@onlabsorg/swan-js/docs/modules/list.md

A simple yet powerful expression language written in JavaScript

list module
============================================================================
This module contains functions for manipulating List items.
Unless specified otherwise, all the functions of this library assume that
their parameter is an item (1-d tuple). If more that one item is passed
to a function, only the first item will be used and the others will be
ignored.
  
`list.size: List l -> Numb n`
------------------------------------------------------------------------
Returns the number of items contained in a List item or `Undefined Number`
if the argument is not a List item. If the argument is a tuple, it
applies only to its first item.
  
`list.reverse: List l1 -> List l2`
------------------------------------------------------------------------
Given a list l1, returns a new list l2, containing the items of l1 in
reversed order.
If the argument is not a List item, this function returns Undefined List.
If the parameter is a tuple, this function applies only to the first
item and ignores the others.
  
`list.find: Item x -> List L -> Numb k`
------------------------------------------------------------------------
Takes an item `x` as argument and returns a function `f`. If the
argument is a tuple, it applies only to its first item.
The returned function `f`:
- takes a list `L` as argument and returns the first position of `x` in
  `L` or `-1` if `x` is not contained in `L`.
- returns Undefined List if the argument of `f` is not a List item
- applies only on the first item if the parameter of `f` is a tuple
  
`list.rfind: Item x -> List L -> Numb k`
------------------------------------------------------------------------
Takes an item `x` as argument and returns a function `f`.
If the argument is a tuple, it applies only to its first item.
The returned function `f`:
- takes a list `L` as argument and returns the last position of `x` in
  `L` or `-1` if `x` is not contained in `L`.
- returns Undefined List if the argument of `f` is not a List item
- applies only on the first item if the parameter of `f` is a tuple
  
`list.head: Numb n -> List L -> List l`
------------------------------------------------------------------------
Takes a number `n` as argument and returns a function `f`.
If the argument is a tuple, it applies only to its first item.
The returned function `f`:
- takes a list `L` as argument and returns the sub-list at the left-side
  of the n-th item. If n is negative, the item position is computed as
  relative to the end of `L`.
- returns Undefined List if the argument of `f` is not a List item
- applies only on the first item if the parameter of `f` is a tuple
  
`list.tail: Numb n -> List L -> List l`
------------------------------------------------------------------------
Takes a number `n` as argument and returns a function `f`.
If the argument is a tuple, it applies only to its first item.
The returned function `f`:
- takes a list `L` as argument and returns the sub-list at the
  right-side of the n-th item (including the latter). If n is negative,
  the item position is computed as relative to the end of `L`.
- returns Undefined List if the argument of `f` is not a List item
- applies only on the first item if the parameter of `f` is a tuple