nv-facutil-fixed-cache-cursor v1.0.2

nv-facutil-fixed-cache-cursor

• mini cache with cursor, its just a array-of-size-8
• same as https://www.npmjs.com/package/nv-facutil-cache-cursor
• for size < 8 using, for performance
• fst,ppprev, pprev, prev, current, next,nnext,nnnext,lst
• forward ,backword, push,pop, push_and_forward ,pop_and_backward

install

• npm install nv-facutil-fixed-cache-cursor

usage

const Cache = require("nv-facutil-fixed-cache-cursor");      

example

    var cache = new Cache()

    /*
    > cache
    Cache(8) [
      undefined, undefined,
      undefined, undefined,
      undefined, undefined,
      undefined, undefined
    ]
    */

    cache.push_and_forward(10)

    /*
    10
    > cache.curr_
    10
    > cache.cursor_
    0
    > cache.length_
    1
    > cache
    Cache(8) [
      10,        undefined,
      undefined, undefined,
      undefined, undefined,
      undefined, undefined
    ]
    >
    */

    cache.push(20)

    /*
    > cache
    Cache(8) [
      10,        20,
      undefined, undefined,
      undefined, undefined,
      undefined, undefined
    ]
    >
    > cache.curr_
    10
    > cache.cursor_
    0
    > cache.length_
    2
    >
    */

    cache.push(30)
    cache.push(40)

    /*
    > cache.cursor_
    0
    > cache.curr_
    10
    > cache.length_
    4
    > cache
    Cache(8) [
      10,        20,
      30,        40,
      undefined, undefined,
      undefined, undefined
    ]
    */

    cache.forward()
    /*

    20
    > cache.curr_
    20
    */

    cache.forward(2)

    /*
    40
    > cache.curr_
    40
    >
    */

    cache.forward()
    cache.forward()
    cache.forward()

    /*
    > cache.curr_
    40
    >
    */

    cache.backward()
    /*
    >
    30
    */

    cache.backward()
    /*
    20
    >
    > cache.curr_
    20
    >
    */


    cache.push(50)
    cache.push(60)
    cache.push(70)
    cache.push(80)

    /*
    > cache
    Cache(8) [
      10, 20, 30, 40,
      50, 60, 70, 80
    ]
    >
    > cache.curr_
    20
    >
    */

    cache.push(100)

    /*
    > cache
    Cache(8) [
      20, 30, 40,  50,
      60, 70, 80, 100
    ]
    > cache.curr_
    30
    >


    */

    cache.forward(6)

    /*

    100
    >
    */

    cache.forward()
    cache.forward()
    cache.forward()
    /*
    100
    >
    */

    cache.pop_and_backward()

    // different behavior from normal pop, it returned current not the popped,
    /*
    > cache.pop_and_backward()
    80
    > cache
    Cache(8) [ 20, 30, 40, 50, 60, 70, 80, undefined ]
    > cache.curr_
    80
    >

    */

    cache.pop_and_backward()
    cache.pop_and_backward()
    cache.pop_and_backward()
    cache.pop_and_backward()

    /*
    > cache.pop_and_backward()
    70
    > cache.pop_and_backward()
    60
    > cache.pop_and_backward()
    50
    > cache.pop_and_backward()
    40
    > cache
    Cache(8) [
      20,        30,
      40,        undefined,
      undefined, undefined,
      undefined, undefined
    ]
    > cache.curr_
    40
    > cache.length_
    3
    >

    */


    cache.pop_and_backward()
    cache.pop_and_backward()
    cache.pop_and_backward()
    /*
    null


    > cache
    Cache(8) [
      undefined, undefined,
      undefined, undefined,
      undefined, undefined,
      undefined, undefined
    ]
    >
    > cache.pop_and_backward()
    already empty
    null
    > cache.curr_
    null
    > cache.length_
    0
    >
    */

    cache.push_and_forward(11)
    cache.push_and_forward(12)
    cache.push_and_forward(13)
    cache.push(14)
    cache.push(15)
    cache.push(16)

    /*
    > cache
    Cache(8) [ 11, 12, 13, 14, 15, 16, undefined, undefined ]
    > cache.curr_
    13
    >

    */
    cache.forward()
    /*
    > cache.forward()
    14
    > cache
    Cache(8) [ 11, 12, 13, 14, 15, 16, undefined, undefined ]
    >

    */

    cache.push(17)
    /*
    > cache
    Cache(8) [ 11, 12, 13, 14, 15, 16, 17, undefined ]
    > cache.curr_
    14
    >

    */

getter : for token-cache using, most language lookahead(3) lookback(3) is enough

    cache.ppprev_
    cache.pprev_
    cache.prev_
    cache.curr_
    cache.next_
    cache.nnext_
    cache.nnnext_


    /*

    > cache.ppprev_
    11
    > cache.pprev_
    12
    > cache.prev_
    13
    > cache.curr_
    14
    > cache.next_
    15
    > cache.nnext_
    16
    > cache.nnnext_
    17
    >
    */

slice

    cache.slice_lt_cursor_
    cache.slice_le_cursor_
    cache.slice_ge_cursor_
    cache.slice_gt_cursor_

    /*
    > cache.slice_lt_cursor_
    [ 11, 12, 13 ]
    >
    > cache.slice_le_cursor_
    [ 11, 12, 13, 14 ]
    >
    > cache.slice_ge_cursor_
    [ 14, 15, 16, 17]
    >
    > cache.slice_gt_cursor_
    [ 15, 16, 17]
    >

    */

clear

    cache.clear()
    /*
    > cache
    Cache(8) [
      undefined, undefined,
      undefined, undefined,
      undefined, undefined,
      undefined, undefined
    ]
    >

    */

forbidden, for safe

    > cache.shift()
    Uncaught 'unreachable'
    > cache.splice()
    Uncaught 'unreachable'
    >
    > cache.unshift()
    Uncaught 'unreachable'
    >

METHODS

    cache.b                        cache.backward                 cache.can_backward_max_steps_
    cache.can_forward_max_steps_   cache.clear                    cache.constructor
    cache.curr_                    cache.cursor_                  cache.f
    cache.forward                  cache.fst_                     cache.is_cant_backward_one
    cache.is_cant_forward_one      cache.is_cursor_at_max         cache.is_cursor_at_min
    cache.is_empty                 cache.length_                  cache.lst_
    cache.max_cursor_              cache.min_cursor_              cache.next_
    cache.nnext_                   cache.nnnext_                  cache.pop
    cache.pop_and_backward         cache.pop_one                  cache.ppprev_
    cache.pprev_                   cache.prev_                    cache.push
    cache.push_and_forward         cache.push_index_              cache.safe_pop
    cache.shift                    cache.slice_ge_cursor_         cache.slice_gt_cursor_
    cache.slice_le_cursor_         cache.slice_lt_cursor_         cache.splice
    cache.unshift

APIS

• Cache._push
• Cache._copy

LICENSE

• ISC