GitHub - melaniew/underscore_cpp: underscore

Inspired by underscore.js

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Implementation of

each
transform
filter_accept
filter_reject
find_if
find_if_not
every
count_by
contains
max
min
intersect
union
size

Setup

Clone the project using git clone https://github.com/farziengineer/underscore_cpp
To run the project you can individually compile the files(.cpp) and link them, or just run the bash file runn.sh using bash runn.sh (on Linux).

Usage

each

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {1, 2, 3};

_::each(vec, display);

Output: 1 2 3

transform

int increment_by_one(int x)
{
   return x + 1;
}

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {1, 2, 3}; 
_::transform(vec, increment_by_one);
_::each(vec, display);

Output: 2 3 4

filter_accept

int is_odd(int x)
{
   return x % 2 == 1;
}

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {1, 2, 3}; 
std::vector<int> res = _::filter_accept(vec, is_odd);
_::each(res, display);

Output: 1 3

filter_reject

int is_odd(int x)
{
   return x % 2 == 1;
}

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {1, 2, 3}; 
std::vector<int> res = _::filter_reject(vec, is_odd);
_::each(res, display);

Output: 2

find_if

int is_odd(int x)
{
   return x % 2 == 1;
}

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {2, 4, 5}; 
int index = _::find_if(vec, is_odd) - vec.begin();
std::cout << vec[index];

Output: 5

find_if_not

int is_odd(int x)
{
   return x % 2 == 1;
}

void display(int x)
{
   cout << x << " ";
}

std::vector<int> vec = {1, 2, 4, 5}; 
int index = _::find_if_not(vec, is_odd) - vec.begin();
std::cout << vec[index];

Output: 2 (returns first index where the container value returns a false over predicate)

every

int is_odd(int x)
{
   return x % 2 == 1;
}

std::vector<int> vec = {3, 7, 5}; 
std:: cout <<< _::every(vec, is_odd) << std::endl;

Output: true (returns true if every container element return true over predicate)

any

int is_odd(int x)
{
   return x % 2 == 1;
}

std::vector<int> vec = {2, 4, 5}; 
std:: cout <<< _::any(vec, is_odd)<< std::endl;

Output: true (returns true if any container element return true over predicate)

count_by

int is_odd(int x)
{
   return x % 2 == 1;
}

std::vector<int> vec = {2, 4, 5}; 
std:: cout << _::count_by(vec, is_odd) << std::endl;

Output: 2 (counts occurrences where the container returns true over predicate. Here the predicate is is_odd)

contains

std::vector<int> vec = {2, 4, 5}; 
std:: cout <<< _::contains(vec, 9)<< std::endl;

Output: false (returns true if any container element return true over predicate)

max

std::vector<int> vec = {2, 4, 5}; 
std:: cout << _::max(vec)<< std::endl;