A main strength of the DSL is that it is intention revealing. “Say what you do, not how you do it.” Scanning code for uses of Select is much faster then deciphering an idiomatic construct. Even worse, any slight variation in the combination of for’s and if’s might turn your select idiom into a reject, or select or detect instead. Thus, I personally prefer the DSL for trivial cases even.

And now, installing lambda4jdt … looks wow!

Select selection = Select.from( words );
for (Select each: selection) {
    each.yield = each.element.charAt(0).isUppercase();
}
Collection names = selection.result();

Vs

Collection names = new ArrayList();
for (String word : words) {
    if (Character.isUpperCase(word.charAt(0)))
        names.add(word);
}

Idiomatic java looks not that bad in comparison

Select<String> selection = Select.from( words );
for (Select<String> each: selection) {
    each.yield = each.element.charAt(0).isUppercase();
}
Collection<String> names = selection.result();

I saw this attempted here as well, but you’re limited to using the Hamcrest matchers: http://code.google.com/p/hamcrest-collections/wiki/GettingStarted

I think it is a clever approach to a thorny issue. Like it a lot. I bet you will get criticism from FP/Rub/Smalltalk people saying that Java sucks and that it should have supported this and that. This may be true, but still you managed to find a good practical solution to a real problem.

Although the trick is really clever, perhaps something like the fragment below would be more closer to what Java developers expect?

Select select = select(words);
for (Select each: select) {
  each.yield = each.value.charAt(0).isUppercase();
}
Collection names = select.result;

@Bruno: Are you doing Wicket development? Looks like it. Indeed you can use Enum’s, but not in place of an Class. Imagine you could, what would the difference be between MyRoles.USER.name() and MyRoles.ADMIN.name()? None, both resolve to the same Enum class. Why don’t you just retrofit/overload it so that you can use Enum instead?

A missed apostrophe, in a non-native language, is hardly worthy of a snarky proofreading comment.

Are you truly *astonished* at the characterization? Did you gasp out loud? At *best* I was mildly intrigued at the characterization, although I do feel they’re at least *a* pretty basic technique.

I think, perhaps, you’re too comfortable with hyperbole and nit-picking.

Missing apostrophes are an abbreviation (as are three letter acronyms). In the same way, “don’t” is not a word either, but an abbreviation no doubt frowned upon by the slaves to language past who insisted instead on the correct usage of full “do not”.