• Adnan (35/35) Apr 13 2020 I want to keep an ordered set of records and the standard
• Adnan (36/71) Apr 13 2020 I also tried creating a new type:
• Steven Schveighoffer (9/53) Apr 13 2020 // do this: (note you don't need binaryFun)

Adnan <relay.public.adnan outlook.com> writes:

I want to keep an ordered set of records and the standard 
provides me with RedBlackTree. The record is of type 
Tuple!(string, uint). Here's what it looks like:

import std.json : parseJSON;

	uint[string] wordTable;
	import std.datetime.stopwatch : StopWatch, AutoStart;

	auto sw = StopWatch(AutoStart.yes);
	const auto j = parseJSON(get(link));
	const long downloadTime = sw.peek.total!"msecs";

	import std.typecons : Tuple, tuple;
	import std.container.rbtree : RedBlackTree;
	import std.functional : binaryFun;

	RedBlackTree!(Tuple!(string, uint), binaryFun!("a[1] > b[1]")) 
records;

	foreach (node; j["posts"].array()) {
		import std.stdio : writeln;
		import std.utf : decode;

		if ("com" in node) {
			import std.algorithm : splitter;

			foreach (word; getStr(node["com"].str()).splitter(' ')) {
				import std.string : strip;

				if (word.strip().length > 0)
					wordTable.require(word, 0)++;

				records ~= (tuple(word, wordTable[word])); // error
			}
		}
	}

Now primarily I used `insert()` method to add a record to the 
records but it causes segfault in runtime. So I decided to use ~= 
to see what's going on. Here's what the compiler says:

Error: cannot append type Tuple!(string, uint) to type 
std.container.rbtree.RedBlackTree!(Tuple!(string, uint), 
binaryFun, false)


So the gist of the question is, if I have an RedBlackTree with a 
custom binaryFun, how can I add tuples to it?

Adnan <relay.public.adnan outlook.com> writes:

On Monday, 13 April 2020 at 23:59:20 UTC, Adnan wrote:
 I want to keep an ordered set of records and the standard 
 provides me with RedBlackTree. The record is of type 
 Tuple!(string, uint). Here's what it looks like:

 import std.json : parseJSON;

 	uint[string] wordTable;
 	import std.datetime.stopwatch : StopWatch, AutoStart;

 	auto sw = StopWatch(AutoStart.yes);
 	const auto j = parseJSON(get(link));
 	const long downloadTime = sw.peek.total!"msecs";

 	import std.typecons : Tuple, tuple;
 	import std.container.rbtree : RedBlackTree;
 	import std.functional : binaryFun;

 	RedBlackTree!(Tuple!(string, uint), binaryFun!("a[1] > b[1]")) 
 records;

 	foreach (node; j["posts"].array()) {
 		import std.stdio : writeln;
 		import std.utf : decode;

 		if ("com" in node) {
 			import std.algorithm : splitter;

 			foreach (word; getStr(node["com"].str()).splitter(' ')) {
 				import std.string : strip;

 				if (word.strip().length > 0)
 					wordTable.require(word, 0)++;

 				records ~= (tuple(word, wordTable[word])); // error
 			}
 		}
 	}

 Now primarily I used `insert()` method to add a record to the 
 records but it causes segfault in runtime. So I decided to use 
 ~= to see what's going on. Here's what the compiler says:

 Error: cannot append type Tuple!(string, uint) to type 
 std.container.rbtree.RedBlackTree!(Tuple!(string, uint), 
 binaryFun, false)


 So the gist of the question is, if I have an RedBlackTree with 
 a custom binaryFun, how can I add tuples to it?

I also tried creating a new type:
		struct Record {
		string k;
		uint v;

		int opCmp(ref const Record other) const {
			return v - other.v;
		}
	}
	
	bool less(Record a, Record b) {
             return a < b;
     }

	RedBlackTree!(Record) records;

	foreach (node; j["posts"].array()) {
		import std.utf : decode;

		if ("com" in node) {
			import std.algorithm : splitter;

			foreach (word; getStr(node["com"].str()).splitter(' ')) {
				import std.string : strip;

				if (word.strip().length > 0)
					wordTable.require(word, 0)++;

				records ~= Record(word, wordTable[word]);
			}
		}
	}

Compiler says:

  Error: cannot append type Record to type 
std.container.rbtree.RedBlackTree!(Recor
d, "a < b", false)
source/app.d(153,18): Error: no [] operator overload for type 
Record
source/app.d(157,58): Error: no [] operator overload for type 
Record
source/app.d(158,40): Error: no [] operator overload for type 
Record

Steven Schveighoffer <schveiguy gmail.com> writes:

On 4/13/20 7:59 PM, Adnan wrote:
 I want to keep an ordered set of records and the standard provides me 
 with RedBlackTree. The record is of type Tuple!(string, uint). Here's 
 what it looks like:
 
 import std.json : parseJSON;
 
      uint[string] wordTable;
      import std.datetime.stopwatch : StopWatch, AutoStart;
 
      auto sw = StopWatch(AutoStart.yes);
      const auto j = parseJSON(get(link));
      const long downloadTime = sw.peek.total!"msecs";
 
      import std.typecons : Tuple, tuple;
      import std.container.rbtree : RedBlackTree;
      import std.functional : binaryFun;

// instead of this:

      RedBlackTree!(Tuple!(string, uint), binaryFun!("a[1] > b[1]")) 
 records;

// do this: (note you don't need binaryFun)
        auto records = new RedBlackTree!(Tuple!(String, uint), "a[1] > 
b[1]");

 
      foreach (node; j["posts"].array()) {
          import std.stdio : writeln;
          import std.utf : decode;
 
          if ("com" in node) {
              import std.algorithm : splitter;
 
              foreach (word; getStr(node["com"].str()).splitter('
')) {
                  import std.string : strip;
 
                  if (word.strip().length > 0)
                      wordTable.require(word, 0)++;
 
                  records ~= (tuple(word, wordTable[word])); //
error
              }
          }
      }
 
 Now primarily I used `insert()` method to add a record to the records 
 but it causes segfault in runtime.

Because RedBlackTree is a class, so you need to initialize it with a 
call to new.

 So I decided to use ~= to see what's 
 going on. Here's what the compiler says:
 
 Error: cannot append type Tuple!(string, uint) to type 
 std.container.rbtree.RedBlackTree!(Tuple!(string, uint), binaryFun, false)

Because RedBlackTree doesn't overload appending.

-Steve