list
====

Scilab object and list function definition



Calling Sequence
~~~~~~~~~~~~~~~~


::

    list(a1,....an)




Description
~~~~~~~~~~~

Creates a `list` with elements `ai`'s which are arbitrary Scilab
objects ( `matrix, list,...`). Type of `list` objects is 15. `list()`
creates the empty `list` (0 element).



Operations on lists
~~~~~~~~~~~~~~~~~~~

:extraction `[x,y,z...]=L(v)` where `v` is a vector of indices;
  `[x,y,z]=L(:)` extracts all the elements.
: :insertion at index i `L(i)=a` (note that it is not an error to use
  `L(i)=a` with *i > 1 + size(L)* but some list entries are then
  undefined and their extraction gives raise to an error).
: :append an element in queue `L($+1)=e`.
: :append an element in head `L(0)=e`. (note that after this operation
  `e` is at index 1, the initial elements being shifted on the right).
: :deletion `L(i)=null()` removes the i-th element of the list `L`.
: :concatenation of two lists `L3 = lstcat(L1,L2)`.
: :number of elements of a list you can use either `nb_elm = size(L)`
  or `nb_elm = length(L)`.
: :iterations with a list it is possible to use a list `L` with a
  `for`_ loop: `for e=L,...,end` is a loop with `length(L)` iterations,
  the loop variable `e` being equal to `L(i)` at the i th iteration.
:



Remarks
~~~~~~~

Scilab provides also other kinds of list, the `tlist`_ type (typed
list) and the `mlist`_ type which are useful to define a new data type
with operator `overloading`_ facilities (`hypermatrices`_ which are
multi-dimensionnal arrays in scilab are in fact *mlist*).

Matlab *struct* are also available.



Examples
~~~~~~~~


::

    l = list(1,["a" "b"])
    l(0) = "foo"
    l($+1) = "hello"
    l(2) = "toto"
    l(3) = `rand`_(1,2)
    l(3) = `null`_()
    lbis = list("gewurtz", "caipirina" ,"debug")
    lter = `lstcat`_(l,lbis)
    `size`_(lter) - `size`_(lbis) - `size`_(l)  // must be zero




See Also
~~~~~~~~


+ `null`_ delete an element in a list
+ `lstcat`_ list concatenation
+ `tlist`_ Scilab object and typed list definition.
+ `mlist`_ Scilab object, matrix oriented typed list definition.
+ `insertion`_ partial variable assignation or modification
+ `extraction`_ matrix and list entry extraction
+ `size`_ size of objects
+ `length`_ length of object


.. _mlist: mlist.html
.. _for: for.html
.. _extraction: extraction.html
.. _size: size.html
.. _length: length.html
.. _insertion: insertion.html
.. _lstcat: lstcat.html
.. _null: null.html
.. _tlist: tlist.html
.. _overloading: overloading.html
.. _hypermatrices: hypermatrices.html