[Issue 5544] New: all() and any() in Phobos

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=5544

           Summary: all() and any() in Phobos
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: Phobos
        AssignedTo: nobody at puremagic.com
        ReportedBy: bearophile_hugs at eml.cc


--- Comment #0 from bearophile_hugs at eml.cc 2011-02-07 14:35:37 PST ---
This is Python 2.6.6 code (shell):

>>> items = [1, 7, 22]
>>> all(x % 2 for x in items)
False
>>> items = [1, 7, 21]
>>> all(x % 2 for x in items)
True


The functions all() and any() are very handy.

With Phobos of DMD 2.051 if you want to translate that Python code to a D2
functional style you need something like:


import std.algorithm;
void main() {
    auto items = [1, 7, 22];
    bool r1 = reduce!q{a && b}(true, map!q{a % 2}(items));
    assert(!r1);
    items = [1, 7, 21];
    bool r2 = reduce!q{a && b}(true, map!q{a % 2}(items));
    assert(r2);
}


While using an all() it becomes shorter and more readable, something like
(untested):

import std.algorithm;
void main() {
    auto items = [1, 7, 22];
    bool r1 = all!q{a % 2}(items);
    assert(!r1);
    items = [1, 7, 21];
    bool r2 = all!q{a % 2}(items);
    assert(r2);
}

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