• flyinghearts (29/29) Nov 15 2010 Page 8, in the example:
• Andrei Alexandrescu (4/33) Nov 15 2010 dmd bug, fixed recently.

flyinghearts <flyinghearts qq.com> writes:

Page 8, in the example:

import std.stdio, std.string;

void main()
{
  uint[string] dictionary;
  foreach (line; stdin.byLine()) {
  // Break sentence into words
  // Add each word in the sentence to the vocabulary
    foreach (word; splitter(strip(line))) {
      if (word in dictionary) continue; // Nothing to do
      auto newlD = dictionary.length;
      dictionary[word] = newlD;
      writeln(newlD,word);
         //Notice: the following line is not exist in the book.
         //foreach(k, v; dictionary) writeln(k, " ", dictionary[k]);
    }
  }
}



There is a buffer reuse problem. The program does not work rightly on my
machine(win xp, DMD 2.050). Moreover, an error, "object.Error: Access
Violation", may occur when the associate array is directly accessed. It can be
tested just by uncommenting the line begin with "//foreach", and setting the
input data as:
a b
b c


The solution to the problem is:

dictionary[word]  ->   dictionary[word.idup]
or:
strip(line)       ->   strip(line.dup)

Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:

On 11/15/10 7:31 AM, flyinghearts wrote:
 Page 8, in the example:

 import std.stdio, std.string;

 void main()
 {
    uint[string] dictionary;
    foreach (line; stdin.byLine()) {
    // Break sentence into words
    // Add each word in the sentence to the vocabulary
      foreach (word; splitter(strip(line))) {
        if (word in dictionary) continue; // Nothing to do
        auto newlD = dictionary.length;
        dictionary[word] = newlD;
        writeln(newlD,word);
           //Notice: the following line is not exist in the book.
           //foreach(k, v; dictionary) writeln(k, " ", dictionary[k]);
      }
    }
 }



 There is a buffer reuse problem. The program does not work rightly on my
 machine(win xp, DMD 2.050). Moreover, an error, "object.Error: Access
 Violation", may occur when the associate array is directly accessed. It can be
 tested just by uncommenting the line begin with "//foreach", and setting the
 input data as:
 a b
 b c


 The solution to the problem is:

 dictionary[word]  ->    dictionary[word.idup]
 or:
 strip(line)       ->    strip(line.dup)

dmd bug, fixed recently.

http://d.puremagic.com/issues/show_bug.cgi?id=2954


Andrei