I have copied more or less verbatim an example from The D Programming Language, under 1.4.3 Counting Frequencies. Lambda Functions

This is the code

import std.stdio,
       std.string;

void main()
{
  uint[string] freqs;
  // Compute counts
  foreach (line; stdin.byLine())
  {
    foreach (word; split(strip(line)))
    {
      ++freqs[word.idup];
    }
  }

  // Print counts
  string[] words = freqs.keys;
  sort!((a, b) { return freqs[a] > freqs[b]; })(words); // won't compile ????
  foreach (word; words)
  {
    writefln("%6u\t%s", freqs[word], words);
  }
}

Both DMD and GDC complain, saying
Error: template instance sort!((a, b)
{
return freqs[a] > freqs[b];
}
) template 'sort' is not defined


Have I made a mistake, or has the D syntax perhaps changed since the book was published?
I don't understand this functional voodoo stuff, so I don't have the faintest clue how to fix it myself

Anyone know how to fix this?

On 01/11/2016 04:28 PM, asdfa wrote:

> Both DMD and GDC complain, saying
> Error: template instance sort!((a, b)
> {
> return freqs[a] > freqs[b];
> }
> ) template 'sort' is not defined

That issue is already in the errata:

  http://erdani.com/tdpl/errata/

Add the following line to fix:

import std.algorithm;

Ali

On Tuesday, 12 January 2016 at 00:36:15 UTC, Ali Çehreli wrote:
> On 01/11/2016 04:28 PM, asdfa wrote:
>
> > Both DMD and GDC complain, saying
> > Error: template instance sort!((a, b)
> > {
> > return freqs[a] > freqs[b];
> > }
> > ) template 'sort' is not defined
>
> That issue is already in the errata:
>
>   http://erdani.com/tdpl/errata/
>
> Add the following line to fix:
>
> import std.algorithm;
>
> Ali

Thank you so much! It works now

well it does after I changed
writefln("%6u\t%s", freqs[word], words);

to
writefln("%6u\t%s", freqs[word], word);

(stupid mistake I made copying)