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digitalmars.D.learn - sscanf() equivalent for D using Phobos library?

reply rocknroll714 <rocknroll714 gmail.com> writes:
Hi. I discovered D recently and I am very, very impressed. I've
decided to switch from C/C++ over to D as my programming language of
choice. Right now I'm porting one of my C++ applications to D, and I
need some help with a simple conversion.

How would I do this:

if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}

In D? I'm looping through a text file using the File.getline() command
and splitting each line into two separate variables with the sscanf
command. The if conditional check is to make sure the line is
formatted properly (the text file is the settings file for my
application).

Help please!
Dec 03 2008
next sibling parent reply "Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:
On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714 <rocknroll714 gmail.com> wrote:

 Hi. I discovered D recently and I am very, very impressed. I've
 decided to switch from C/C++ over to D as my programming language of
 choice. Right now I'm porting one of my C++ applications to D, and I
 need some help with a simple conversion.

 How would I do this:

 if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}

 In D? I'm looping through a text file using the File.getline() command
 and splitting each line into two separate variables with the sscanf
 command. The if conditional check is to make sure the line is
 formatted properly (the text file is the settings file for my
 application).

 Help please!


import std.cstream;, and use din.readf.  readf is documented in std.stream.  :)
Dec 03 2008
parent reply Spacen Jasset <spacenjasset yahoo.co.uk> writes:
Jarrett Billingsley wrote:

 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714 <rocknroll714 gmail.com> wrote:

 Hi. I discovered D recently and I am very, very impressed. I've
 decided to switch from C/C++ over to D as my programming language of
 choice. Right now I'm porting one of my C++ applications to D, and I
 need some help with a simple conversion.

 How would I do this:

 if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}

 In D? I'm looping through a text file using the File.getline() command
 and splitting each line into two separate variables with the sscanf
 command. The if conditional check is to make sure the line is
 formatted properly (the text file is the settings file for my
 application).

 Help please!


 
 import std.cstream;, and use din.readf.  readf is documented in std.stream.  :)


This seems to work on a file, but can this be done on a char[] ?
Dec 04 2008
parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
"Spacen Jasset" wrote

 Jarrett Billingsley wrote:

 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714 <rocknroll714 gmail.com> 
 wrote:

 Hi. I discovered D recently and I am very, very impressed. I've
 decided to switch from C/C++ over to D as my programming language of
 choice. Right now I'm porting one of my C++ applications to D, and I
 need some help with a simple conversion.

 How would I do this:

 if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}

 In D? I'm looping through a text file using the File.getline() command
 and splitting each line into two separate variables with the sscanf
 command. The if conditional check is to make sure the line is
 formatted properly (the text file is the settings file for my
 application).

 Help please!


 import std.cstream;, and use din.readf.  readf is documented in 
 std.stream.  :)


 This seems to work on a file, but can this be done on a char[] ?


might be talking out of my ass, since I'm a tango user, but I think readf is 
a function used by all streams?  So you just need to make that char[] into a 
stream, and then you get readf functionality, maybe.

-Steve
Dec 04 2008
parent reply "Bill Baxter" <wbaxter gmail.com> writes:
On Fri, Dec 5, 2008 at 9:06 AM, Steven Schveighoffer
<schveiguy yahoo.com> wrote:

 "Spacen Jasset" wrote

 Jarrett Billingsley wrote:

 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714 <rocknroll714 gmail.com>
 wrote:

 Hi. I discovered D recently and I am very, very impressed. I've
 decided to switch from C/C++ over to D as my programming language of
 choice. Right now I'm porting one of my C++ applications to D, and I
 need some help with a simple conversion.

 How would I do this:

 if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}

 In D? I'm looping through a text file using the File.getline() command
 and splitting each line into two separate variables with the sscanf
 command. The if conditional check is to make sure the line is
 formatted properly (the text file is the settings file for my
 application).

 Help please!


 import std.cstream;, and use din.readf.  readf is documented in
 std.stream.  :)


 This seems to work on a file, but can this be done on a char[] ?


 might be talking out of my ass, since I'm a tango user, but I think readf is
 a function used by all streams?  So you just need to make that char[] into a
 stream, and then you get readf functionality, maybe.


I think that's what std.stream.MemoryStream is for, but I might be
talking out of my ass too because I've never used it.  But it looks
like you could say

   scope thestream = new std.stream.MemoryStream(thebuffer);

then use thestream just like it was a file.
You may have to cast(byte[])thebuffer, though.

--bb
Dec 04 2008
parent reply BCS <ao pathlink.com> writes:
Reply to Bill,


 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714
 <rocknroll714 gmail.com> wrote:
 

 I'm looping through a text file using the File.getline()
 command








 scope thestream = new std.stream.MemoryStream(thebuffer);
 


One new MemoeryStream per line!?!?
Dec 04 2008
next sibling parent reply "Bill Baxter" <wbaxter gmail.com> writes:
On Fri, Dec 5, 2008 at 11:09 AM, BCS <ao pathlink.com> wrote:

 Reply to Bill,


 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714
 <rocknroll714 gmail.com> wrote:


 I'm looping through a text file using the File.getline()
 command








 scope thestream = new std.stream.MemoryStream(thebuffer);


 One new MemoeryStream per line!?!?


It's scope!  No worries mate! ;-)

But seriously, it does sound heavyweight compared to a single sscanf
function call.
Honestly, std.stream is just barely functional enough to write the
simplest stream code, so I wouldn't be surprised if that's what it
takes to scan strings with it.  Not much worse than what it takes to
do it with std::stream in c++ though.

I'm really talking out of my ass though, because I can probably count
on one hand how many times written code to use scanf or stringstream
in my life.  If I have to parse input I'm much more likely to reach
for the regexp hammer or write a simpler parser.

--bb
Dec 04 2008
parent BCS <ao pathlink.com> writes:
Reply to Bill,


 On Fri, Dec 5, 2008 at 11:09 AM, BCS <ao pathlink.com> wrote:
 

 Reply to Bill,
 

 On Wed, Dec 3, 2008 at 6:37 PM, rocknroll714
 <rocknroll714 gmail.com> wrote:

 I'm looping through a text file using the File.getline() command
 








 scope thestream = new std.stream.MemoryStream(thebuffer);
 


 One new MemoeryStream per line!?!?
 


 It's scope!  No worries mate! ;-)
 
 But seriously, it does sound heavyweight compared to a single sscanf
 function call.
 Honestly, std.stream is just barely functional enough to write the
 simplest stream code, so I wouldn't be surprised if that's what it
 takes to scan strings with it.  Not much worse than what it takes to
 do it with std::stream in c++ though.
 I'm really talking out of my ass though, because I can probably count
 on one hand how many times written code to use scanf or stringstream
 in my life.  If I have to parse input I'm much more likely to reach
 for the regexp hammer or write a simpler parser.
 
 --bb
 


there should so be a std.scan.scan function to go with the std.format.format.
Dec 04 2008
prev sibling parent reply "Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:
On Thu, Dec 4, 2008 at 9:25 PM, Bill Baxter <wbaxter gmail.com> wrote:

 It's scope!  No worries mate! ;-)

 But seriously, it does sound heavyweight compared to a single sscanf
 function call.
 Honestly, std.stream is just barely functional enough to write the
 simplest stream code, so I wouldn't be surprised if that's what it
 takes to scan strings with it.  Not much worse than what it takes to
 do it with std::stream in c++ though.

 I'm really talking out of my ass though, because I can probably count
 on one hand how many times written code to use scanf or stringstream
 in my life.  If I have to parse input I'm much more likely to reach
 for the regexp hammer or write a simpler parser.


I could never quite figure out why Stream.readf was not separated out
into a separate function in std.format.  It probably wouldn't be a lot
of work.
Dec 04 2008
next sibling parent BCS <ao pathlink.com> writes:
Reply to Jarrett,


 On Thu, Dec 4, 2008 at 9:25 PM, Bill Baxter <wbaxter gmail.com> wrote:
 

 It's scope!  No worries mate! ;-)
 
 But seriously, it does sound heavyweight compared to a single sscanf
 function call.
 Honestly, std.stream is just barely functional enough to write the
 simplest stream code, so I wouldn't be surprised if that's what it
 takes to scan strings with it.  Not much worse than what it takes to
 do it with std::stream in c++ though.
 I'm really talking out of my ass though, because I can probably count
 on one hand how many times written code to use scanf or stringstream
 in my life.  If I have to parse input I'm much more likely to reach
 for the regexp hammer or write a simpler parser.
 


 I could never quite figure out why Stream.readf was not separated out
 into a separate function in std.format.  It probably wouldn't be a lot
 of work.
 


do it, submit patch, become hero. <G>
Dec 04 2008
prev sibling parent reply =?ISO-8859-1?Q?Anders_F_Bj=F6rklund?= <afb algonet.se> writes:
Jarrett Billingsley wrote:


 I could never quite figure out why Stream.readf was not separated out
 into a separate function in std.format.  It probably wouldn't be a lot
 of work.


I thought that was what std.unformat was for ?

But I would have put readf in std.stdio too...

--anders
Dec 05 2008
parent reply "Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:
On Fri, Dec 5, 2008 at 5:43 AM, Anders F Bj=F6rklund <afb algonet.se> wrote=
:

 Jarrett Billingsley wrote:


 I could never quite figure out why Stream.readf was not separated out
 into a separate function in std.format.  It probably wouldn't be a lot
 of work.


 I thought that was what std.unformat was for ?


Such a library exists?  It's not in the D docs.  I don't see anything
in the Phobos source dir either.


 But I would have put readf in std.stdio too...

 --anders
Dec 05 2008
parent =?ISO-8859-1?Q?Anders_F_Bj=F6rklund?= <afb algonet.se> writes:
Jarrett Billingsley wrote:


 I could never quite figure out why Stream.readf was not separated out
 into a separate function in std.format.  It probably wouldn't be a lot
 of work.


 I thought that was what std.unformat was for ?


 
 Such a library exists?  It's not in the D docs.  I don't see anything
 in the Phobos source dir either.


It was suggested for DMD 0.128, but I don't think it made it.

--anders
Dec 05 2008
prev sibling parent BCS <ao pathlink.com> writes:
Reply to rocknroll714,


 Hi. I discovered D recently and I am very, very impressed. I've
 decided to switch from C/C++ over to D as my programming language of
 choice. Right now I'm porting one of my C++ applications to D, and I
 need some help with a simple conversion.
 
 How would I do this:
 
 if(sscanf(line, "%[^:]: %[^\r\n]", name, value) != 2) {...}
 
 In D? I'm looping through a text file using the File.getline() command
 and splitting each line into two separate variables with the sscanf
 command. The if conditional check is to make sure the line is
 formatted properly (the text file is the settings file for my
 application).
 
 Help please!
 


the quick and wrong way that works is to go find std.c.stdio and call the 
C sscanf function. (be sure to uses toStringz on the line arg and to allocate 
for the outputs as you would in c

as for a native D equivalent... I'm not sure.
Dec 03 2008