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https://github.com/siffiejoe/lua-table.n

Clone of Lua's table library that uses '.n'.
https://github.com/siffiejoe/lua-table.n

lua lua-table

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Clone of Lua's table library that uses '.n'.

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README 

        
#            table.n -- Alternative Table Library for Lua            #



Lua doesn't have a native array type. Instead it uses the concept of

"sequences" (tables containing small consecutive integer keys with

non-`nil` values) to represent arrays. One drawback is that it is

difficult to check whether a table is a valid sequence (and neither

the length operator `#` nor the default `table` library do check), and

this may lead to surprising bugs. This module is a drop-in replacement

of the default table library that doesn't use sequences or the `#`

operator, but instead requires you to explicitly set and maintain a

length field `n` in your arrays (the functions in this module will

update `n` for you, though).



##                            Extensions                            ##



This module additionally contains some useful table-related functions

that are not part of the original `table` standard library.



*   `table.replace(t1 [, i [, j]], t2 [, m [, n]])`



    Replaces the elements with indices `i, ..., j` in `t1` with the

    elements `t2[m], ..., t2[n]`. If the two ranges have a different

    number of indices, the following elements in `t1` are shifted

    to make room or fill the gap, and `t1.n` is updated accordingly.

    The default value for `i` is `t1.n+1` (which results in appending

    to `t1`), `j` defaults to `t1.n`. Default values for `m` and `n`

    are `1` and `t2.n`, respectively.



*   `table.zip(f, t1, ...)`



    Iterates over all indices from `1` to `n` (where `n` is the

    smallest integer value of the `.n` fields of all argument tables)

    and calls the function `f` with `(t1[i], t2[i], etc.)` as

    arguments. All return values of these function calls are appended

    to a result array that is returned at the end. If `f` is `nil`,

    `table.pack` is used as a default which results in the usual

    behavior of the `zip` function known from other programming

    languages:



    ```lua

    table.zip( nil, { 1, 2, 3, n=3 }, { "a", "b", "c", n=3 } )

    --> { { 1, "a", n=2 }, { 2, "b", n=2 }, { 3, "c", n=2 }, n=3 }

    ```



    However, with a suitable choice of `f` you can for instance

    interleave values



    ```lua

    local function id( ... ) return ... end

    table.zip( id, { 1, 2, 3, n=3 }, { "a", "b", "c", n=3 } )

    --> { 1, "a", 2, "b", 3, "c", n=6 }

    ```



    or emulate the well-known `map` or `filter` functions:



    ```lua

    local function plus3( a ) return a + 3 end

    table.zip( plus3, { 1, 2, 3, n=3 } )

    --> { 4, 5, 6, n=3 }

    local function not_nil( a )

      if a ~= nil then return a end

    end

    table.zip( not_nil, { 1, nil, 2, 3, nil, 4, n=6 } )

    --> { 1, 2, 3, 4, n=4 }

    ```



*   `table.npairs(t [, i])` (or `npairs(t [, i])`)



    Returns an iterator tuple that, when used in a generic `for`-loop,

    iterates over the pairs `(1, t[1])`, `(2, t[2])`, ..., until the

    index reaches `t.n`. You may specify a starting index different

    from `1`. For convenience and consistency the `npairs` function is

    also available in the globals table.



*   `table.reverse(t [, i [, j]])`



    Reverses the elements between indices `i` and `j` in table `t`

    inplace. `i` and `j` default to `1` and `t.n`, respectively.



*   `table.rotate(t, m [, i [, j]])`



    Shifts the elements between indices `i` and `j` in table `t` `m`

    positions to the right. Elements that are shifted beyond `j` are

    reinserted at `i`. `m` may be negative to rotate in the other

    direction. Default values for `i` and `j` are `1` and `t.n`,

    respectively.



*   `table.shuffle(t [, i [, j]])`



    Randomly reorders the elements between indices `i` and `j` in

    table `t`.



##                           Installation                           ##



    luarocks install --server=http://luarocks.org/dev table.n



If you want to install manually: Compile the file `ltablib.c` into a

shared library `table\n.dll` or `table/n.so` and put it somewhere into

your `package.cpath`.



##                             Contact                              ##



Philipp Janda, siffiejoe(a)gmx.net



Comments and feedback are always welcome.



##                             License                              ##



**table.n** is a slightly modified copy of the table library in Lua

5.3 and as such is distributed under the same license (MIT). The full

license text follows:



    Copyright (C) 1994-2016 Lua.org, PUC-Rio.



    Permission is hereby granted, free of charge, to any person obtaining

    a copy of this software and associated documentation files (the

    "Software"), to deal in the Software without restriction, including

    without limitation the rights to use, copy, modify, merge, publish,

    distribute, sublicense, and/or sell copies of the Software, and to

    permit persons to whom the Software is furnished to do so, subject to

    the following conditions:



    The above copyright notice and this permission notice shall be

    included in all copies or substantial portions of the Software.



    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 AND NONINFRINGEMENT.

    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.



This module also uses code from the [Compat-5.3][1] project, which is

available under the same license (MIT).



  [1]: https://github.com/keplerproject/lua-compat-5.3