Replace boost range by header only dependency.

This removes boost as an dependency from our code and makes our project
again only dependent on C++11 compilers (no external dependency).

NOTES.md

@@ -4,6 +4,14 @@ A collection of stuff that we noticed during development.
 Useful later on two write a project report and to go back
 in time to find out why certain decisions where made.
 
+## 14.06.2019 - Range Class
+
+For iterating on integers (e.g. from 0 to 10) a translation from
+integers to iterators on them is necessary.
+Instead of rolling out our own implementation we found a
+[standalone header file](https://bitbucket.org/AraK/range/src/default/)
+that we will use for now to not have the boilerplate work.
+
 ## 11.06.2019 - Parallel Scan
 
 Our parallel scan is oriented on the

lib/pls/CMakeLists.txt

@@ -31,14 +31,14 @@ add_library(pls STATIC
         include/pls/internal/helpers/profiler.h
         include/pls/internal/helpers/mini_benchmark.h
         include/pls/internal/helpers/unique_id.h
+        include/pls/internal/helpers/range.h
 
         include/pls/internal/scheduling/thread_state.h
         include/pls/internal/scheduling/scheduler.h src/internal/scheduling/scheduler.cpp
         include/pls/internal/scheduling/scheduler_impl.h
         include/pls/internal/scheduling/task.h src/internal/scheduling/task.cpp
         include/pls/internal/scheduling/scheduler_memory.h src/internal/scheduling/scheduler_memory.cpp
-        include/pls/internal/scheduling/lambda_task.h include/pls/internal/data_structures/deque.h
-        )
+        include/pls/internal/scheduling/lambda_task.h include/pls/internal/data_structures/deque.h)
 # Add everything in `./include` to be in the include path of this project
 target_include_directories(pls
         PUBLIC

lib/pls/include/pls/algorithms/for_each.h

@@ -6,7 +6,7 @@ namespace pls {
 namespace algorithm {
 
 template<typename Function>
-void for_each_range(size_t first, size_t last, const Function &function);
+void for_each_range(unsigned long first, unsigned long last, const Function &function);
 
 template<typename RandomIt, typename Function>
 void for_each(RandomIt first, RandomIt last, const Function &function);

lib/pls/include/pls/algorithms/for_each_impl.h

@@ -6,9 +6,7 @@
 #include "pls/internal/scheduling/scheduler.h"
 
 #include "pls/internal/helpers/unique_id.h"
-
-// TODO: Replace with own integer iterator to remove dependency
-#include <boost/range/irange.hpp>
+#include "pls/internal/helpers/range.h"
 
 namespace pls {
 namespace algorithm {
@@ -44,8 +42,8 @@ void for_each(RandomIt first, RandomIt last, const Function &function) {
 }
 
 template<typename Function>
-void for_each_range(size_t first, size_t last, const Function &function) {
-  auto range = boost::irange(first, last);
+void for_each_range(unsigned long first, unsigned long last, const Function &function) {
+  auto range = pls::internal::helpers::range(first, last);
   internal::for_each(range.begin(), range.end(), function);
 }
 

lib/pls/include/pls/internal/helpers/RANGE_LICENSE.txt

+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

lib/pls/include/pls/internal/helpers/range.h

+/*
+                Range
+                =====
+
+    Copyright (c) 2009-2011 Khaled Alshaya
+
+    Distributed under the Boost Software License, version 1.0
+    (See the license at: http://www.boost.org/license_1_0.txt).
+*/
+
+/*
+                Rationale
+                =========
+
+    In Python, there is a beautiful function called "range".
+    "range" allows the programmer to iterate over a range elegantly.
+    This concept is not as general as "for-loops" in C++,
+    but non the less, it expresses the intent of the programmer
+    clearer than the general "for-loops" in many cases.
+
+
+                Design
+                ======
+
+    Range is made to be STL-like library. In fact, it is 
+    built on top of the concepts of STL. The library is designed to
+    work with STL algorithms as well. Range is more flexible
+    than the Python "range", because:
+    
+    Range is an "immutable ordered random access container"
+
+
+                Specifications
+                ==============
+
+    Range satisfies the following requirements:
+
+        * Immutable.
+        * Random Access Container.
+        * Random Access Iterator Interface.
+        * Constant Time Complexity Operations.
+
+
+    Range models an ordered sequence of elements,
+    where a range is defined by:
+
+        [begin, end)
+
+        * begin: the first element in the range. (Inclusive)
+        * end  : the last element in the range.  (Exclusive)
+        * step : the distance between two consecutive elements in a range.
+
+        where each element in the range is defined by:
+
+        element = begin + step * i
+
+        * i: is the index of the element in range.
+
+        The following precondition must be met for the sequence
+        to be a valid range:
+
+            step != 0
+            &&
+            (    
+                begin <= end && step > 0
+                ||
+                begin >= end && step < 0
+            )
+
+
+                Portability
+                ===========
+
+    Range Generator is written in standard C++ (C++98). It depends
+    -only- on the standard C++ library.
+*/
+
+// TODO: See if we should swap this out for our own implementation, for now this is fine, as it is self contained.
+/**
+ * Notes on Modification:
+ * The code was adpated to fit into our namespacing/naming scheme for simpler use.
+ * This includes ifdef's, namespace and code formatting style.
+ */
+
+#ifndef PLS_range_h__
+#define PLS_range_h__
+
+#include <iterator>
+#include <stdexcept>
+#include <cstddef>
+#include <cmath>
+
+namespace pls {
+namespace internal {
+namespace helpers {
+
+template<class IntegerType>
+struct basic_range {
+  struct const_iterator_impl {
+    typedef IntegerType value_type;
+    typedef std::size_t size_type;
+    typedef IntegerType difference_type;
+    typedef value_type *pointer;
+    typedef value_type &reference;
+    typedef
+    std::random_access_iterator_tag
+        iterator_category;
+
+    const_iterator_impl() : r(0), index(0) {}
+
+    const_iterator_impl(const const_iterator_impl &rhs)
+        : r(rhs.r), index(rhs.index) {}
+
+    const_iterator_impl(basic_range<IntegerType> const *p_range, size_type p_index)
+        : r(p_range), index(p_index) {}
+
+    const_iterator_impl &operator=(const const_iterator_impl &rhs) {
+      r = rhs.r;
+      index = rhs.index;
+      return *this;
+    }
+
+    bool operator==(const const_iterator_impl &rhs) const {
+      return *r == *(rhs.r) && index == rhs.index;
+    }
+
+    bool operator!=(const const_iterator_impl &rhs) const {
+      return !(*this == rhs);
+    }
+
+    bool operator<(const const_iterator_impl &rhs) const {
+      return index < rhs.index;
+    }
+
+    bool operator>(const const_iterator_impl &rhs) const {
+      return index > rhs.index;
+    }
+
+    bool operator<=(const const_iterator_impl &rhs) const {
+      return index <= rhs.index;
+    }
+
+    bool operator>=(const const_iterator_impl &rhs) const {
+      return index >= rhs.index;
+    }
+
+    value_type operator*() const {
+      return r->m_first_element + r->m_step * index;
+    }
+
+    // operator->
+    // is not implemented because the value_type is an integer type
+    // and primitive types in C++ don't define member functions.
+
+    const_iterator_impl &operator++() {
+      ++index;
+      return *this;
+    }
+
+    const_iterator_impl operator++(int) {
+      const_iterator_impl temp = *this;
+      ++index;
+      return temp;
+    }
+
+    const_iterator_impl &operator--() {
+      --index;
+      return *this;
+    }
+
+    const_iterator_impl operator--(int) {
+      const_iterator_impl temp = *this;
+      --index;
+      return temp;
+    }
+
+    const_iterator_impl &operator+=(difference_type increment) {
+      index += increment;
+      return *this;
+    }
+
+    // operator+
+    // is friend operator but operator-
+    // is not, because we want to allow the following for "+":
+    // iterator+5
+    // 5+iterator
+    // For the "-" it is not correct to do so, because
+    // iterator-5 != 5-iterator
+    friend const_iterator_impl operator+
+        (const const_iterator_impl &lhs, difference_type increment) {
+      const_iterator_impl sum;
+      sum.r = lhs.r;
+      sum.index = lhs.index + increment;
+      return sum;
+    }
+
+    const_iterator_impl &operator-=(difference_type decrement) {
+      index -= decrement;
+      return *this;
+    }
+
+    const_iterator_impl operator-(difference_type decrement) const {
+      const_iterator_impl shifted_iterator;
+      shifted_iterator.r = r;
+      shifted_iterator.index = index - decrement;
+      return shifted_iterator;
+    }
+
+    difference_type operator-(const const_iterator_impl &rhs) const {
+      return index - rhs.index;
+    }
+
+    value_type operator[](difference_type offset) const {
+      size_type new_index = index + offset;
+      return r->m_first_element + r->m_step * new_index;
+    }
+
+   private:
+    basic_range<IntegerType> const *r;
+    size_type index;
+  };
+
+  struct const_reverse_iterator_impl {
+    typedef IntegerType value_type;
+    typedef std::size_t size_type;
+    typedef IntegerType difference_type;
+    typedef value_type *pointer;
+    typedef value_type &reference;
+    typedef
+    std::random_access_iterator_tag
+        iterator_category;
+
+    const_reverse_iterator_impl() : r(0), index(0) {}
+
+    const_reverse_iterator_impl(const const_reverse_iterator_impl &rhs)
+        : r(rhs.r), index(rhs.index) {}
+
+    const_reverse_iterator_impl(basic_range<IntegerType> const *p_range, size_type p_index)
+        : r(p_range), index(p_index) {}
+
+    const_reverse_iterator_impl &operator=(const const_reverse_iterator_impl &rhs) {
+      r = rhs.r;
+      index = rhs.index;
+      return *this;
+    }
+
+    bool operator==(const const_reverse_iterator_impl &rhs) const {
+      return *r == *(rhs.r) && index == rhs.index;
+    }
+
+    bool operator!=(const const_reverse_iterator_impl &rhs) const {
+      return !(*this == rhs);
+    }
+
+    bool operator<(const const_reverse_iterator_impl &rhs) const {
+      return index < rhs.index;
+    }
+
+    bool operator>(const const_reverse_iterator_impl &rhs) const {
+      return index > rhs.index;
+    }
+
+    bool operator<=(const const_reverse_iterator_impl &rhs) const {
+      return index <= rhs.index;
+    }
+
+    bool operator>=(const const_reverse_iterator_impl &rhs) const {
+      return index >= rhs.index;
+    }
+
+    value_type operator*() const {
+      size_type reverse_index
+          = (r->m_element_count - 1) - index;
+      return r->m_first_element + r->m_step * reverse_index;
+    }
+
+    // operator->
+    // is not implemented because the value_type is integer type
+    // and primitive types in C++ don't define member functions.
+
+    const_reverse_iterator_impl &operator++() {
+      ++index;
+      return *this;
+    }
+
+    const_reverse_iterator_impl operator++(int) {
+      const_reverse_iterator_impl temp = *this;
+      ++index;
+      return temp;
+    }
+
+    const_reverse_iterator_impl &operator--() {
+      --index;
+      return *this;
+    }
+
+    const_reverse_iterator_impl operator--(int) {
+      const_reverse_iterator_impl temp = *this;
+      --index;
+      return temp;
+    }
+
+    const_reverse_iterator_impl &operator+=(difference_type increment) {
+      index += increment;
+      return *this;
+    }
+
+    // operator+
+    // is friend operator but operator-
+    // is not, because we want to allow the following for "+":
+    // iterator+5
+    // 5+iterator
+    // For the "-" it is not correct to do so, because
+    // iterator-5 != 5-iterator
+    friend const_reverse_iterator_impl operator+
+        (const const_reverse_iterator_impl &lhs, difference_type increment) {
+      const_reverse_iterator_impl sum;
+      sum.r = lhs.r;
+      sum.index = lhs.index + increment;
+      return sum;
+    }
+
+    const_reverse_iterator_impl &operator-=(difference_type decrement) {
+      index -= decrement;
+      return *this;
+    }
+
+    const_reverse_iterator_impl operator-(difference_type decrement) const {
+      const_reverse_iterator_impl shifted_iterator;
+      shifted_iterator.r = r;
+      shifted_iterator.index = index - decrement;
+      return shifted_iterator;
+    }
+
+    difference_type operator-(const const_reverse_iterator_impl &rhs) const {
+      return index - rhs.index;
+    }
+
+    value_type operator[](difference_type offset) const {
+      size_type new_reverse_index
+          = (r->m_element_count - 1) - (index + offset);
+      return r->m_first_element + r->m_step * new_reverse_index;
+    }
+
+   private:
+    basic_range<IntegerType> const *r;
+    size_type index;
+  };
+
+  typedef IntegerType value_type;
+  typedef const_iterator_impl iterator;
+  typedef const_iterator_impl const_iterator;
+  typedef const_reverse_iterator_impl reverse_iterator;
+  typedef const_reverse_iterator_impl const_reverse_iterator;
+  typedef value_type &reference;
+  typedef const value_type &const_reference;
+  typedef value_type *pointer;
+  typedef IntegerType difference_type;
+  typedef std::size_t size_type;
+
+  // In the case of default construction,
+  // the range is considered as an empty range with no elements.
+  // step can be anything other than 0. 1 is
+  // an implementation convention, and it doesn't have
+  // a significance in this case because the range is empty.
+  basic_range() : m_first_element(0), m_element_count(0), m_step(1) {}
+
+  // first_element: is begin in specifications.
+  // last_element: is end in specifications.
+  basic_range(value_type first_element, value_type last_element, value_type step)
+      : m_first_element(first_element),
+        m_step(step) {
+    // We need to count the number of elements.
+    // The only case where a range is invalid,
+    // when the step=0. It means that the range
+    // is infinite, because the number of elements
+    // in a range, is the length of that range
+    // divided by the difference between
+    // every two successive elements.
+
+    if (step == 0)
+      throw std::out_of_range("Invalid Range: step can't be equal to zero!");
+    if (first_element < last_element && step < 0)
+      throw std::out_of_range("Invalid Range: step can't be backward, while the range is forward!");
+    if (first_element > last_element && step > 0)
+      throw std::out_of_range("Invalid Range: step can't be forward, while the range is backward!");
+
+    m_element_count = (last_element - first_element) / step;
+    if ((last_element - first_element) % step != 0)
+      ++m_element_count;
+  }
+
+  // The following constructor, determines the step
+  // automatically. If the range is forward, then
+  // step will be one. If the range is backward,
+  // step will be minus one. If the begin is equal
+  // to end, then the step must not equal to zero
+  // and it is set to one as a convention.
+  basic_range(value_type first_element, value_type last_element)
+      : m_first_element(first_element) {
+    if (last_element >= first_element) *this = basic_range<IntegerType>(first_element, last_element, 1);
+    else *this = basic_range<IntegerType>(first_element, last_element, -1);
+
+  }
+
+  // The following constructor is a shortcut
+  // if you want the first element as zero.
+  // the step is determined automatically, based
+  // on the last element. If the last element is
+  // positive, then step is one, but if it is negative
+  // then step is minus one.
+  basic_range<IntegerType>(value_type last_element)
+      : m_first_element(0) {
+    if (last_element >= m_first_element) *this = basic_range<IntegerType>(m_first_element, last_element, 1);
+    else *this = basic_range<IntegerType>(m_first_element, last_element, -1);
+  }
+
+  basic_range<IntegerType>(const basic_range<IntegerType> &r)
+      : m_first_element(r.m_first_element),
+        m_element_count(r.m_element_count),
+        m_step(r.m_step) {}
+
+  basic_range<IntegerType> &operator=(const basic_range<IntegerType> &r) {
+    m_first_element = r.m_first_element;
+    m_element_count = r.m_element_count;
+    m_step = r.m_step;
+
+    return *this;
+  }
+
+  bool operator==(const basic_range<IntegerType> &r) const {
+    return m_first_element == r.m_first_element
+        &&
+            m_element_count == r.m_element_count
+        &&
+            m_step == r.m_step;
+  }
+
+  bool operator!=(const basic_range<IntegerType> &r) const {
+    return !(*this == r);
+  }
+
+  // The following four functions enable the user to compare
+  // ranges using ( <, >, <=, >=).
+  // The comparison between two ranges is a simple lexicographical
+  // comparison(element by element). By convention, if two ranges
+  // R1, R2 where R1 has a smaller number of elements. Then if
+  // R1 contains more elements but all R1 elements are found in R2
+  // R1 is considered less than R2.
+  bool operator<(const basic_range<IntegerType> &r) const {
+    // ********** This function needs refactoring.
+
+    if (m_element_count == 0 && r.m_element_count == 0)
+      return false;
+    if (m_element_count == 0 && r.m_element_count > 0)
+      return true;
+    if (m_element_count > 0 && r.m_element_count == 0)
+      return false;
+
+    // At this point, both has at least one element.
+    if (m_first_element < r.m_first_element)
+      return true;
+    if (m_first_element > r.m_first_element)
+      return false;
+
+    // At this point, the first element of both are equal.
+    if (m_element_count == 1 && r.m_element_count == 1)
+      return false;
+    if (m_element_count == 1 && r.m_element_count > 1)
+      return true;
+    if (m_element_count > 1 && r.m_element_count == 1)
+      return false;
+
+    // At this point, both have at least two elements with
+    // a similar first element. Note than the final answer
+    // in this case depends on the second element only, because
+    // we don't need to compare the elements further.
+    // Note that the second element is at (index == 1), because
+    // the first element is at (index == 0).
+    if (m_first_element + m_step * 1 < r.m_first_element + r.m_step * 1)
+      return true;
+    if (m_first_element + m_step * 1 > r.m_first_element + r.m_step * 1)
+      return false;
+
+    // if the first two elements of both ranges are equal, then
+    // they are co-linear ranges(because the step is constant).
+    // In that case, they comparison depends only on
+    // the size of the ranges by convention.
+    return m_element_count < r.m_element_count;
+  }
+
+  bool operator>(const basic_range<IntegerType> &r) const {
+    // ********** This function needs refactoring.
+
+    if (m_element_count == 0 && r.m_element_count == 0)
+      return false;
+    if (m_element_count == 0 && r.m_element_count > 0)
+      return false;
+    if (m_element_count > 0 && r.m_element_count == 0)
+      return true;
+
+    // At this point, both has at least one element.
+    if (m_first_element < r.m_first_element)
+      return false;
+    if (m_first_element > r.m_first_element)
+      return true;
+
+    // At this point, the first element of both are equal.
+    if (m_element_count == 1 && r.m_element_count == 1)
+      return false;
+    if (m_element_count == 1 && r.m_element_count > 1)
+      return false;
+    if (m_element_count > 1 && r.m_element_count == 1)
+      return true;
+
+    // At this point, both have at least two elements with
+    // a similar first element. Note than the final answer
+    // in this case depends on the second element only, because
+    // we don't need to compare the elements further.
+    // Note that the second element is at (index == 1), because
+    // the first element is at (index == 0).
+    if (m_first_element + m_step * 1 < r.m_first_element + r.m_step * 1)
+      return false;
+    if (m_first_element + m_step * 1 > r.m_first_element + r.m_step * 1)
+      return true;
+
+    // if the first two elements of both ranges are equal, then
+    // they are co-linear ranges(because the step is constant).
+    // In that case, they comparison depends only on
+    // the size of the ranges by convention.
+    return m_element_count > r.m_element_count;
+  }
+
+  bool operator<=(const basic_range<IntegerType> &r) const {
+    return !(*this > r);
+  }
+
+  bool operator>=(const basic_range<IntegerType> &r) const {
+    return !(*this < r);
+  }
+
+  const_iterator begin() const {
+    return const_iterator(this, 0);
+  }
+
+  const_iterator end() const {
+    return const_iterator(this, m_element_count);
+  }
+
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(this, 0);
+  }
+
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(this, m_element_count);
+  }
+
+  size_type size() const {
+    return m_element_count;
+  }
+
+  size_type max_size() const {
+    // Because this is an immutable container,
+    // max_size() == size()
+    return m_element_count;
+  }
+
+  bool empty() const {
+    return m_element_count == 0;
+  }
+
+  // exist() and find() are similar except that
+  // find() returns the index of the element.
+  iterator find(value_type element) const {
+    value_type element_index = (element - m_first_element) / m_step;
+    bool in_range = element_index >= 0 && element_index < m_element_count &&
+        (element - m_first_element) % m_step == 0;
+    if (in_range)
+      return begin() + element_index;
+    return end();
+  }
+
+  bool exist(value_type element) const {
+    return find(element) != end();
+  }
+
+  // In the standard, the operator[]
+  // should return a const reference.
+  // Because Range Generator doesn't store its elements
+  // internally, we return a copy of the value.
+  // In any case, this doesn't affect the semantics of the operator.
+  value_type operator[](size_type index) const {
+    return m_first_element + m_step * index;
+  }
+
+ private:
+  // m_first_element: begin (see specifications).
+  // m_element_count: (end - begin) / step
+  value_type m_first_element, m_element_count, m_step;
+};
+
+// This is the default type of range!
+typedef basic_range<int> range;
+}
+}
+}
+
+#endif // range_h__