Re^2: String to Hex

http://www.perlmonks.org?node_id=616892

in reply to Re: String to Hex
in thread String to Hex

Update: Unstruck on advice ;)

I also agree that it deserved being unstruck. But:

I would $num >>= 32;
AIUI from earlier posts by knowledgeable people, the technique is valid for numbers such that the loop will always involve one or at most two iterations of the loop.

Update: s/16/32/ applied above, thanks GF.

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Re^3: String to Hex by BrowserUk (Patriarch) on May 22, 2007 at 22:40 UTC
I would $num >>= 16; Both methods have problems on 32-bit systems. GrandFather's produces the correct result and warnings, but yours gives the wrong result? `print 24600988483 / 2**32;; 5.72786398301832 print 24600988483 / 0x100000000;; Integer overflow in hexadecimal number at (eval 24) line 1 Hexadecimal number > 0xffffffff non-portable at (eval 24) line 1 5.72786398301832 print 24600988483 >> 16;; 65535` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l]
Re^4: String to Hex by GrandFather (Saint) on May 22, 2007 at 23:57 UTC
Warnings? With AS Perl 5.8.7 I see no warnings with either the code I posted or with the (corrected) `$num >>= 32;` variant suggested by blazar. You did `use bigint;` didn't you? DWIM is Perl's answer to Gödel	[reply] [d/l] [select]
Re^5: String to Hex by BrowserUk (Patriarch) on May 23, 2007 at 00:05 UTC
You did use bigint; didn't you? Rhetorical I assume, but I'll answer it anyway. No. I missed that slightly significant detail :) Annoyingly, I did look for `use Math::BigInt;`, but completely missed the presence of the pragma variant! 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. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l]

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