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digitalmars.D.learn - Formatted read of tokens?

reply Jerry <jlquinn optonline.net> writes:
Hi all,

I'm porting some C++ code into D that uses istream to read lines like

label 3

where there can spaces or tabs between the 2 fields.  In c++, this is:

string l;
int i;
istr >> l >> i;

What's the equivalent in D?  It appears that D formatted read for
strings grabs everything up to a newline and doesn't support whitespace
tokenization.

If I do

f.readf("%s %s", &l, &i);

it fails if the whitespace is a tab.

Thanks
Jerry
Jun 17 2014
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
Jerry:


 If I do

 f.readf("%s %s", &l, &i);

 it fails if the whitespace is a tab.


In you can use byLine, followed by a split, and then assignment 
of the pieces, followed by to!int where necessary.

Bye,
bearophile
Jun 17 2014
parent reply Jerry <jlquinn optonline.net> writes:
"bearophile" <bearophileHUGS lycos.com> writes:


 Jerry:


 If I do

 f.readf("%s %s", &l, &i);

 it fails if the whitespace is a tab.


 In you can use byLine, followed by a split, and then assignment of the pieces,
 followed by to!int where necessary.


I actually can't use byLine in this instance.  I'm really wanting the %s
behavior of scanf().
Jun 17 2014
parent reply "John Colvin" <john.loughran.colvin gmail.com> writes:
On Tuesday, 17 June 2014 at 13:16:38 UTC, Jerry wrote:

 "bearophile" <bearophileHUGS lycos.com> writes:


 Jerry:


 If I do

 f.readf("%s %s", &l, &i);

 it fails if the whitespace is a tab.


 In you can use byLine, followed by a split, and then 
 assignment of the pieces,
 followed by to!int where necessary.


 I actually can't use byLine in this instance.  I'm really 
 wanting the %s
 behavior of scanf().


If you really need/want fscanf behaviour then just use it:

import core.stdc.stdio : fscanf;
Jun 17 2014
parent Jerry <jlquinn optonline.net> writes:
"John Colvin" <john.loughran.colvin gmail.com> writes:


 On Tuesday, 17 June 2014 at 13:16:38 UTC, Jerry wrote:

 "bearophile" <bearophileHUGS lycos.com> writes:


 Jerry:


 If I do

 f.readf("%s %s", &l, &i);

 it fails if the whitespace is a tab.


 In you can use byLine, followed by a split, and then assignment of the
 pieces,
 followed by to!int where necessary.


 I actually can't use byLine in this instance.  I'm really wanting the %s
 behavior of scanf().


 If you really need/want fscanf behaviour then just use it:

 import core.stdc.stdio : fscanf;


Thanks, I forgot the obvious.

It would be nice to have a way to do the same thing in D formatted
reading.  Does it seem like it would be useful to specify this kind of
thing?

For example, you could have:

%' '         grabs all isWhite() chars
%t           reads a single token - all chars !isWhite()

Any takers?

Jerry
Jun 17 2014