On Mon, May 17, 2010 at 4:07 PM, David Herman <[email protected]> wrote:
> [snip] For example, consider: > > module M = load "http://example.com/foo.js";; > module N = load "http://example.com/foo.js";; > > These two modules are loaded from the exact same MRL, but the module system > treats them as two completely separate, independent modules. (Even custom > module loaders shouldn't be able to change this fact, since all they can do > is deliver the bits of a module resource.) > > The reason for this is that on the web, there's just no way to know that two > URL's point to the "same" resource-- fetching the bit-for-bit-same URL even > microseconds apart can result in completely different data, since web servers > are free to deliver whatever they want. So the module loading semantics is > resolutely non-clever about interpreting MRL's. > > Dave > > That's surprising. Within a moduleloader I would have thought that same url meant the same static module. Across moduleloaders maybe not. For the following scenario: <script> module ModA = "http://acme.com/moda.js";; module ModB = "http://acme.com/modb.js";; ... source </script> Both ModA and ModB use a utility module - that is the moda.js and modb.js files both contain: module ModUtils = "http://widgets.com/modutils.js";; I would have guessed that ModA and ModB are using the exact same static utility module. Firstly for efficiency - "hey this source has been fetched and compiled already". But also, simple modules seem like 'traditional' modules. That is, if a top level variable is declared in a C source file, that variable occurs once in the resulting compiled image/program. Thus the source files (modules) author can reason about the (shared state) of the variable. However, if an ES module source can be declared multiple times (within a moduleloader) - doesn't it become harder for the author of the module to reason about a top level variable. If multiple instance of a module variable are required - then maybe an object should be used. Also, it seems unlikely that a new module source would be generated by a server within the context of a moduleloader fetching/compiling source. Maybe the rule should be - first source fetched for a url is the source used for subsequent module references. _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
