantage in specifying the language version in each and every file You obviously stuck with this mindset and not thinking about it hard enough.

nradov 10y ago
No I'm not stuck, but realistically when you make a change like that you're going to have to update the entire module. There's no way that having a mix of incompatible different language versions in individual source code files within a single module is ever going to be practical for real world large scale product development.
- xaduha 10y ago
  Don't try to make it a technical issue, because it totally isn't. Every single one of those files goes through a compiler of some kind. Source code gets transformed to a tree, AST, whatever. They only thing changing here is that somewhere near the root of that tree there's a version. In many languages there is already a mechanism for specifying that kind of info, like pragmas or CDATA in SGML descended markup languages. And it's not hard to introduce either way. Javascript borrowed 'use strict' from Perl 5, for example. In the end you write something in a language. What language you use to write that isn't defined in some external file, it's an inherent property of the text. You can't write a note in Ye Olde English and expect it to be understood by modern people without issues.

by xaduha 10y ago

nradov 10y ago

No I'm not stuck, but realistically when you make a change like that you're going to have to update the entire module. There's no way that having a mix of incompatible different language versions in individual source code files within a single module is ever going to be practical for real world large scale product development.

xaduha 10y ago
Don't try to make it a technical issue, because it totally isn't. Every single one of those files goes through a compiler of some kind. Source code gets transformed to a tree, AST, whatever. They only thing changing here is that somewhere near the root of that tree there's a version. In many languages there is already a mechanism for specifying that kind of info, like pragmas or CDATA in SGML descended markup languages. And it's not hard to introduce either way. Javascript borrowed 'use strict' from Perl 5, for example. In the end you write something in a language. What language you use to write that isn't defined in some external file, it's an inherent property of the text. You can't write a note in Ye Olde English and expect it to be understood by modern people without issues.