Re: Help with Regular Expressions (std.regex)

2019-03-05 Thread Samir via Digitalmars-d-learn

On Monday, 4 March 2019 at 18:57:34 UTC, dwdv wrote:

There is also std.file.slurp which makes this quite easy:
slurp!(int, int, int, int, int)("03.input", "#%d @ %d,%d: 
%dx%d");


That's brilliant!  This language just keeps putting a smile on my 
face every time I learn something new like this!


Re: Help with Regular Expressions (std.regex)

2019-03-04 Thread dwdv via Digitalmars-d-learn

On 3/3/19 7:07 PM, Samir via Digitalmars-d-learn wrote:
I am belatedly working my way through the 2018 edition of the Advent of 
Code[1] programming challenges using D and am stumped on Problem 3[2].  
The challenge requires you to parse a set of lines in the format:

#99 @ 652,39: 24x23
#100 @ 61,13: 15x24
#101 @ 31,646: 16x28

I would like to store each number (match) as an element in an array so 
that I can refer to them by index.


There is also std.file.slurp which makes this quite easy:
slurp!(int, int, int, int, int)("03.input", "#%d @ %d,%d: %dx%d");

You can then later expand the matches in a loop and process the claims:
foreach(id, offX, offY, width, height; ...


Re: Help with Regular Expressions (std.regex)

2019-03-04 Thread Samir via Digitalmars-d-learn

On Sunday, 3 March 2019 at 19:27:17 UTC, user1234 wrote:

oops forgot the bang

  auto allMatches = matchAll(line, pattern).map!(a => 
a.hit).array;


Thanks, user1234!  Looks like `map` is another topic I need to 
read up upon.  I slightly modified your suggestion and went with:


auto allMatches = matchAll(line, pattern).map!(a => 
to!int(a.hit)).array;


which also takes care of converting the string to int.

Samir



Re: Help with Regular Expressions (std.regex)

2019-03-03 Thread user1234 via Digitalmars-d-learn

On Sunday, 3 March 2019 at 18:32:14 UTC, user1234 wrote:

On Sunday, 3 March 2019 at 18:07:57 UTC, Samir wrote:
or  // sorry i don't have the regex API in mind

  import std.array: array;
  import std.alogrithm.iteration : map;
  auto allMatches = matchAll(line, pattern).map(a => 
a.hit).array;


oops forgot the bang

  auto allMatches = matchAll(line, pattern).map!(a => 
a.hit).array;





Re: Help with Regular Expressions (std.regex)

2019-03-03 Thread user1234 via Digitalmars-d-learn

On Sunday, 3 March 2019 at 18:07:57 UTC, Samir wrote:
I am belatedly working my way through the 2018 edition of the 
Advent of Code[1] programming challenges using D and am stumped 
on Problem 3[2].  The challenge requires you to parse a set of 
lines in the format:

#99 @ 652,39: 24x23
#100 @ 61,13: 15x24
#101 @ 31,646: 16x28

I would like to store each number (match) as an element in an 
array so that I can refer to them by index.  For example, for 
the first line:


m = [99, 652, 39, 24, 23]
assert(m[0] == 99);
assert(m[1] == 652);
// ...
assert(m[4] == 23);

What is the best way to do this?  (I will worry about 
converting characters to integers later.)


I have the following solution so far based on reading Dmitry 
Olshansky's article on std.regex[3] and the std.regex 
documention[4]:


import std.stdio;
import std.regex;

void main() {
auto line= "#99 @ 652,39: 24x23";
auto pattern = regex(r"\d+");
auto m   = matchAll(line, pattern);
writeln(m);
}

which results in:
[["99"], ["652"], ["39"], ["24"], ["23"]]

But this doesn't seem to be an iterable array as changing 
writeln(m) to writeln(m[0]) yields

Error: no [] operator overload for type RegexMatch!string

Changing the line to writeln(m.front[0]) yields
99

but m.front doesn't allow me to access other elements (i.e. 
m.front[1]):

requested submatch number 1 is out of range

??:? _d_assert_msg [0x4dc27a]
??:? inout pure nothrow @trusted inout(immutable(char)[]) 
std.regex.Captures!(immutable(char)[]).Captures.opIndex!().opIndex(ulong) [0x4d8d57]

??:? _Dmain [0x49ffc8]

I've tried something like
foreach (m; matchAll(line, pattern))
writeln(m.hit);

which is close but doesn't result in an array.  Do I need to 
use matchFirst?


Thanks in advance.
Samir

[1] https://adventofcode.com/2018
[2] https://adventofcode.com/2018/day/3
[3] https://dlang.org/articles/regular-expression.html
[4] https://dlang.org/phobos/std_regex.html


Hello, Something like this should work:

  import std.array: array;
  auto allMatches = matchAll(line, pattern).array;

or  // sorry i don't have the regex API in mind

  import std.array: array;
  import std.alogrithm.iteration : map;
  auto allMatches = matchAll(line, pattern).map(a => a.hit).array;


What happened with `writeln` is that it iterates the `matchAll` 
results which is an input range, which is lazy. `.array` stores 
the results in an array.