cl-ellipsis

Ellipsis DSL for node, construct something like a1,a2, ..., an

install

npm i cl-ellipsis --save

usage

expand number list

Expand a list by writing ellipsis.

• normaly

1, 2, ..., 5 => 1, 2, 3, 4, 5

2, ..., 5 => 2, 3, 4, 5

2, 4, ..., 7 => 2, 4, 6, 7

• only consider at most two elements before ellipsis

-10, 1, 2, ..., 5 => -10, 1, 2, 3, 4, 5

-10, 2, 4, ..., 7 => -10, 2, 4, 6, 7

• code example

let pattern = require('cl-ellipsis');
let expand = pattern.expand;

let t1 = expand([1, 2, 3, '...', 9]); 
console.log(t1);// [1, 2, 3, 4, 5, 6, 7, 8, 9]

let t2 = expand([1, 4, 2, '...', -3]);
console.log(t2);// [1, 4, 2, 0, -2, -3]

• you can use more than one ellipsises

You can use more than one ellipsises in one array, the ellipsises will be reduced one by one.

4, 6, ..., 9, ..., 12 => 4, 6, 8, 9, ..., 12 => 4, 6, 8, 9, 10, 11, 12

code example

let pattern = require('cl-ellipsis');
let expand = pattern.expand;

let t1 = expand([4, 6, '...', 9, '...', 12]); 
console.log(t1);// [4, 6, 8, 9, 10, 11, 12]

• you can just use string instead of array

let pattern = require('cl-ellipsis');

let ret = expand('1 2 ... 6');
console.log(ret); // [1, 2, 3, 4, 5, 6]

• you can mix array

let pattern = require('cl-ellipsis');
let expand = pattern.expand;

let t1 = expand(['a', null, 6, '...', 9]); 
console.log(t1);// ['a', null, 7, 8, 9]

expand array

It's almost the same with number list, but point out which array. See the code:

let pattern = require('cl-ellipsis');
let expand = pattern.expand;

let A = [3, 5, 2, 9, 0, 20, 38, -1, -20];
let ret = expand([-1, tagList([2, 4, '...', 7], A), 9]);
console.log(ret); // [-1, 2, 0, 38, -1, 9]

reduce

• example

let pattern = require('cl-ellipsis');

let E = pattern.E;

let add = (a, b) => a + b;

let ret = E(add, [1, 2, 4, '...', 9]);
console.log(ret); // 30

In the code, E(add, [1, 2, 4, '...', 9]) means 1 + 2 + 4 + ... + 9

E(add, [1, 2, 4, '...', 9]), first, expand [1, 2, 4, '...', 9], then use add operation on the list.