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April 12, 2002 How to resolve "cch" ambiguity | ||||
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When lexically parsing D, how do you decide if the string "cch" is an identifer (possible type, function, or variable name) or the hex value 0xcc? -- The Villagers are Online! villagersonline.com .[ (the fox.(quick,brown)) jumped.over(the dog.lazy) ] .[ (a version.of(English).(precise.more)) is(possible) ] ?[ you want.to(help(develop(it))) ] |
April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Russ Lewis | We might want to debate whether "hex suffix" even makes sense. Frankly, I've found hex suffixes make it really hard to tell (at a glance) that the thing is a number and not an obscure variable name. -- The Villagers are Online! villagersonline.com .[ (the fox.(quick,brown)) jumped.over(the dog.lazy) ] .[ (a version.of(English).(precise.more)) is(possible) ] ?[ you want.to(help(develop(it))) ] |
April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Russ Lewis | "Russ Lewis" <spamhole-2001-07-16@deming-os.org> wrote in message news:3CB626D5.A9829740@deming-os.org... > When lexically parsing D, how do you decide if the string "cch" is an identifer (possible type, function, or variable name) or the hex value 0xcc? 'cch' is an identifier. '0cch' would be a hex value. |
April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Walter | Walter wrote: > "Russ Lewis" <spamhole-2001-07-16@deming-os.org> wrote in message news:3CB626D5.A9829740@deming-os.org... > > When lexically parsing D, how do you decide if the string "cch" is an identifer (possible type, function, or variable name) or the hex value 0xcc? > > 'cch' is an identifier. '0cch' would be a hex value. But it doesn't have to start with 0, right? I was looking at math2.d line 1299 (still from version 0.25, iirc), and it has the constant 1A2h which I understood to mean 0x1A2 right? -- The Villagers are Online! http://villagersonline.com .[ (the fox.(quick,brown)) jumped.over(the dog.lazy) ] .[ (a version.of(English).(precise.more)) is(possible) ] ?[ you want.to(help(develop(it))) ] |
April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Russ Lewis | Russ Lewis wrote:
> Walter wrote:
>
>
>>"Russ Lewis" <spamhole-2001-07-16@deming-os.org> wrote in message
>>news:3CB626D5.A9829740@deming-os.org...
>>
>>>When lexically parsing D, how do you decide if the string "cch" is an
>>>identifer (possible type, function, or variable name) or the hex value
>>>0xcc?
>>>
>>'cch' is an identifier. '0cch' would be a hex value.
>>
>
> But it doesn't have to start with 0, right? I was looking at math2.d line
> 1299 (still from version 0.25, iirc), and it has the constant
> 1A2h
> which I understood to mean
> 0x1A2
> right?
I think it has to start with a digit for the parser's
benefit; the leading zero is only necessary if the
hex representation leads with an alpha character.
Though what was wrong with good old 0xCC, I don't know.
--the other other Russell
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April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Russell Borogove | "Russell Borogove" <kaleja@estarcion.com> wrote in message news:3CB64AC1.8010402@estarcion.com... > I think it has to start with a digit for the parser's > benefit; the leading zero is only necessary if the > hex representation leads with an alpha character. It seems so. By the way, it is exactly how assemblers with Intel syntax parse hex numbers: 1000h - correct A000h - invalid 0A000h - correct |
April 12, 2002 Re: How to resolve "cch" ambiguity | ||||
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Posted in reply to Pavel Minayev | "Pavel Minayev" <evilone@omen.ru> wrote in message news:a95mdc$7ak$1@digitaldaemon.com... > "Russell Borogove" <kaleja@estarcion.com> wrote in message news:3CB64AC1.8010402@estarcion.com... > > I think it has to start with a digit for the parser's > > benefit; the leading zero is only necessary if the > > hex representation leads with an alpha character. Yes. > It seems so. By the way, it is exactly how assemblers with Intel > syntax parse hex numbers: > 1000h - correct > A000h - invalid > 0A000h - correct That's why it's in there <g>. |
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