dataPulverizer

Introduction

Compile time sequences in D are insane, not insane "crazy" but insanely interesting. One of the selling points of D is that it takes compile time programming in C++ to another level, where templates in C++ were a 'happy?' accident, in D they were purposely built into the language along with other generic and meta-programming tools. To highlight this aspect of the D language, we will implement a selection of templates to manipulate compile time sequences of types, only the text function from the standard library in the std.conv module will be imported which is for concatenating text, we will build everything else including AliasSeq and Nothing from the std.meta module which they are easy one-liners.

This article builds on the concepts of a

dataPulverizer

use CPtr;
use Math;

record DotProduct {
  type T;
  proc kernel(xrow:c_ptr, yrow:c_ptr(?T), p: int): T
  {
    var ret: T = 0: T;
    for i in 0..#p {
      ret += xrow[i] * yrow[i];

dataPulverizer

#[
  Byte order functions for Nim intendend for 2, 4, 6, 8, 16 - byte basic types
]#

#[ Basic functions for in-place reversing bytes 2, 4, 6, 8, 16 ]#
proc reverse2(x: var array[0..1, byte]): void {.inline.} =
  var tmp: byte = x[0];
  x[0] = x[1];
  x[1] = tmp;

dataPulverizer

/*
  Basic use of std.parallelism in D to play with it before 
  using it in my library.
*/
import std.parallelism;
import std.random : Mt19937_64, unpredictableSeed, uniform01;
import std.math : exp, log;
import std.range : iota;
import std.array: array;
import std.stdio: writeln;

dataPulverizer

# Write binary file
function write_bin(x::Array{T, 1}, fileName::String)::Int64 where T
  
  # Open the file
  io = open(fileName,"w")
  
  # Cast this number to make sure we know its type
  write(io, Int64(size(x)[1]))

  # Get the type as a string

dataPulverizer

#=
  Notes on Regular expressions in Julia:
  Sources:
          Regular Expressions Cookbook, Jan Goyvaerts & Steven Levithan.
          https://www.regular-expressions.info/wordboundaries.html
          https://www.regular-expressions.info/lookaround.html
          http://www.rexegg.com/regex-disambiguation.html
          Julialang Gitter Chat.
=#

dataPulverizer

# Delegates in Julia
function makeFun(x::Float64)
  return y::Float64 -> y^2 + x^2
end

ff = makeFun(4.0)
# (generic function with 1 method)

ff(5.0)
# 41.0

dataPulverizer

#==
  Feature wish list for julia in no particular order:
==#

"1. Immutable members of mutable types, something like:"
mutable struct myType
  immutable x::Int64 # to break all that old code! :-)
end