in reply to Re^3: Infinity and Inf? (MAX_INT)
in thread Infinity and Inf?

The range operator seems only to be implemented for signed 32bits integers

On a 64-bit perl, it handles integers greater than 32-bit.

Though there appears to be a bug. Somewhere in between, the 64-bit integers are being transitioned through an NV (double) before being converted back to integers for the iterator it seems: 

for my $p ( 32 .. 64 ) { 
    my $n = 2**$p; 
    printf "\n$p"; 
    printf " $_" for $n .. $n + 2;
};;

32 4294967296 4294967297 4294967298
33 8589934592 8589934593 8589934594
34 17179869184 17179869185 17179869186
35 34359738368 34359738369 34359738370
36 68719476736 68719476737 68719476738
37 137438953472 137438953473 137438953474
38 274877906944 274877906945 274877906946
39 549755813888 549755813889 549755813890
40 1099511627776 1099511627777 1099511627778
41 2199023255552 2199023255553 2199023255554
42 4398046511104 4398046511105 4398046511106
43 8796093022208 8796093022209 8796093022210
44 17592186044416 17592186044417 17592186044418
45 35184372088832 35184372088833 35184372088834
46 70368744177664 70368744177665 70368744177666
47 140737488355328 140737488355329 140737488355330
48 281474976710656 281474976710657 281474976710658
49 562949953421312 562949953421313 562949953421314
50 1125899906842624 1125899906842625 1125899906842626
51 2251799813685248 2251799813685249 2251799813685250
52 4503599627370496 4503599627370497 4503599627370498
53 9007199254740992 9007199254740993 9007199254740994
54 18014398509481984
55 36028797018963968
56 72057594037927936
57 144115188075855872
58 288230376151711744
59 576460752303423488
60 1152921504606846976
61 2305843009213693952
62 4611686018427387904
63[Range iterator outside integer range at (eval 21) line 1, <STDIN> l
+ine 17.

[download]

Good luck in trying to track that bug down :)

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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Re^5: Infinity and Inf? (MAX_INT)
by ikegami (Patriarch) on Sep 01, 2010 at 16:08 UTC

    Though there appears to be a bug. Somewhere in between, the 64-bit integers are being transitioned through an NV (double) before being converted back to integers for the iterator it seems:

    There is code that assumes NV vars can handle larger integers than IV and UV vars can. That's not the case for all builds anymore, so these builds have unexpected overflow conditions.

    (BrowserUK probably knows that, but I thought someone else might be curious.)

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Re^5: Infinity and Inf? (MAX_INT)
by LanX (Saint) on Sep 01, 2010 at 15:09 UTC
    Thanks but thats not my problem, its the break of symmetry between .. and ++ which "bugs" me!

    IMHO it doesn't make sense to restrict the rangeoperator to signed integers when floats can still represent bigger integers (which are perfectly transparent when used with arithmetic operators).

    Cheers Rolf

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      IMHO it doesn't make sense to restrict the rangeoperator to signed integers when floats can still represent bigger integers

      I can sort of sympathise with that.

      But for counterpoint, does it make sense to restrict the iteration of a float iterator to unitary integer increments?

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
        I don't know if I understand you right, you mean to allow rational stepwidth?

        Something like BASIC's FOR 3.3 TO 7.8 STEP 0.5?

        IMHO the C-Style for is already meant to handle this.

        Cheers Rolf

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