getfield list field extraction

## Syntax

    [x,...] = getfield(i,l)

## Arguments

x

  matrix of any possible types.

l

  `list`, `tlist` or `mlist` variable.

i

  field index, see extraction for more details.

## Description

This function is an equivalent of `[x,...]=l(i)` syntax for field extraction with the only difference that it also applies to `mlist` objects.

## Examples

    l = list(1,'qwerw',%s)
    [a,b] = getfield([3 2],l)

    // Rationals are encoded as t-lists:
    r = [%z/(1-%z) %z^2/(1+%z)]
    type(r)
    [num, den] = getfield([2 3],r)

    // Structures arrays are encoded as M-lists:
    s.r = %pi
    s.b = %t
    s.t = "Scilab"
    s(2).t = "Basile"
    getfield(2,s)==size(s)
    getfield(1,s)(3:5)==fieldnames(s)'
    [r,b,t] = getfield([3 4 5],s)

## See also

- extraction